ANALYSES OF CRANIOFACIAL AND DENTAL MORPHOLOGY IN MONOZYGOTIC TWINS DISCORDANT FOR CLEFT-LIP AND UNILATERAL CLEFT-LIP AND PALATE

The Michigan Cleft Twin Sample data was analyzed in order to investiga te dental arch and craniofacial morphology. The present study consiste d of 12 monozygotic twins discordant for either cleft lip or unilatera l cleft lip and palate. Individuals having CL (repaired) alone did not differ from their unaffected counter parts in dental arch and skeleta l morphology. Repaired UCLP subjects were characterized by having a sh orter and more posteriorly positioned maxilla. Although reduction of d ental arch width as a result of scar contraction following surgery was evident, the effects of scar tissue pull did not affect maxillary bas al width.