RELAPSE

DEFINITION:

ENLOW: ‘A histogenetic and morphogenetic response to some anatomical and

functional violation of an existing state of anatomic balance.

REBOUND: ‘Movement in which teeth recoil Bach somewhere close to their initial
positions, once retentive forces are removed.

ANGLE – 1907
‘The problem involved with retention is so great as to test the utmost skill of the most
competent orthodontist, often being greater than the difficulties being encountered in the
treatment of the case upto this point’.

BEGG – 1954.

TWEED – 1944 – 1966 ‘Clinical Orthodontics.

‘ Anterior Limit Of The Denture is The Key to Stability’

Class ‘C’ – Growth trend.

Hawley:
‘I would give half my fee to anyone who would be responsible for the retention of my
results when active appliances are removed’.

Mershon:
“The final position of teeth is like an argument with mother nature, who always wins”.

‘Our ability to achieve long term stability and our understanding of factors underlying
stability are the least understood’.

Instability.
1. Changes related to growth, maturation, and aging of the dentition and occlusion.
2. Changes related to inherent instability of occlusion produced by orthodontic
therapy.

RELAPSE.
SKELETAL DENTAL SOFT-
TISSUES.

1. Functional appliance therapy.

Herbst
Twin block
Early (VS) Late treatment
 2. Surgical Correction.

Maxilla Mandible
Impaction Advancement
Advancement Set Back
Down Graft Genioplasty
Expansion Superior
Contraction Inferior
Augmentation
Reduction.

Distraction Osteogenesis.

MAXILLARY EXPANSION
“The debate seems to have been all the more heated because little scientific evidence
existed to support any of these views. Opinions were never the less so firmly stated that
one could be forgiven for wondering if it was, indeed, the same human animal that was
being treated in each instance. While individual cases abound, there appear to have been
few studies conducted on Consecutive cases”
- Timms.

- Skieller - 1964

o 13 Girls and 7 boys

- Expansion – 0.5mm/week – 7 months
Stabilization – 12 months.
Avg. Relapse – 25% of total opening.
Decrease 9 years > Dental Relapse > Increase 12 years.
“ At a rate of 0.5mm/ week, the widening is 1/5th – Growth at mid palatal future. 4/5th –
Tooth movement.”

- Storey – 1973.
o 1mm/week
(1980) Haas – Over expansion.
- Harold Chapman – CROSS BITES.

Townend - ‘The Comedy of expansion and the tragedy of Relapse’

John Mew – 1983.

- Slow expansion (Semi vapid)

- 1mm per week and over expansion.
sample of 25 patients
 Appliance:- Bio block.
- 1mm per week.

Over expansion – 2-4 mm

Retention – 1 ½ to 4 years.

- Relapse of over expansion

Expansion:- Minimum distance between mo/ass at gingival level.
- Little’s Index

Results:-
3.5mm increase intermolar width – Number of relapse.

- Previous studies based on maximum expansion.

- Relapse – irrelevant to some extent.

Natural Growth: -
Moorrees – Increase 1mm per year – Boys
Decrease 1 mm per year – Girls

- Irregularity of growth

‘During the initial expansion, the teeth tilt to some extent but tend to upright
spontaneously during the long period of retention.”

Arch lengthening Vs. Expansion.

- Over expansion – Comparison.

Conclusion:
‘Maxillary expansion can provide a useful increase in arch size. when over expansion
was combined with proclination and subsequent wearing of an activator, incisor
alignment was achieved in all but 2 of the twenty cases. A permanent exp. of 3.5mm was
obtained with a little tendency for relapse.’

‘Expansion may be comic but extraction can be tragic’.

Maxillary Osteotomies:
Schuchardt – 1959.
Kufner and perko - 1970.
‘Complete sectioning of the perpendicular portion of the palatine bone would not
jeopardize the blood supply’

- Bell and Epker - 1975.

- willimar 1974.
o First follow up study using surgically placed metal markers.
o 10% superior relapse of anterior marker.
 - Schendell et al – 30 patients – Relapse tends to be in the same direction as
surgical movement.

West and Epker - 1972.

