The study of the maximum bite force after mandibular distraction osteogenesis in hemifacial microsomia deformities

Abstract

Objective To investigate the influence of mandibular distraction osteogenesis on masticatory function by analyzing the maximal bite force before and after surgery. Methods From May 2014 to November 2015, 22 hemifacial microsomia cases, ageing from 6 to 10 years old, underwent mandibular distraction osteogenesis and their biting force data were collected. The maximal bite forces in incisor area, bilateral premolar area and molar area were measured before surgery and 1 year after surgery. Results The average maximum bite forces in the molar area of the affected side, premolar area of the affected side, incisor area, premolar area of the unaffected side, molar area of the unaffected side were (170.6±42.8)N, (141.9±34.9)N, (89.7±18.8)N, (169.3±29.0)N and (230.2± 56.4)N respectively before surgery. Statistics indicated that most patients had uneven distribution of bite force between the affected side and unaffected side before surgery. And they changed to (198.8±44.0)N, (151.8±31.1)N, (88.9±18.0) N, (167.8±26.1)N and (234.3±52.5)N respectively 1 year after surgery, showing that the bite force in the molar area of the affected side was significantly improved by the surgery(P<0.05). Regression analysis showed that the postoperative bite force distribution had a tendency to become more symmetrical in hemifacial microsomia patients. Conclusions Mandibular distraction osteogenesis can improve the bite force of the affected side in hemifacial microsomia patients and enhance the balance of masticatory in the long-term postoperatively. Key words: Hemifacial microsomia; Osteogenesis, distraction; Bite force