Volume 29 Issue 2 Article 4

2017

Non-surgical Treatment of an Adult Class III Patient with Facial Asymmetry by Unilateral Mandibular Arch Distalization

Chi-Yu Tsai Department of , Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan

Shiu-Shiung Lin Department of Orthodontics, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan

Yi-Hao Lee Department of Orthodontics, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan

Li-Tyng Sun Department of Orthodontics, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan

Yu-Jen Chang Department of Orthodontics, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College Fofollow Medicine, this and Kaohsiung, additional T aiwanworks at: https://www.tjo.org.tw/tjo

Part of the Orthodontics and Orthodontology Commons See next page for additional authors

Recommended Citation Tsai, Chi-Yu; Lin, Shiu-Shiung; Lee, Yi-Hao; Sun, Li-Tyng; Chang, Yu-Jen; and Wu, Te-Ju (2017) "Non-surgical Treatment of an Adult Class III Malocclusion Patient with Facial Asymmetry by Unilateral Mandibular Arch Distalization," Taiwanese Journal of Orthodontics: Vol. 29 : Iss. 2 , Article 4. DOI: 10.30036/TJO.201706_29(2).0004 Available at: https://www.tjo.org.tw/tjo/vol29/iss2/4

This Case Report is brought to you for free and open access by Taiwanese Journal of Orthodontics. It has been accepted for inclusion in Taiwanese Journal of Orthodontics by an authorized editor of Taiwanese Journal of Orthodontics. Non-surgical Treatment of an Adult Class III Malocclusion Patient with Facial Asymmetry by Unilateral Mandibular Arch Distalization

Authors Chi-Yu Tsai, Shiu-Shiung Lin, Yi-Hao Lee, Li-Tyng Sun, Yu-Jen Chang, and Te-Ju Wu

This case report is available in Taiwanese Journal of Orthodontics: https://www.tjo.org.tw/tjo/vol29/iss2/4 Case Report

Non-surgical Treatment of an Adult Class III Malocclusion Patient with Facial Asymmetry by Unilateral Mandibular Arch Distalization

1 1 1 1 1 1 Chi-Yu Tsai, Shiu-Shiung Lin, Yi-Hao Lee, Li-Tyng Sun, Yu-Jen Chang, Te-Ju Wu, 1 Department of Orthodontics, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan

This article reports the treatment of a 22-year-old male with Class III malocclusion and facial asymmetry by non-surgical camouflage orthodontic approach. This patient presented with anterior and deviated midline, mild protrusive mandible and chin deviation. The Class III malocclusion was marked with anterior functional shift resulted from the premature contact of the incisors. Unilateral mandibular buccal shelf miniscrew was applied for the correction of the skewed mandibular arch. After treatment, the deviated dental midline and Class III molar relation were both corrected. This patient exhibited harmonious profile and . (Taiwanese Journal of Orthodontics. 29(2): 99-107, 2017)

Keywords: Class III malocclusion; orthodontic camouflage; functional shift

1 among Caucasian descent (< 5%). The components of INTRODUCTION Class III deformities included maxillary , 2 The skeletal Class III inter-jaw relation describes mandibular , or a combination of both. craniofacial anomaly involving sagittal jawbone The growth maturity plays a major role in the treatment discrepancies between the maxilla and mandible, and of patients with Class III malocclusion. Orthopedic usually characterized with disharmonious concave facial appliances are commonly used to treat young patients profile. The incidence of Class III malocclusion varies or adolescents with great growth potential, and early by different races, with a higher prevalence among the diagnosis and intervention contribute to improvements of 1,3 Asian population (15% - 23%) and lower prevalence skeletal discrepancies by growth modification. However,

Received: April 01, 2017 Revised: June 21, 2017 Accepted: June 23, 2017 Reprints and correspondence to: Dr. Te-Ju Wu, Department of Orthodontics, Kaohsiung Chang Gung Memorial Hospital No.123, Dapi Rd., Niaosong Dist., Kaohsiung City 833, Taiwan (R.O.C.) Tel: 07-7317123 ext. 8291 E-mail: [email protected]