‘A small amount of average post surgical movement was in the direction of the surgical
change’.
Anterior Arnjo et al – 1978.
- ‘Maxillary advancement with or without bone Grafts’
- Bone Grafts – Optimal Stability
- Minimal adv. – overcorrection.

Diagram
Epker E N. – 1981.

‘ Instability of maximum impaction is most often manifested by skeletal relapse during

fixation and/or very soon after release of fixation.’

William R Proffit – 1987.

‘Maxilla show a strong tendency to move further upward in patients in whom it was not
stable’ - 80% to 90% stable
- Presurgical incisor movement
- Multiple segments
- Age
- Genioplasty
- Suspension wires.
- No evidence

- (Anterior maxilla is less stable)

- Maxilla showed a tendency of moving back after advancement.
- Teeth tend to extrude under the forces of 1 MF
- May rein trade post fixation.

Factors to remember:
1. Age
2. Amount of presurgical orthodontics

‘Mobility of teeth following tooth movement is much more function of the magnitude
and pattern of orthodontic force than the distance the teeth have moved.’
3. Genioplasty : No significance.
4. Identify of the surgeon
‘Maxilla would be more stable with only a single segment than multiple segments,
especially since patients with multiple segments might require larger movement at
surgery’.
Phillips and associates:- 1985.
‘Maxilla tends to intrude slightly after surgery.’
Age decrease 19 years – Average downward movement of 2mm during follow-up - Late
vertical Growth.

Samir E Bishara – 1988.

‘Stability of LeFort ] one piece maxillary osteotomy’

Sample : 31 patients - 10 Male

- 21 Female.

Diagram
Vertical :
33% - Increase superior movement at A.
12.3% - Increase superior movement Mxp.

Horizontal.
1.01mm or 39.8% - Post relapse at A.
0.83 or 32% - Mxp.

Diagram
Vertical :
1. 1.31mm/47% increase sup. movement at maxillary incisor.
2. 0.29mm/8.6% increase movement at maxillary incisor molars.

Horizontal:
1. 0.56/26.8% Post movement of upper incisors.
2. 0.58/23.7% post movement of upper molars.

Diagram
Horizontal Skeletal :
1. Significant movement posteriorly - Fixation
- Post Fixation.

2. Differential posteriorly movement at A and Mxp. – Rotation.

Horizontal Dental :
1. Significant Posterior molars movement after splint removal.
Mandibular changes:
- Superior movement post surgery

Fixation: - Slight posterior movement of mandibular landmarks

Splint Removal:-
- Superior and anterior rotation – gonion – Inferior Auto Rotation.
- Mandibular Incisal Edge:- Post movement.

Diagrams
Discussion:
a. Vertical Skeletal:
1. Max moved further in the superior direction post surgically.
2. Fixation : A and Mxp. – Phillips et al.

Why?
 Resorption and remodeling at surgical site.
 ‘Telescoping effect’
 Tightening of suspension wires.

b. Vertical dental.
1. Incisors and molars moved significantly superiorly during fixation.
2. Total dental movement >skeletal - α Shendell et al.

Why?
 Tightening of suspension wires attached to orthodontic arch wire – Localized dental
intrusion

Care?
 Avoid burying the incisors beneath the lip, as it moves superiorly after surgery.
Post: Fixation.

Over cone?
 Vertical intermaxillary clastics.

A Redefinition of bilateral sagittal osteotomy (BSO) Advancement Relapse.

- William Arnett.

 Increasing prevalence of combine of surgical – orthodontic procedures.

 Correction of unyielding skeletal and dental dysplasias.
 Skeletal Dysphasia’s
Orthognathic surgery.

Severe Progressive Deformities.

- Skeletal Relapse - Surgical changes

Most Noteworthy Complications Stable Predictable

Mandibular Advancement:
Skeletal class II Malocclusion - Mandibular Retrognathism - Conjoint Management
- Function Esthetics.

“SAGITTAL SPLIT RAMUS OSTEOTOMY.”

Poulton and Ware – 1972.

‘In the retrusion corrected by sagittal split: Ramus osteotomy, major amountof change is
seen in the first few months after surgery.

