title: Tooth eruption: altered gene expression in the dental follicle of patients with cleidocranial dysplasia.
abstract: OBJECTIVE
  The dental follicle plays an important role in tooth eruption by providing key regulators of osteogenesis and bone resorption. Patients with cleidocranial dysplasia (CCD) exhibit delayed tooth eruption in combination with increased bone density in the maxilla and mandible, suggesting disturbances in bone remodeling. The aim of this study was to determine the expression of genes relevant for tooth eruption and bone remodeling in the dental follicles of patients with CCD and normal subjects.
  
  
  METHODS
  Thirteen dental follicles were isolated from five unrelated patients with CCD, and fourteen dental follicles were obtained from 10 healthy individuals. All teeth were in the intraosseous phase of eruption. The expression of RANK, RANKL, OPG, and CSF-1 was determined by quantitative RT-PCR.
  
  
  RESULTS
  In patients with CCD, the mRNA levels of RANK, OPG, and CSF-1 were significantly elevated compared with the control group. Accordingly, the ratios of RANKL/OPG and RANKL/RANK mRNAs were significantly decreased in patients with CCD.
  
  
  CONCLUSIONS
  The observed alterations in the expression and ratios of the aforementioned factors in the dental follicle of CCD individuals suggest a disturbed paracrine signaling for bone remodeling that could be responsible for the impaired tooth eruption seen in these patients.
authors: Department of Orthodontics, School of Dentistry, University of Geneva, Geneva, Switzerland. domna.dorotheou@unige.ch
authors: D
authors: D
authors: Dorotheou
authors: N
authors: N
authors: Gkantidis
authors: M
authors: M
authors: Karamolegkou
authors: D
authors: D
authors: Kalyvas
authors: S
authors: S
authors: Kiliaridis
authors: E
authors: E
authors: Kitraki
mesh_terms: D000293:Adolescent; D000328:Adult; D016723:Bone Remodeling / Q000235:genetics; D016022:Case-Control Studies; D002973:Cleidocranial Dysplasia / Q000235:genetics* / Q000503:physiopathology*; D003795:Dental Sac / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D006801:Humans; D016173:Macrophage Colony-Stimulating Factor / Q000235:genetics; D008297:Male; D053244:Osteoprotegerin / Q000235:genetics; D053245:RANK Ligand / Q000235:genetics; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000235:genetics; D018709:Statistics, Nonparametric; D014078:Tooth Eruption / Q000235:genetics*; D055815:Young Adult
chemical_list: D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D016173:Macrophage Colony-Stimulating Factor