Principles of Management

of Impacted Teeth

Larry 1. Peterson

INDICATIONS FOR REMOVAL OF IMPACTED TEETH CLASSIFICATION SYSTEMS OF IMPACTED TEETH

Prevention of Periodontal Disease Angulation
Prevention of Dental Caries Relationship t o Anterior Border of Ramus
Prevention of Pericoronitis Relationship t o Occlusal Plane
Prevention of Root Resorption Summary
Impacted Teeth under a Dental Prosthesis ROOT MORPHOLOGY
Prevention of Odontogenic Cysts and Tumors Size of Follicular Sac
Treatment of Pain of Unexplained Origin Density of Surrounding Bone
Prevention of Fracture of the jaw Contact w i t h Mandibular Second Molar
Facilitation of Orthodontic Treatment Relationship t o Inferior Alveolar Nerve
Optimal Periodontal Healing Nature of Overlying Tissue
CONTRAINDICATIONS FOR REMOVAL OF IMPACTED MODIFICATION OF CLASSIFICATION SYSTEMS FOR
TEETH MAXILLARY IMPACTED TEETH
Extremes of Age DIFFICULTY OF REMOVAL OF OTHER IMPACTED TEETH
Compromised Medical Status SURGICAL PROCEDURE
Probable Excessive Damage t o Adjacent Structures PERIOPERATIVE PATIENT MANAGEMENT
Summary

n impacted tooth is one that fails to erupt into the Teeth most often become impacted because of inade-

d' dental arch within the expected time. The tooth

becomes impacted because adjacent teeth,
dcnse overlying bone, or excessive soft tissue prevents
eruption. Because impacted teeth do not erupt, they are
retained for the patient's lifetime unless surgically removed.
quate dental arch length and space in which to erupt;
that is, the total length of the alveolar bone arch is small-
er than the total length of the tooth arch. The most com-
mon impacted teeth are the maxillary and mandibular
third molars, followed by the maxillary canines and
The term lrtzerilpted includes both impacted teeth and mandibular premolars. The third molars are the most fre-
teeth that are in the process of erupting, The term embed- quently impacted, because they are the last teeth to
c l d is occasionally used interchangeably with the term erupt; therefore they are the most likely to have inade-
impnctod. quate space for eruption.
 Principles of Management of lmpocted Teeth m CHAPTER 9 185

In the anterior maxilla, the canine tooth is also com- and are relatively superficially positioned with respect to
monly prevented from erupting by crowding from other the occlusal plane of the adjacent second molar.
teeth. The canine tooth usually erupts after the maxillary Finally and perhaps most importantly, sufficient space
lateral incisor and maxillary first premolar. If space is exists between the anterior border of the ramus and the
inadequate to allow eruption, the canine tooth becomes second molar tooth to allow e r u p t i ~ n . ' Likewise,
,~ if the
impacted. In the anterior mandible a similar situation tooth does not erupt after age 20, it is most likely covered
affects the mandibular premolars, because they erupt with bone. In addition, the tooth is likely a mesioangular
after the mandibular first molar and mandibular canine. impaction and located lower in the alveolar process near
Therefore if room for eruption is inadequate, one of the the cervical level of the adjacent second molar. Finally,
premolars, usually the second premolar, remains un- inadequate space exists to allow eruption. Therefore the
erupted and becomes impacted. dentist and surgeon can use these parameters to predict
As a general rule, all impacted teeth should be re- whether or not a tooth will erupt into the arch or remair!
moved unless removal is contraindicated. Extraction impacted.
should be performed as soon as the dentist determines Early removal reduces the postoperative morbidity and
that the tooth is impacted. Removal of impacted teeth allows for the best healing.3-"ounger patients tolerate
becomes more difficult with advancing age. The dentist the procedure better and recover more quickly and with
should not recommend that impacted teeth be left in less interference to their daily lives. Periodontal healing is
place until they cause difficulty. If the tooth is left in better in the younger patient, because of better and more
place until problems arise, the patient may experience an complete regeneration of the periodontal tissues. More-
increased incidence of local tissue morbidity, loss of adja- over, the procedure is easier to perform in younger
cent teeth and bone, and potential injury to adjacent patients. The ideal time for removal of impacted third
vital structures. Additionally, if removal of impacted molars is when the roots of the teeth are one-third
teeth is deferred until they cause problems later in life, formed and before they are two-thirds formed, usually
surgery is more likely to be complicated and hazardous, during the late teenage years, between ages 17 and 20.
because the patient may have compromising systemic If impacted teeth are left in the alveolar process, it is
diseases. A fundamental precept of the philosophy of highly probable that one or more of several problems will
dentistry is that problems should be prevented. Preven- r e ~ u l t . ~To, ~ prevent this, impacted teeth should be
tive dentistry dictates that impacted teeth are t o be removed.
removed before complications arise.
This chapter discusses the management of impacted
Prevention of Periodontal Disease
teeth. It is not a thorough or in-depth discussion of the
technical aspects of surgical impaction removal. Instead Erupted teeth adjacent to impacted teeth are predisposed
its goal is to provide both the information necessary for to periodontal disease (Figs. 9-1 and 9-2). The mere pres-
proper management and a basis for determining the dif- ence of an impacted mandibular third molar decreases
ficulty of surgery. the amount of bone on the distal aspect of an adjacent
second molar (see Fig. 9-1). Because the most difficult
tooth surface to keep clean is the distal aspect of the last
INDICATIONS FOR REMOVAL tooth in the arch, the patient may have gingival inflam-
OF IMPACTED TEETH
- - -- - -- .--- -
* . - mation with apical migration of the gingival attachment
All impacted teeth should be considered for removal as on the distal aspect of the second molar. With even
soon as the diagnosis is made. The average age for com- minor gingivitis the causative bacteria have access to a
pletion of the eruption of the third molar is age 20, large portion of the root surface, which results in the
although eruption may continue in some patients until early formation of severe periodontitis (see Fig. 9-2).
age 25. During normal development the lower third Patients with impacted mandibular third molars often
molar begins its development in a horizontal angulation, have deep periodontal pockets on the distal aspect of the
and as the tooth develops and the jaw grows, the angula- second molars but have normal sulcuIar depth in the
tion changes from horizontal t o mesioangular to vertical. remainder of the mouth.
Failure of rotation from the mesioangular t o the vertical The accelerated periodontal problem resulting from an
direction is the most common cause of the tooth remain- impacted third molar is especially serious in the maxilla.
ing impacted. The second major factor is that the As a periodontal pocket expands apically, it becomes
mesiodistal dimension of the teeth versus the length of involved with the distal furcation of the maxillary second
the jaw is such that inadequate room exists in the alveo- molar relatively early, which makes advancement of the
lar process anterior to the anterior border of the ramus to periodontal disease more rapid and severe. In addition,
allow the tooth to erupt into position. treatment of the localized periodontal disease around the
As noted earlier, some third molars will continue to maxillary second molar is more difficult because of the
erupt after age 20, coming into final position by age 25. distal furcation involvement.
Multiple factors are associated with continued eruption. By removing the impacted third molars early, peri-
When late eruption occurs, the unerupted tooth is usual- odontal disease can be prevented and the likelihood of
ly covered only with soft tissue or very slightly with bony healing and bone fill into the area previously occu-
bone. These teeth are almost always in a vertical position pied by the crown of the third molar is increased."-'j
186 PART 11 l'rir1c-i/1lc.~of Exotlor~titr

Rad~ographof mand~bularth~rdmolar Impacted aga~nstsecond molar, wlth bone

loss result~ngfrom presence of t h ~ r drnolar

R,~iiogr,lpi>i, l ~ o w v,ir~,ilioni 01 rn,~iidil~iilar

ttl~rdrnolar impacted agai12st srcond molar,
with severe bone loss secondary to periodontal disease and third molar.

Prevention of Dental Caries Prevention of Pericoronitis

When a third molar is impacted or partially impacted, When a tooth is partially impacted with a large amount
t h e bacteria that cause dental caries can be exposed to of soft tissue over the axial and occlusal surfaces, the
t h e distal aspect of the second molar, as ell as to t h e patient frequently has o n e or more episodes of pericoro-
third molar. Even in situations in which n o obvious nitis." Pericoronitis is a n infection of the soft tissue
communication between t h e m o i ~ t hand t h e impacted around the crown of a partially impacted tooth and is
third molar exists, there may be enough communica- caused by the normal oral flora. For most patients the
tion t o allow for caries production (Fig$. 9-3 through bacteria and host defenses maintain a delicate balance,
9-5). but host defenses cannot eliminate the bacteria.
 Principles o f M~~r~cz~yt~tnetlt
uf It?~lxzctr~ri
Erc3fll @ CHAPTER 9 187

FIC ' 5 Radiograph o f carles In mandibular second molar secondarv to i)lr\t'llic ot rni).tct-
ed third molar.

