2根性の口蓋根を有するヒト上顎大臼歯の異常形態

―肉眼的, X線的ならびにマイクロCT所見―

抄録

Abstract : There are three roots : the mesiobuccal, the distobuccal, and the palatal (lingual) in the maxillary first and second molars. However, these teeth seldom show malformation of crown or roots. Dental radiographs may reveal variations with two separate palatal roots, each of which has its own canal. The practitioner should be aware of variations in the root canal system.

 This paper reports the case of a 47-year old man in whom a second maxillary molar with two palatal roots was found. A radiograph of the tooth showed a large radiolucency extending to the apex related to severe periodontal disease. The extracted tooth was evaluated macroscopically, radiographically and by using micro-CT.

 The tooth had two widely divergent palatal roots that were long. The buccal separate roots were shorter and were parallel. A well-defined enamel projection extended into the furcation proper of the two separate palatal roots on the lingual side of the tooth. A large accessory Carabelli cusp was located on the mesiopalatine cusp of the tooth. The cusp had its own root with pulp canal which lay mesial to the palatal root. The Carabelli cusp and splitting of palatal root were unilateral in the maxillary left second molar.