2018 Volume 56 Issue 3 Pages 384-389
Tooth gemination rarely occurs among permanent mandibular posterior teeth. Furthermore, fusion has a similar clinical appearance, making differential diagnosis difficult. Gemination is generally defined as division of a single tooth germ by invagination, whereas fusion is a conjunction of 2 isolated tooth germs. However, a geminated tooth can also be regarded as fusion when ordinary and supernumerary teeth are involved. We report here gemination of a permanent mandibular second molar in a 12-year-old girl. A form abnormality of the mandibular left second molar in a healthy girl was seen in X-ray images obtained at the age of 5 and 7 years old in examinations conducted at a private dental clinic, and the tooth erupted at the age of 12 years. Typically, a geminated tooth has a large crown with complicated fissures and ridges, thus utilization of 3 D imaging modalities, such as CBCT, is crucial for correct diagnosis and establishment of an adequate plan for prevention of dental caries in geminated teeth.