Abstract:

Objective: To investigate the imaging characteristics of supernumerary teeth fused with molars. Methods: The imaging data of 24 supernumerary teeth fused with molars in our hospital were retrospectively analyzed. Results: Among the 24 cases, 19 occurred in the upper jaw and 5 in the lower jaw; 6 occurred in the second molar area and 18 in the third molar area. There were 2 supernumerary teeth fused with molar crowns and 22 fused with molar roots. In 14 cases which manifested by panoramic radiographs, 11 cases of supernumerary teeth could clearly be found and indicated the possibility of fusion teeth; 2 cases only indicated the possibility of supernumerary teeth; 1 case was only found to be morphological abnormal third molar. In 24 cases of which manifested by CBCT images, 22 cases of root fusion (11 was impacted and 11 was erupted) showed abnormally thick fused roots; the two crowns were separated and the root canal system was connected. There were 2 cases (one was impacted and the other was erupted) of crown fusion with a huge fused crown, in which the root canal system was connected and the root was independent. Conclusion: CBCT images can show the complex anatomical structure of supernumerary teeth fused with molars, which may helpful for diagnosis and differential diagnosis.

Key words: supernumerary teeth, fused teeth, cone beam computed tomography, panoramic radiograph

摘要：

目的：探讨多生牙与相邻磨牙融合的影像学特点。方法：对我院收治的24例多生牙与磨牙融合患者的影像学资料进行回顾性分析。结果：24例多生牙与磨牙融合的患者中，发生于上颌的19例，下颌5例；第二磨牙区6例，第三磨牙区18例。多生牙与磨牙牙冠融合2例，牙根融合22例。14例全景片中11例能够明确发现多生牙，并提示融合牙可能；2例仅能提示多生牙的存在；1例仅发现第三磨牙形态怪异。24例中锥形束CT（cone beam computed tomography，CBCT）显示牙根融合22例，其中11例萌出，11例阻生，影像学表现为融合的牙根异常粗大，多生牙与其融合磨牙的牙冠独立，根管系统相通。牙冠融合2例，其中1例阻生，1例萌出，均表现为巨大的融合牙冠，根管系统相通，牙根各自独立。结论：锥形束CT能够显示多生牙与磨牙融合的复杂解剖结构，有助于诊断和鉴别诊断。

关键词: 多生牙, 融合牙, 锥形束CT, 全景片