Crown-root ratio of permanent teeth in cleft lip and palate patients

To determine root lengths of fully developed permanent teeth of cleft lip and palate (CLP) patients and to define their crown-root (C/R) ratios. Crown height and root length of permanent teeth were measured from panoramic radiographs of 44 CLP patients and 37 controls. A total of 1397 teeth were measured, and C/R ratios were calculated. Higher C/R ratios were found in CLP patients; this was statistically significant for both maxillary and mandibular incisors and canines. Bilateral CLP subjects showed higher C/R ratios in general than unilateral CLP subjects. Roots of maxillary incisors, canines, and some other teeth were significantly shorter in CLP patients than in controls. CLP patients should be considered to have unfavorable C/R ratios, which could be the result of short root lengths for some teeth.