颅骨锁骨发育不良患者乳牙牙根吸收特点及牙齿结构分析

Analysis of root resorption and dental structure in patients with cleidocranial dysplasia

目的:研究颅骨锁骨发育不良(cleidocranial dysplasia,CCD)患者乳牙牙根的吸收特点以及乳牙结构的异常。方法:收集CCD患者因治疗需要而拔除的滞留乳牙,在扫描电镜下观察CCD患者乳牙牙根吸收面的情况;同时制备牙齿结构的病理磨片,在偏光显微镜下观察CCD患者牙齿结构的特点。结果:CCD患者具有典型的临床表现。扫描电镜的观察结果显示,与正常对照相比,CCD患者乳牙牙根的吸收陷窝表浅,底部平坦、光滑、大小不一,吸收陷窝的数目相对较少。病理磨片显示,CCD患者乳牙的髓腔内有大量不规则的、结构不清晰的钙化团块沉积,钙化团块的形成量与牙根吸收的程度密切相关;患者乳牙牙根尖1/3处的牙骨质由细胞性或无细胞性牙骨质构成。结论:CCD患者乳牙牙根的吸收特点与正常乳牙不一致,患者髓腔内钙化团块的形成可能与牙髓细胞在牙根吸收时的调控功能异常有关,根部牙骨质的类型可能不是乳牙滞留的原因。

Objective：To observe the morphologic characteristic of root resorption surfaces and the histological structure of primary teeth in patients with cleidocranial dysplasia（CCD）.Methods： The primary teeth of CCD patients were collected,the resorption lacunae of which were analyzed by scanning electron microscope and the histological structure was analyzed by the polarized light microscope.Results： Comparing with the normal teeth,the patients have typically clinical characteristics of CCD.Scanning electron microscopy examination revealed shallower and smoother resorption lacunae at the cervical thirds of the roots,and dentinal tubules were relatively uncommon.Ground examination of primary teeth under the polarized light microscope showed massive and irregular calcification formed in the pulp chamber in response to root resportion.The apical thirds of roots were covered by cellular or acellular cementum.Conclusion： Root resorption lacunae of primary teeth from CCD patients were different with that of normal children.The abnormal dentin in the pulp chamber may be related to disfunction of pulp cells when root resorption took place.The presumption that a lack of cellular cementum causes the increased number of retained primary teeth in patients with CCD is not supported by the present study.