Chipashvili N, Vadachkoria D, Beshkenadze E
Tbilisi State Medical University, Department of Odontology, UniDent - Dental Clinic, Training and Research Center, Tbilisi, Georgia.
Georgian Med News. 2011 May(194):28-33.
Gemination and fusion are anomalies in size, shape and structure of teeth. Gemination more frequently affects the primary teeth, but it may occur in permanent dentitions, usually in the incisor region. Geminated teeth are typically disfigured in appearance due to irregularities of the enamel. Fused teeth can have separated pulpal space, one pulp chamber and two canals or take the form of a large bifid crown with one pulpal space. It is hard to differentiate between fusion and gemination, especially if the supernumerary tooth bud is fused with the adjacent one. Usually, fusion may be differentiated from germination by a reduced number of teeth. An exception is in the unusual case in which the fusion is between a supernumerary tooth and normal tooth. A 20-year-old male referred to us at - "UniDent" - Dental Clinic, Training and Research Center. The patient complained about the large, unusual maxillary central incisors, lip irritation and aesthetic problems. According clinical examination and radiological findings, clinical diagnose was - bilateral germination of central incisors. Several treatment methods have been described in the literature with respect to the different types and morphological variations of fused and geminated teeth, including endodontic, direct\indirect restorative, surgical, periodontal and/or orthodontic treatment. Our patient has demanded for better aesthetics and he choose the treatment option to make two separate PFM crowns. In the beginning of treatment, the length of tooth 11 was 9.5mm, after prosthodontic treatment it has become 11.5mm. For tooth 21, it was 9.9 millimeter and became - 10.8 mm, while the primary width of right central incisor appeared 13.2 millimeter and was narrowed until 10.8 mm. 12.8 mm was the - width of left central incisor, which finally became - 10.4 mm. Despite the considerable number of cases reported in the literature, the differential diagnosis between these abnormalities is very difficult, as well as, to find guideline of proper outcome of treatment therapy of abovementioned abnormalities. That's why, the aesthetic rehabilitation of doubled teeth, has been suggested, to depend upon the patient's desires, but at the same time, avoid treatment plans with aggressive management.
双生牙和融合牙是牙齿大小、形状和结构的异常情况。双生牙更常影响乳牙,但也可能发生在恒牙列,通常在切牙区域。双生牙由于釉质不规则,外观通常有缺陷。融合牙可能有分开的髓腔、一个牙髓腔和两条根管,或者表现为带有一个髓腔的大的双裂冠的形式。很难区分融合牙和双生牙,特别是当额外牙胚与相邻牙胚融合时。通常,融合牙可通过牙齿数量减少与双生牙区分开来。例外情况是额外牙与正常牙之间发生融合的不寻常病例。一名20岁男性到我们“UniDent”牙科诊所、培训和研究中心就诊。患者抱怨上颌中切牙过大、异常,唇部受刺激以及美观问题。根据临床检查和影像学检查结果,临床诊断为双侧中切牙双生。关于融合牙和双生牙的不同类型及形态变异,文献中描述了几种治疗方法,包括牙髓治疗、直接/间接修复治疗、外科治疗、牙周治疗和/或正畸治疗。我们的患者要求改善美观,他选择制作两个单独的烤瓷熔附金属冠的治疗方案。治疗开始时,11号牙的长度为9.5毫米,修复治疗后变为11.5毫米。21号牙开始时为9.9毫米,变为10.8毫米,而右侧中切牙的原始宽度为13.2毫米,变窄至10.8毫米。左侧中切牙宽度为12.8毫米,最终变为10.4毫米。尽管文献中报道了相当数量的病例,但区分这些异常情况非常困难,同样,找到上述异常情况治疗的适当结果指南也很困难。这就是为什么有人建议,双牙的美学修复应取决于患者的意愿,但同时要避免采用激进管理的治疗方案。