齒顎矯正協會-TJO

*
Case Report

The Orthodontic Treatment of Class III Malocclusion with Anterior Cross bite and Severe deep bite

School of Dentistry, College of Dental Medicine,
Kaohsiung Medical University, Kaohsiung, Taiwan
Department of Orthodontics, Dental Clinics, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan


Running title: Anterior Cross Bite with Deep OB
This 22-year-old female presents with skeletal Class III malocclusion, complicated by anterior cross bite, deep bite, and congenital missing of bilateral mandibular second premolars. The treatment modality was full-mouth fixed edgewise appliances. A favorable result of ideal overbite and overjet and closure of bilateral spaces of missing teeth were achieved. The patient was satisfied the improvement of function and esthetics after treatment.

Keywords: pseudo-Class III malocclusion; anterior cross bite; deep bite; congenital missing
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INTRODUCTION

For correction of skeletal Class III malocclusion, Proffit states that there are three treatment options: 1) growth modification, use differential growth of the maxilla relative to the mandible; 2) camouflage of the skeletal discrepancy through tooth movements to correct the dental occlusion while maintain the skeletal discrepancy; or 3) orthognathic surgical correction.1 The treatment option is depending on the patient’s age, the facial profile, the skeletal pattern, the alveolar bone reaction on mandibular incisors, and the severity of malocclusion before treatment.
As for anterior cross bite, except some patients are truly skeletal Class III malocclusion, some others are pseudo-Class III malocclusion. These pseudo-Class III patients may present some characteristics as: 1) normal or mildly larger size of mandible; 2) normal or mildly smaller size of maxilla; 3) incisors could be guided to edge-to-edge in resting position; 4) difference between centric occlusion (CO) and centric relation (CR); 5) first molars may occlude in Angle’s Class III relationship.
The profiles of pseudo-Class III patients usually are concave, upper lips are less prominent due to insufficient support of upper incisors, while soft tissue menton and lower lips are more protrusive, but these Class III profiles are much improved in rest position while incisors are in edge to edge position. Anterior crossbite has been associated with a variety of complications, such as gingival recession of the lower incisors, incisal edge wear, and eventually lost of these teeth. Correction of anterior crossbite could enhance the oral health and achieve better occlusion. The aim of this article is to present the treatment of a pseudo-Class III malocclusion in an adult patient complicated by deep bite and congenital teeth missing.
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CASE REPORT

A 22-year-old female patient who had no history of illness or trauma, presented the following complaints including anterior crossbite and mandibular protrusion. The dental spaces in the lower arch came from congenital tooth missing.
The extraoral examination revealed that the patient had skeletal Class III malocclusion with midface deficiency, mandibular prognathism, acceptable lower facial height, insufficient display of upper incisors while smiling (Figure 1).
The intraoral examination revealed that the patient had Angle’s Class III malocclusion with anterior crossbite and deep bite with an accentuated curve of Spee in the lower arch and supra-eruption of lower incisors. The dental spaces in the lower arch resulted from the congenital missing of bilateral lower second premolars (Figures 1, 2). Besides, this patient was a pseudo-Class III malocclusion since her mandible could be guided to incisors edge to edge position (Figures 3, 4). The initial cephalometric analysis revealed that this patient was skeletal Class III malocclusion with normal mandibular plane angle, retroclined upper and lower incisors and retrusive upper lip (Figures 5, Table 1).

Diagnosis
  • Skeletal Class III jaw relation
  • Orthodivergent facial pattern
  • Angle’s Class III malocclusion
  • Anterior crossbite and deep bite
  • Congenital missing of #35, 45

Treatment objective
  • To correct the anterior crossbite and deep bite, achieve normal overbite and overjet by upper anterior teeth proclination and lower anterior teeth retraction.
  • To improve the facial profile and lip posture.
  • To close the mandibular dental space.

Treatment plan
No further tooth extraction was planned for this patient. Full-mouth fixed edgewise appliances were bonded for leveling and alignment in the upper and lower dentition. The mandibular space was closed by lower anterior retraction and intrusion. Class III elastic was also used to correct the anterior crossbite and rotate the mandible in clockwise direction. Thus, mild mandibular protrusive posture was improved by the Class III mechanics.

