Soft tissue profile changes following orthodontic treatment of Chinese adults with Class III malocclusion

Thirty-eight adult Chinese patients (mean age 24.3 +/- 3.2 years) exhibiting true Class III dental and skeletal malocclusions were treated orthodontically with the edgewise appliance and extractions of mandibular first premolars together with simultaneous anterior expansion of the maxillary arch. A retrospective cephalometric study was undertaken to determine the soft tissue profile changes at least 6 months postretention. Significant cephalometric changes included decrease in the mandibular incisor protrusiveness by 6.4 mm (P less than .001) and accompanying lower lip protrusiveness by 4.4 mm (P less than .01), together with a slight forward movement of the maxillary incisors by 1.7 mm (P less than .05) and, consequently, a slight increase in upper lip protrusiveness by 1.2 mm (P less than .05) and decrease in nasolabial angle (P less than .05). The overall improvement in lip profile provided by this mandibular arch contraction/maxillary arch expansion orthodontic approach appears to be a viable alternative in mild-to-moderate Class III patients who decline orthognathic surgery.