Diagnostic Measures in Borderline Surgical Cases of Unilateral Cleft Lip and Palate and Noncleft Class III Malocclusions

Linton, Jina Lee

Abstract

Patients with complete unilateral cleft lip and palate present difficulty in maxillary growth problems, necessitating orthognathic surgery in 25%. The aims of this study were; (1) to delineate diagnostic measures in borderline surgical cases of unilateral cleft lip and palate, (2) to verify the significance of negative overjet as a measure of anteroposterior discrepancy, and (3) to compare these diagnostic measures with those of borderline surgical cases of noncleft Class III malocclusion. The sample consisted of 29 patients with unilateral cleft lip and palate and 25 noncleft Class III patients; all had crossbites of all four incisors. Each of pretreatment study casts and cephalograms were analyzed. The Cleft group showed smaller SNA and SNB angles than the noncleft Class III group, but the ANB angles and the amount of anterior crossbites showed no statistical difference. For borderline surgical Class III unilateral cleft lip and palate cases, ANB angles, Wits appraisal, and ABGoGn angle were critical diagnostic parameters. On the other hand, the magnitude of anterior crossbite, the negative overjet, was shown not to be a significant measure of anteroposterior discrepancy.