Taiwanese Journal of Orthodontics. 2017, Vol. 29. No. 2 99 Tsai CY, Lin SS, Lee YH, Sun LT, Chang YJ, Wu TJ for those adult patients, the treatment strategies restrict normal developed maxilla. The patient also exhibited the to either orthodontic teeth movement alone, or combine mandibular deviation toward right side for 2 mm, no lip 4-8 surgical orthodontic treatment. incompetence, gummy smile or canting occlusal plane The dento-alveolar compensations of specific were observed (Figure 1, 3). patients characterized with skeletal Class III jaw relation The intraoral examination revealed dental Class III but acceptable profiles have been extensively utilized in malocclusion with both anterior and posterior crossbite, treating those patients don’t accept orthognathic surgery. the original overjet was -2.5 mm, and was 3 mm, The camouflage treatment usually includes compensated patient had 2 mm and 0.5 mm space distal to the lower left incisor movements within the boundary limitations of and right canines, respectively, the lower dental midline underlying jawbones to improve the dental occlusion. deviated to the right by 2 mm relative to facial midline at The extraction of mandibular teeth to provide space for patient’s centric occlusal position (Figure 2). retraction of lower anterior teeth is a common treatment During the functional examination, patient 7 strategy. On the contrary, the alternative involves demonstrated anterior functional shift of the mandible whole mandibular dental arch distalization without resulted from the premature contact of the incisors (Figure 8 sacrificing any natural teeth. Clinicians should consider 2), the edge-to-edge incisor relationship could be achieved these treatment options based on meticulous clinical and mentioned. Despites the improvement of the sagittal examination, and evaluate the adverse effects during the jaw discrepancies, the mandibular right side deviation still orthodontic treatment. presented in the centric relation (CR) position.

DIAGNOSIS AND ETIOLOGY TREATMENT OBJECTIVE

One 22-year-old healthy male patient presented Clinician’s treatment objectives were to establish with a chief complaint of “reversed occlusion and chin proper overjet and overbite, to eliminate the mandibular prominence”, an extra-oral examination revealed skeletal functional shift, to correct dental midline discrepancies, to Class III jaw relationship with prognathic mandible and achieve bilateral Class I molar and canine relationship.

Figure 1. Initial extraoral photographs.

100 Taiwanese Journal of Orthodontics. 2017, Vol. 29. No. 2 Non-surgical Treatment of Class III Asymmetry

Figure 2. Initial intraoral photographs and functional examination. (edge-to- edge incisal relationship).

Figure 3. Pretreatment panoramic and cephalometric radiographs.

Taiwanese Journal of Orthodontics. 2017, Vol. 29. No. 2 101 Tsai CY, Lin SS, Lee YH, Sun LT, Chang YJ, Wu TJ

® (0.022 slot Damon system) were used for treatment. The TREATMENT PLAN initial leveling was performed with 0.014-inch nitinol After discussion of all possible treatment alternatives, wires, followed by 0.014x0.025-inch CuNiTi wire, and the camouflage treatment plan set up as: 0.018-inch nitinol wires for alignment. After 4 months, 1. Full mouth orthodontic treatment without orthognathic the miniscrew (2.0 mm in diameter; Bio-Ray, Syntec surgery Scientific Corp., Taipei, Taiwan) was placed in the left 2. Extraction bilateral lower third molars mandibular buccal shelf. The unilateral mandibular arch 3. Unilateral miniscrew inserted over left mandibular distalization were performed over a 0.018x0.025-inch buccal shelf 4. Close all the remaining space stainless-steel archwire. The miniscrew initially provided 5. Retention with fixed and bimaxillary Hawley indirect to close the excessive space mesial retainer to mandibular left first premolar. Positive overjet was rd achieved at the 3 month after initiation of miniscrew- TREATMENT ALTERNATIVES facilitated mechanism. The long power arm was then used for the succeeding unilateral distalization (Figure 4) 1. Orthodontic camouflage treatment by extraction of mandibular first premolars and maxillary second and protraction of right side mandibular dentition. In the th premolars for anterior retraction. 26 month, all the residual space was closed and dental 2. Orthodontic treatment combined with two-jaw midline became coincident. The bilateral Class III orthognathic surgery for correction of mandibular were used for improvement of molar relationship followed prognathism and facial asymmetry. by finshing procedures. After 32 months of orthodontic treatment, the bands and braces were removed. The TREATMENT PROGRESS 0.0175-inch tripleflex wire were bonded from canine to The orthodontic treatment initiated after extraction canine in the upper jaw, meanwhile the fixed bonded wire of bilateral lower third molars. The self-ligating brackets extended between the first premolars in the lower arch.

