[Biochemical studies of three cases of a compound odontoma].

This study was conducted to investigate some biochemical characteristics of compound odontoma obtained from three cases, all found in the mandible. The results were compared with data obtained from deciduous teeth (3) and permanent teeth (3). The mole ratios of calcium to inorganic phosphorus (Ca/P) among three groups were deviated between 1.67 and 1.68 in the enamel extracts and between 1.65 and 1.69 in the dentine extracts. No significant differences were found in each case. Amino acid analysis of dentine showed apparent differences among these groups in the degrees of hydroxylation of proline (Hyp/Pro + Hyp) and of lysine (Hyl/Lys + Hyl). Hydroxylation rates of proline were 43.1 +/- 0.98% for the permanent teeth, 44.4 +/- 0.47% for the deciduous teeth and 40.9 +/- 0.44% for the odontoma. Hydroxylation rates of lysine were 32.0 +/- 0.67% for the permanent teeth, 27.3 +/- 0.0% for the deciduous teeth and 26.5 +/- 0.46% for the odontoma. T-test confirmed the significance of the differences between the permanent teeth and odontoma in the case of lysine (p less than 0.5%) and between the deciduous teeth and odontoma in the case of proline (p less than 0.5%). These results suggest the differential organization of dentine matrix between human permanent teeth, deciduous teeth and compound odontoma.