Original Article

Success rate of miniplate anchorage for bone anchored maxillary protraction

Eline E. B. De Clercka; Gwen R. J. Swennenb

ABSTRACT
Objective: To evaluate the success rate of Bollard miniplate anchorage for bone anchored
maxillary protraction (BAMP).
Materials and Methods: Twenty-five consecutive patients (mean age, 12.0 6 1.2 years; range,
8.7–14.8 years) with maxillary hypoplasia without congenital or acquired deformation were
included in this study. A total of 100 Bollard modified miniplates were placed by the same surgeon.
Ninety-nine miniplates were inserted under general anesthesia, and one was placed under local
anesthesia because of initially soft bone conditions. Loading of the miniplates with 150 g elastics
was initiated at 17.5 6 6.9 days (range, 11–38 days) after surgery. Mean follow-up was provided at
20.8 6 11.1 months (range, 6.5–46.2 months).
Results: The overall success rate of miniplate anchorage in terms of stability was 97%. During
orthodontic loading, five miniplates showed signs of mobility. After interruption of loading over 2 months,
two miniplates became stable again. However, a total of three miniplates needed to be removed and
were successfully replaced under local anesthesia after a mean healing period of 3 months.
Conclusion: Skeletal anchorage by means of Bollard modified miniplates is effective for BAMP.
Success depends on proper presurgical patient counseling, minimal invasive surgery, good
postsurgical instructions, and orthodontic follow-up. (Angle Orthod. 2011;81:1010–1013.)
KEY WORDS: Miniplate anchorage; Bone anchored maxillary protraction; Success rate

INTRODUCTION anchorage in the upper jaw.16–18 The first two modified

methods of maxillary protraction involved Le Fort I
Correction of maxillary hypoplasia during growth by
corticotomy or osteotomy; the two latter protocols still
orthopedic maxillary protraction was pioneered by
involved the use of a face mask.
Delaire in the 1970s.1,2 The main disadvantages of
Over several years, bone anchored maxillary pro-
Delaire face mask therapy are noncompliance due to
traction (BAMP) without corticotomy or osteotomy with
discomfort, dentoalveolar compensation, and clock-
the use of class III elastics between miniplate skeletal
wise rotation of the mandible.3–6 To reduce these side
anchorage in the upper and lower jaw was intro-
effects, modified methods of maxillary protraction were
duced.19,20 With this approach, an extraoral face mask
developed consisting of (1) maxillary distraction by a is no longer needed and intermaxillary traction can be
rigid external distractor7–12; (2) maxillary distraction applied 24 hours a day. Preliminary studies based on
with a face mask after Le Fort I corticotomy in cleft conventional two-dimensional (2D) cephalometric
patients13–15; and (3) face mask combined with skeletal analysis21,22 and three-dimensional (3D) virtual treat-
ment outcome analysis23 showed already very prom-
a
Medical student, Katholieke Universiteit Leuven, Belgium;
research assistant, Division of Maxillo-Facial Surgery, Depart- ising results. However, the stability and success rate of
ment of Surgery, General Hospital St-Jan Bruges, Rudershove, miniplate anchorage for BAMP had not been investi-
Bruges, Belgium. gated yet. Hence, the aim of this prospective study
b
Professor, Division of Maxillo-Facial Surgery, Department of was to evaluate the success rate of Bollard miniplate
Surgery, General Hospital St-Jan Bruges, Bruges, Belgium. anchorage for BAMP in growing children.
Corresponding author: Professor Gwen R. J. Swennen, MD,
LDS, DMD, PhD, FEBOMFS, Division of Maxillo-Facial Surgery,
Department of Surgery, General Hospital St-Jan Bruges, Rudder- MATERIALS AND METHODS
shove 10, 8000 Bruges, Belgium
(e-mail: gwen.swennen@azsintjan.be) This prospective study was approved by the
Institutional Review Board of the AZ St-Jan Hospital.
Accepted: April 2011. Submitted: January 2011.
Published Online: June 23, 2011 A total of 25 consecutive patients were included. All
G 2011 by The EH Angle Education and Research Foundation, patients were referred for BAMP by four different
Inc. orthodontists (L.G.: n 5 4; T.B.: n 5 1; V.G.: n 5 1;

