title: [Analysis of root resorption and dental structure in patients with cleidocranial dysplasia].
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Pediatric Dentistry, Peking University School, Beijing 100081, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Yang
authors.forename: Chen ying
authors.initials: Cy
authors.lastname: Zhang
authors.forename: Shu guo
authors.initials: Sg
authors.lastname: Zheng
mesh_terms: D002648:Child; D002973:Cleidocranial Dysplasia / Q000150:complications / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D012391:Root Resorption / Q000209:etiology / Q000473:pathology*; D014092:Tooth Root / Q000473:pathology*; D014094:Tooth, Deciduous / Q000473:pathology*