Odontometrics of the permanent teeth in cleft lip and palate: systemic size reduction and amplified asymmetry.

Mesiodistal diameters of the permanent teeth of 70 isolated cleft lip and palate cases were analyzed. Subjects with unilateral cleft lip and palate (CLP) exhibit significantly smaller crown sizes than controls. Size reduction averages 2.3 percent, which translates to a 5.2-mm mean difference summed across all 28 permanent teeth. Bilateral cases are twice as affected, with a 4.2 percent reduction (9.3 mm). The baseline level of left-right asymmetry is significantly amplified across the whole dentition, encompassing both early- and late-forming teeth and constituting a 30-percent increase in overall asymmetry. Also, there is a localized peak of disproportionately high asymmetry centered on the upper lateral incisor but extending to both the central incisor and canine. The consistency of these differences across all tooth types and among early- and late-forming teeth implies that isolated CLP is a sequelae of a systemic, generalized restriction of these individuals' growth potential.