The characteristics of pseudo class III malocclusion in mixed dentition

Objective To find the dentoskeletal characteristics of pseudo Class III malocclusion in mixed dentition. Methods Thirty six patients (15 females, 21males with mean age: 10 7±2 0 years) were included in the pseudo Class III malocclusion group. Forty patients (21 females, 19 males with mean age:9 7±2 2 years) with Class III incisor relationship and Class III molar relationship were included in the skeletal Class III malocclusion group. All the subjects were followed up after growth spurt and were diagnosed either as pseudo Class III malocclusion or skeletal Class III malocclusion. Thirty one patients with Class Ⅰ malocclusion were included in the Class Ⅰ malocclusion group. Selection criteria included: 1. skeletal Class Ⅰ malocclusion with normal overjet and overbite. 2. mild to moderate crowding with Class Ⅰ molar relationship. 3. straight facial profile. Cephalograms were taken in the mixed dentition for pseudo Class III malocclusion, skeletal Class III malocclusion and Class Ⅰ malocclusion groups to compare the dentoskeletal characteristics. Results Females in the pseudo Class III malocclusion group showed more retrusion of A point with an average value of -1 63 mm compared with 0 52 mm in the Class Ⅰ malocclusion group ( P 0 05). The upper in cisors in the pseudo Class III malocclusion group were upright.Conclusions Pseudo Class III malocclusion is characterized by decreased midface length, mandibular displacement, retroclined upper incisors and normal vertical development.