Figure 4. Miniscrew facilitated correction of skewed mandibular dental arch.

102 Taiwanese Journal of Orthodontics. 2017, Vol. 29. No. 2 Non-surgical Treatment of Class III Asymmetry

TREATMENT RESULT skeletal relationship. The proclination of upper incisors The negative overjet was successfully corrected and retroclination of lower incisors were noted as by non-surgical camouflage orthodontic treatment (-2.5 expectation as the results of camouflaged approach (Figure mm to +2.5 mm) with the aid of miniscrew and Class III 6, 7). The superimposition revealed 3 mm extrusion of elastics. The original incisal interference was eliminated maxillary molars which result from the usage of Class and the functional shift of the mandible was no longer III elastics (Figure 8). To be addressed, the total distal observed, patient’s chin became less prominent (Figure movement of mandibular left first molar was 7 mm, which 5). Proper alignment and bilateral Class I molar and would be contributed by the recovery from functional canine relationship were achieved. The post-treatment shift and 3 mm unilateral distalization, mostly with bodily showed the improvement of the movement.

Figure 5. Posttreatment extraoral photograph.

Figure 6. Posttreatment intraoral photograph.

Taiwanese Journal of Orthodontics. 2017, Vol. 29. No. 2 103 Tsai CY, Lin SS, Lee YH, Sun LT, Chang YJ, Wu TJ

Figure 7. Posttreatment panoramic and cephalometric radiographs.

Figure 8. Pretreatment and posttreatment superimposition. Black line, before treatment; red line, after treatment.

Table 1. Patient’s cephalometric analysis

Norm Pre-Tx Post-Tx Dental

Skeletal U1-SN 107.2° ± 6.0 109 117 SNA 82.9° ± 3.4 89 89 U6-PP (mm) 22.5 ± 1.5 32 35 SNB 79.8° ± 3.1 93 90.5 L1-MP 98.1° ± 5.2 83 79 ANB 3.1° ± 2.1 -4 -1.5 L1-NB (mm) 6.0 ± 1.9 5 4 SN-MP 32.0° ± 4.6 25 27 U1-L1 135.4° ± 5.8 140 137 Wits Appraisal -1.1 ± 2.3 -13.5 -5 Soft tissue Mx Length 93.6 ± 3.2 97 97 U lip to E-line 1.4 ± 2.1 1 2 Md Length 121.6 ± 4.5 147 147 L lip to E-line 3.1 ± 2.3 3 2 ALFH/ATFH 55 ± 2 % 59.5% 60.4% Nasolabial angle 102° ± 8 87 85 PFH/TFH 62-65% 71.6% 70.8% H angle 7-15° 10 8.5