- Suprahyoid Muscles.

Advancement – Muscular Flexion - Forward Traction of Hyoid Bone and As. Vertebrae
- Head Flexion.
Suprahyoid myotomy
Pitkin Collar
Sternal mandibular brace.

Freihofer and Petresevic - 1975.

‘Poor condylar positioning into the glenoid fossa during surgery.

Markell et al – 1978.

‘Skeletal relapse may represent and cause and effect relationship mediated through the
soft – tissue attachments of periosteum and muscle that are stretched at the time of
surgery”

- Monty Reitzik (1980)

- Anatomy of relapse
 Supra Hyoid
 Infra Hyoid ( digastric and masticotory muscles)
- Vector of massetric sling.
Diagram
1980 – J.Brammer et al.

Advancement in high angle mandibular def. and superior maxillary repositioning

1981 – G.M. Yellich.et al.
‘ Shortening of muscles attached to proximal segment.’

- Rotation
 Superior
 Anterior

Eiichi Komovi – 1989.

“Preservation of proximal segment in its exact anatomical site” and Skeletal fixation.

Worms – 1980
- Condylar resorption.
 BSSO
 BVO
“ Resorption is more apparent in mandibular adv. procedures that rotate mandible in a
counter clockwise direction.”.

Kerstans et al – 1989.
- Condylar resorption
 All orthognathic procedures.
- Females (20-30years)
- High MPA
- TMJ Dysfunction
- Large Amount of Advancement
- Kent and moore et al 1991.
- Nakajima et al.
“ No significant factor is responsible for the development of relapse, significant relapsing
potential may exist when the amount of correction exceeds lomms.”

- RECAP

Prevention:
1. Proper condylar repositioning
2. Skeletal fixation.

Ineborg et al – 1990.
- Screw fixation (dis ady)
- Superior border wiring
 - Int. border wiring
- Fig. of 8 wiring etc.,
3. Supra hyoid myotomics.
- Large magnitude of advancement.

Mc Neill et al – 1973.

- ‘The mandible can be advanced successfully in all types of mandibular deficiencies.

The relapse is multificatorial, but is greatly influenced by the surgeons technique and
experience”.
- S A Schendel – 1980.
‘ A Redefinition of Bilateral sagittal osteotomy advancement relapse.
‘William Arnett. AJO-1993 Nov.

- Condylar sag.
 Proximal segment positional change.
Relapse -
Two anatomic sites.
1. Point B.
2. 2.Overjet increase (Incisor)
a. Osteotomy site – Slippage
b. TMJ – Condylar sag.
c. TMJ – Morphological change.

Osteotomy Slippage:
Def.’Any decrease in the length from condylion to the lower incisors that occurs at the
surgical site before bony union”.
-Para mandibular connective tissue streach (Skin, Muscle, C.t. Periosteum).
- Vector pulling tooth bearing segment posteriorly.

Diagram
Counter vector:
- Osteosynthesis hardware
- Condyle
 Large adv.
 Counter clockwise rotation
 High mandibular plane angle.

Consequences:
Lippage – Post b-Point Migration.

Diagram
Condylar Sag.:
A condyle that is
1. Positioned inferior or anterior inferior to the glenoid fassa seated position.
2. Has no ability to support B. Point in the advanced position.
- Inadequate *
- Non contact condylar seg.

Diagram
Condylar compression and Morphologic change:
1. Posterior condylar compression:- (PCC)
Occurs as a result of changing the pre.O.P. condylar position to a more posterior
position during surgical procedure.
* Animal Studies.
‘this type of remodelling occurs after mandibular set. back.

Remodeling 9+8 months post surgical.

- Skeletal and dental relapse occurs at same time
- No. dental compensations.
B. Medical or Lateral Compression:
- May cause TMJ remodeling and produce late B.Point dental relapse.

Diagram
- Depends on first point of contact between tooth bearing and condyle
bearing segment.
- If clamping/screws close the gap.
- Condylar Torquing.
- Associated with bicortical screws.
Prevention:
Intra operative condylar seating
- Allow glenoid fossa and disk to guide condyle into upper most position.
- Bivector seating*
Hardware: Hold condyle in higher most position without deflection.