Angle Orthodontist, Vol 81, No 6, 2011 1010 DOI: 10.2319/012311-47.1

SUCCESS RATE OF MINIPLATE ANCHORAGE FOR BAMP 1011

Figure 1. Placement of Bollard modified miniplates for bone

anchored maxillary protraction (BAMP). In this particular case, a
square wire was placed in the 0.018 3 0.025-inch tube of the lower
left Bollard to slightly modify the vector of intermaxillary traction to
avoid irritation of gingival soft tissues in the left lower jaw.

and H.D.C.: n 5 19), and all presented with maxillary

hypoplasia and Angle Class III malocclusion. No
patients had clefts, syndromes, or traumatic history.
The mean age of patients at the time of surgery was Figure 2. The upper miniplate is fixed by three monocortical screws
12.0 6 1.2 years (range, 8.7–14.8 years). Seven male at the infrazygomatic crest, and the lower miniplate with two screws
between the lateral incisor and the canine.
(mean age, 12.0 6 1.2 years; range, 10.7–14.8 years)
and 18 female patients (mean age, 12.2 6 1.3 years;
range, 8.7–13.7 years) were included. modified miniplates with 150 g elastics was initiated
Presurgical patient counseling and surgery under by the referring orthodontist 17.5 6 6.9 days (range,
general anesthesia were provided in a one-day clinic 11–38 months) after surgery and was maintained for a
visit to all patients by the same surgeon. Although period of 12 months. Mean follow-up was 20.8 6
insertion of four plates can be done under local 11.1 months (range, 6.5–46.2 months).
anesthesia, young patients feel more comfortable with
a procedure done under sedation or under a short RESULTS
general anesthesia. In all patients, the same miniplate In 25 consecutive patients, 99 Bollard modified
anchorage system (Bollard Modified Miniplate, Tita- miniplates could be placed with excellent primary
Link, Brussels, Belgium) was placed in a standardized stability under general anesthesia. In one 12-year-old
way after a minimal invasive flap was raised, as male patient, fixation of the upper miniplate at the right
previously described.24 In the upper jaw, ‘‘Upper infrazygomatic crest with good primary stability was
Bollards with hooks’’ were placed at the right and left not feasible because bone conditions were soft. After a
infrazygomatic crest, while in the lower jaw, ‘‘Lower bone healing period of 12 weeks, the upper miniplate
Bollards with hooks’’ were placed on both sides could be successfully fixed under local anesthesia. In
between the lower canine and the lateral incisor the lower jaw, miniplates could be placed in all patients
(Figure 1). In all patients, the Bollard miniplates were between the lateral incisor and the canine.
fixed with monocortical (5–7 mm length; 2.3 mm No infections occurred. Four patients, however,
diameter) Titamed Bollard Miniplate Screws (Titamed, complained about irritation of the mucosa of the
Wervik, Belgium). Upper miniplates were fixed by three cheeks or lower lip at the first visit after surgery. This
screws, and two screws were used in the mandible was easily solved by covering the fixation unit of the
(Figure 2). In the first six patients, self-tapping screws miniplate with a small piece of soft wax, until edema of
were used, and in the following 19 patients, self-drilling the soft tissues completely disappeared. The overall
screws were applied. A single dose of IV antibiotics success rate in terms of stability of Bollard miniplate
(amoxicillin and clavulanic acid) was given during anchorage was 97%. During orthodontic loading, five
surgery, but no corticosteroids were administered. miniplates in five different patients showed signs of
Postsurgical instructions were given to all patients by mobility with small discomfort. In these cases, loading
the same surgeon and by the referring orthodontist. was interrupted for 2 months. After this period, two
Patients were instructed not to manipulate the mini- miniplates became stable again, and three miniplates
plates with tongue or fingers. Loading of Bollard needed to be removed and replaced under local

