Incidence of supernumerary teeth in a group of Thai children
Ten thousand three hundred and ninety three child patient charts and x-ray films for the diagnosis of supernumerary teeth, during 1979-1982, were studied for the incidence of supernumerary teeth, five thousand two hundred and four being boys and five thousand one hundred and eighty nine being girls. Ninety-four cases were found to have supernumerary teeth with seventy cases (0.63 percent) of boys and twenty-four cases (0.231 percent) of girls. Seventy-three cases (77.66 percent) were of the erupting type and twenty-one cases (22.34 percent) were of the enbedding type. The majority, sixty-five cases (69.15 percent), of the supernumerary teeth were found in midline, called mesiodens and eight cases (8.51 percent) erupted outside the midline area. Eighty-two cases (87.23 percent) had only one and twelve cases (12.77 percent) had two supernumerary teeth. Thirty-three collected supernumerary teeth were studied for their shapes as well as sizes of crowns and roots. The researcher found twelve conical or peg-shaped teeth (36.36 percent), seventeen tubercle-like or cusp-shaped teeth (51.52 percent) and four teeth (12.12 percent) showing normal crown appearance. All collected teeth also waried in crown width, length, root length and root form. There was no significant diference between the shape of the root and crown.