CAUSE OF EARLY SKELETAL RELAPSE AFTER MANDIBULAR SET-BACK

Eikhi Komori et al.
AJO – 1989. January.
- Relapse during fixation – Early
- Release of IM.Wiring – Late.
- Downwards and Backward Jaw Rot.*
Digram

-Skeletal suspension wiring

- Bell
- EPKER
- Komori et al
 Cephalometric study
 Decrease Symphyseal shift.

Diagram
Unplanned compensatory tooth movement.
- Post surgical orthodontic problems.

Yellich and Mc Namara – 1981.

- May encourage later relapse.

Treatment objective – Control of upward shift during fixation.

Contributing Factors.
1. Divergent facial pattern
2. Direction and amount of correction
3. Displacement of proximal segment
a. Change in facial height.
No. specific factors reflecting the degree of early relapse during fixation.

AIM: To determine if any cephalometric measurements related to ostotomy could be

sued as predictive parameters reflecting early skeletal relapse.
- 15 patients.- Absolute mandibular prognathism. (16-28yrs)
- 0.18inch edgewise appliance
- Modified sag. split osteotomy.

Distal. Seg.: Repositioned into a desired occlusal relation with a prefabricated inter
occlusal water splint as a guide.
- Proximal segment positioning.
- Buccal cortical bone gap. Maintained at pre surgical SITE.
- Circumramal wiring.
- Skeletal Fixation
 Per Alveolar
 Circom mandibular and IMF – 4.5 weeks

4. Lateral cephalograms
- Pre-surgical
- Few days after surgery
- Before release of IMF ( 4 weeks)

-Surgical
Post-surgical changes – Angular and point coordinate measurements. x-axis parallel to
FH
- 2 – cephalometric point gonions.
 1. True post operative gonion
- After surgical ramal split. – P.GO
2. Hypothetical gonion constructed on the distal segment to monitor posterior end of
the distal segment. – d.go.

Diagram

-Forward and upward readings: ‘+ve’

- Backward downwards readings: ‘-ve’

Results:
1. Skeletal relapse vs. surgical changes.
a. Relapse in terms of upward shift of post segment (end) of distal segment.

Significant
Anterior – post rotation of proximal segment at surgery *
b. Relapse – measurements rel to surgical set back and rotation of distal
segment. *
c. Surgical movement of distal set. vs. proximal:
Degree of proximal segment rotation at surgery (change in x-cordinate of 8-90 and
change in ramal inclination)

Extent of surgical set back of distal segment. (change in x-coordinates of Pog. and D-90)

- The proximal segment was contrary to intention rotated forward or

backward depending on amount of surgical distal segment set back.
- Faulty Technical IR end.*

Discussion:
‘A certain degree of skeletal relapse invariably occurs after surgical correction, regardless
of kind of ramus surgery and technique of intersegmental osteosynthesis applied’
- Lysell – 1961
- Issacson – 1978
- Pass cus – 1982
- Sandor – 1984.

Primary Factor ?
- Varied results
- Speculative conclusions.
- Skeletal Relapse – Multifactorial.

Ceph study of late relapse:-

- Possible mandibular growth
- Bone remodeling
- Posterior op. Orthodontic treatment.
- Removal of Inter occlusal water – obscure cephalometric measurements.
Early Relapse – Rather definitive ceph. study.
1. Distal Segment Set. Back:
Surgical procedure – No error.
Distal segment - Relapse.
- Surgical improvement of malocclusion and esthetics. – Bio-mech
drawbacks.
- Unbalanced forces on stomato :-Gnathic sys.
Ex:- a. Sag. Split.
b. Mand. Adv.
- Elasticity of skin
 C.T.
 Elements of peri-mand soft tissue forces.- Relapse.

Avoid?
- Muscle detachment.
- Modified ramus osteotomy.

2. Proximal Segment Positioning:

- Individual differences in relapse behaviour – Surgeon’s Technique –
Relapse.
- Loss of post face ht. And steel mand. And steep mand. Plane angle.
- Problem rel to proximal segment.

