title: The effect of hereditary disorders on tooth components: a radiographic morphometric study of two syndromes.
abstract: OBJECTIVE
  The purpose of this study was to compare tooth components (enamel and dentin) in Familial Dysautonomia (FD) and Down syndrome (DS) in order to assess the extent to which each was affected.
  
  
  METHODS
  The design was cross-sectional. The sample consisted of 20 FD patients and 45 DS patients. The control group comprised 250 healthy subjects. Mesio-distal crown width (CW), enamel and dentin thickness and pulp chamber dimensions were measured on standardized bitewing radiographs of mandibular second primary and first permanent molars. Statistical analyses were performed between groups using SAS programs.
  
  
  RESULTS
  CW was reduced in both hereditary disorders. In the DS group enamel height (EH) and dentin thickness were reduced. In FD enamel thickness in the primary and permanent molars as well as dentin height (DH) in permanent molars was increased.
  
  
  CONCLUSIONS
  In both syndromes the reduction in CW suggests reduced proliferation during tooth germ formation. However, the differences in enamel and dentin thickness suggest that ameloblasts and odontoblasts were affected differently in the later phases of cell function. In FD cell function is stimulated resulting in thicker enamel and dentin. In DS cell function is reduced resulting in thin enamel and dentin.
authors.affiliation: Laboratory of Bioanthropology and Ancient DNA, Faculty of Dental Medicine, Hebrew University, Hadassah, Jerusalem, Israel. uri-z@inter.net.il
authors.forename: Uri
authors.initials: U
authors.lastname: Zilberman
authors.forename: Smith
authors.initials: S
authors.lastname: Patricia
authors.forename: Ari
authors.initials: A
authors.lastname: Kupietzky
authors.forename: Eliyahu
authors.initials: E
authors.lastname: Mass
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003743:Dental Enamel / Q000000981:diagnostic imaging*; D003804:Dentin / Q000000981:diagnostic imaging*; D004314:Down Syndrome / Q000000981:diagnostic imaging*; D004402:Dysautonomia, Familial / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008963:Molar; D011859:Radiography