Soft and Hard Tissue Changes in Class III Patients Treated by Bimaxillary Surgery

A cephalometric study of 17 non-growing dentate Class III subjects treated by bimaxillary surgery was undertaken to assess the results of treatment and to evaluate the correlation between soft and hard tissue change. It was concluded that: (i) the orthognathic profiles achieved were brought about by a combination of maxillary advancement and mandibular setback; (ii) a strong correlation in the horizontal direction occurred between all the selected landmarks of the lower lip and chin, but only between superior labial sulcus and point A in the upper lip; highest intra-group correlations were seen between corresponding soft and hard tissue points; the ratios of soft tissue to corresponding hard tissue movements in lower lip and chin approached 1:1; (iii) in the vertical direction, a strong correlation occurred in the lower lip and chin; highest intra-group correlations were not necessarily with corresponding landmarks; and (iv) vertical movement of landmarks on the nasal base and upper lip generally showed poor or weak correlation with corresponding soft tissue points. The most reliable hard tissue predictors of horizontal and vertical soft tissue change are tabulated for application in bimaxillary surgery for the Class III patient.