title: Dentin dysplasia type I-novel findings in deciduous and permanent teeth.
abstract: BACKGROUND
  Dentin dysplasia type I (DD-I) is a rare autosomal dominant hereditary disorder which seriously affects the root development of teeth, causing spontaneous tooth loss (in teenagers). At present, the study of DD-I focuses on familial and phenotypic analyses and reports regarding the ultrastructural study of DD-I are few. The purpose of this study was to clarify and discuss the clinical, histopathological, and ultrastructural features of the dentin defects in DD-I. In addition, the study further explores the root development and provides clues for uncovering virulent genes associated with the disease.
  
  
  METHODS
  We recruited 31 members of a four-generation Chinese family, including eleven with dentin defects. Four permanent teeth and four deciduous teeth were obtained from individuals affected by DD-I. At the same time, two caries-free like-numbered permanent teeth and deciduous teeth served as controls, respectively. Analyses of these teeth were carried out using stereomicroscopy, light microscopy, and scanning and transmission electron microscopy, respectively.
  
  
  RESULTS
  Similar to previous reports, extracted teeth showed typical histopathological and ultrastructural features of DD-I and teeth had short roots with obliterated pulp chambers. Furthermore, several novel discoveries were found in teeth affected by DD-I, including; (1) thinner dentin; (2) larger scalloped dentinoenamel junctions; (3) teardrop-shaped lacunae in the enamel; (4) rodless enamel and (5) irregular collagen fibers.
  
  
  CONCLUSIONS
  The results exhibited defined features of DD-I in the family and further confirmed that abnormal dentin structure affected both the deciduous and permanent dentitions. In addition, these findings may contribute to a better understanding of the pathogenesis of DD-I as well as aid in the subclassification of this disease.
authors.affiliation: Department of Periodontics, School of Stomatology, Zhengzhou University, Zhengzhou, Henan, China. yexin881216@163.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Ye
authors.affiliation: Department of Stomatology, The Second Affiliated Hospital of Henan Traditional Chinese Medicine College, Zhengzhou, Henan, China. liyang2717@126.com.
authors.forename: Kunyang
authors.initials: K
authors.lastname: Li
authors.affiliation: Department of Periodontics, School of Stomatology, Zhengzhou University, Zhengzhou, Henan, China. liuling1213@yahoo.com.
authors.forename: Ling
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Periodontics, School of Stomatology, Zhengzhou University, Zhengzhou, Henan, China. 915389348@qq.com.
authors.forename: Fangfang
authors.initials: F
authors.lastname: Yu
authors.affiliation: Department of Medical Genetics, Southern Medical University, Guangzhou, China. xf7803@aliyun.com.
authors.forename: Fu
authors.initials: F
authors.lastname: Xiong
authors.affiliation: Department of Periodontics, School of Stomatology, Zhengzhou University, Zhengzhou, Henan, China. fanyunkq@163.com.
authors.forename: Yun
authors.initials: Y
authors.lastname: Fan
authors.affiliation: Department of Medical Genetics, Southern Medical University, Guangzhou, China. xixm@smu.edu.cn.
authors.forename: Xiangmin
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Stomatology, The Second Affiliated Hospital of Henan Traditional Chinese Medicine College, Zhengzhou, Henan, China. leftspringthen@126.com.
authors.forename: Chunran
authors.initials: C
authors.lastname: Zuo
authors.affiliation: Department of Periodontics, School of Stomatology, Zhengzhou University, Zhengzhou, Henan, China. chendongfmmu@163.com.
authors.forename: Dong
authors.initials: D
authors.lastname: Chen
mesh_terms: D003743:Dental Enamel / Q000473:pathology; D003786:Dental Pulp Cavity / Q000473:pathology; D003804:Dentin / Q000473:pathology / Q000648:ultrastructure*; D003805:Dentin Dysplasia / Q000503:physiopathology*; D006801:Humans; D014094:Tooth, Deciduous / Q000473:pathology*