Surgically Mod. Pertygo Mesenteric sling.

- Source of relapse.

Decrease control of proximal segment bearing sling during surgery.

Condylar Rotation of segment.

Distraction.

Forward Backward.

Less Concern. Increase Length

-Masseter
-Med. Pt.
- Vellich
- Mc. Namara
- Tody.
- Improvement of post-surgical stability.
Decrease Technical retinements. compensate for inaccuracies in osteotomy and
prediction.
- Cephalometric data in O.T. – Beneficial
- Impractical.
Conclusion.:
1. In advertent ant. post rot. of proximal segment – significant factor in distal
segment relapse.
2. Important to preserve proximal segment in its exact pre-surgical anatomic
position with out rotating it.
3. Combination of skeletal suspension wiring and accurate anatomic positioning. if
proximal segment is essential for providing a stable treatment result in mandibular
set back surgery.
Diagram

ORTHOGRATHIC SURGERY – A hierarchy of stability.

- W.R.Proffit
- T.a.Turrey
- C.Phillips.
- Int. I Adult orthod. Orthognathic Surg. 1996.

Stability after surgical jaw repositioning:

- Direction.
- Fixation.
- Technique

More Maxillary Up.

Mandibular FWD
Maxillary FWD

Stable Max up and Mandibular FORWARD

Predictable Max FWD and Mandibular Back.
Mandibular Back.
Maxillary Down

Less. Maxillary Wider.

Maxilla – Superior Repositioning:

- Long face deformities
- Late 1960’s
- Increase Freeway space.

Study- Group A – Wire/MMF

Group B – RIF

One year post-surgery – ‘Maxilla was vertically within 2mm of immediate post surgical
position.’
- 90% patient MMF.

RIF – Similar
RIF- No. Significant difference in surgical stabilty.
‘There is a better than 90% chance of excellent skeletal stability when maxilla is moved
up with the LeFort, down fracture regardless of type of fixation’.

Mandibular Advancement:
ADV- Treatment of Openbite.

UNC Data base-

Wire/MMF – Increase 1/3rd of patients – Increase 2mm
Posterior relapse per 6 weeks.

RIF – Smaller tendency of backward movement.

6 Weeks – 1 year.
WIRE/MMF – ‘Recovered initial position when function was resumed.
- No statistically difference bet. both groups after 1yrs,
- 90% - Mandibular remains within 2mm of immd. posterior op. position.

Advancement – ‘Long face and open bite’

RIF – Increase stability
- Inter positional bone grafts.
- Heavy bone plates.

3. Mandibular ADV and Sup. Maxillary repositioning.

Indication – Long face and Mandibular deficiency.
WIRE/MMF
20% - MAX. moved slightly sup. and tendency to rotate.
6 weeks –
50% - Mandibular slipped posterior

6 weeks – 1 years – Cont. relapse 1/3rd patients.

Post 1 year – 60% (Excellent clinical cond.)

RIF/
6 weeks – Increase stability
6 weeks – 1 year – Partial mandibular relapse.
- 90% (excellent outcome)
- A.Ayoub – 1993
- Henees JA – 1988.
4. Maxillary Advancement.
- Indication – Class III patients without mandibular deficiency .
- Less prevalent than other orthognathic problems.

A.P. Plane – 80% - Stable

20% - Modest relapse.
Post. surgery :- Anterior mandibular landmarks.
- Forward movement.

- Mandibular Rotation.
Therefore 2-4mm movements – clinically insignificant
A 4mm: - ‘upward maxillary movement.

Downward max. Movement – unstable

‘Patients with increase 4 mm of forward movement of mandibular landmarks were those
who experience upward relapse of maxilla after it had been moved downward as it was
advanced’

Mandibular setback:
-‘Original orthognathic surgical procedure’
-TOVRO (or) BSSO
1 year (Posterior OP) – TOVRO
- ‘Increase chance of further backward mandibular movement.
- BSSO- No post surgical backward movement.
Forward relapse> Tovico
RIF+BSSO – ‘Make relapse tendency worse’
Forward relapse – ‘Controllable technical problem.
If remus pushed vertically – Musculature
-Chiro forward.