Treatment progress
Orthodontic treatment was carried out by using the pre-adjusted 0.022-inch slot self-ligation system, and lower anterior resin bite blocks were also added in the initial stage to disocclude the bite and facilitate the correction of anterior crossbite (Figure 6). It took about seven months to accomplish the leveling and alignment and correct the anterior crossbite. Reposition of some brackets to calibrate the position and root angulation after mid-term panoramic film taking. Continuing the crossbite correction and closing the residual mandibular spaces were accomplished in another nine months. After a total treatment duration of 32 months, the upper wraparound retainer and the lower fixed retainer were used for retention (Table 2).

Treatment results
The facial profile maintained in mild concave at midface (Figure 7). Normal overbite and overjet, Class I canine relationships as well as coincident facial and dental midlines were achieved (Figure 8). The molar relation was finished in bilateral Class III due to the dental space closure of congenital missing mandibular bilateral second premolars. Canine relation was finished in Class I relationship by lower anterior retraction and Class III elastics. The superimposition of cephalometric tracings revealed that the upper incisors were proclined, and the upper lip also became more prominent after treatment. In addition, the upper first molar was mesialized; lower incisors were retracted and intruded while lower first molar was mesialized and extruded; and the mandible showed clockwise rotation (Figure 9, 10). The root parallelism and root resorption were acceptable and within the normal range (Figure 11). The cephalometric analysis comparing the initial and final conditions indicted that the ANB angle increased from -1° to 1.5°, the SN line to mandibular plane angle (SN-MP) also increased from 36° to 38°. The distance between upper incisor to NA line increased from 4 mm to 7.5 mm, and the angle between upper incisor to SN plane increased from 92° to 104.5°. The lip posture was improved by increase the distance of upper lip to E-line from -3.5 mm to -0.5 mm (Table 1).
 
Figure 1

Figure 1

Extraoral and intraoral photographs, before treatment.

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Figure 2

Figure 2

Study models before treatment.

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Figure 3

Figure 3

Intraoral photographs, mandible guided to CR position

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Figure 4

Figure 4

Extraoral lateral photographs, (A) CO position (B) CR position

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Figure 5

Figure 5

(A) Lateral cephalometric film, (B) Panoramic radiograph, before treatment

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Figure 6

Figure 6

Intraoral photographs, DBS

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Figure 7

Figure 7

The facial and intraoral photographs, after treatment

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Figure 8

Figure 8

The study models, after treatment

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Figure 9

Figure 9

Superimposition of cephalometric tracings. Black line, before treatment; red line, after treatment.

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Figure 10

Figure 10

Superimposition of cephalometric tracings. (A) Maxilla (B) Mandible Black line, before treatment; red line, after treatment.

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Figure 11

Figure 11

(A) Lateral cephalometric film, (B) Panoramic radiograph, after treatment

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Table 1

Table 1

Cephalometric measurements before and after treatment.