Angle Orthodontist, Vol 81, No 6, 2011

1012 DE CLERCK, SWENNEN

anesthesia 3 months later. In two patients, fracture of a Table 1. Postsurgical Instructions to the Patienta,b
hook of the miniplate occurred and was solved by N Cooling during 48 hours
insertion of a custom-made hook of a square wire in N Slight upright position during 48 hours
the 0.018 3 0.025-inch tube of the fixation unit. N Increase in blood pressure avoided during the first week
N Rinsing twice per day with chlorhexidine over 12 days
N Extensive rinsing with sparkling water (5–10 times/d)
DISCUSSION N NSAID over 3 days
N Orthodontic loading of Bollard modified miniplates at approxi-
Failure and success rates of miniscrews have been mately 14 days after surgery
well investigated in the literature.25–29 Miniplates have N Manipulation of Bollard modified miniplates with tongue or fingers
been shown to be well accepted as skeletal anchorage avoided
by both patients and providers and have turned out to a
No antibiotics are prescribed after surgery.
be a safe and effective adjunct for complex orthodontic b
NSAID indicates nonsteroidal anti-inflammatory drug.
treatment.24 However, the success rate of miniplates
for skeletal anchorage in orthodontics30–33 has not been fixed by self-taping or self-drilling screws. Therefore
investigated so thoroughly as that of miniscrews, and the authors recommend self-drilling screws, which are
research has been limited to adolescent and adult easier to use.
patients. Compared with miniscrews and microscrews, The high success rate in this study may be related to
miniplates showed greater stability.31 However, only several factors: (1) presurgical counseling of the
the effect of continuous loading on miniplate stability patient, (2) minimal invasive surgery with decreased
has been investigated. The forces generated by patient morbidity and adequate postsurgical instruc-
intermaxillary elastics are discontinuous in time, tions (Table 1), and (3) good orthodontic follow-up.
magnitude, and direction because of movements of Presurgical counseling is extremely important to
the mandible during speech, chewing, and swallowing. prepare both young patients and their parents. Special
To our knowledge, up to now no report has been attention should be paid to the importance of avoiding
published on the failure rate of miniplates used for repetitive manipulation of the miniplates by tongue or
maxillary protraction by intermaxillary elastics in young fingers after surgery. Minimal invasive surgery con-
growing patients. BAMP is the most critical procedure sisting of small incisions, tunnel preparation, and
regarding stability and patient morbidity in the use of gentle handling of the soft tissues is of major
miniplate anchorage in orthodontics. Initial mechanical importance. Application of Elocom cream (mometa-
retention of osteosynthesis screws is mainly influenced sone furoate 1 mg) to the lips, additional local
by the thickness and density of the external cortical anesthesia (xylocaine 1% adrenaline) for vasocon-
bone and is reduced in growing children compared striction, and topical application of Exacyl (tranexamic
with adult patients. In a prospective study on 200 acid) proved useful in decreasing postsurgical swelling
miniplates, most failures occurred in the youngest and patient morbidity. Extensive rinsing with NaCl
patients.24 However, the mean age of patients in this during surgery is important to avoid infection; applica-
study was 24 years, and different miniplate designs tion of wax to the miniplates at the end of surgery
and loading protocols were used. proved very helpful in decreasing soft tissue irritation.
Results of this prospective study showed a high Last but not least, good orthodontic follow-up
overall success rate of 97%. All failures occurred in the consisting of oral hygiene instructions and evaluation
upper jaw in contrast to reported higher failure rates of of miniplate anchorage (ie, local gingival status,
miniscrews in the lower jaw.29,34–36 The latter data, mobility, hygiene, elastic force) is essential for treat-
however, were derived from clinical studies in older ment outcome.
patients. Only a few studies37–39 have documented the
success rates of miniscrews in early teenagers. Also, CONCLUSIONS
in a retrospective study on the stability of 68
N Miniplate anchorage with Bollard modified miniplates
miniplates, all failures were observed in the mandi-
is highly effective for bone anchored maxillary
ble.30 However, the patients were adults, the plates in
protraction (BAMP).
the lower jaw were inserted between the first and N Success depends on proper presurgical patient
second molars, and the design of the plates compli- counseling, minimal invasive surgery, good postsur-
cated oral hygiene. All failures in our study occurred in gical instructions, and orthodontic follow-up.
the youngest patients. The authors therefore propose
not to place miniplates for skeletal anchorage in
orthodontics before the age of 11 years, because of ACKNOWLEDGMENTS
increased risk of poor bone quality. No significant The authors thank the orthodontists T. Bataille, V. Geerinckx,
differences were observed in the stability of plates L. Govaert, and H. De Clerck for their cooperation.