Inferior Maxillary Repositioning:

- Treatment of V.M.D.
- ‘Strong relapse tendency’
RIF – ‘Strong relapse tendency’
Without ‘Almost all vertical change was lost’

Reason? - Occlusal forces

- 3 possible solutions.

a. Heavy fixation barb.

b. Synthetic hydroxyapatite graft
c. Simultaneous ramus osteotamy

Transverse Expansion: Maxilla

- Least stable
- Multisegment effort I and maxillary expansion.

1 year post OP – Increase 2mm relapse in 2/3rd of patient

- Increase 2nd molar –50%
- Elastic rebound of palatal mucosa.

Control?
 - Over correction
- Retention
 Heavy wire
 Palatal Bar
- Palate covering retainer – 1 year
- Surgically assisted RPE
 Bays – 1992
 Roxrel. 1992
 Ways to improve stability
- Jack screw - microfracture of mid. palatal suture stability.
‘ As with lefort –I, relapse does occur from the point of maximum exp.
- Lefort I and RPE
Principles influencing Post-Surgical stability:
1. ‘Stability is greatest when soft-tissues are relaxed during surgery.
2. Excellent stability requires neuromuscular adaptation. – Max. Moved upward?
Neuromuscular adaptation does not occur – Mandibular osteotomies.
- Open bite treatment.
- Max. Downward movement.
3. Neuromuscular adaptation affects muscular length, not muscular orientation.

1. Stability and effect on the soft-tissue profile of mandibular setback with sagittal
split osteotomy rigid internal fixation. – Ingervall et al.
1995.
- 29 consecutively treated patients.

2. Aim: Compare the stability of mandibular set back with sag. split osteotomy and
JF with mandibular adv. performed by the same team.
- No mandibular splint was used for stabilization.
- Maxillo mandibular fixation.
- Profile radiographs.
 T1 0-8days before surgery
 T2 1-8days after surgery
 T3 12-19 months
Present study – AVG Relapse – 18%
AVG relapse – 20% - Krekmanov et.al.
And Franco and proffiteltal – 60%
8 patients – 0.2-1.8mm further posterior.
21 patients – partial relapse.
Average : 1.8mm – 26%
1 patient – 4.8mm relapse
Set back 10.3mm

3. Setback showed greater stability than advancement series. Further advancement

in some patient majority – partial relapse – 26%
Why?
1. Kundert et al. –1980.
‘Condylar rotation was more frequent after set back than advancement’
- Spitzel et al- 1984.
2. Technique – Individual surgeons
- Proffit et al
- Watzke et a
- Van sickel’s et al.
- Franco et al.

3. Surgical class III treatment long term stability and patient perceptions of
treatment outcome. – 1998.
- I. Bailer
- W. R.Profitt
- Duong
- Class III patients – 25% - Orthognathic surgery population.
- Mandibular set back - Most frequent procedure till mid 80 decrease 10%
- Maxillary adv - Increase 45-60%
- Remaining – ‘Iwo-Gaw Surgery’
Horizontal maxillary adv. – 80% stable
Set-back – 40% to 60% - Increase 2mm change post. surgery.
Considerable no. have 4mm.
- 1year stability f Two-jaw surgery
- Intermediate.
‘Paper reports stability after 3.5years concern) in class III patient treated wih current
surgical technique’
Maxilla forward – 34 patients
Mandibular back- 18 patient
Two Jaw – n=40.
- “Mandibular set back for class III – ‘move stable with maxillar adv.
- ‘fewer long term changes after class III than class II.
 Increase stability when max is moved forward and down than
when it is moved up.
 Long term remodeling at condyle adv. (vs) set back.
4. ‘Stability of sagittal split advancement osteolomy:- single – versus double jaw
surgery’
- Ashraf ayoub
- D.Stirrups.
- Int.J.Adult orthod. 1995.
-Early studies of stability of double jaw surgeries reported that patients
experiences less mandibular relapse but increase maxillary relapse than when the
procedures are carried out independently.
- Brammer et al 1980
- I kelly et al 1987.
Aim: to compare the stability of mandibular adv. in 40 patients divided equally into 2
groups.
Group 1 - Simultaneous maxillary impaction and sagittal split mandibular adv
Group 2 – Sag split mandibular adv.

