Supernumerary primary first molar and first premolar: clinical report.

A case is presented of a nine-year-old male having a supernumerary maxillary right first primary molar together with a supernumerary maxillary right first premolar. The implications of early diagnosis and orthodontic management are discussed. The occurrence of supernumerary teeth in both the primary and permanent dentitions in the same patient seems to be rare. A review of the literature (including computer search) revealed 28 cases reported in 10 publications.,-,0 In the 28 cases there were 35 supernumerary primary teeth with permanent successors: 32 were in the maxillary incisor and canine regions, 3 in the mandibular incisor region. Most of the permanent supernumerary teeth occurred at the same site as their primary predecessors, although in 3 cases they were found at the site of the adjacent teeth (the position of the other 7 was not reported). The side of occurrence was reported in 27 cases, 16 being on the left and 11 on the right. In the primary dentition, 32 teeth were of normal morphology and more correctly would be termed supplemental teeth, 1 was geminated, and 2 were conical. In the permanent dentition, 25 were supplemental, I geminated, 8 conical, and 1 showed insufficient calcification to establish crown morphology. The sex of the patient was reported in 21 cases; 14 were male and 7 female, a 2:1 male-to-female ratio. As far as can be ascertained, no fully developed supernumerary primary molars have been reported occurring either singly or in conjunction with a successional supernumerary premolar. However O6ell reported a case of a tooth germ between the first and second primary molars of a five-month-old fetus, but at this stage it appeared only as a thickening of the dental lamina. Lethe la reported a tooth germ in the cap stage in a three-month infant, located between the upper primary canine and first primary molar, but it is not known whether this tooth would have developed into a primary canine or first molar. Grahnen and Granath 5 examined 1,173 records of Swedish children aged three to five years and found 3 cases of supernumerary primary teeth (0.3%). Out another group of 46 patients referred specifically because they had an abnormal number of teeth, 20 had supernumerary primary teeth and 6 of these had supernumerary permanent teeth in the corresponding region (30%). In 1961 Grahnen and Lindahl reported that the prevalence of supernumerary teeth in the permanent dentition in the Swedish population was 2-3%.15 The occurrence in both dentitions is, therefore, greater than would be expected by chance alone. Jarvinen and Lehtinenl0 examined 1,141 children who were three to four years old and found 5 supernumerary primary teeth (0.4%), one of which developed a similar anomaly in the permanent dentition (20%). Again, the occurrence is six times greater than would be expected by chance. An association between supernumerary teeth in the primary and permanent dentitions is to be expected since primary enamel organs normally produce a successional dental lamina for the permanent teeth. Berkovitz and Thompsow4 performed a histological investigation of supernumerary primary and permanent incisors in the albino ferret and believe they arose by dichotomy of primary first incisor tooth germs. Permanent supernumerary teeth appeared to develop from the successional dental lamina associated with the corresponding primary supernumerary incisor, but frequently were lost from the functional dentition by fusion with the developing first permanent incisor enamel organ.