Prosthodontic abutment in four patients with unilateral cleft lip and palate

An examination of the relation between the number of teeth used as the abutment of a fixed prosthesis and the increase of the functional loading capacity of the upper jaw was conducted in four male patients with unilateral cleft lip and palate (age range, 19 to 21 years). This was measured at the maximum biting force at each two teeth adjacent to the cleft under various splint extension conditions and compared with that in the nonsplint condition. In all subjects, the maximum biting force under every splinted condition was significantly increased compared with the nonsplint condition. The increase was proportional to the number of teeth included in the splinting. Results indicated that two teeth should be used in each segment in the abutment of the splint across the cleft in order to increase the functional loading capability of the upper jaw comparable to that of the lower jaw. The results also indicated that inclusion of more than two teeth has no further advantageous effect on the functional loading capability.