104 Taiwanese Journal of Orthodontics. 2017, Vol. 29. No. 2 Non-surgical Treatment of Class III Asymmetry

and dental casts. However, the dynamic change of the DISCUSSION mandible position from habitual protruded position to The strategies to treat adult Class III malocclusion the retruded position, or functional shift of the mandible, patients usually involving either a combination of surgical is easily ignored. Therefore, the diagnosis made from orthodontic treatment or dento-alveolar compensation the occlusion of the dental cast or photos may be totally by orthodontic tooth movement alone. For critical cases, different from the diagnosis made after the position of the the differences should be the key points of all treatment lower jaw was correctly determined, and consequently 10 plans, several clinical guidelines were proposed, Kerr result in inadequate treatment planning. The current case suggested that the threshold values of orthognathic demonstrated CO-CR discrepancy, the interference from treatment for angle ANB and lower incisal inclination labial surface of maxillary incisors made the mandible 6 were -4 and 83 degrees, respectively. In addition, the function shift forward, thus worsen the negative overjet critical measurements with maxillary or mandibular (M/ and masked the true CR position. The elimination of M) ratio of 0.84 and Holdaway angle of 3.5° should incisal interference revealed edge-to-edge relationship 6 also be considered for surgery. Stellzig-Eisenhauer and retruded mandible position, which made the dental developed a formula by stepwise discriminant analysis camouflage of Class III malocclusion possible. and claimed that Wits appraisal, anterior cranial base The dento-alveolar camouflage treatment for skeletal length, M/M ratio, and lower gonial angle were variables Class III malocclusion patients are usually presented to determine the critical score between surgical and non- with proclination of upper incisors and retroclination 6 surgical orthodontics. Tseng used receiver operating of lower incisors. The treatment modalities include characteristic (ROC) analysis and illustrated that if a selective tooth extraction (premolars, lower incisors, or Class III malocclusion patient meet at least 4 of 6 criteria lower second molars), the use of the MEAW technique (overjet ≤ -4.73 mm; Wits appraisal ≤ -11.18 mm; L1-MP and temporary anchorage devices to distalize the entire 7,8 angle ≤ 80.8°; Mx/Mn ration ≤ 65.9%; overbite ≤ -0.18 mandible dentition. There are few factors should mm; and gonial angle ≥ 120.8°), then the patient would be taken into consideration and inform patient before 5 be recommended to have surgical treatment. Despites determining the treatment plan. of lower surgical correction might be indicated by cephalometric premolars usually involve large amount of lower incisors analysis and recommended by dental specialists, self- retraction to improve the overjet. However, the incisors perceptions of profile could have more affect to the should not be moved beyond the envelope of discrepancy, 9 11-13 patient's decision. In this case, patient was considered as a or boundary limitations. In addition, patient’s chin critical surgical or orthodontic case with facial asymmetry may appear more protrusive, and subsequently result in (ANB: -4°, L1-MP angle: 83°, Mx/Mn ratio: 65.9%, unaesthetic outcome. Moreover, the only extraction in Wits appraisal: -13.5 mm, gonial angle: 120°). However, mandibular premolars lead to “full unit Class III molar patient deemed the OGS to be invasive, uncomfortable relationship,” with the upper second molar having no and increased expenses, and therefore opted to receive occlusal contact and consequently overeruption. The orthodontic camouflage. MEAW technique contains multiple L-loops and tip Clinically, the clinicians make diagnosis and prepare back bends that could be able to upright posterior teeth, treatment plan based on the standardized intra-oral and to change the occlusal plane inclination, and to correct extra-oral photographs, frontal and lateral cephalograms, the sagittal relationship with the use of intermaxillary 14 panoramic and temporomandibular (TMJ) X-ray film, elastics, but the effective distal movement of the

Taiwanese Journal of Orthodontics. 2017, Vol. 29. No. 2 105 Tsai CY, Lin SS, Lee YH, Sun LT, Chang YJ, Wu TJ mandibular dentition in response to MEAW approach bonded on the upper and lower anterior teeth, and this highly depends on patient’s cooperation. In addition, Jing patient was advised to practice a tongue posture to contact also reported a case with remarkable proclined maxillary the palatal surface. Since the risk of occlusal interference incisors when combined with short Class III elastics, by overeruption maxillary third molars may cause anterior 8 and consequently compromised the pleasing smile. functional shift of the mandible, extraction of those teeth 10 Miniscrews applied vertically in the external oblique ridge were strongly recommended. Despite this patient was areas of the mandibular ramus could be served as skeletal informed about the risk, patient still refused to extract 15 anchorage for distalization of the mandibular dentition. upper third molars. Therefore, it is critical to closely The introduction of miniscrews has increased the observe the occlusal stability. One-year-follow-up record reliability of results because of decreasing requirements of showed there is no more anterior and lateral functional patient’s compliance, minimizing the side effects of using shift of the mandible. The occlusion was stable without intermaxillary elastics and reducing the situation of dental CO-CR discrepancy and the mandibular incisor alignment extractions to retract anterior teeth to a great extent. was also maintained well. In this case, the jaw discrepancies became less severe after eliminating the mandibular functional shift, which CONCLUSION allowed clinicians to perform non-extraction treatment instead of large amount of retraction. The miniscrew Several orthodontic camouflage treatment modalities was prepared for enhancing posterior anchorage and could be used to treat mild Skeletal Class III patients midline correction. Besides, in conjunction with the self- with high performance, provided by appropriate initial ligation system, the lower frictional resistance might also examination and diagnosis. In this case, clinicians detected contribute to the effective distalization of mandibular CO-CR discrepancy during functional examination, teeth, and positive overjet was obtained with the aid of the which prompted clinicians to review the feasibility of miniscrew and Class III elastics. The clockwise mandible original treatment plan. More importantly, the benefits reposition and the increase of anterior lower facial height and disadvantages, and the limitations of camouflage would be factors contributed to successful camouflage the treatment should be explained carefully to patient before prognathic mandible and to obtain satisfying profile. the beginning of treatments. The gingival black triangles and labial root prominence in anterior mandible were presented, this REFERENCE might be caused from the reduction in alveolar bone width at the coronal level and pronounce labial movement of the 1. Chang HP, Tseng YC, Chang HF. Treatment of 12,16 roots. This patient should be followed for periodontal mandibular prognathism. J Formos Med Assoc health after camouflage treatment. Xiong demonstrated 2006;105:781-790. the relapse of lower incisors toward labial movement in 2. Guyer EC, Ellis EE 3rd, McNamara JA Jr, et al. 17 the camouflage patient for 3 years long-term follow-up. Components of class III malocclusion in juveniles and Besides the fact that the mandibular anterior alignment adolescents. Angle Orthod 1986;56:7-30. is prone to relapse toward the original position, the 3. Tollaro I, Baccetti T, Franchi L. Craniofacial changes reduction in tongue space after arch distalization may induced by early functional treatment of Class III result in extreme tongue pressure exerted on the lower malocclusion. Am J Orthod Dentofacial Orthop 18 incisors. For retention, lingual fixed retainers were 1996;109:310-318.

