| Abstract: | It is mandatory that the prosthodontic devices for the cleft palate patients not only prevent the relapse of the corrected arch and teeth by orthodontic and/or surgical intervention but also equilibrate the tooth-borne ability between the upper and the lower jaw. The purpose of this paper is to set up a criterion for the extension of the splint from the point of the tooth-borne ability. Four patients with unilateral cleft lip and palate were examined for the maximal biting force at the tooth adjacent to the cleft in each alveolar segment in the case of various extensions of the splints. The findings were as follows: 1. The maximal biting force increased significantly in every splint, compared with the non-splint. 2. The maximal biting force increased significantly in the splints where the neighbouring tooth in the same segment was involved, compared with that in the splints where only the tooth adjacent to the cleft was involved, even if the tooth in another segment increased in number for splinting. 3. The maximal biting force did not increase significantly in most splints where three teeth in the same segment were involved, compared with that in the splints where two teeth in that segment were involved. |
