Skeletal class III with laterognathia and lower facial third asymmetry. Surgical-orthodontic treatment

Abstract

Female patient, 16 years of age, who attended the Department of Orthodontics at the National Autonomous University of Mexico. The main reason for consultation was: «I have a deviated jaw». Upon facial clinical examination, from the front view an oval and elongated face may be noted as well as an increased lower third, the chin deviated to the right, the facial midline did not match the dental midline, a non-consonant neutral smile and a 60% exposure of the incisor clinical crowns. On a lateral view: a straight profi le, competent lips, acute nasolabial angle and increased mentocervical length may be observed. Intraorally there is an ovoid-shaped arch, non-coincident dental midlines, crowded teeth, anterior and posterior right crossbite, absence of the first upper molars (nonassessable molar relationship) right and left canine class III, -2 mm overjet and a 2 mm overbite. Radiographic records included a lateral headfilm, a posteroanterior radiograph and a panoramic radiograph as well. The cephalometric analysis revealed a skeletal Class III due to mandibular prognathism, a neutral growth pattern, proclined upper incisors and lower incisor retroclination. The posteroanterior radiograph showed a discrepancy of the maxillo-mandibular line of 4o and a postural asymmetry of 5o. In the panoramic radiograph asymmetric mandibular ramus, ACJ at alveolar crest level, 2:¼ root-crown ratio, upper and lower third molars, absence of the first upper molars and maxillary lateral incisor root with endodontic treatment may be noted. Functionally, the patient presented without any apparent TMJ problems. Treatment consisted of three phase: pre-surgical orthodontic phase, surgical phase and post-surgical orthodontic phase. The objectives were: to correct in all three planes of space the skeletal disharmony presented by the patient, to provide functional occlusion and optimal facial and dental aesthetics as well as joint stability and periodontal health.