Soft tissue chin thickness in different vertical skeletal patterns

Abstract Objective To evaluate and compare the soft tissue chin (STC) thickness at different chin levels with different vertical growth patterns among the adult patients in a sample from Egyptian population. Patients and methods One hundred eighty pretreated lateral cephalograms of Egyptian orthodontic patients of both sexes with class Ι malocclusion (ANB 2°–4° according to Aboul-Azm and colleagues) and different vertical skeletal patterns. With age ranging from 16 to 22 years old. The enrolled cases were divided into three groups based on their vertical skeletal patterns using angular measurements of Steiner analysis (SN-GoGn). High angle SN-MP angle more than 37, low angle SN-MP angle less than 27, and average angle SN-MP angle 27–37. The STC thicknesses were measured at pogonion (Pog), gnathion (Gn), and menton (Me). Group differences were evaluated with two-way analysis of variance and Students t test. The Pearson product moment correlation gauged associations between parameters. Results The STC values were greater in men than women ( P < 0.04) and were smaller in the high group (9.06 ± 1.28 mm) than in all other groups at Gn (mean values 20.672 m; P = 0.001) and at Me (high group 8.22 ± 1.94 mm; other groups 10.18 ± 3.56 mm, STC 9.11 ± 2.37 mm; P = 0.001). Conclusion The STC thickness had the highest measurements in the hypodivergent group at pogonion, gnathion, and menton and the lowest being in the hyperdivergent group. This differential thickness warrants focused research as it implies that it is possible. The STC thickness apparently adapts to severe hyperdivergence through increased stretching of the STC thickness with progressive increase in facial divergence. The possibility that more advancement genioplasty to achieve better chin projection may be needed in patients with severe hyperdivergence.