title: Assessment of infrazygomatic bone depth for mini-screw insertion.
abstract: OBJECTIVE
  To investigate the bone depth at the infrazygomatic crest with regard to orthodontic mini-screw insertion.
  
  
  METHODS
  Twenty-nine adult human dry skulls were imaged using CBCT technology, slice data were generated and multiple measurements were undertaken at three sites associated with the infrazygomatic crest and five different measurement levels. The data were analyzed using intraclass correlation and repeated measures ANOVA.
  
  
  RESULTS
  The greatest bone depth was available at, on average, 11.48+/-1.92 mm apical from the cemento-enamel junction of the maxillary first molar and decreased rapidly further apically. Maximum bone depth (7.05+/-3.7 mm) was present at the lowest measurement level. However, here, insufficient clearance to the molar roots was present. Both the measurement site and the level at which the measurements were conducted had a significant impact on bone depth.
  
  
  CONCLUSIONS
  When inserting orthodontic mini-screws (6 mm or longer) into the infrazygomatic crest while staying clear of the molar roots perforation of the maxillary sinus or the nasal cavity can be expected, but bone depth varies considerably between individuals.
authors.affiliation: Department of Orthodontics, School of Dental Medicine, Case Western Reserve University, Cleveland, OH 44106, USA. sxb155@case.edu
authors.forename: Sebastian
authors.initials: S
authors.lastname: Baumgaertel
authors.forename: Mark G
authors.initials: MG
authors.lastname: Hans
mesh_terms: D000328:Adult; D001857:Bone Matrix / Q000033:anatomy & histology*; D001863:Bone Screws; D054893:Cone-Beam Computed Tomography; D006801:Humans; D009929:Organ Size; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation* / Q000592:standards; D012016:Reference Values; D014716:Vertical Dimension; D015050:Zygoma / Q000033:anatomy & histology*