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Table 2

Table 2

Summary of treatment progress

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DISCUSSION

For correction for skeletal Class III malocclusion, there are three main treatment options: growth modification, orthodontic camouflage therapy, and surgical-orthodontics. Growth modification by dentofacial orthopedic appliances is an effective method to resolve skeletal Class III jaw discrepancies in children.2-5 Proffit indicated the criteria of case selection to enhance the outcome of orthodontic camouflage therapy, including: (1) average or short facial pattern; (2) mild anteroposterior jaw discrepancy; (3) crowding less than 4-6 mm; (4) normal soft tissue features (nose, lips, chin); (5) no transverse skeletal problem.1 Tseng et al. used the receiver operating characteristic analysis of cephalometric variables to distinguish the skeletal Class III malocclusions who requiring orthognathic surgery. There should meat 4 of these 6 measurements that indicated for surgical treatment: (1) overjet, ≦ –4.73 mm; (2) Wits appraisal, ≦ –11.18 mm; (3) L1-MP angle, ≦8 0.8°; (4) Mx/Mn ratio, ≦ 65.9%; (5) overbite, ≦ –0.18 mm; and (6) gonial angle, ≧120.8°.6 For this patient, only 2 of these 6 measurements (L1-MP angle=79°; gonial angle=122°) met the surgical indication. Besides, this patient had average facial pattern, mild anteroposterior jaw discrepancy with upper dentition crowding, no transverse skeletal problem; patient’s incisors could be shifted to edge to edge position with relative normal soft tissue features in this position; so, this patient was arranged for camouflage orthodontic treatment.
For correction of the anterior crossbite, disoccluding the bite for unrestricted pathway in the initial tooth movement is essential. Various treatment methods have been proposed to correct anterior dental crossbite, such as tongue blades, reversed stainless steel crowns, fixed acrylic planes, bonded resin-composite slopes and removable acrylic appliances with finger springs.7-10 The aforementioned appliances might be huge, uncomfortable, and only applicable in young patients. For adult patients, fixed appliances with Class III elastics and bondable resin bites for disocclusion was effective to correct the anterior crossbite. The anterior resin bites also help to intrude the supra-eruptive lower anterior teeth. The upper teeth show was insufficient before treatment. By flaring of upper anterior incisors, the crowding in upper dentition was relived and the pleasing smile curve was also achieved. The patient’s upper lip rests on the gingiva margin of upper incisors when smile. The tooth show exceeds the proposed minimum of 0 to 2 mm of upper lip coverage of the anterior teeth for posed smile in Asian female standard.11
In treating anterior crossbite with camouflage orthodontic treatment, lingual tipping of lower anterior teeth may result in wash-board appearance and periodontal damage. The cephalometric analysis indicated the change of lower incisor inclination was few ( L1-MP: 78° to 77°). The reasons for the few change in the lower incisors may be attributed to: (1) light force and short distance of Class III elastics (3/16” 2 oz) were applied when small-sized initial working NiTi wires (0.013 / 0.014 inch) were used to avoid unwanted side effect of over-retraction in lower anterior teeth; (2) gradually increase the size of working wires with appropriate amount of buccal crown torque in lower anterior teeth when closing lower dental space; (3) the combination of pre-torque NiTi wire (.017 x .025 NiTi with 20 degree lingual root torque) for torque control of lower anterior teeth.
The mandibular second premolars are the most frequent congenitally missing teeth followed by mandibular and maxillary lateral incisors.12 The etiology of tooth agenesis is considered to involve the disturbance of dental development by genetic factors, environmental factors, or combination of both. Many researchers have reported that tooth size is often smaller in patients with tooth agenesis than in patients without tooth agenesis.13-18 Two treatment approaches are available to solve the missing tooth space: (1) close the spacings and allow the permanent first molar drift mesially and then complete the space closure orthodontically; (2) retain or regain the spaces for prothesis.19 As for this patient, the dental spacings were small (< 3mm) and the lower anterior teeth retraction was required for the cross bite correction, the space was closed for camouflage treatment and no further prosthesis. To finish in Class III molar occlusion, the occlusion should be evaluated for the existence of mandibular third molars to make sure that there are antagonist teeth to occlude the maxillary second molars. Some adjustment might be required to occlude the mandibular first with maxillary premolars in finishing a good Class III molar relationship, including positioning the mandibular first molars lingually than normal; no offset in mandibular first molar; more offset in the maxillary premolars and molars; no toe-in in maxillary molars; lingual crown torque in mandibular molars; reduced palatal crown torque in maxillary premolars and molars. Some contouring or occlusal adjustment was required for better intercuspation, such as reduction of the palatal cusps in the maxillary premolars and molars or the augmentation of the buccal cusps of the mandibular molars with restortion.20
When reviewing the long treatment duration (32M) for this patient, the main time was spent on correction of anterior crossbite. The time to use the lower anterior resin bite blocks was not long enough, so the patient still could move the mandible forward as the upper anterior teeth were still locked within the lower anterior teeth while biting or eating. The anterior crossbite was further corrected after the use of .017 x .025 pre-torque NiTi (20-degree, buccal crown torque) combined short Class III elastics. When remove the resin bite block, the mandible position should be re-evaluated and confirmed for stability.
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CONCLUSION

Class III malocclusion may be a difficult task in orthodontic treatment, since we need to differentiate between skeletal or dental Class III malocclusion. The factors in identifying the patient as dental or skeletal Class III malocclusion and the factors in achieving good results of camouflage treatment were reviewed. The patient with dental Class III malocclusion can be well treated with proper evaluation before camouflage treatment.
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REFERENCES

