No abstract

Submerging of deciduous molars was examined in 1,042 preschool children. The process of submerging was detected as early as the age of 3 years. First deciduous molars were affected more often than second deciduous molars. Submerging was more frequent in the mandible than in the maxilla. Differences were found between sexes and between age groups.The phenomenon of submerged teeth appears clinically as a disruption in the continuity of the occlusal plane of the dental arch. The distance from the marginal ridges of the submerged tooth to the existing occlusal plane can vary between fractions of a millimeter to complete "submerging" of the tooth within bone.Reports on the epidemiology of submerged teeth based on random samples are sparse, although the subject itself has received considerable attention in the literature. It is not clear at which age this local disturbance first becomes apparent clinically because most of the investigations on submerged teeth have been carried out with children older than 7 years of age.1-4

Dental study casts of 1530 Israeli rural children aged 3-13 years, evenly represented by the sexes, were examined for submersion of their primary molars, 24.8% of the children had one or more of these teeth affected. Out of 8250 teeth at risk, 8.81% were submerged to various degrees. Over 50% of them were primary mandibular first molars, close to 26% were primary mandibular second molars. The number of affected teeth rose with age in both sexes. Sex differences were significant only at 5-7 years, when girls were more frequently affected. Children with one or two affected teeth predominated. The submerged teeth were predominantly located in one or in both quadrants of the same arch. The degree of submersion became more severe with age.

The accuracy for predicting mesiodistal widths of unerupted permanent canines and premolars from x-rays and their estimations based on the already erupted permanent teeth were tested in a group of Israeli children. The observed posteruptive widths related more closely to predicted values obtained from x-ray measurements than from tabulated estimations.

Dental submergence, linked primarily with tooth ankylosis, has been reported to have a possible genetic predisposition. The submergence of primary molars was examined in a sample of 1530 children, 2.5-13.5 yr old, appertaining to seven ethnic groups living in Israel. It was found that the frequency of submergence varied among the ethnic groups, and that, on the whole, it was considerably higher than that in North American children.