Radiology forum ORAL SURGERY ORAL MEDICNE ORAL PATHOLOGY August I993

Fig. 2. Reconstructed specimen.

second crown and the root were successfully removed using elevations. The reconstructed tooth showed two crowns and a single root (Fig. 2). A radiograph of the specimen showed a tooth with a single pulp chamber and bifid crowns (Fig. 3).

DISCUSSION There are two possible theories to explain this find-

ing. First, this could be a case of gemination of the paramolar, an attempt at division of a single tooth. The second possibility, which is a more remote one, is that of fusion of two supernumerary tooth germs. Paramolar teeth are not common findings, and, as far as we know, there is no previous report of a paramo- lar with two crowns.

Supernumerary teeth in twins

Two 12-year-old white twin boys were seen at Lenval Children’s Hospital for orthodontic treatment. Pan- tomographic examination revealed a mirror-imaging of three mandibular supernumerary premolars in

Fig. 3. Radiograph of reconstructed tooth shows two dis- tinct crowns and one root canal.

When a difficult extraction is encountered, one should include among the various causes of difficult extractions, the possibility of a tooth with two crowns, one of which is buried within bone. Fun-Chee Loh, BDS, MDS, MSc, FAMS, FDS RCSEd

Jinn-Fei Yeo, BDS, MS,> MDS, FAMS Department of Oral d Maxillofacial Surgery

National University of Singapore National University Hospital

5 Lower Kent Ridge Road Singapore 0511

Republic oaf Singapore

both children. In Marc the mandibular right side ex- hibits two supernumerary teeth, one between the first and the second premolar, the other between the sec- ond premolar and the first molar. The left side shows a supernumerary tooth between the second premolar and the first molar (Fig. I). And in Luc on the right,

ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY Volume 76, Number 2

Radiology forum 259

Fig. 1. Marc’s pantomograph. Arrows indicate supernumerary tooth germs

Fig. 2. Luc’s pantomograph. Arrows indicate supernumerary tooth germs

one supernumerary tooth germ is between the second premolar and the first molar. On the left, two super- numerary tooth germs between the first and the sec- ond premolar and the second premolar and the first molar (Fig. 2).

Luc’s mineralization of the supernumerary germs was less advanced than in his brother, This feature could be classified as an individual variation within the same identical genetic pattern. The twins pre- sented in this report showed similarities in their phys-

ical and dental make-up to a very high degree. This evidences monozygous twining.

Jean R. Jasmin, DCD, DSO, DE Nicole Jonesco-Benaiche, DCD, DU

Michele Muller-Giamarchi, DCD, DU UFR d’Odontologie

Pare Valrose Avenue Joseph Vallot

060108 Nice Cedex FRANCE