  1. Proffit WR. Contemporary Orthodontics. 5th Ed. St. Louis, MO, Elsevier Mosby, 2013.
  2. Chang HP, Lin HC, Liu PH, Chang CH. Geometric morphometric assessment of treatment effects of maxillary protraction combined with chin cup appliance on the maxillofacial complex. J Oral Rehabil 2005;32:720-8.
  3. Chang HP, Liu PH, Chang HF, Chang CH. Thin-plate spline (TPS) graphical analysis of the mandible on cephalometric radiographs. Dentomaxillofac Radiol 2002;31:137-41.
  4. Chang ZC, Chang HP, Chen YJ, Yao CC, Liu PH, Chang HF. The treatment effects of the face mask therapy in the midfacial configurations in skeletal Class III growing patients by means of morphometric techniques. J Formosa Med Assoc 2005;104:935-41.
  5. Lin HC, Chang HP, Chang HF. Treatment effects of occipito-mental anchorage appliance of maxillary protraction combined with chincup traction in children with Class III malocclusion. J Formosa Med Assoc 2007;106:380-91.
  6. Tseng YC, Pan CY, Chou ST, Liao CY, Lai ST, Chen CM, Chang HP, Yang YH. Treatment of adult Class III malocclusions with orthodontic therapy or orthognathic surgery: receiver operating characteristic analysis. Am J Orthod Dentofac Orthop 2011;139:e485-e493.
  7. Olsen CB. Anterior cross bite correction in uncooperative or disabled children.
    Case reports. Aust Dent J 1996;2013:304–9.
  8. Valentine F, Howitt JW. Implications of early anterior cross bite correction. J Dent Child 1970;2013:420–7.
  9. Deam JA, McDonald RE, Avery DR. Managing the developing occlusion. In: McDonald RE, editor., ed. Dentistry for the child and adolescent. 7th ed London: Mosby, 2000;677–741.
  10. Vadiakas G, Viazis AD. Anterior crossbite correction in the early deciduous dentition. Am J Orthod Dentofac Orthop 1992;2013:160–2.
  11. Ioi H, Kang S, Shimomura T, Kim SS, Park SB, Son WS, Takahashi I. Effects of vertical positions of anterior teeth on smile esthetics in Japanese and Korean orthodontists and orthodontic Patients. J Esthet Restor Dent 2013;25:274-282.
  12. Higashihori N, Takada JI, Katayanagi M, Takashi Y, Moriyama K. Frequency of missing teeth and reduction of mesiodistal tooth width in Japanese patients with tooth agenesis. Prog Orthod 2018;19:30.
  13. Baum BJ, Cohen MM. Agenesis and tooth size in the permanent dentition. Angle Orthod 1971;41(2):100–2.
  14. Brook AH, Griffin RC, Smith RN, Townsend GC, Kaur G, Davis GR, et al. Tooth size patterns in patients with hypodontia and supernumerary teeth. Arch Oral Biol 2009;54(Suppl 1):S63–70.
  15. Garn SM, Lewis AB. The gradient and the pattern of crown-size reduction in simple hypodontia. Angle Orthod 1970;40:51–8.
  16. Gungor AY, Turkkahraman H. Tooth sizes in nonsyndromic hypodontia patients. Angle Orthod 2013;83:16–21.
  17. McKeown HF, Robinson DL, Elcock C, al-Sharood M, Brook AH. Tooth dimensions in hypodontia patients, their unaffected relatives and a control group measured by a new image analysis system. Eur J Orthod. 2002;24(2):131–41.
  18. Schalk-van der Weide Y, Steen WH, Beemer FA, Bosman F. Reductions in size and left-right asymmetry of teeth in human oligodontia. Arch Oral Biol 1994;39(11):935–9.
  19. Jha P, Jha M. Management of congenitally missing second premolars in a growing child. J Conserv Dent 2012;15:187-190.
  20. Farret MMB, Farret MM, Farret AM. Strategies to finish orthodontic treatment with a Class III molar relationship: three patient reports. World J Orthod 2009;10:323-333.
Figure 1

Figure 1

Extraoral and intraoral photographs, before treatment.

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Figure 2

Figure 2

Study models before treatment.

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Figure 3

Figure 3

Intraoral photographs, mandible guided to CR position

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Figure 4

Figure 4

Extraoral lateral photographs, (A) CO position (B) CR position

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Figure 5

Figure 5

(A) Lateral cephalometric film, (B) Panoramic radiograph, before treatment

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Figure 6

Figure 6

Intraoral photographs, DBS

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Figure 7

Figure 7

The facial and intraoral photographs, after treatment

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Figure 8

Figure 8

The study models, after treatment

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Figure 9

Figure 9

Superimposition of cephalometric tracings. Black line, before treatment; red line, after treatment.