If the host defenses are compromised (e.g., during minor

illnesses, such as influenza or an upper respiratory infec-
tion, or from severe fatigue), infection can occur. Thus
although the impacted tooth has been present for some
time without infection, if the patient experiences a mild,
transient decrease in host defenses, pericoronitis may result.
Pericoronitis can also arise secondary to minor trauma
from a maxillary third molar. The soft tissue that covers the
occlusal surface of the partially erupted mandibular third
molar (known as the operculum) can be traumatized and
become swollen. Often the maxillary third molar further
traumatizes the already swollen operculum, which causes
increased swelling that again can be traumatized more eas-
ily. This spiraling cycle of trauma and swelling is often
interrupted only by removal of the maxillary third molar.
Another common cause of pericoronitis is entrapment
of food under the operculum. During eating, a small
amount of food may be packed into the pocket between
the operculum and the impacted tooth. Because this
pocket cannot be cleaned, bacteria invade it and peri-
coronitis begins.
Streptococci and a large variety of anaerobic bacteria
(the usual bacteria that inhabit the gingival sulcus) cause
pericoronitis. It can be treated initially by mechanically
dCbriding the large periodontal pocket that exists under
the operculum by using hydrogen peroxide as an irrigat- treatment and management of this problern vary from
ing solution. Hydrogen peroxide not only mechanically very mild to aggressive.
removes bacteria with its foaming action, it also reduces In its mildest form, pericoronitis is a localized tissue
the number of anaerobic bacteria by releasing oxygen swelling and soreness. For patients with a mild infection,
into the usually anaerobic environment of the oral cavi- irrigation and curettage by the dentist and home irriga-
ty. Other irrigates, such as chlorhexidine or iodophors, tions by the patient usiially suffice.
can reduce the bacterial population of the pocket. If the infection is slightly more severe with a large
Pericoronitis can present as a very mild infection or as amount of local soft tissue s~vellingthat is traumatized by a
a severe infection that requires hospitalization of the maxillary third molar, the dentist shoulti consider extract-
patient. Just as the severity of the infection varies, the ing the rnaxillarv third molar in addition to local irrigation.
 188 PART I1 Principles of Exodontio

iiC. '3-5 Rad~ographof canes In both ~mpactedth~rdmolar and second molar.

For patients who have (in addition to local swelling Prevention of Root Resorption
and pain) mild facial swelling, mild trismus secondary to Occasionally, an impacted tooth causes sufficient pres-
inflammation extending into the muscles of mastication, sure on the root of an adjacent tooth to cause root resorp-
and a low-grade fever, the dentist should consider admin- tion (Figs. 9-6 and 9-7). Although the process by which
istering an antibiotic along with irrigation and extrac- root resorption occurs is not well defined, it appears to be
tion. The antibiotic of choice is penicillin. similar to the resorption process primary teeth undergo
Pericoronitis can lead to serious fascial space infections. in the presence of the succedaneous teeth. Removal of
Because the infection begins in the posterior mouth, it can the impacted tooth may result in salvage of the adjacent
spread rapidly into the fascial spaces of the mandibular tooth by cementa1 repair. Endodontic therapy may be
ramus and the lateral neck. If a patient develops trismus required to save these teeth.
(with an inability to open the mouth more than 20 mm),
a temperature of greater than 101" F, facial swelling, pain,
and malaise, the patient should be referred to an oral and Impacted Teeth under a Dental Prosthesis
maxillofacial surgeon, who may admit the patient to the When a patient has an edentulous area restored, there are
hospital. several reasons that impacted teeth in the area should be
Patients who have had one episode of pericoronitis, removed before the prosthetic appliance is constructed.
although managed successfully by these methods, will After teeth are extracted, the alveolar process slowly
continue to have episodes of pericoronitis, unless the undergoes resorption. Thus the impacted tooth becomes
offending mandibular third molar is removed. The closer to the surface of the bone, giving the appearance of
patient should be informed that the tooth should be erupting. The denture may compress the soft tissue on
removed at the earliest possible time to prevent recurrent the impacted tooth, which is n o longer covered with
infections. The mandibular third molar should not be bone; the result is ulceration of the overlying soft tissue
removed until the signs and symptoms of pericoronitis and initiation of an odontogenic infection (Fig. 9-8).
have been completely resolved. The incidence of postop- Impacted teeth should be removed before prosthesis
erative complications, specifically dry socket and postop- is constructed because, if the impacted tooth must be
erative infection, increases if the tooth is removed during removed after construction, the alveolar ridge may be so
the time of active infection. altered by the extraction that the prosthesis becomes
Prevention of pericoronitis can be achieved by remov- unattractive and less functional (Fig. 9-9). In addition, if
ing the impacted third molars before they penetrate the removal of impacted teeth in edentulous areas is
oral mucosa and are visible. Although excision of the sur- achieved before the prosthesis is made, the patient is
rounding soft tissue, or operculectomy, has been advo- probably in good physical condition. Waiting until the
cated as a method for preventing pericoronitis without overlying bone has resorbed and ulceration with infec-
removal of the impacted tooth, it is very painful and usu- tion occurs does not produce a favorable situation for
ally does not work. The soft tissue excess tends to recur, extraction. If extraction is postponed, the patient will be
because it drapes over the impacted tooth and causes older and more likely to be in poorer health. Further-
regrowth of the operculum. The overwhelming majority more, the mandible may have become atrophic, which
of cases of pericoronitis can be prevented only by extrac- increases the likelihood of fracture during tooth removal
tion of the tooth. (Fig. 9-10).
 Prirlciples of Mnnn,yernent of lr?lpoctetl Teeth m CHAPTER 9 189

FIG. ' -6, Root resorption of second molar as result of Impacted

third molar.

Prevention of Odontogenic Cysts and Tumors

When impacted teeth are retained within the alveolar
process, the associated follicular sac is also retained.
Although in most patients the dental follicle maintains . ,' Root resorpt~onof max~llarylateral lnclsors as result of
its original size, it may undergo cystic degeneration and ~mpactedcanine.
become a dentigerous cyst or keratocyst. If the patient is
closely followed, the dentist can diagnose the cyst before
it reaches large proportions (Fig. 9-1 1). However, unmon- Prevention of Fracture of the Jaw
itored cysts can reach enormous sizes (Fig. 9-12). As a
general guideline, if the follicular space around the crown An impacted third molar in the mandible occupies space
of the tooth is greater than 3 mm, the diagnosis of a that is usually filled with bone. This may weaken the
dentigerous cyst is a reasonable one. mandible and render the jaw more susceptible to fracture
In the same way that odontogenic cysts can occur (Fig. 9-14). If the jaw fractures through the area of an
around impacted teeth, odontogenic tumors can arise impacted third molar, the impacted third molar is fre-
from the epithelium contained within the dental follicle. quently removed before the fracture is reduced and inter-
The most common odontogenic tumor to occur in this maxillary fixation is applied.
region is the ameloblastoma. Usually, ameloblastomas in
this area must be treated aggressively by excision of the Facilitation of Orthodontic Treatment
overlying soft tissue and of at least a portion of the
mandible. Occasionally, other odontogenic tumors may In patients who require retraction of first and second
occur in conjunction with impacted teeth (Fig. 9-13). molars by orthodontic techniques, the presence of
Although the overall incidence of odontogenic cysts impacted third molars may interfere with the treatment.
and tumors around impacted teeth is not high,'" the over- It is therefore recommended that impacted third molars
whelming majority of pathologic conditions of the be removed before orthodontic therapy is begun.
mandibular third molar are associated with unerupted Another consideration is that, after orthodontic treat-
teeth. It is therefore recommended that impacted teeth be ment has been concluded, there may be crowding of the
removed to prevent the occurrence of cysts and tumors. mandibular incisor teeth. This has been attributed to the
mesial force transmitted to the molar and premolar teeth
by impacted third molars, especially mesiallv inclined
Treatment of Pain of Unexplained Origin impaction^.^^,'^ Several other factors influence crowding.
Occasionally, patients come to the dentist complaining of Growth of the maxilla stops before growth of the
pain in the retromolar region of the mandible for no mandible. If the upper and lower incisors are in a proper
obvious reasons. If conditions such as myofascial pain overbite and overjet relationship, and if the mandible
dysfunction syndrome and temporomandibular joint continues to grow after the maxilla stops growing, the
(TMJ) disorder are excluded and if the patient has an mandibular incisors then become crowded to accommo-
unerupted tooth, removal of the tooth sometimes results date the constriction imposed on them by the maxillary
in resolution of the pain. incisors. This explanation appears sound, because crowd-
 190 PART Il a Priric~i/~l~s
of'Exotior1tit7

Impacted tooth retalned under denture Tooth 1s now at surface and is causing ~nfection.

EtCt I r i ~ \ w t i t dtout11 ur~tlc~rlrxpri i~riclge Toot11 mu,t be Irnpact~o~)In atroplilc nidnd~ble,whlch may result In law
removed and therefore may leopard~zebr~dge. fracture during extract~on.

ing occurs after the age at which the maxilla stops grow- health after third molar surgery; that is, bone height on
ing and the mandible continues forward growth. the distal aspect of the second molar and attachment
Many orthodontists still refer their patients to sur- level on the distal aspect of the second molar.
geons for removal of irnpacted third molars after ortho- Recent studies have provided information on which to
dontic treatment is complete. Although the surgeon base the likelihood of optimum periodontal tissue heal-
should explain the other reasons for surgery, the decision ing.'."'"he two most important factors have been
to remove irnpacted teeth to help prevent crowding shown to be the extent of the preoperative infrabony
should be supported. defect on the distal aspect of the second molar and the
patient's age at the time of surgery. If a large amount of
distal bone is missing because of the presence of the
Optimal Periodontal Healing impacted tooth and the associated follicle, it is less likely
As noted earlier, one of the most important indications that the infrabony pocket can be decreased. Likewise, if
for removal of impacted third molars is to preserve the the patient is older, then the likelihood of optimum bony
periodontal health. A great deal of attention has been healing is decreased. Patients whose third molars are
given to the two primary parameters of periodontal removed before age 25 are more likely to have better bone
 Plirit iplcs of ,V\.lrli~n~qt~i~irr~t Ec~tll
of Ir71/1c1ctrti CHAPTER 9 191

i r r > , ~ l li l e ~ ~ t i c i t ~cysl
t o ~ i(Irlclng
i a r o ~ ~ nimpacted
d tooth.

