Does postoperative masticatory training for prognathism contribute to functional improvement?

Abstract

ObjectiveIntroduction of postoperative oral rehabilitation has been expected to improve the oral function after orthognathic surgery for mandibular prognathism, but remains uncertain on its efficacy. This study was to clarify what kind of improvement in oral function is associated with postoperative oral rehabilitation. Methods51 patients of mandibular prognathism underwent orthognathic surgery. Gum chewing exercise was introduced in all patients from the third month after surgery. At the fourth month only 12 patients (EG) performed training perfectly and continued till the sixth month, however another group of 12 patients (NEG) quitted training then. The occlusal contact area(OCA), the maximum bite force(MBF), and the chewing ability(CA) were measured at the day before surgery, the first, the third, and the sixth month compared with a control group comprised of 20 normal subjects. The chewing pathway area of EG and NEG were measured using a mandibular movement measurement device. Each measured value was compared by Shapiro-Wilk normality test. Analysis of variance was performed by ANOVA, and multiple comparison test (p Value＜0.05). ResultsOCA and MBF were low significantly at the sixth month after surgery compared to the control group. There was no difference in OCA and MBF at the third month between in EG and in NEG, but CA was improved and the chewing pathway area was higher at the sixth month in EG. ConclusionGum chewing exercise as postoperative oral rehabilitation may restore chewing ability even in a short period of months after orthognathic surgery for mandibular prognathism.