Introduction
Class II malocclusion cases are of interest to orthodontist since they constitute a significant percentage of cases they treat. However, they are one of the most challenging malocclusions to diagnose and treat.
There lies a significant difference in prevalence of Class II malocclusion among various populations. Emmanuel 1 observed 1.1% prevalence in Nigerian, where as Silva et al 2 observed as high as 21.5% prevalence of Class II malocclusion in Latino adolescents. Prevalence of Class II malocclusion in India varies from 1.9% in Rajasthan to 8.37% in South India. 3, 4
Class II malocclusions have dental or skeletal or combination entities. Furthermore, they can be attributed to maxillary prognathism, mandibular retrognathism or combination of both along with vertical and transverse problems. Success in the management of skeletal Class II cases relies on proper diagnosis and treatment planning. The treatment approach of skeletal Class II malocclusion depends upon the growth status of the patient. In adolescent cases, growth modulation with either removable or fixed myofunctional appliances to stimulate mandibular growth, head gear to restrict excessive maxillary growth or a combination approach is recommended.
However, in adults, esthetics is the major concern in severe Class II cases. The treatment of severe dentofacial deformities in adult patients is a challenging task for both the orthodontist and the maxillofacial surgeon. Treatment is difficult because of the skeletal and facial disharmony, absence of jaw growth and a tendency to relapse. 5 Critical diagnosis and ortho-surgical combination treatment approach is to be relied on for gaining optimum esthetic harmony and functional efficiency. Furthermore, acceptance of pleasing facial appearance is the prime importance factor in determining social relationship. 6
Case Report
This case report describes a 20 years old male patient who reported to Orthodontic Department of a Government Dental Centre in Pune, Maharashtra, India with the chief complaint of forwardly placed upper front teeth.
Clinical examination
Extraorally, the patient exhibited square face with convex profile, incompetent lips and deep mentolabial sulcus (Figure 1). Intraorally, patient presented with Class II molar and canine relationship bilaterally, with proclined incisors, deep bite and increased overjet. Both the arches exhibited moderate spacing in the anterior teeth with deep curve of spee (Figure 2). Cephalometrically patient had skeletal Class II jaw bases on account of normal maxilla with retrognathic mandible and patient was in CVMI Stage-6 (Figure 3).
Treatment alternatives
There were two treatment alternatives, the first alternative was orthodontic treatment with dentoalveolar compensation (Camouflage) using fixed orthodontic appliance. However, in this approach, the underlying skeletal problem of mandibular retrognathism couldn’t be addressed. The second alternative was ortho-surgical treatment approach with bilateral sagittal split osteotomy with mandibular advancement.
Both treatment options were explained to the patient. As esthetics and overall facial appearance was the main concern, second treatment alternative was selected. This option would improve the existing profile and also reduce the severity of the mandibular retrognathism.
Treatment plan and progress
Presurgical orthodontic phase
Both maxillary and mandibular arches were banded and bonded using 0.22” MBT prescription and initially 0.014” NiTi wire was placed for levelling & alignment. After leveling and alignment of the upper and lower arches was complete (Figure 4), upper and lower anterior teeth space consolidation was carried out in 0.018” SS wire. Subsequently 0.019”X 0.025” NiTi wires were placed which were followed by 0.019”X 0.025” SS wires in both the arches. Patient’s presurgical photographs (Figure 5, Figure 6) and radiographs were recorded again, then the case was re-evaluated. Prediction tracing was done (Figure 7), Mock surgery was carried out and surgical splint was fabricated (Figure 8). 0.021” X 0.025” stainless steel wires with soldered interproximal spurs were ligated in the maxillary and mandibular arches at the end of presurgical phase.
Surgical phase
The orthognathic BSSO surgery (Figure 9) was carried out with 7mm mandibular advancement to correct anteroposterior skeletal discrepancy. The surgical splint was then used to position & stabilize the mandible with the help of I-plates (Figure 10).
Postsurgical orthodontic phase
Four weeks post surgery the stabilizing archwires & splint were removed. Post-surgical occlusal settling was started in 0.014” Australian super plus wires in upper and lower arches and short Class II elastics (3/16”) were administered in rectangular fashion (Figure 11). After ensuring the achievement of all intended goals, fixed orthodontic appliance was removed. Patient was then given upper Hawley’s and lower FSW retainer.
Table 1
Cephalometric reading
Treatment results
Excellent facial and occlusal results were achieved. Significant improvement of the facial profile was appreciated (Figure 12). Intraorally, bilateral Class I molar and canine relation was achieved with normal overjet and overbite relation (Figure 13). Deep mentolabial sulcus was corrected. Mandibular retrognathism was improved from ANB 7˚ TO ANB 2˚(Table 1). Post treatment radiographs before debonding (Figure 14) showed increase in lower anterior facial height and correction of mandibular retrognathism. (Figure 15) shows pretreatment and post treatment cephalometric superimposition. Overall, the treatment results were achieved as estimated during the treatment planning stage.
Discussion
Class II malocclusion can be corrected depending on the growth status and severity of the case. In adolescents, orthodontic correction can be carried out using removable/fixed functional appliances.7 However, in adult patients’ correction is done by orthodontics alone (Camouflage) or orthodontic-surgical combination. Orthognathic surgery is indicated when dental discrepancy cannot be corrected by orthodontic treatment alone or when facial esthetics is compromised. Many adult cases exhibiting severe skeletal Class II Div 1 malocclusion with mandibular retrognathism treated successfully with BSSO have been reported.8, 9 Cases in whom mandibular advancement is carried out with BSSO are quite stable on long term basis with minimal to moderate relapse. 10, 11
In the present case, an adult case of severe skeletal Class II Div1 malocclusion was treated with orthodontic-orthognathic combination. The treatment was focused to relieve upper anterior proclination, correct skeletal antero-posterior discrepancy and improve facial esthetics. Post-treatment results showed improved facial esthetics and dental occlusion. Convex facial profile and deep mentolabial sulcus were corrected and anterior vertical facial height was increased along with the correction of mandibular retrognathism.