Larqc cieiit~gcroi~s
c \ i t tli,lt c \tcritls irqm corono~d Large arneloblastoma In mand~bleas result of Impacted
process to mental foramen Cyst has d~splacedImpacted thlrd molar t h ~ r dmolar
to Inferlor border of mand~ble

healing than those whose impacted teeth are removed in older patients will clearly result in pocket depths and
after age 25.11 In the younger patient, not only is the ini- alveolar bone loss, which will be greater than if t h e tooth
tial periodontal healing better but the long-term contin- were left in place.
ued regeneration of the p e r i o d o n t i i ~ ~isn clearly better.Ii
.As mentioned previously, unerupted teeth may con-
tinue tc) erupt until ngc 25. I3ecnuse the terminal portion
of the eruption process occur< relatively slo~vly, the
chances of developing pericoronitis increase, as cio the All impacted teeth should be removed unless specific
amount of contact hetizTecnthe third molar and second contraindications justify leaving them in position. When
molar. Both of these factors decrease the possibility for the potential benefit? outweigh the potential complica-
optimum periodontal healing. However, it should be tions and risks, the procedure s h o ~ l l dbe performed. Sim-
noted that the coniplctely bony impacted third molar in ilarly, when the rislis are greater than the potential bene-
a patient older than age 30 s h o ~ l l dprobably be left in fit$, the procedure thould be deferred.
place unless some specific pathology develops. Removal Contraindications for t h e removal of impacted teeth
of such asyniptoniatic completely impacted third molars primarily involve the patient's physical status.
192 PART I1 8 Prirzciples of Exodontin

or the impacted tooth, if it is a single impacted tooth

underneath a prosthesis with thin overlying bone, or if it
becomes symptomatic as the result of infection, the tooth
must be removed.

Compromised Medical Status

Similar to extremes of age, compromised medical status
may contraindicate the removal of an impacted tooth.
Frequently, compromised medical status and advancing
age go hand-in-hand. If the impacted tooth is asympto-
matic, its surgical removal must be viewed as elective. If
the patient's cardiovascular or respiratory function or
host defenses for combating infection are compromised
or the patient has a serious acquired or congenital coagu-
lopathy, the surgeon must consider leaving the tooth in
the alveolar process. On the other hand, if the tooth
becomes symptomatic, the surgeon must work carefully
with the patient's physician to remove the tooth with the
least operative and postoperative medical sequelae.

Probable Excessive Damage to Adjacent Structures

If the impacted tooth lies in an area in which its removal
FIG. ? - I d Fracture of mandible that occurred through location of
may seriously jeopardize adjacent nerves, teeth, or previ-
impacted third molar.
ously constructed bridges, it may be prudent to leave the
tooth in place. When the dentist makes the decision not
to remove a tooth, the reasons must be weighed against
Extremes of Age
potential future complications. For younger patients who
The third molar tooth bud can be radiographically visu- may suffer the sequelae of impacted teeth, it may be wise
alized by age 6. Some surgeons think that removal of the to remove the tooth while taking special measures to pre-
tooth bud at age 7 to 9 can be accomplished with mini- vent damage to adjacent structures. However, for the older
ma1 surgical morbidity and therefore should be per- patient with n o signs of impending complications and for
formed at this age. However, most surgeons believe that whom the probability of such complications is low, the
it is not possible to predict accurately if the forming third impacted tooth should not be removed. A classic example
molar will be impacted. The consensus is that very early of such a case is the older patient with a potentially severe
removal of third molars should be deferred until an accu- periodontal defect on the distal aspect of the second
rate diagnosis of impaction can be made. molar but in whom removal of the third molar would
The most common contraindication for the removal almost surely result in the loss of the second molar. In this
of impacted teeth is advanced age. As a patient ages the situation the impacted tooth should not be removed.
bone becomes highly calcified, therefore less flexible and
less likely to bend under the forces of tooth extraction.
Summary
The result is that more bone must be surgically removed
to displace the tooth from its socket. The preceding discussion of indications and contraindi-
Similarly, as patients age, they respond less favorably cations for the removal of impacted third molars has
and with more postoperative sequelae. An 18-year-old been designed to point out that there are various risks
patient may have 1 or 2 days of discomfort and swelling and benefits for removing impacted teeth in patients.
after the removal of an impacted tooth, whereas a similar Patients who have one or more pathologic symptoms or
procedure may result in a 4- or 5-day recovery period for problems should have their impacted teeth removed.
a 50-year-old patient. Most of the symptomatic, pathologic problems that result
Finally, if a tooth has been retained in the alveolar from impacted third molars occur because of partially
process for many years without periodontal disease, erupted teeth and occur less commonly with a complete
caries, or cystic degeneration, it is unlikely that these bony impaction.
unfavorable sequelae will occur. Therefore in an older It is less clear what should be done with impacted
patient (usually over age 35) with an impacted tooth that teeth before they cause symptoms or problems. In mak-
shows n o signs of disease and that has a radiographically ing a decision as to whether or not an impacted third
detectable layer of overlying bone, the tooth should not molar should be removed, a variety of factors must be
be removed (Fig. 9-15). The dentist caring for the patient considered. First, the available room in the arch into
should check the impacted tooth radiographically every 1 which the tooth can erupt must be considered. If ade-
or 2 years to ensure that n o adverse sequela occurs. quate room exists, then the clinician may choose to defer
If the impacted tooth shows signs of cystic formation removal of the tooth until eruption is complete. A second
or periodontal disease involving either the adjacent tooth consideration is the status of the impacted tooth and the
 Principles of Mann,yrment of It?1p(~cteiiEetlr e CHAPTER 9 193

l' ic,. '+-I5 Impacted rnax~llaryr ~ g htth ~ r drnolar In 63-year-old patient. Th~srnolar should not be extracted because
it is deeply embedded and no signs of disease are present.

age of the patient. It is critical to remember that the aver- es will be necessary or if the patient will encounter any
age age of complete eruption is 20, but that eruption may postoperative problems.
continue to occur up to age 25. A tooth that appears to be The majority of the classifying result5 from analysis of
a mesioangular impaction at age 17 may eventually be- the radiograph. For most situations the periapical radio-
come more vertical and erupt into the mouth. If insuffi- graph provides adequate detail and should be the radio-
cient room exists to accommodate the tooth and a soft graph most commonly used. The panoramic radiograph
tissue operculum exists over the posterior aspect, then shows a more accurate picture of the total anatomy of the
pathologic sequelae are likely to occur. region and can be used as an adequate sub5titute.
Although there have been some attempts at making For each patient the dentist should carefully analyze
very early predictions of whether or not a tooth was the factors discussed in this section. Ry combining these
going to be impacted, these efforts have not yet resulted factors, the dentist can assess the difficulty of the surgery
in a reliable predictive model. However, by the time the and elect to extract the impacted teeth that are within his
patient reaches age 18, the dentist and surgeon can rea- skill level. However, for the patient's sake the dentist
sonably predict whether there will be adequate room into should refer the patient to a specialist if a tooth presents
which the tooth can erupt with sufficient clearance of the a difficult surgical problem.
anterior ramus to prevent soft tissue operculum forma-
tion. At this time, if surgical removal is chosen, soft tissue
Angulation
and bone tissue healing will occur at its maximal level. At
age 18 or 19, if the diagnosis for inadequate room for The first classification system employs a description of
functional eruption can be made, then the asymptomatic the angulation of the long axis of the impacted third
third molar can be removed and the long-term periodon- molar with respect to the long axis of the second molar.
tal health of the second molar will be maximized. Because teeth at certain inclinations have ready-made
pathways for withdrawal, whereas pathways for teeth of
other inclinations require the removal of substantial
CLASSIFICATION SYSTEMS amounts of bone, this classification system provides an
OF IMPACTED TEETH .--
initial evaluation of the difficulty of extractions.
Removal of impacted teeth can be either extremely diffi- The mesioangular impaction is generally acknowl-
cult or relatively straightforward and easy. To determine edged as the least difficult impaction to remove (Fig.
the degree of difficulty preoperatively, the surgeon 9-16). The mesioangular-impacted tooth is tilted toward
should examine the patient methodically. The primary the second molar in a mesial direction. This type of
factor determining the difficulty of the removal is acces- impaction is also the most commonly seen and compris-
sibility. Accessibility is determined by the ease of expos- es approximately 43% of all impacted teeth.
ing the tooth, of preparing a pathway for its delivery, and In a severe mesial inclination the impacted tooth is
of preparing a purchase point (or taking advantage of a horizontal (Fig. 9-17). This type of itnpaction is usually
natural purchase point). With careful classification of the considered more difficult to remove than the mesioangu-
impacted teeth using a variety of systems, the surgeon lar impaction. Horizontal impactions occur less frequent-
can approach the proposed surgery in an orderly fashion ly and are only seen in approximately 3'%1 of all mandibu-
and predict whether any extraordinary surgical approach- lar impactions.
 194 PART 11 I'ritlc-iplo of Exotlorltilr

FIG. 9-16 A, Mesioangular impaction-most common and easlest Impaction to remove. B, blcilo-
angular impaction is usually in close proximity to second molar.

FIG. 9-17 A, Horizontal impaction-uncommon and more d~fficultto remove than mes~oangular
impaction. B, Occlusal surface of horizontal impacted third molar is usually immediately adjacent to
root of second molar, which often produces early severe periodontal disease.

In the vertical impaction the long axis of the impact- ond molar. This impaction is the most difficult to
ed tooth runs in the same direction as the long axis of the remove because the tooth has a withdrawal pathway that
second molar. This impaction occurs with the second runs into t h e mandibular ramus, a n d its removal
greatest frequency, accounts for approximately 38% of all requires greater surgical intervention. Distoangular
impactions, and is third in difficulty of removal (Fig. impactions occur uncommonly and account for only
9-18). approximately G'XI of all impacted third molars. Erupted
Finally, the distoangular impaction is the tooth with third molars may be in a distoangular position. When
the most difficult angulation for removal (Fig. 9-19). In this occurs, they are extremely difficult to remove rou-
t h e distoangular impaction the long axis ot t h e third tinely, compared ~ i i t hthe removal o f other erupted
molar is distally or posteriorly angled away from the sec- teeth.
 17ririricipkc~sof .Mnr~r~~y~irr~irt
o f lr~ifltrc't(~ti
7?(*tlr CHAPTER 9 195

FIG. 9-18 A, Vertical impaction-second most common impaction and second most drfl~cultto
remove. B, Vertical impaction is frequently covered on its posterior aspect with bone of anterior rarnus
of mandible.