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Figure 10

Figure 10

Superimposition of cephalometric tracings. (A) Maxilla (B) Mandible Black line, before treatment; red line, after treatment.

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Figure 11

Figure 11

(A) Lateral cephalometric film, (B) Panoramic radiograph, after treatment

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Table 1

Table 1

Cephalometric measurements before and after treatment.

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Table 2

Table 2

Summary of treatment progress

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  1. Proffit WR. Contemporary Orthodontics. 5th Ed. St. Louis, MO, Elsevier Mosby, 2013.
  2. Chang HP, Lin HC, Liu PH, Chang CH. Geometric morphometric assessment of treatment effects of maxillary protraction combined with chin cup appliance on the maxillofacial complex. J Oral Rehabil 2005;32:720-8.
  3. Chang HP, Liu PH, Chang HF, Chang CH. Thin-plate spline (TPS) graphical analysis of the mandible on cephalometric radiographs. Dentomaxillofac Radiol 2002;31:137-41.
  4. Chang ZC, Chang HP, Chen YJ, Yao CC, Liu PH, Chang HF. The treatment effects of the face mask therapy in the midfacial configurations in skeletal Class III growing patients by means of morphometric techniques. J Formosa Med Assoc 2005;104:935-41.
  5. Lin HC, Chang HP, Chang HF. Treatment effects of occipito-mental anchorage appliance of maxillary protraction combined with chincup traction in children with Class III malocclusion. J Formosa Med Assoc 2007;106:380-91.
  6. Tseng YC, Pan CY, Chou ST, Liao CY, Lai ST, Chen CM, Chang HP, Yang YH. Treatment of adult Class III malocclusions with orthodontic therapy or orthognathic surgery: receiver operating characteristic analysis. Am J Orthod Dentofac Orthop 2011;139:e485-e493.
  7. Olsen CB. Anterior cross bite correction in uncooperative or disabled children.
    Case reports. Aust Dent J 1996;2013:304–9.
  8. Valentine F, Howitt JW. Implications of early anterior cross bite correction. J Dent Child 1970;2013:420–7.
  9. Deam JA, McDonald RE, Avery DR. Managing the developing occlusion. In: McDonald RE, editor., ed. Dentistry for the child and adolescent. 7th ed London: Mosby, 2000;677–741.
  10. Vadiakas G, Viazis AD. Anterior crossbite correction in the early deciduous dentition. Am J Orthod Dentofac Orthop 1992;2013:160–2.
  11. Ioi H, Kang S, Shimomura T, Kim SS, Park SB, Son WS, Takahashi I. Effects of vertical positions of anterior teeth on smile esthetics in Japanese and Korean orthodontists and orthodontic Patients. J Esthet Restor Dent 2013;25:274-282.
  12. Higashihori N, Takada JI, Katayanagi M, Takashi Y, Moriyama K. Frequency of missing teeth and reduction of mesiodistal tooth width in Japanese patients with tooth agenesis. Prog Orthod 2018;19:30.
  13. Baum BJ, Cohen MM. Agenesis and tooth size in the permanent dentition. Angle Orthod 1971;41(2):100–2.
  14. Brook AH, Griffin RC, Smith RN, Townsend GC, Kaur G, Davis GR, et al. Tooth size patterns in patients with hypodontia and supernumerary teeth. Arch Oral Biol 2009;54(Suppl 1):S63–70.
  15. Garn SM, Lewis AB. The gradient and the pattern of crown-size reduction in simple hypodontia. Angle Orthod 1970;40:51–8.
  16. Gungor AY, Turkkahraman H. Tooth sizes in nonsyndromic hypodontia patients. Angle Orthod 2013;83:16–21.
  17. McKeown HF, Robinson DL, Elcock C, al-Sharood M, Brook AH. Tooth dimensions in hypodontia patients, their unaffected relatives and a control group measured by a new image analysis system. Eur J Orthod. 2002;24(2):131–41.
  18. Schalk-van der Weide Y, Steen WH, Beemer FA, Bosman F. Reductions in size and left-right asymmetry of teeth in human oligodontia. Arch Oral Biol 1994;39(11):935–9.
  19. Jha P, Jha M. Management of congenitally missing second premolars in a growing child. J Conserv Dent 2012;15:187-190.
  20. Farret MMB, Farret MM, Farret AM. Strategies to finish orthodontic treatment with a Class III molar relationship: three patient reports. World J Orthod 2009;10:323-333.
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