‘Simultaneous mobilization of both maxilla and mandible to produce a harmonious facila

esthetics produces the most effective correction of occlusion.

- ? - Biological and bio-mechanical Advantages.

- Finn et al.

Present study –
Patient who underwent bimaxillary ost did not seem to gain the estimate bone fit of a
simultaneous maxillary impaction.

Both groups: Condyle wee pushed posterior in glenoid fossa.

ADJ: 6 months. – Relapse.

- Remodeling changes detected at 1 year follow up

- Self adaptation to achieve equilibrium when surrounding musculature was
stretched
Beyond its biologic physiologic limitation
Relapse:
Alteration of the relation ship of the bone segments to each other.

Present study:
Maxillary stabilized within 1mm of immediate posterior op. position.
1. Mandibular stability is not influenced by impaction of maxilla.
2. Increase attention to condylar segment placement.
3. Condylar displacement - Skeletal relapse.
4. Counter clockwise rotation of distal segment – unstable procedure.

Growth Considerations:
- Kingsley – 1980.
“Occlusion of teeth is the most potent factor in determinign stability in a new position”

-Angle – “As the tendency of teeth, that have been moved into occlusion, is to return to
their former malposition, the main principle is the antagonizing of this force in the
direction of its tendency”

-Late Growth changes – Reidel

- Moyers.

General Facial Growth:

Bjork – 1955:- “there is a great variation not only with respect to direction of G.F-G, but
abo with respect to growth of maxilla and mandible and to the eruption of teeth within
each jaw” (Prior)
Normal Mandibular Growth:
- Bjork and Skieller
- ‘Great individual variation in the growth pattern of Lower Jaw’ -42
- Influence of surface remodeling condylar growth – upward and forward
posterior growth rot.
1. Pronounced forward condylar growth – dental changes.
2. Backward condylar growth- Increase vertical dir of eruption of posteriors. –
Secondary crowding?

Stability of occlusion:
Mandibular Growth Rotation: - 1969-Bjork
- ‘Pronounced upward – forward growth of mandibular condyle is
associated with counter clockwise rotation of the lower jaw.
Fulcum point- Incisors (Tongue+Lip)

Goal of Treatment: ‘Establish and maintain normal overbite and overjet relationships by
creating a solid fulcrum point at the incisors.
1. Interior incisor – Not too obtuse
2. L.J.- Not too upright
3. Proper torque in U.J.

Tweed:
Severe malocclusions:- Additional stability problems.
(Class II – skeletal + Deep bite.
L.J. to be maintained in position for a longtime.
- Stabilizing L.J. – Practical problem.
- Loss of primary canines – Fixed lingual retainer and passive bite plate
- Functional appliance.
Posterior Rotation: AFH>PFK
- More vertical eruption of lower incisors
- Additional potential for retroclination
- Secondary Crowding- long term stabilization – essential.

Maxillary Growth:
Stability:
‘In the maxilla, untreated subjects have rotational changes in the same direction as in the
lower jaw but of less intensity.
- Mesial migration of posteriors – Maxila – ‘Less forward movement of ant.
than posterior teeth.
- 1. Function of lips
 Upper
 Lower – Imp. factor
- Lower lip and extreme tendency towards anterior maxillary rotation.
- Subjects with increase forward growth rotation of jaws.- Molar relation
– class II. -unde – 1983.
Dentoalveolar Development Occlusion.:
- Skeletal discrepancies – Dento-alveolar (masked) compensation.
- Abnormal function of lips and tongue can cause dysplastic DA changes
that make the dental malocclusion worse than the underlying skeletal
problem.
 Stability – Soft-tissue matrix surrounding the facial skeleton.