Angle Orthodontist, Vol 81, No 6, 2011

SUCCESS RATE OF MINIPLATE ANCHORAGE FOR BAMP 1013

REFERENCES 21. Cevidanes L, Baccetti T, Franchi L, McNamara JA Jr, De

Clerck H. Comparison of two protocols for maxillary
1. Delaire J. Manufacture of the ‘‘orthopedic mask.’’ Rev protraction: bone anchors versus face mask with rapid
Stomatol Chir Maxillofac. 1971;72:579–582. maxillary expansion. Angle Orthod. 2010;80:799–806.
2. Delaire J. Treatment of Class III with dentofacial orthopedic 22. De Clerck H, Cevidanes L, Baccetti T. Dentofacial effects of
mask. Acta Odontol Venez. 1979;17:168–200. bone-anchored maxillary protraction: a controlled study of
3. Baik HS. Clinical results of the maxillary protraction in Korean consecutively treated Class III patients. Am J Orthod
children. Am J Orthod Dentofacial Orthop. 1995;108:583–592. Dentofacial Orthop. 2010;138:577–581.
4. Kapust AJ, Sinclair PM, Turley PK. Cephalometric effects of 23. Heymann GC, Cevidanes L, Cornelis M, De Clerck HJ,
face mask/expansion therapy in Class III children: a Tulloch JF. Three-dimensional analysis of maxillary protrac-
comparison of three age groups. Am J Orthod Dentofacial tion with intermaxillary elastics to miniplates. Am J Orthod
Orthop. 1998;113:204–212. Dentofacial Orthop. 2010;137:274–284.
5. Takada K, Petdachai S, Sakuda M. Changes in dentofacial 24. Cornelis MA, Scheffler NR, Mahy P, Siciliano S, De Clerck
morphology in skeletal Class III children treated by a modified HJ, Tulloch JF. Modified miniplates for temporary skeletal
maxillary protraction headgear and a chin cup: a longitudinal anchorage in orthodontics: placement and removal surger-
cephalometric appraisal. Eur J Orthod. 1993;15:211–221. ies. J Oral Maxillofac Surg. 2008;66:1439–1445.
6. Baccetti T, McGill JS, Franchi L, McNamara JA Jr, Tollaro I. 25. Chen YJ, Chang HH, Lin HY, Lai EH, Hung HC, Yao CC.
Skeletal effects of early treatment of Class III malocclusion Stability of miniplates and miniscrews used for orthodontic
with maxillary expansion and face-mask therapy. Am J anchorage: experience with 492 temporary anchorage
Orthod Dentofacial Orthop. 1998;113:333–343. devices. Clin Oral Implants Res. 2008;19:1188–1196.
7. Polley JW, Figueroa AA. Rigid external distraction: its 26. Schätzle M, Männchen R, Zwahlen M, Lang NP. Survival
application in cleft maxillary deformities. Plast Reconstr and failure rates of orthodontic temporary anchorage
Surg. 1998;102:1360–1372; discussion 1373–1374. devices: a systematic review. Clin Oral Implants Res.
8. Figueroa AA, Polley JW. Management of severe cleft 2009;20:1351–1359. Epub 2009 Sep 30. Review.
maxillary deficiency with distraction osteogenesis: procedure 27. Viwattanatipa N, Thanakitcharu S, Uttraravichien A, Pitiphat
and results. Am J Orthod Dentofacial Orthop. 1999;115:1–12. W. Survival analyses of surgical miniscrews as orthodontic
9. Figueroa AA, Polley JW, Ko EW. Maxillary distraction for the anchorage. Am J Orthod Dentofacial Orthop. 2009;136:29–36.
management of cleft maxillary hypoplasia with a rigid 28. Chen Y, Kyung HM, Zhao WT, Yu WJ. Critical factors for the
external distraction system. Semin Orthod. 1999;5:46–51. success of orthodontic mini-implants: a systematic review.
10. Swennen G, Dujardin T, Goris A, De Mey A, Malevez C. Am J Orthod Dentofacial Orthop. 2009;135:284–291.
Maxillary distraction osteogenesis: a method with skeletal 29. Crismani AG, Bertl MH, Celar AG, Bantleon HP, Burstone
anchorage. J Craniofac Surg. 2000;11:120–127. CJ. Miniscrews in orthodontic treatment: review and