FIG. 9-79 A, Distoangular impaction-uncommon a n d most d~ff~cult

of t h e f o ~ type,
~ r to reinovr,.
B, Occlusal surface of distoangular impaction is usually embedded in ramus of mandible and requires
significant bone removal for extraction.

In addition to the relationship between the angulation dicular occlusal film. However, this determination is usu-
of the long axes of the second and third molars, the teeth ally not necessary, because the surgeon can make this
can also be angled in a buccal or lingual direction. As is identification early in the operation, and the buccal or
noted earlier, the linguocortical plate of t h e mandible lingual position of the tooth does not greatly influence
becomes thinner as it progresses posteriorly. Therefore the difficulty of the surgery.
most mandibular third molars are angled toward t h e lin-
gual direction or in lingual version. Occasionally, a tooth
Relationship to Anterior Border of Ramus
is angled toward the buccal aspect of t h e mandible or in
buccal version. Another method for classifying impacted mandibular
Rarely a tooth is a transverse impaction, that is, in a n third molars is based o n the amount of impacted tooth
absolutely horizontal position in a buccolingual direc- that is covered with the bone of the mandil~ularrarnus.
tion. The occlusal surface of the tooth can face either the This classification is known as the Pel1 clrrri Gr-c~~yor?~ c-lnssi-
buccal or lingual direction. To determine buccal o r tin- ficntior? and is sometimes referred to as the P ~ l clrui l (;rz:go-
gual version accurately, the dentist must take a perpen- n c.lnssc..~1 , 2, nrid 3. For this classificatiorl it is important
196 PART I1 Prirlciples of Exudot?tia

that the surgeon carefully examine the relationship Relationship to Occlusal Plane
between the tooth and the anterior part of the ramus. If The depth of the impacted tooth compared with the
the mesiodistal diameter of the crown is completely ante- height of the adjacent second molar provides the next
rior t o the anterior border of the mandibular ramus, it is classification system for determining the difficulty of
in a class 1 relationship. If the tooth is angled in a verti- impaction removal. This classification system was also
cal direction, the chances for the tooth to erupt into a suggested by Pell and Gregory and is called Pel1 and Gre-
normal position are good (Fig. 9-20). gory A, R, ar~rlC classification. In this classification the
If the tooth is positioned posteriorly so that approxi- degree of difficulty is measured by the thickness of the
mately one half is covered by the ramus, the tooth's rela- overlying bone; that is, the degree of difficulty increas-
tionship with the ramus is class 2. In the class 2 situation es as the depth of the impacted tooth increases. As the
the tooth cannot become completely free from bone, tooth becomes less accessible and it becomes more dif-
because a small shelf of bone overlies the distal portion of ficult to section the tooth and to prepare purchase
the tooth (Fig. 9-21). A class 3 relationship between the points, the overall difficulty of the operation increases
tooth and ramus occurs when the tooth is located com- substantially.
pletely within the mandibular ramus (Fig. 9-22). It should A class A impaction is one in which the occlusal sur-
be obvious that the class 1 relationship will provide the face of the impacted tooth is level or nearly level with the
greatest accessibility to the impacted tooth and therefore occlusal plane of the second molar (Fig. 9-23). A class B
will be easiest to remove. The class 3 relationship pro- impaction is an impacted tooth with an occlusal surface
vides the least accessibility and therefore presents the between the occlusal plane and the cervical line of the
greatest difficulty. second molar (Fig. 9-24). Finally, the class C impaction is

FIG. 9-20 Pell and Gregory class 1 impaction. Mandibular third FIG. 9-22 Pell and Gregory class 3 impaction. Impacted third
molar has sufficient anteroposterior room (i.e., anterior-to-anterior molar is completely embedded in bone of ramus of mandible.
border of ramus) to erupt.

FIG. 9-21 Pell and Gregory class 2 impaction. Approximately half FIG. 9-23 Pell and Gregory class A impaction. Occlusal plane of
is covered by anterior portion of ramus of niandible. impacted tooth is at same level as occlusal plane of second molar.
 Prirlciples of ,Vori17~yerner1t
of lr?rpnctellTeeth CHAPTER 9 197

one in which the occlusal surface of the impacted tooth

is below the cervical line of the second molar (Fig. 9-25).

Summary
The three classification systems discussed so far are used
in conjunction to determine the difficulty of an extrac-
tion. For example, a mesioangular impaction with a class
1 ramus and a class A depth is easy to remove and is
essentially the extraction of an erupted tooth (Fig. 9-26).
However, as the ramus relationship changes to a clats 2
and the depth of the impaction increases to a class R, the
degree of difficulty becomes greater. A horizontal
impaction with a class 2 ramus relationship and a class R
depth is a moderately difficult extraction and one that
most general practitioners do not want to attempt (Fig.
9-27). Finallv, the most difficult of all impactions is a dis-
i J
toangular impaction with a class 3 ramus relationship at
FIG. 9-26 Mesioangular impaction with class 1 ramus relationship
a class C depth. Even specialists view removing this tooth
and class A depth. All three classifications make it easiest type of
as a surgical challenge (Fig. 9-28).
impaction to remove.

I I 1

FIG. 9-24 Pell and Cregory class B impaction. Occlusal plane of FIG. 9-27 Horizontal impaction with class 2 ramus relationship
impacted tooth is between occlusal plane and cervical line of second and class B depth makes it moderately difficult to extract.
molar.

I I I I
FIG. 9-25 Pell and Cregory class C impaction. Impacted tooth is FIG. 9-28 Impaction with distoangular, class 3 ramus relationship
below cervical line of second molar. and class C depth makes it extremely difficult to remove.
198 PART I1 m I'rit~ci[~lr,s
of Exotlonticl

ROOT MORPHOLOGY
abnormal root morphology and for fracture of the root
Just as the root morphology of the erupted tooth has a tips during extraction. If the root development is insuffi-
major influence on the degree of difficulty of a closed cient (i.e., less than one third complete), the tooth is more
extraction, root morphology plays a major role in deter- difficult to remove, because it tends to roll in its crypt like
mining the degree of difficulty of the impacted tooth's a ball in a socket, which prevents easy elevation (Fig.
removal. Several factors must be considered when assess- 9-30). The next factor to be assessed is whether the roots
ing the morphologic structure of the root. are fused into a single, conic root (Fig. 9-31), or if they are
The first consideration is the length of the root. As dis- separate and distinct roots. The fused, conic roots are eas-
cussed earlier, the optimal time for removal of an impact- ier to remove than widely separate roots (Fig. 9-32).
ed tooth is when the root is one third to two thirds The curvature of the tooth roots also plays a role in the
formed. When this is the case, the ends of the roots are difficulty of the extraction. Severely curved or dilacerated
blunt and almost never fracture (Fig. 9-29). If the tooth is roots are more difficult to remove than straight or slight-
not removed during the formative stage and the entire ly curved roots (see Fig. 9-32). The surgeon should care-
length of the root develops, the possibility increases for fully examine the apex area of the radiograph to assess

. , Roots that are two th~rdsformed, wh~chare less difficult >. Lack of root development. If extraction is attempted,
to remove. crown will roll around in crypt, whlch makes ~td~fflcultto remove.

Fused roots w ~ t hconic shape

 Principles of Monngevient of Impacted Teeth m CHAPTER 9 199

the presence of small, abnormal, and sharply hooked tion will be more difficult. More bone must be removed or
roots that probably fracture if the surgeon does not give the tooth must be sectioned before extraction.
them special consideration. Finally, the surgeon should assess the periodontal liga-
The direction of the tooth root curvature is also impor- ment space. Although in most patients the periodontal
tant to examine preoperatively. During removal of a ligament space is of normal dimensions, it sometimes is
mesioangular impaction, roots that are curved gently in the wider or narrower. The wider the periodontal ligament
distal direction (following along the pathway of extraction) space, the easier the tooth is to remove (Fig. 9-33). A third
can be removed without the force that can cause fracture of molar that is in the proper stage of development for
the roots. However, if the roots of a mesioangular removal has a relatively broad periodontal ligament
impaction are curved mesially, the roots almost always frac- space, which eases extraction. However, older patients,
ture or must be sectioned before the tooth can be delivered. especially those over age 40, tend to have a much nar-
The total width of the roots in the mesiodistal direction rower periodontal ligament space, which thereby increas-
should be compared with the width of the tooth at the es the difficulty of the extraction.
cervical line. If the tooth root width is greater, the extrac-
Size of Follicular Sac
The size of the follicle around the impacted tooth can
help determine the difficulty of the extraction. If the fol-
licular sac is wide (almost cystic in size), much less bone
must be removed, which makes the tooth easier to extract
(Fig. 9-34). (Young patients are more likely to have large
follicles, which is another factor that makes extractions
easier in younger patients.) However, if the follicular
space around the crown of the tooth is narrow or nonex-
istent, the surgeon must create space around the entire
crown, which increases both the difficulty of the proce-
dure and the time required to remove the tooth. The sur-
geon must carefully examine the follicle size when deter-
mining the difficulty of an extraction.