Treatment Timing:
1. Majority of orthodontic patients: Prior or during pubertal growth spurt –
Instability
Loss of deciduous teeth (Posterior) – Lack of support - Long retention period.
2. Majority of malocclusions.
- Skeletal differences – Goal-Growth modulation ex: class II.
3. Growth is not completed at the end of the growth spurt. – Retention?
Mandibular growth – Peak – 14 ½ years. – Males.
19years
Range – 15years – 23years.

Maxillary growth – 2-2 ½ years prior to mandibular growth.

Eaviliest 14years – Latest 2 years.

Dentoalveolar structures have a difficulty in masking discrepancies – Relpase.

“There is little doubt that growth – in particular, redual growth – influences the post
treatment stability of orthodontic treatment.”
- Leth. Meilson.

‘The dynamics of facial development should be were understood before we expect to

create more stable treatment results.

Stability of extraction and nonextraction treatment.

‘Nature always starts out to build a perfect denture in each individual and malocclusions
are caused by local factors. – Angle.

Calvin case-
‘Theory of biological variation and inheritance in the development of malocclusions.’

‘Upon no basis but the bible theory of special creation can I reconcile the teaching that
nature puts teeth into an individuals mouth that do not belong to his or her physiognomy.
- Pronounced anterior rotation – extraction – Lower arch – Avoided.
- Expansion to be considered before extraction.
- Extraction – upright lowers (anterior segment)- Interior incisor angle –
Lack of anterior fulcrum points.
Extraction – Not be carried out early. – Retention (critical) ( Condy. lar growth
completion)
Posterior condylar growth:
- Increase incisor crowding with time. – extraction decision to be delayed
till the patient is past maximal pubertal growth.
- Following treatment mandibular anterior teeth should be supported
lingually.

BASIC THEOREMS
Theorem.1:
Teeth that have been moved tend to return to their former positions.
- Musculature – Welch – 1965.
- Apical base – Lopez, Moorees, Richardson.
- Iransseptal fibres – Reiton
- Bone morphology.

Theorem 2:
Elimination of the cause of malocclusion will prevent recurrence – Nance.
- Habits.
- Tongue posture open-bite – Lopez et al – 35%- Mouth breathing.

Theorem – 3.
Malocclusion should be overcorrected as a safety factor.
- Class II – Glastics
- Quessen berry’s study-1969
- Class III
- Deep bite
- Rotations.

Theorem-4:
Proper occlusion is a potent factor in holding teeth in their corrected positions.
- Gold Stein.
- Periodontium
- ‘Pounding of mandibular canines.
- Doubtful.

Theorem-5:
Bone and adjacent tissues must be allowed to reorganize around newly positioned teeth
- Histological evidence
- Fixed
- Inhibitory – Oppenheim
‘Mature bone ensures greater stability’
Bone-Plastic
Tooth position – Muscular equilibrium.

Theorem – 6:
It lower incisors are placed upright over the basal bone they are more likely to remain in
good alignment.
 - Teeth having attributes of stability can actually be in a state of
malocclusion.
- Mechanical Standpoint: it is probably better to err in the direction of a
lingual rather than a labial inclination.
- Growing patient.

Theorem – 7:
Corrections carried out during periods of growth are less likely to relapse.
- Earliest possible age.
- Retardation or change in direction
- Early diagnosis and treatment planning
 Use of growth
 Immature sutures-progressive tissue damage
 Muscle balance -Normal direction
 Interception of malocclusion.

Theorein-8
The further teeth have moved, the less likelihood of relapse.
- Less retention
- Wisdom of the ruse
- Guidance of eruption and Early interception- Minimize extensive
movement
 Functional environment
 Suproceastal fibres

Theorem – 9
Arch form, particularly in the mandibular arch, cannot be permanently altered by
appliance therapy. = Maintaining arch form – Strang
‘Since these two mandibular dimensions, molar width and canine width, are of such an
uncompromising nature, one might establish them as fixed quantities and build the arches
around them. – Mccavley

‘I am firmly convinced that the axiom of the mandibular canine width may be stated as
follows: the width as measured across from one canine to the other in the mandibular
denture is an accurate index to the muscular balance inherent to the individual and
dictates 0the limit of denture expansion in this area of treatment.
-Strang –1946.