ISRCTN29932826.

ISRCTN29932826.

Fosse G, Saele PK, Eide R. Numerical density and distributional pattern of dentin tubules. Acta Odontol Scand 1992;50;201-210. Oslo. ISSN 0001-6357. By a new method the numerical density and distributional pattern of transversely cut dentin tubules and the diameters of their peritubular dentin walls were measured in sections near the dentin-enamel junction (DEJ), midway to the pulp, and near the pulp wall in human premolars. For each section the mean and standard deviation of these variables were expressed. At all three levels the measurements comprised the same bundle of tubules from the DEJ to pulp in the coronal dentin. The number of tubules per square millimeter increased more than three times, and the diameters of peritubular dentin decreased one-tenth, whereas central distances between tubules were halved from DEJ to pulp. Thus the pulpward reduction of intertubular dentin is quantified. The distribution of the tubules is not regularly hexagonal, but the distances between them at each given depth are still very uniform in all directions. The pattern of cross-cut tubules often showed distinct short curved rows. The quantitative method might be used to determine taxonomic affinities. 0 Dentin; morphometry; peritubular dentin; tubules Gble Fosse,

Summary Background Children born with unilateral cleft lip and palate (UCLP) are reported to display several dental anomalies including agenesis, supernumeraries, as well as variations in dental size, shape, and path of eruption. The extensive sample of individuals with UCLP included in the Scandcleft randomized control trials offers the opportunity to study more rare conditions, which is seldom possible with limited samples. Objectives The aim was to study dental anomalies at 8 years of age in children born with UCLP included in the Scandcleft randomized control trials. Methods Panoramic and intraoral radiographs from 425 individuals (279 males and 146 females) with a mean age of 8.1 years were assessed by four orthodontists regarding dental anomalies. Results Agenesis was found in 52.5 per cent and supernumerary teeth in 16.9 per cent of the participants. The cleft lateral was missing in 43.8 per cent and was found peg shaped in 44.7 per cent. The distribution of ectopic eruption was 14.6 per cent, mainly affecting maxillary first molars, while transposition was found in 3.4 per cent of the individuals. In addition, infraocclusion of one or several primary molars was registered in 7.2 per cent of the participants. Conclusion We conclude that 8-year-old children born with UCLP display multiple dental anomalies. The Scandcleft sample allowed rarely studied conditions such as infraocclusion of primary molars and transposition to be studied in children born with UCLP. Trial registration ISRCTN29932826.

ISRCTN29932826.