Maxillary Constriction With Skeletal class II Malocclusion-A Comprehensive Treatment Approach

This case report reiterates the fact that a bilateral posterior crossbite with severe skeletal class II malocclusion in the growth period could be effectively treated by a comprehensive approach with a rapid palatal expansion appliance followed by fixed appliance therapy. A 14-year-old boy presented with a severe skeletal Class II malocclusion with an orthognathic maxilla, retrognathic mandible and a high mandibular plane angle with an Angles’ Class II division 1 subdivision malocclusion with maxillary constriction, increased overjet, deep bite and severe crowding of maxillary and mandibular incisors. A banded rapid palatal expansion appliance was initially given to correct the bilateral posterior cross bite and subsequently maxillary and mandibular first premolars were extracted and Roths’ Pre adjusted edgewise appliance therapy (0.022 x 0.28-inch slot) was strapped up to correct the severe tooth size-arch length discrepancy. The patient’s soft tissue profile and dentofacial esthetics improved dramatically with increased self-confidence and enthused self-esteem. J o u r n a l D e n t a l a n d O r a l I m p l a n t s ISSN NO: 2473-1005 RESEARCH ARTICLE DOI : 10.14302/issn.2473-1005.jdoi-16-1159 Corresponding author: A. ARIF YEZDANI, MDS, FWFO, Professor and HOD, Dept. of Orthodontics and Dentofacial Orthopaedics, Sree Balaji Dental College and Hospital, Narayanapuram, Pallikaranai, Chennai-600100, E-mail: arifyezdani@yahoo.com


Introduction
Growth period of an individual is an ideal period for the treatment of desired orthopaedic effects of skeletal jaw discrepancies. It has been reported that a deficiency in maxillary arch width is associated with Class II malocclusion. Skeletal maxillary constriction treated with rapid palatal expansion appliance has been widely reported in literature, however, other possible indications of this technique have also been proposed in addition to its prime objective of correction of posterior cross bite. 1,2 Haas 3 opined that all Class II division 1 and Class division 2 patients present mandibular functional retrusion and that with Class II division 1 group the retrusion was due to constriction of maxillary dental arch, especially between the canines. It has been reported that skeletal Class II malocclusion with retrognathic mandible have benefited immensely with spontaneous forward positioning of the mandible facilitated by the widening of the constricted maxilla. 4,5 This case report illustrates the treatment of a skeletal Class II malocclusion with an orthognathic maxilla and retrognathic mandible with Angles' Class II division 1 subdivision malocclusion with maxillary constriction and severe maxillary and mandibular tooth size-arch length discrepancy. Initial treatment with rapid palatal expansion appliance to correct the maxillary constriction to promote spontaneous forward positioning of the mandible and subsequent orthodontic treatment with fixed appliance therapy resulted in a remarkable change in the patient's dentofacial esthetics. Extraoral assessment. (Fig 1a-c).

Diagnosis and etiology
The patient had a leptoprosopic face, convex profile, posterior divergence, incompetent lips, clinical high mandibular plane angle, complete maxillary incisor display on smiling with no signs of temporomandibular joint dysfunction.
The maxillary arch was V-shaped with severely proclined and rotated maxillary incisors with a palatally placed 12. The mandibular arch was U-shaped with severe crowding of mandibular incisors, with 43 partially germs with normal alveolar bone levels. (Fig 2).
Cephalometric analysis revealed a skeletal Class II pattern, with an orthognathic maxilla and retrognathic mandible with high mandibular plane angle and severely proclined maxillary and mandibular incisors with increased lower anterior facial height. (Fig.3).

Treatment objectives
The main treatment objective was to improve the phonation, lip competence, smile esthetics and soft Subsequent to correction of the same, maxillary and mandibular first premolars were extracted and the orthodontic phase was commenced to correct the severe crowding of the maxillary and mandibular dental arch.

Treatment alternatives
An orthopaedic phase with a functional appliance for the retrognathic mandible could have been contemplated, but the need of the hour was to correct the maxillary constriction and the severe tooth size-arch length discrepancy. Correction of maxillary constriction would release the mandible anteriorly to express its inherent genetic potential.
Bonded RME consists of an acrylic capping covering the occlusal surfaces of maxillary premolars and molars, housing the arms of the rapid maxillary expansion screw which is cemented to the maxillary posteriors with glass ionomer cement. This is useful in high angle cases to achieve mild intrusion of the maxillary posteriors to facilitate autorotation of the mandible in an upward and forward direction.
Though bonded RME could have been used, we however, preferred to use banded RME as it is more hygienic and easy to maintain with good patient cooperation.

Treatment progress
The mandibular first premolars were first

Results
The soft tissue frontal and profile improved dramatically. (Fig.7a-b). The bilateral posterior crossbite was corrected. The severe increase in overjet of about 13mm was effectively reduced to 3mm and the severe deep bite was also corrected ( Fig.7c-d). Fixed maxillary and mandibular lingual retainers were given. (Fig.7e-f).
Post orthodontic treatment, normal root inclinations of the teeth and normal alveolar bone levels was observed.
Post treatment lateral cephalometric radiograph was taken to assess the treatment changes. (Fig.9). The changes in maxilla in the anteroposterior direction was insignificant, however an increase in the length of the mandible measured from Condylion (Co) to Gnathion (Gn) and an increase in anterior facial height was observed. Maxillary incisors were retracted dramatically by 8mm and the mandibular incisors were proclined by 3mm to camouflage the skeletal class II malocclusion.
( Table 1). Effective expansion of the maxillary constriction as an end-of treatment goal was achieved.
( Fig.10a-b). have no real effect on mandibular length 6, 7 while others believe that mandibular growth can be increased with functional appliance treatment [8][9][10] . However, Wendling 11 was of the opinion that a spontaneous correction of some Class II malocclusions is favoured with initial rapid palatal expansion. It has been reported in the literature that in the Class II, division 1 group, the retrusion was due to constriction of the maxillary dental arch and that in such cases, it is important to expand the maxillary arch to obtain a permanent orthopedic effect on the maxilla by releasing the mandible to move anteriorly.