Management of Skeletal Class III Malocclusion due to Mandibular Prognathism Coexisting with Vertical Maxillary Excess

Praveen Kumar Neela

doi:10.4103/jios.jios_61_17

Abstract

This case report describes combined orthodontic and orthognathic management of skeletal Class III malocclusion in a female patient presenting with prognathic mandible, increased maxillary height, severe hyperdivergence, gummy smile, and upper anterior proclination. Presurgical orthodontics involved extraction of maxillary first premolars and decompensating the proclined upper incisors. Orthognathic surgery involving differential maxillary impaction, mandibular bilateral sagittal split osteotomy setback, and sliding genioplasty. Postsurgical orthodontics was initiated one month after the surgery to finish the case in Class II molar relationship and Class I canine relationship with proper intercuspation. The outcome had acceptable results with good esthetics and occlusion.

Highlights

Orthodontic management of skeletal malocclusion, after growth period, often requires a combination of orthodontic and orthognathic treatment to achieve the desired goals
This case report describes combined orthodontic and orthognathic management of skeletal Class III malocclusion in a female patient presenting with prognathic mandible, increased maxillary height, severe hyperdivergence, gummy smile, and upper anterior proclination
The results show that there was an improvement in sagittal position of the prognathic mandible, correction of gummy smile, and achievement of normal overjet and overbite

Summary

Introduction

Orthodontic management of skeletal malocclusion, after growth period, often requires a combination of orthodontic and orthognathic treatment to achieve the desired goals. Class III skeletal problems with prognathic mandible sometimes present with an excessive maxillary height and mandibular rotation. Management of such cases requires presurgical orthodontics involving decompensation to facilitate proper surgical correction and postsurgical orthodontics for minor occlusion correction so as to achieve a functional occlusion with proper overjet and overbite.[1,2]. Intraoral examination [Figures 3 and 4] revealed the presence of all permanent teeth except upper third molars. Both the arches were U‐shaped, apparently symmetrical, and with mild anterior crowding. In this case, high beta angle (50°) indicated severe Class III skeletal base relationship This contradiction can be attributed to the existence of vertical. SNA SNB ANB Wits appraisal Dental base relationship Upper incisor to NA (mm/degree) Lower incisor to NB (mm/degree) Upper incisor to SN plane Lower incisor to mandibular plane angle Dental relationship Inter‐incisal angle (°) Lower incisor to APo line Overbite Overjet Vertical skeletal relationships Maxillary‐mandibular planes angle SN plane ‐ mandibular plane Upper anterior face height Lower anterior face height Face height ratio Jarabak ratio Maxillary length Mandibular length ‐ effective (McNamara) Soft tissues Lower lip to Ricketts E‐plane Nasolabial angle

27-35 Class I

Results

Discussion