11. Swennen G, Figueroa AA, Schierle H, Polley JW, Malevez analysis of published clinical trials. Am J Orthod Dentofacial
C. Maxillary distraction osteogenesis: a two-dimensional Orthop. 2010;137:108–113.
mathematical model. J Craniofac Surg. 2000;11:312–317. 30. Choi BH, Zhu SJ, Kim YH. A clinical evaluation of titanium
12. Hierl T, Hemprich A. A novel modular retention system for miniplates as anchors for orthodontic treatment. Am J Orthod
midfacial distraction osteogenesis. Br J Oral Maxillofac Dentofacial Orthop. 2005;128:382–384.
Surg. 2000;38:623–626. 31. Chen YJ, Chang HH, Huang CY, Hung HC, Lai EH, Yao CC.
13. Molina F, Ortiz Monasterio F, de la Paz Aguilar M, Barrera J. A retrospective analysis of the failure rate of three different
Maxillary distraction: aesthetic and functional benefits in orthodontic skeletal anchorage systems. Clin Oral Implants
cleft lip-palate and prognathic patients during mixed Res. 2007;18:768–775. Epub 2007 Sep 14.
dentition. Plast Reconstr Surg. 1998;101:951–963. 32. Chen CH, Hsieh CH, Tseng YC, Huang IY, Shen YS, Chen
14. Swennen G, Colle F, De May A, Malevez C. Maxillary CM. The use of miniplate osteosynthesis for skeletal anchor-
distraction in cleft lip palate patients: a review of six cases. age. Plast Reconstr Surg. 2007;120:232–235; 236–237.
J Craniofac Surg. 1999;10:117–122. 33. Eroğlu T, Kaya B, Cetinşahin A, Arman A, Uçkan S.
15. Rachmiel A, Aizenbud D, Ardekian L, Peled M, Laufer D. Success of zygomatic plate-screw anchorage system.
Surgically-assisted orthopedic protraction of the maxilla in J Oral Maxillofac Surg. 2010;68:602–605.
cleft lip and palate patients. Int J Oral Maxillofac Surg. 1999; 34. Park HS. Clinical study on success rate of microscrew
28:9–14. implants for orthodontic anchorage. Korean J Orthod. 2003;
16. Singer SL, Henry PJ, Rosenberg I. Osseointegrated 33:151–156.
implants as an adjunct to facemask therapy: a case report. 35. Chen CH, Chang CS, Hsieh CH, et al. The use of
Angle Orthod. 2000;70:253–262. microimplants in orthodontic anchorage. J Oral Maxillofacial
17. Enacar A, Giray B, Pehlivanoglu M, Iplikcioglu H. Facemask Surg. 2006;64:1209–1213.
therapy with rigid anchorage in a patient with maxillary 36. Miyawaki S, Koyama I, Inoue M. Factors associated with the
hypoplasia and severe oligodontia. Am J Orthod Dentofacial stability of titanium screws placed in the posterior region for
Orthop. 2003;123:571–577. orthodontic anchorage. Am J Orthod Dentofacial Orthop.
18. Kircelli BH, Pektas ZO. Midfacial protraction with skeletally 2003;124:373–378.
anchored face mask therapy: a novel approach and 37. Park HS, Jeong SH, Kwon OW. Factors affecting the clinical
preliminary results. Am J Orthod Dentofacial Orthop. 2008; success of screw implants used as orthodontic anchorage.
133:440–449. Am J Orthod Dentofacial Orthop. 2006;130:18–25.
19. De Clerck HJ, Geerinckx V, Silicano S. The zygoma 38. Gelgor IE, Buyukyilmaz T, Karaman AI, Dolanmaz D,
anchorage system. J Clin Orthod. 2002;36:455–459. Kalayci A. Intraosseous screw-supported upper molar
20. De Clerck HJ, Cornelis MA, Cevidanes LH, Heymann GC, distalization. Angle Orthod. 2004;74:838–850.
Tulloch CJ. Orthopedic traction of the maxilla with mini- 39. Herman RJ, Currier GF, Miyake A. Mini-implant anchorage
plates: a new perspective for treatment of midface deficien- for maxillary canine retraction: a pilot study. Am J Orthod
cy. J Oral Maxillofac Surg. 2009;67:2123–2129. Dentofacial Orthop. 2006;130:228–235.

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