Density of Surrounding Bone

The density of the bone surrounding the tooth plays a
role in determining the difficulty of the extraction.
Although some clues can be seen on the radiographs,
variations in radiograph
- . density and angulation render

FrG. 0 :: Divergent roots with severe curvature. Such roots are interpretations based on radiographs unreliable. Bone
more difficult to remove. density is best determined by the patient's age. Patients

FIG. 9-33 Wide periodontal ligament space. Such space makes extraction process
less difficult.
200 PART I1 Principles of Exodontia

who are 18 years of age or younger have bone densities Contact with Mandibular Second Molar
favorable for tooth removal. The bone is less dense, is If space exists between the second molar and the impacted
more likely to be pliable, and expands and bends some- third molar, the extraction will be easier. However, if the
what, which allows the socket to be expanded by eleva- tooth is a mesioangular or horizontal impaction, it is fre-
tors or by luxation forces applied to the tooth itself. Addi- quently in direct contact with the adjacent second molar. To
tionally, the bone is easier to cut with a dental drill and remove the third molar safely without injuring the second
can be removed more rapidly than denser bone. molar, the surgeon must be cautious with pressure from ele-
Conversely, patients who are older than age 35 have vators or with the bur when removing bone. If the second
denser bone and thus decreased flexibility and ability to molar has caries or a large restoration or root canal, the sur-
expand. In these patients the surgeon must remove all geon must take special care not to fracture the restoration or
interfering bone, because it is not possible to expand the a portion of the carious crown (see Fig. 9-17, B).
bony socket. In addition, as the bone increases in densi-
ty, it becomes more difficult to remove with a dental drill,
and the bone removal process takes longer. Relationship to Inferior Alveolar Nerve
Impacted mandibular third molars frequently have roots
that are superimposed on the inferior'alveoiar canal on
radiographs. Although the canal is usually on the buccal
aspect of the tooth, it is in close proximity to the tooth.
"i heref fore one of the potential seiuelae of impacted third
molar removal is damage to or bruising of the inferior
alveolar nerve. This usually results in some altered sensa-
tion (paresthesia or anesthesia) of the lower lip on the
injured side. Although this altered sensation is usually
brief (lasting only a few days), it may extend for weeks or
months; o n rare occasions it can be permanent. If the
root ends of the tooth appear to be close to the inferior
alveolar nerve, the surgeon must take special care to
avoid injuring the nerve (Fig. 9-35), which makes the
procedure more difficult.

Nature of Overlying Tissue

The preceding systems all classify factors that make third
molar extraction easier or more difficult. The classifica-
tion system discussed in this section does not fit into this
category. However, it is the system used by most dental
FiG. s - - 3 , 6 Large foll~cularsac. When space of sac is large, amount insurance companies and the one by which the surgeon
of required bone removal is decreased. charges for his services.

r f 5 . i' 35 A, Radiographic view of mandibular third molar suggests that it is surrounding or adjacent
to inferior alveolar neurovascular canal. B, Hole and indentation in two roots of mandibular third molar
indicate position of roots of this tooth to inferior alveolar canal. When this tooth was removed, inferi-
or alveolar neurovascular bundle was severed (not same tooth as shown in A).
 Principles of Mnnngement of lmpncted Teeth . CHAM'ER 9 201

According to this scheme, the three types of im-

pactions are (1) soft tissue impaction, (2) partial bony
impaction, and (3) full bony impaction. An impaction is
defined as a soft tissue impaction when the height of the
tooth's contour is above the level of the alveolar bone,
and the superficial portion of the tooth is covered only by
soft tissue (Fig. 9-36). To remove the soft tissue
impaction, the surgeon must incise the soft tissue and
reflect a small soft tissue flap to obtain access to the tooth
to elevate it from its socket. The soft tissue impaction is
usually the easiest of the three extractions.
The partial bone impaction occurs when the superfi-
cial portion of the tooth is covered by soft tissue, but the
height of the tooth's contour is below the level of the sur-
rounding alveolar bone (Fig. 9-37). To remove the tooth,
the surgeon must incise the soft tissue, reflect a soft tissue
flap, and remove the bone above the height of the con-
tour. The surgeon may need to divide the tooth in addi- FIG. 9-36 Soft tissue impaction in which crown of tooth is covered
tion to removing bone. by soft tissue only and can be removed without bone removal.
The complete bone impaction is an impacted tooth
that is completely encased in bone so that, when the sur-
geon reflects the soft tissue flap, n o tooth is visible (Fig.
9-38). To remove the tooth, extensive amounts of bone
must be removed and the tooth almost always must be
sectioned. The complete bony impaction is often the
most difficult to remove.
Although this classification is extensively used, it fre-
quently has no relationship to the difficulty of the extrac-
tion (Boxes 9-1 and 9-2). The parameters of angulation,

Factors t h a t Make Impaction Surgery Less Difficult

1. Mesioanqular
- 7. Large follicle*
position 8. Elastic bone*
2. Class 1 ramus 9. Separated from second
FIG. 9-37 Partial bony impaction in which part of tooth, usually
3. Class A depth molar
.----
4. Roots one .LC.
LIIII
n c---- ated from :-F.-..:...
u. >cpat<
posterior aspect, is covered with bone and requires either bone
removal or tooth sectioning for extraction.
two thirds for alveol'ar nerve*
5. Fused conic r( 1. Soft tissue impa
6. Wide period0
liga~
-
*Present in the young patient.

Factors that Make Impaction Surgery More Difficult

1. Distoangular 7. Thin follicle*

2. Class 3 ramus 8. Dense, inelastic UUI IC
3. Class C depth 9. Contact with second
4. Long, thin roots* molar
5. Divergent curved 10. Close to inferior alveolar
roots canal
6 . Narrow perioclontal 1 1. C o mdete
~ bony impaction
ligament* FIG. 9-38 Complete bony impaction in which tooth is completely
covered with bone and requires extensive removal of bone for
*Present in older patients. extraction.
202 PART I1 . Principles of Exodontio

FIG. 9-39 A, Vertical impaction of maxillary third molar. This angle accounts for 63% of impactions.
6, Distoangular impaction of maxillary third molar. This angle accounts for 25% of impactions.
C, Mesioangular impaction of maxillary third molar. This angle accounts for 12% of impactions.

ramus relationship, root morphology, and patient age are palatal aspect of the alveolar process. This makes the tooth
more important than this system. The surgeon should use much more difficult to extract, because greater amounts of
all of the information available to determine the difficul- bone must be removed to gain access to the underlying
ty of the proposed surgery. tooth. A combination of radiographic assessment and clin-
ical digital palpation of the tuberosity area can determine
if the maxillary third molar is in the buccopalatal position.
MODIFICATION OF CLASSIFICATION SYSTEMS If the tooth is positioned toward the buccal, a definite pal-
FOR MAXILLARY IMPACTED TEETH pable bulge is found in the area; if the tooth is palatally
The classification systems for the maxillary impacted positioned, a bony deficit is found in that region. When
third molar are essentially the same as for the impacted either is determined by clinical examination, the surgeon
mandibular third molar. However, several distinctions must anticipate a longer, more difficult procedure.
and additions must be made to assess more accurately the The Pel1 and Gregory A, B, and C classification used to
difficulty of removal during the treatment-planning diagnose the depth of impaction in the mandible is also
phase of the procedure. used in the maxilla (Fig. 9-40). Preoperative assessment of
Concerning angulation, the three types of maxillary the remaining classifications is the same. The factors that
third molars are (1)the vertical impaction (Fig. 9-39, A), (2) influence the difficulty of mandibular impacted third
the distoangular impaction (Fig. 9-39, R), and ( 3 ) the molar removal are the same for maxillary third molar
mesioangular impaction (Fig. 9-39, C). The vertical removal. For example, the individual impacted tooth root
impaction occurs approximately 63% of the time, the dis- morphology plays a substantial role in determining the
toangular approximately 25%, and the mesioangular degree of extraction difficulty. The most common factor
position approximately 12% of the time. Rarely other posi- that causes difficulty with maxillary third molar removal
tions, such as a transverse, inverted, or horizontal position, is a thin, nonfused root with erratic curvature (Fig. 9-41).
are encountered; these unusual positions account for less The majority of maxillary third molars have fused roots
than 1%of impacted maxillary third molars. that are conic. However, the surgeon should examine the
The same angulations in mandibular third molar preoperative radiograph carefully to ensure that this is
extractions cause opposite degrees of difficulty for maxil- the situation with each individual impaction. The sur-
lary third molar extractions. Vertical and distoangular geon should also check the periodontal ligament, because
impactions are the easiest to remove, whereas mesioan- the wider the ligament space the less difficult the tooth is
gular impactions are the most difficult (exactly the oppo- to remove. In addition, similar to mandibular third
site of impacted mandibular third molars). Mesioangular molars, the periodontal ligament space tends to decrease
impactions are more difficult to remove because the bone as the patient increases in age.
that overlies the impaction and that must be removed or The follicle surrounding the crown of the impacted
expanded is on the posterior aspect of the tooth and is tooth also has an influence on the difficulty of the
much heavier than in the vertical or distoangular im- extraction. If the follicular space is broad, the tooth will
paction. In addition, access to the mesioangularly posi- be easier to remove than if the follicular space is thin or
tioned tooth is more difficult. nonexistent.
The position of the maxillary third molar in a bucco- Bone density is also an important factor in maxillary
palatal direction is also important for determining the dif- impaction removal and is related closely to the age of the
ficulty of the removal. Most maxillary third molars are patient. The younger the patient, the less dense and more
angled toward the buccal aspect of the alveolar process, elastic-and therefore more expandable-is the bone sur-
which makes the overlying bone in that area thin and rounding the impacted third molar. As the patient ages,
therefore easy to remove or to expand. Occasionally, the the bone becomes denser and less elastic, and the tooth
impacted maxillary third molar is positioned toward the becomes more difficult to remove.
 Prirlciple~of of
.W[lrli1,yr~111riit Get11 a
lrnl~octc~ri CHAPTER 9 203

FIG. 9-40 A, Pell and Gregory class A occlusal surface of third molar is at same level as that of sec-
ond molar. B, Pell and Gregory class B occlusal surface of third molar is located between occlusal plane
and cervical line of second molar. C, Pell and Gregory class C impacted maxillary third molar is deep
to cervical line of second molar.

