title: Evaluation of maxillary sinus width on cone-beam computed tomography for sinus augmentation and new sinus classification based on sinus width.
abstract: OBJECTIVE
  The degree of difficulty in performing lateral window sinus augmentation may depend on the morphology of the maxillary sinus. The aim of this was to measure the distances between the medial and lateral sinus wall (sinus width [SW]) at different levels and apply those SW values to formulate a new sinus classification.
  
  
  METHODS
  Edentulous sites adjacent to maxillary sinuses with inadequate ridge height (RH; <10 mm) were included from cone-beam computed tomography database in the University of Michigan. SW was measured at the heights of 5, 7, 10, 13, and 15 mm from alveolar crest at the edentulous sites. Mean SW was stratified by residual RH into three different groups (group 1: <4 mm, group 2: ≥4 and <7, and group 3: ≥7 and <10), study sites (first and second premolars and molars), and measurement levels.
  
  
  RESULTS
  Three hundred and twenty subjects (mean 50.1 years old) with 422 edentulous sites were included. Mean SW was wider at molar sites, higher measurement levels, and sites with shorter residual RH. Mean SW at the lower (average 2.3 mm from sinus floor) and higher boundary (15 mm from the alveolar crest) of lateral window osteotomy was 9.0 (2.8) and 16.0 (4.4) mm, respectively. Narrow, average, or wide sinuses were classified when the SW was <8, 8-10 and >10 mm at the lower boundary or <14, 14-17 and >17 mm at the upper boundary, respectively.
  
  
  CONCLUSIONS
  SW at levels that were relevant to lateral window sinus augmentation was measured. The proposed sinus classification could facilitate communication between health providers and determine the degree of easiness of sinus augmentation. It might be particularly useful for the selection of grafting materials and surgical approaches. Further studies are required to test its clinical implications.
authors.affiliation: Graduate Periodontics, Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA.
authors.forename: Hsun-Liang
authors.initials: HL
authors.lastname: Chan
authors.forename: Fernando
authors.initials: F
authors.lastname: Suarez
authors.forename: Alberto
authors.initials: A
authors.lastname: Monje
authors.forename: Erika
authors.initials: E
authors.lastname: Benavides
authors.forename: Hom-Lay
authors.initials: HL
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D054893:Cone-Beam Computed Tomography; D005260:Female; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000000981:diagnostic imaging; D008297:Male; D008443:Maxillary Sinus / Q000000981:diagnostic imaging* / Q000601:surgery; D008875:Middle Aged; D059546:Sinus Floor Augmentation