Comparison of Soft Tissue Profile between Subgroups of Skeletal Class III Malocclusion

Abstract

Aim:The aim of this study is to compare the soft tissue profiles of patients with skeletal Class III malocclusions originated from; maxillary retrusion, mandibular protrusion and the combination of maxillary retrusion and mandibular protrusion.Material and Method:Lateral cephalomet-ric radiographs of 66 subjects were divided into three groups according to the Nperp-A and Nperp-Pg variables; Group 1-maxil-lary retrusion (n:23; mean age:13.44 years), Group 2-mandibular protrusion (n:22; mean age:13.31 years), and Group 3-combination of maxillary retrusion and mandibular protrusion (n:21; mean age:13.04 years). Besides the descriptive parameters of Class III subgroups, 13 soft tissue measurements (Gl-Sn, Sn-Me, ULL, St-Me, Sn-LLV, LLV-Me, interlabial distance, upper lip, lower lip, Chin, Gl-Sn/Sn-Me, Sn-St/St-Me and Sn-LLV/LLV-Me) were achieved for evaluating the possible differences between Class III subgroups. The differences between all Class III groups were evaluated by Analysis of Variance (ANO-VA) and Duncan test.Results:Chin measurement (distance between soft tissue pogonion to vertical reference plane) showed the highest value in Group 1 (5.14 ± 2,93) compared with Groups 2 (2.94 ± 2,15) and 3 (3.05 ± 1,98) (p<.01). Although the differences in Sn-Me and LLV-Me are insignificant among groups, these parameters representing the lower anterior soft tissue heights have the highest values in group 3. The rest of the parameters did not show statistical significance between the groups.Conclusion:Decreased lower lip and significantly increased soft tissue chin measurement were found in maxillary ret-rusion group. Both cephalometric and clinical examinations of soft tissues are needed for a proper diagnosis and treatment of orthognathic surgery cases.

Keywords

• facial profile
• soft tissue
• class iii