[Structure, ultrastructure and microanalysis of the enamel of teeth near maxillary clefts].

: Teeth located in the vicinity of cleft palate were studied using correlated light microscopy, microradiography, SEM, TEM and microanalysis. Structural, ultrastructural and chemical abnormalities were found in enamel. The enamel surface presented micro and gross hypoplasia, associated with hypomineralization. Microradiography showed the antenatal enamel to be more mineralized than postnatal enamel. Microanalysis showed the Ca/P ratio measured at the enamel surface to be higher in the teeth associated with cleft palate, compared with controls. The Ca/P value was due to a Ca increase and a P decrease in the enamel surface. The Ca increase was correlated with a decrease in Mg, supporting the hypothesis of a Mg/Ca substitution in the apatitic structure.