title: Evaluation of bone thickness around the mental foramen for potential fixation of a bone-borne functional appliance: a computer tomography scan study.
abstract: OBJECTIVE
  A mandible bone-borne Herbst appliance (MBBHA) would avoid the proclination of the lower incisors that occurs with any teeth-borne functional appliance. But mapping of the bone characteristics at potential fixation areas around the mental foramen has not been carried out so far. The aim of this computer tomographic (CT) study was to evaluate bone thickness at specific positions around the mental foramen.
  
  
  METHODS
  CT scans of 60 randomly chosen adult Hong Kong Chinese subjects (mean age 28 ± 6.3 years) were used to measure the bi-cortical bone thickness in the mandible in the mental foramen area. The thickness of buccal and lingual cortical and cancellous bone was assessed at the following locations: 10 mm (A10 mm) and 5 mm (A5 mm) anterior, 10 mm (P10 mm) and 5 mm (P5 mm) posterior, and 5 mm (Inf5 mm) below the mental foramen.
  
  
  RESULTS
  The amount of buccal cortical bone thickness ranged between 1.89 mm, 10 mm anterior of the mental foramen, and 2.16 mm, 10 mm posterior to its location. At the A10 mm level, cortical thickness showed a marginal statistically significant difference between A5 and A10 mm. The total amount of bone thickness ranged from 10.19 to 12.06 mm.
  
  
  CONCLUSIONS
  At the locations studied around the mental foramen, a mean bicortical bone thickness of 10-12 mm was measured. No large variation in the thickness was found between bicortical bone thicknesses in the measured locations around the mental foramen. Thorough evaluation on a case-by-case basis is advisable.
authors.affiliation: Department of Orthodontics, Prince Philip Dental Hospital, Faculty of Dentistry, University of Hong Kong, Sai Ying Pun, Hong Kong, China.
authors.forename: Abdullah A
authors.initials: AA
authors.lastname: Al-Kalaly
authors.forename: Ricky W K
authors.initials: RW
authors.lastname: Wong
authors.forename: Lim K
authors.initials: LK
authors.lastname: Cheung
authors.forename: Shimanto K
authors.initials: SK
authors.lastname: Purkayastha
authors.forename: Marc
authors.initials: M
authors.lastname: Schätzle
authors.forename: A Bakr M
authors.initials: AB
authors.lastname: Rabie
mesh_terms: D000328:Adult; D015519:Bone Density / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D052280:Orthodontic Anchorage Procedures / Q000379:methods*; D009967:Orthodontic Appliances; D011857:Radiographic Image Interpretation, Computer-Assisted; D014057:Tomography, X-Ray Computed