The relationship to the adjacent second molar tooth

also influences the difficulty of the extraction. It may
require that additional bone be removed to displace the
tooth from underneath the second molar. In addition,
because the use of elevators is common in the removal of
maxillary third molars, the surgeon must be aware of the
existence of large restorations or caries in the adjacent
second molar. Injudicious use of elevators can result in
the fracture of restorations or carious teeth.
The type of impaction, with respect to overlying tis-
sue, must also be considered for maxillary third molars.
The classification system used for mandibular teeth is the
same as the system that is used for maxillary teeth: soft
tissue impaction, partial bony impaction, and complete
bony impaction. The definitions of these types of
impactions are precisely the same as those used for the
mandibular third molars.
Two additional factors influence the difficulty of max-
illary third molar removal but do not exist for the
mandibular third molars. Both are related to the structure
and position of the maxillary sinus. First, the maxillary
sinus is in intimate contact with the roots of the molar
teeth; and, frequently, the maxillary third molar actually
forms a portion of the posterior sinus wall. If this is the
case, removal of the maxillary third molar may result in
maxillary sinus complications, such as sinusitis or an
oroantral fistula. The presence of the maxillary sinus does
not necessarily make the removal of the impacted tooth
more difficult, but it increases the likelihood of postoper-
ative complications and morbidity.
Finally, in maxillary third molar removal, the tuberos-
ity of the posterior maxilla can be fractured. Such frac- I it Q ': ' The rnax~llarythlrd molar has the most erratlc and blzarre
tures are possible, especially when dense and nonelastic root formation of all teeth.
bone exists, such as in older patients. In addition, a large
maxillary sinus makes the surrounding alveolar bone
thin and more susceptible to fracture when excessive mesiocervical line, fracture of the tuberosity becomes a
force is applied. A root morphology that is not fused but greater risk if: (1) the bone is nonelastic (as in older
has divergent roots requires greater force to remove and patients), (2) the tooth is multirooted with large bulbous
can make fracture more likely. In addition, mesioangular roots (as in older patients), (3) the maxillary sinus is large
impactions increase the possibility of fractures (see Fig. 9- and expanded to include the roots of the impacted third
39, C). In these situations the overlying tuberosity is molar, or (4) the surgeon has to use excessive force to ele-
heavier, but the surrounding bone is usually thinner. vate the tooth. Management of the fractured tuberosity is
When the surgeon prepares a purchase point at the discussed in Chapter 11.
FIG. 9-42 A, Labially posit~onedimpacted maxillary canine. Tooth should be uncovered with apical-
ly positioned flap procedure to preserve attached gingiva. B, Mucoperiostealflap is outlined, allowing
for repositioning of keratinized mucosa over exposed tooth. C, When flap is reflected, thin overlying
bone is removed. D, Tissue is retracted and bonded to tooth with a wire or with a gold chain (E).
F, Flap is apically sutured to tooth.
 Principles of Management of Impacted Tf~eth CHAPTER 9 205

%i toward the palate, or in the middle of the alveolar

process. If the tooth is on the labial aspect, it is easy to
reflect a soft tissue flap and to remove the underlying
bone and the tooth. However, if the tooth is on the
palatal aspect or in the intermediate buccolingual posi-
tion, it is much more difficult to remove. Therefore when
assessing the impacted maxillary canine for removal, the
G
surgeon's most important assessment is of the buccolin-
gual position of the tooth.
Similar considerations are necessary for other im-
pactions, such as mandibular premolars and supernumer-
ary teeth. The supernumerary tooth in the midline of the
maxilla, called a mesiodens, is almost always found on the
palate and should be approached from a palatal direction
when it is removed.
* . ,4 J ~ L tor)? c i G,After 6 months, exposed tooth IS In des~red
posit~on,with broad zone of attached ging~va.
SURGICAL PROCEDURE

DIFFICULTY OF REMOVAL OF OTHER the same as for other surgical extractions. Five basic steps
IMPACTED TEETH make up the technique: The first step is to have adequate
After the mandibular and maxillary third molars, the next exposure of the area of the impacted tooth. This means
most commonly impacted tooth is the maxillary canine. If that the reflected soft tissue flap must be of an adequate
the patient seeks orthodontic care, the orthodontist will dimension to allow the surgeon to retract the soft tissue
frequently request that the maxillary canine simply have and perform the necessary surgery. The second step is to
the overlying soft and hard tissue removed so that the assess the need for bone removal and to remove a suffi-
tooth can be manipulated into its proper position by cient amount of bone to expose the tooth for sectioning
orthodontic appliances. When the tooth is positioned in and delivery. The third step is to divide the tooth with a
such a way that orthodontic manipulation can assist the bur or chisel to allow the tooth to be extracted without
proper positioning of the impacted canine, the tooth is removing excessive amounts of bone. In the fourth step
exposed and bracketed (Fig. 9-42, A ) . A four-corner flap is the sectioned tooth is delivered from the alveolar process
created to allow the soft tissue to be repositioned apically with the appropriate elevators. Finally, in the fifth step the
should this be required for maximu& keratinized tissue wound is thoroughly cleansed with irrigation and mechan-
management (Fig. 9-42, B). The overlying bone tissue is ical debridement with a curette and is closed with simple
then removed with chisel or burs as is necessary (Fig. 9-42, interrupted sutures. The following discussion elaborates on
C). Once the area is debrided, the surface of the tooth is these steps for the removal of impacted third molars.
prepared by the usual standard procedures of etching and Although the surgical approach to the removal of
applying primer. The bracket is then luted to the surface of impacted teeth is similar to other surgical tooth extrac-
the tooth (Fig. 9-42, D). A wire can be used to connect the tions, it is important to keep in mind several distinct dif-
bracket to the orthodontic appliance or more commonly a ferences. For instance, the typical surgical extraction of a
gold chain is attached from the orthodontic bracket to the tooth or tooth root requires the removal of a relatively
orthodontic arch wire. The gold chain provides a greater small amount of bone. However, when an impacted
degree of flexibility and the incidence of breakage of the tooth (especially a mandibular third molar) is extracted,
chain is much less than breakage of a wire. The soft tissue the amount of bone that must be removed to deliver the
is then sutured in such a way as to provide the maximum tooth is substantially greater. This bone is also much
coverage of the exposed tissue with keratinized tissue (Fig. denser than it is for typical surgical extractions, and its
9-42, E ) . As the tooth is pulled into place with the ortho- removal requires better instrumentation and a higher
dontic appliances, the soft tissue surrounding the newly degree of surgical skill.
positioned tooth should have adequate keratinized tissue Impacted teeth also frequently require sectioning,
and the tooth should be in an ideal position. whereas other types of tooth extractions do not.
If the tooth is positioned toward the palatal aspect, the Although erupted maxillary and mandibular molars are
tooth may be either repositioned or removed. If the tooth occasionally divided for removal, it is not a routine step
is repositioned, it is surgically exposed and moved into in the extraction of these teeth. However, with impacted
position orthodontically. In this procedure the overlying mandibular third molars, the surgeon is required to
soft tissue is excised; flaps are not needed to gain attached divide the tooth in a substantial majority of patients. The
tissue. Because the bone in the palate is thicker, a bur is surgeon must therefore have the necessary equipment for
usually necessary to remove the overlying bone. The such sectioning and the necessary skills and experience
exposed tooth then is managed in the same manner as is for dividing the tooth along the proper planes.
the labially positioned tooth. Unlike most other types of surgical tooth extractions,
If the dentist decides the tooth should be removed, it for an impacted tooth removal the surgeon must be able to
must be determined if the tooth is positioned labially, balance the degree of bone removal and sectioning. Essen-
206 PART I1 Principles of Exodontia