106 Taiwanese Journal of Orthodontics. 2017, Vol. 29. No. 2 Non-surgical Treatment of Class III Asymmetry

4. Stellzig-Eisenhauer A, Lux CJ, Schuster G. Treatment 15. Poggio PM, Incorvati C, Velo S, et al. "Safe zones": a decision in adult patients with Class III malocclusion: guide for miniscrew positioning in the maxillary and orthodontic therapy or orthognathic surgery? Am J mandibular arch. Angle Orthod 2006;76:191-197. Orthod Dentofacial Orthop 2002;122:27-37. 16. Sperry TP, Speidel TM, Isaacson RJ, et al. The role of 5. Tseng YC, Pan CY, Chou ST, et al. Treatment of dental compensations in the orthodontic treatment of adult Class III with orthodontic mandibular prognathism. Angle Orthod 1977;47:293-299. therapy or orthognathic surgery: receiver operating 17. Xueyan Xiong, Yaxin Yu, Fengshan Chen. characteristic analysis. Am J Orthod Dentofacial Orthodontic camouflage versus orthognathic surgery: Orthop 2011;139:e485-493. A comparative analysis of long-term stability and 6. Kerr WJ, Miller S, Dawber JE. Class III malocclusion satisfaction in moderate skeletal Class III. Open surgery or orthodontics? Br J Orthod 1992;19:21-24. Journal of Stomatology 2013;3:89-93. 7. Rabie AB, Wong RW, Min GU. Treatment in 18. Farret MM, Farret MMB, Farret AM. Orthodontic Borderline Class III Malocclusion: Orthodontic camouflage of skeletal Class III malocclusion with Camouflage (Extraction) Versus Orthognathic Surgery. miniplate: a case report. Dental Press Journal of Open Dent J 2008;2: 38-48. Orthodontics 2016;21:89-98. 8. Jing Y, Han X, Guo Y, Li J, Bai D. Nonsurgical correction of a Class III malocclusion in an adult by miniscrew-assisted mandibular dentition distalization. Am J Orthod Dentofacial Orthop 2013;143:877-887. 9. Bell R, Kiyak HA, Joondeph DR, et al. Perceptions of facial profile and their influence on the decision to undergo orthognathic surgery. Am J Orthod 1985;88:323-332. 10. Chang HF, Chen KC, Shiau YY. The importance of determination of jaw position in orthodontic diagnosis and treatment planning for adult patients. Dent Clin North Am 1997;41: 49-66. 11. Proffit, W.R. and Ackerman, J.L. (1982) Diagnosis and Treatment Planning. In: Graber, T.M. and Swain, B.F., Eds., Current Orthodontic Concepts and Techniques, Chapter 1, Mosby, St. Louis, 3-100. 12. Sarikaya S, Haydar B, Ciger S, et al. Changes in alveolar bone thickness due to retraction of anterior teeth. Am J Orthod Dentofacial Orthop 2002;122:15-26. 13. Kim SJ, Choi TH, Baik HS, et al. Mandibular posterior anatomic limit for . Am J Orthod Dentofacial Orthop 2014;146:190-197. 14. Yang WS, Kim BH, Kim YH. A study of the regional load deflection rate of multiloop edgewise arch wire. Angle Orthod 2001;71:103-109.

Taiwanese Journal of Orthodontics. 2017, Vol. 29. No. 2 107