[Mandibular movements in dentulous cleft lip and palate patients with lingualized occlusion]

Most dentulous unilateral cleft lip and palate patients show a tendency toward lingualized occlusion in lateral segment teeth. The purpose of this study was to investigate the effect on the stomatognathic function by changing the occlusal contacts of buccal cusps in lateral segment teeth in dentulous unilateral cleft lip and palate patients with lingualized occlusion. Three patients were selected and two types of experimental upper crowns, L crown (with occlusal contact only at the lingual cusp), B crown (with occlusal contacts both at lingual and buccal cusps), were fabricated. The border jaw movements and mandibular movements during chewing an almond were recorded with MMJI-E (Shofu inc.). The results were as follows: 1. By using B crown, the area of border jaw movements in the frontal plane and the amount of maximum opening on the experimental crowns side were increased. 2. By using B crown, mandibular movements in the occlusal phase were converged and stabilized during chewing. 3. It was suggested that favorable mandibular movements during chewing were due to proper occlusal contacts provided in lateral segment teeth.