title: Trabecular bone ratio of the mandibular condyle according to the presence of teeth: a micro-CT study.
abstract: OBJECTIVE
  During mastication, mechanical pressure from the dentition is transmitted to the trabecular bone of the mandible. The occlusal forces, which could thus affect condylar growth, vary with tooth loss, age, and sex. The trabecular bone of the mandibular condyle is denser in dentate subjects than in edentate subjects. However, since the different tooth groups (incisor, premolar, and molar) have different functions, they could exert different effects on the mandibular condyle. The aim of this study was to elucidate the bone quantity of the Korean mandibular condyle according to the presence of teeth using micro-computed tomography (micro-CT), thereby clarifying the influences of tooth presence on the condylar microstructure.
  
  
  METHODS
  Thirty-one sides were scanned and reconstructed into a 3D structure using a micro-CT system. The specimen was sectioned vertically, passing through the medial and lateral poles of the mandibular condyle (P0) to enable measurement of the trabecular bone ratio. Likewise, three additional images, parallel with P0, were acquired. Mean and standard deviation values were calculated, and the t test, one-way ANOVA and post hoc analysis were performed to examine the differences among each group, classified according to the presence of teeth and according to sex.
  
  
  RESULTS
  The density of the trabecular bone of the mandibular condyle was significantly associated with the presence of the molars, but not the incisors or premolars. There were significant differences between sexes.
  
  
  CONCLUSIONS
  The present study has provided data regarding the bone quantity of the trabeculae of the mandibular condyle according to the presence or absence of teeth.
authors.affiliation: Division in Anatomy and Developmental Biology, Department of Oral Biology, Human Identification Research Center, Yonsei University College of Dentistry, Seoul, South Korea.
authors.forename: D Y
authors.initials: DY
authors.lastname: Choi
authors.forename: K H
authors.initials: KH
authors.lastname: Sun
authors.forename: S Y
authors.initials: SY
authors.lastname: Won
authors.forename: J G
authors.initials: JG
authors.lastname: Lee
authors.forename: K S
authors.initials: KS
authors.lastname: Hu
authors.forename: K D
authors.initials: KD
authors.lastname: Kim
authors.forename: H J
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001641:Bicuspid / Q000000981:diagnostic imaging; D015519:Bone Density; D002102:Cadaver; D003817:Dentition; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007180:Incisor / Q000000981:diagnostic imaging; D007723:Korea; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging; D008335:Mandibular Condyle / Q000000981:diagnostic imaging*; D008875:Middle Aged; D008963:Molar / Q000000981:diagnostic imaging; D017678:Sex Distribution; D014070:Tooth / Q000000981:diagnostic imaging*; D016388:Tooth Loss / Q000000981:diagnostic imaging*; D055114:X-Ray Microtomography / Q000379:methods*