tially, all impacted teeth can be removed without section- The recommended incision for the maxillary third
ing if a large amount of bone is removed. However, the molar is also an envelope incision. It extends posteriorly
removal of excessive amounts of bone unnecessarily pro- from the distobuccal line angle of the second molar and
longs the healing period and may result in a weakened jaw. anteriorly to the mesial aspect of the first molar (Fig.
Therefore the surgeon should remove most mandibular 9-44, A and B). In situations in which greater access is
third molars only after sectioning them. On the other required (e.g., in a deeply embedded impaction), a release
hand, removal of a small amount of bone with multiple incision extending from the mesial aspect of the second
divisions of the tooth may cause the tooth sectioning molar can be used (Fig. 9-44, C and D).
process to take an excessively long time, thus unnecessari- In the removal of third molars it is vital that the flap be
ly prolonging the operation. The surgeon must remove an large enough for adequate access and visibility of the sur-
adequate amount of bone and section the tooth into a rea- gical site. The flap must have a broad base if a releasing
sonable number of pieces, both to hasten healing and to incision is used. The incision must be made with a smooth
minimize the time of the surgical procedure. stroke of the scalpel, which is kept in contact with bone
Step I : Reflecting adequate flaps for accessibility. The dif- throughout the entire incision so that the mucosa and
ficulty of removing an impacted tooth depends on its periosteum are completely incised. This allows a full-
accessibility. To gain access to the area and to visualize thickness mucoperiosteal flap to be reflected. The incision
the overlying bone that must be removed, the surgeon should be designed so that it can be closed over solid bone
must reflect an adequate mucoperiosteal flap. The reflec- (rather than over a bony defect). This is achieved by
tion must be of a dimenrion adequate to allow the place- extending the incision at least one tooth anterior to the
ment and ctabilization of retractors and instruments for surgical site when a vertical releasing incision is used. The
the removal of bone. incision should avoid vital anatomic structures. Only a
In moyt situations the envelope flap is the preferred single releasing incision should be used.
technique. The envelope flap is easier to close and heals Step 2: Removal of overlying bone. Once the soft tissue is
better than the three-cornerrd flap. However, if the sur- elevated and retracted so that the surgical field can be
geon requires greater access to the more apical areas of the visualized, the surgeon must make a j dgment concern-
tooth, which might stretch and tear the envelope flap, the ing the amount of bone to be removed. In some situa-
surgeon should consider using a three-cornered flap. tions the tooth can be sectioned with a chisel and deliv-
The preferred incision for the removal of an impacted ered without bone removal. In most cases, however, some
mandibular third molar is an envelope incision that bone removal is required.
extends from the mesial papilla of the mandibular first Although chisels can be used to remove bone overlying
molar, around the necks of the teeth to the distobuccal line impacted teeth, most surgeons and patients prefer that
angle of the second molar, and then posteriorly to and lat- bone be removed with a drill. The preferred instrument is a
erally up the anterior border of the mandible (Fig. 9-43, A). handpiece with adequate speed, high torque, and the abili-
The incision must not continue posteriorly in a ty to be sterilized completely, usually in a steam autoclave.
straight line, because the mandible diverges laterally. An The bone on the occlusal aspect and on the buccal and
incision that extends straight posteriorly falls off the distal aspects down to the cervical line of the impacted
bone and into the sublingual space and may damage the tooth should be removed initially. The amount of bone
lingual nerve, which is in close proximity to the man- that must be removed varies with the depth of the
dible in the area of the third molar. If this nerve is trau- impaction, the morphology of the roots, and the angula-
matized, the patient will probably have a lingual nerve tion of the tooth. Bone should not be removed from the
anesthesia, which may be distracting to the patient. The lingual aspect of the mandible because of the likelihood
incision must always be on bone; therefore the surgeon of damaging the lingual nerve.
should carefully palpate the retromolar area before begin- The burs that are used to remove the bone overlying the
ning the incision. impacted tooth vary with surgeons' preferences. A large
The flap is laterally reflected to approximately the exter- round bur, such as a no. 8, is desirable, because it is an end-
nal oblique ridge with a periosteal elevator (Fig. 9-43, B). cutting bur and can be effectively used for drilling with a
The surgeon should not reflect beyond :he external pushing motion. The tip of a fissure bur, such as a no. 703
oblique ridge, because this rerults in increased morbidity bur, does not cut well, but the edge rapidly removes bone
and an increased number of complications after surgery. and quickly sections teeth when used in a lateral direction.
The retractor is placed on the buccal shelf, just at the exter- The typical bone removal for the extraction of an
nal oblique ridge, and it is stabilized by applying pressure impacted mandibular tooth is illustrated in Fig. 9-45. The
toward the bone, which results in a retractor that is stable bone on the occlusal aspect of the tooth is removed first
and does not continually traumatize the soft tissue. to expose the crown of the tooth. Then the cortical bone
The Austin and the Minnesota retractors are the most on the buccal aspect of the tooth is removed down to the
commonly used for flap reflection when removing cervical line. Next, the bur can be used to remove bone
mandibular third molars. between the tooth and the cortical bone in the cancellous
If the impacted third molar is deeply embedded in area of the bone with a maneuver called ditching. This
bone and requirer more extenrive bone removal, a releas- provides access for elevators to gain purchase points and
ing incision may be useful (Fig. 9-43, C and D). The flap a pathway for delivery of the tooth. No bone is removed
created by this incision can be reflected farther apically, from the lingual aspect so as to protect the lingual nerve
without risk of tearing the tissue. from injury.
 Principles of Management of Impacted Teeth CHAPTER 9

FIG. 9-43 A, Envelope incision is most commonly used to reflect soft tissue for removal of impacted
third molar. Posterior extension of incision should laterally diverge to avoid injury to lingual nerve.
B, Envelope incision is laterally reflected to expose bone overlying impacted tooth. C, When three-
cornered flap is made, a releasing incision is made at mesial aspect of second molar. D, When soft tis-
sue flap is reflected by means of a releasing incision, greater visibility is possible, especially at apical
aspect of surgical field.

FIG. 9-44 A, Envelope flap is most common-

ly used flap for removal of maxillary impacted
teeth. B, When soft tissue is reflected, bone
overlying third molar i s easily visualized. C, If
tooth i s deeply impacted, a releasing incision
can be used to gain greater access. D, When
three-cornered flap is reflected, the bone's
more apical portions become more visible.
208 PART I1 Principlec of Exodontin

For maxillary teeth, bone is removed primarily on the

buccal aspect of the tooth, down to the cervical line to
expose the entire clinical crown. Additional bone must be
removed on the mesial aspect of the tooth to allow an
elevator an adequate purchase point to deliver the tooth.
Because the bone overlying maxillary teeth is usually
thin, it can be easily removed with a unibevel chisel with
only hand pressure.
Step 3: Sectio~~ingtlze tootl~.Once sufficient amounts of
bone have been removed from around the impacted
tooth, the surgeon should assets the need to section the
tooth. Sectioning allows portions of the tooth to be
removed separately with elevators through the opening
provided by hone removal.
The direction in which the impacted tooth should be
divided depends primarily on the angulation of the
impacted tooth. Although minor modifications are nec-
essary for teeth with divergent roots or for teeth that are
more or less deeply impacted, the most important deter-
minant is the tooth's angulation.
I Tooth sectioning can be performed with either a bur
FIG. 9-45 A, After soft tissue has been reflected, bone overlying or chisel; however, the bur is used by most surgeons. If
occlusal surface of tooth is removed with a fissure bur. B, Bone on a chisel is used, it must be extremely sharp, and the
buccodistal aspect of impacted tooth is then removed with bur. blows delivered to it by the mallet must be sharp and

____----

FiG. 9-46 A, When removing mesioangular impaction, buccodistal bone is removed to expose crown
of tooth to cervical line. B, Distal aspect of crown i s then sectioned from tooth. Occasionally, it is nec-
essary to section entire tooth into two portions rather than to section distal portion of crown only.
C, After distal portion of crown has been delivered, small straight elevator is inserted into purchase point
on mesial aspect of third molar, and tooth is delivered with rotational and lever motion of the elevator.
 of Mflnqqenlc'ntof lr?zpnctetl Teeth
Prii~cipl~~s . CHAPTER 9 209

forceful enough to split the tooth. For the conscious removed down to the cervical line to expose the superi-
patient the sound of the chisel striking the tooth may be or aspect of the distal root and the majority of the buc-
bothersome. cal surface of the crown, the tooth is sectioned by divid-
When the bur is used, the tooth is sectioned three ing the crown of the tooth from the roots at the cervical
fourths of the way toward the lingual aspect. A straight ele- line. The crown of the tooth is removed, and the roots
vator is inserted into the slot made by the bur and rotated are displaced with a Cryer elevator into the space previ-
to split the tooth. The bur should not be used to section ously occupied by the crown. If the roots of an i~npacted
the tooth completely through in the lingual direction, third molar are divergent, they may require sectioning
because this is more likely to injure the lingual nerve. into two separate portions to be delivered individually
The mesioangular impaction is usually the least difficult (Fig. 9-47).
to remove of the four basic angulation types. After sufficient The vertical impaction is one of the two most difficult
bone has been removed, the distal half of the crown is sec- impactions to remove. The procedure of bone removal
tioned off at the buccal groove to just below the cervical line and sectioning is similar to the mesioangular impaction;
on the distal aspect. This portion is delivered. The remainder that is, the occlusal buccal and distal bone is removed.
of the tooth is removed with a no. 301 elevator placed at the The distal half of the crown is sectioned and removed,
mesial aspect of the cervical line. A mesioangular impaction and the tooth is elevated by applying an elevator at the
can also be removed by preparing a purchase point in the mesial aspect of the cervical line of the tooth. This is
tooth with the drill and using a Crane pick elevator to ele- more difficult than a mesioangular removal, because
vate the tooth from the socket (Fig. 9-46). access around the mandibular second molar is difficult to
The next most difficult impaction to remove is the obtain and requires the removal of substantially more
horizontal impaction. After sufficient bone has been bone on the buccal and distal sides (Fig. 9-48).

I
FIG. 9-47 A, During removal of horizontal impaction, bone overlying tooth (i.e., bone on distal and
buccal aspect of tooth) is removed with bur. B, Crown is then sectioned from roots of tooth and deliv-
ered from socket. C, Roots are then delivered together or independently by Cryer elevator used with
rotational motion. Roots may require separation into two parts; occasionally, purchase point is made
in root to allow Cryer elevator to engage it. D, Mesial root of tooth is elevated in similar fashion.
210 PART I1 Principles of Exodontia
-

FIG. 9-48 A, When removing vertical impaction, the bone on the occlusal, buccal, and distal aspects
of crown is removed, and the tooth is sectioned into mesial and distal sections. If the tooth has a
single-fused root, the distal portion of crown is sectioned off in a manner similar to that depicted for
mesioangular impaction. 6, Posterior aspect of the crown is elevated first with Cryer elevator inserted
into small purchase point in distal portion of the tooth. C, Small straight elevator no. 301 is then used
to elevate the mesial aspect of the tooth by rotary-and-lever type of motion.

The most difficult tooth to remove is the distoangular Impacted maxillary teeth are rarely sectioned, because
impaction. After sufficient bone is removed from the buc- the overlying bone is usually thin and relatively elastic.
coocclusal and the distal sides of the tooth, the crown is In situations in which the bone is thicker or the patient
sectioned from the roots just above the cervical line. The is older (and therefore the bone not so elastic), tooth
entire crown is usually removed, because it interferes extraction is usually accomplished by bone removal
with visibility and access to the root structure of the rather than tooth sectioning. Under no circumstances
tooth. If the roots are fused, a Cryer or straight elevator should a chisel be used t o section maxillary teeth,
can be used to elevate the tooth into the space previous- because displacement of the tooth into the maxillary
ly occupied by the crown. If the roots are divergent, they sinus is highly likely.
are usually sectioned into two pieces and individually In general, impacted teeth elsewhere in the mouth are
delivered. Extracting this impaction is difficult, because usually sectioned only at the cervical line. This permits
much distal bone must be removed and the tooth tends removal of the crown portion of the tooth, displacement
to be elevated distally and into the ramus portion of the of the root portion into the space previously occupied by
mandible (Fig. 9-49). the crown, and removal of the root portion.
 Principles of Management of lrnpacted Teeth . CHAPTER 9 211

FIG. 9-49 A, For distoangular impaction, occlusal, buccal, and distal bone is removed with bur. It is
important to remember that more distal bone must be taken off than for vertical or rnesioangular
impaction. B, Crown of tooth is sectioned off with bur, and crown is delivered with straight elevator.
C, Purchase point is put into remaining root portion of tooth, and roots are delivered by Cryer eleva-
tor with wheel-and-axle type of motion. If roots diverge, it may be necessary in some cases to split
them into independent portions.

Step 4: Delivery of the sectioned tooth with elevator. Once Application of excessive force may result in unfavor-
adequate bone has been removed to expose the tooth and able fracturing of the tooth, of excessive buccal bone, of
the tooth has been sectioned in the appropriate fashion, the adjacent second molar, or possibly of the entire
the tooth is delivered from the alveolar process with den- mandible.
tal elevators. In the mandible the most frequently used Elevators are designed not to deliver excessive force but
elevators are the straight elevator, the paired Cryer eleva- to engage the tooth or tooth root and to apply force in the
tor, and the Crane pick. proper direction. Some highly skilled surgeons use the peri-
An important difference between the removal of an apical curette to remove sectioned roots from their sockets.
impacted mandibular third molar and of a tooth else- Because the impacted tooth has never sustained occlusal
where in the mouth is that almost n o luxation of the forces, the periodontal ligament is weak and permits the
tooth occurs for the purpose of expansion of the buccal easy displacement of the tooth root if appropriate bone is
or linguocortical plate. Instead bone is removed and teeth removed and force is delivered in the proper direction.
are sectioned to prepare an unimpeded pathway for deliv- Delivery of maxillary third molars is accomplished
ery of the tooth. with small straight elevators such as the no. 301 elevator,
 212 PART I1 Principles of Exodontio

will pull free from the surrounding hard and soft tissue.
A final irrigation and a thorough inspection should be
performed before the wound is closed.
The surgeon should check for adequate hemostasis.
Bleeding can occur from a vessel in the flap, from the
bone marrow that has been cut with a bur, or the inferior
alveolar nerve. Specific bleeding points should be con-
trolled if they exist. If brisk generalized ooze is seen, after
the sutures are placed the surgeon should apply firm pres-
sure with a small, moistened gauze pack. I'ostoperative
bleeding occurs relatively frequently after third molar
extraction, and therefore adequate hemostasis at the time
of the operation is important.
Usually the closure of the incision should be a primary
closure. If the flap was well designed and not traumatized
during the surgical procedure, it will fit into its original
position. The initial suture should be placed through the
attached tissue on the posterior aspect of the second
molar. Additional sutures are placed posteriorly from that
position and anteriorly through the papilla on the mesial
side of the second molar. Usually three or four sutures are
necessary to close an envelope incision. If a releasing inci-
sion was used, attention must be directed to closing that
portion of the incision as well.

PERlOPERATlVE
-- - -PATIENT MANAGEMENT
FIG. 9-50 Delivery of impacted maxillary third molar. A, Once soft
tissue has been reflected, small amount of buccal bone is removed The removal of impacted third molars is a surgical proce-
with bur or hand chisel. B, Tooth is then delivered by small straight dure that is associated with a large amount of patient
elevator, with rotational and lever types of motion. Tooth is deliv- anxiety. In addition, this surgical procedure can involve
ered in distobuccal and occlusal direction. unpleasant noises and sensations. As a result, surgeons
who routinely perform surgical removal of impacted
third molars commonly recommend to their patients
which distobuccally luxates the tooth. Some surgeons some type of profound anxiety control such as a general
prefer angled elevators, such as the Potts or Miller eleva- anesthetic or deep intravenous (IV) sedation.
tors, which aid in gaining access to the impacted tooth. The choice of technique is based on the surgeon's pref-
The elevator tip is inserted into the area at the mesial cer- erence. However, the goals are to achieve a level of
vical line, and force is applied to displace the tooth in the patient comfort that allows the surgeon to work effi-
distobuccal direction (Fig. 9-50). The surgeon should be ciently and that limits the patient's experience to the
cautious about applying excessive pressure anteriorly to minimal number of unpleasant effects.
avoid damage to the root of the maxillary second molar. Whether a deep IV sedative or a light general anesthet-
In addition, as pressure is applied to displace the tooth ic is used, most surgeons intend their patients to have lit-
posteriorly, the surgeon should have a finger on the tle, if any, unpleasant memory of the surgical experience.
tuberosity of the maxilla (especially if the impaction is In addition to the increased need for anxiety control,
mesioangular) so that if a fracture does occur, steps can be a variety of medications are required to control the seque-
taken to salvage the tuberosity of the maxilla. lae of third molar extraction surgery. The use of long-
Step 5: De'bridement of wound and wound closure. Once acting local anesthetics should be considered in the
the impacted tooth ic removed from the alveolar procecc, mandible. They will provide the patient with a pain-free
the surgeon must direct attention to debriding the period of 4 to 6 hours during which prescriptions can be
wound of all particulate bone chips and debris. The sur- filled and analgesics taken. The surgeon should consider
geon should irrigate the wound with sterile saline, taking writing a prescription for a potent oral analgesic for every
special care to irrigate thoroughly under the reflected soft patient who undergoes surgical removal of an impacted
tissue flap. The periapical curette is used to mechanically third molar. Enough tablets should be prescribed to last
debride both the superior aspect of the socket and the for 3 or 4 days. Combinations of codeine or codeine con-
inferior edge of the reflected soft tissue to remove any geners with aspirin or acetaminophen are commonly
particulate material that might have accumulated during used. Nonsteroidal antiinflammatory drugs (NSAIDs)
surgery. The bone file is used to smooth any sharp, rough may be of some value for certain patients.
edges of bone. A mosquito hemostat can be used to To minimize the swelling common after the surgical
remove any remnants of the dental follicle. Once the fol- removal of impacted third molars, some surgeons prefer
licle is grasped, it is lifted with a slow, steady pressure and to give parenteral steroids. IV administration of a modest
 Principles of Management of lmpacted Teeth . CHAPTER 9 213

amount of a glucocorticoid steroid provides sufficient REFERENCES

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administration of 8 mg of dexamethasone before surgery. 2. Venta I et al: Clinical follow-up study of third molar erup-
This is a relatively long-acting steroid, and its efficacy in tion from ages 20 to 26 years, Oral Sztr;p Orrll Merl Oral Pathol
controlling third molar postsurgical swelling is docu- 72:150, 1991.
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Ani Dent Assoc 101:240, 1980.
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4. Marmary J et al: Alveolar bone repair following extraction of
must be carefully followed before the decision is made to impacted mandibular third molars, Oral Slrrg Oral Med Oral
give these drugs routinely. Pathol 61:324, 1986.
Many surgeons recommend t h e use of ice packs o n the 5. Meister F Jr et al: Periodontal assessment following surgical
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unlikely that the ice has much effect o n preventing 1986.
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provides them the opportunity to participate in their o(ioiito1 53:93, 1982.
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The intraoral use of ice may have additional benefit. Gent- 17:161, 1988.
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Popsicles may be of some value in helping patients feel mandibular third molar, Swed Dent / 11:23-29, 1987.
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Another medication that is sometimes used is a n antibi- molar, Oral Slrry Oral Med Oral Patl?ol 62:245, 1986.
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local infection, antibiotics are usually not indicated. 12. Richardson ME: The role of the third molar in the cause of
The normal postoperative experience of a patient after late lower arch crowding: a review, A m / Ortl~odDentofac
surgical removal of a n impacted third molar is more Ortliop 95:79, 1989.
involved than after a routine extraction. The patient can 13. Kugelberg CF: Periodontal healing two and four years after
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pating by about 5 t o 7 days. A modest amount of dis- 14. Kugelberg CF et al: The influence of anatomical, pathophysi-
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/ Max-
routine basis and intermittently for several more days. illofrlc S~rr'y20: 18, 1991.
The patient may have some mild soreness in t h e region
for 2 t o 3 weeks after the surgery. BIBLIOGRAPHY
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All of the sequelae of t h e surgical removal of impacted Lytle JJ: Indications and contraindications for removal of the
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Ortliod 28:660, 1942.
35 to 40 years have a significantly more difficult time Peterson LJ: Principles of management of impacted teeth. In
after the extraction of impacted third molars than d o Peterson IJ, editor: Principl(~\ of om1 ond inoxillofaciol slrrgew,
healthy 17-year-old patients. Philadelphia, 1992,JB Lippincott.
See Chapter 1 0 for a more detailed description of post- von Wowern N, Nielsen HO: The fate of impacted lower third
operative care. molars after the age of 20, Itit/ Oral McrxillofncS~rrg18277, 1989.