title: Prevalence of sinus membrane thickening and association with unhealthy teeth: a retrospective review of 831 consecutive patients with 1,662 cone-beam scans.
abstract: OBJECTIVE
  The purposes of this retrospective review of cone-beam computed tomographic (CBCT) scans were to 1) determine the prevalence of sinus membrane thickening in a consecutive series of patients; 2) identify the prevalence of healthy or unhealthy teeth associated with sinus membrane thickening; and 3) document changes of the sinus membrane after the removal of unhealthy teeth.
  
  
  METHODS
  Consecutive patients had CBCT scans examined and the sinuses were graded. Grade 1 represented membrane thickening of 0 to less than 2 mm; grade 2 represented thickening of 2 to 5 mm; grade 3 represented membrane or material thickening greater than 5 mm to the level of the ostium; and grade 4 represented soft tissue material superior to the ostium. Cross-sectional images were examined using software by the manufacturer of the CBCT scanner. Unhealthy teeth were identified. The examiner used a standardized approach in viewing the CBCT scans. Intraexaminer error was determined.
  
  
  RESULTS
  Eight hundred thirty-one patients had 1,662 sinuses evaluated, with thickening of at least 1 sinus membrane in 46.7% (388 patients) and 30.1% (469) of all sinuses evaluated. The prevalence of patients and sinuses with sinus membrane thickening according to the grading criteria was grade 2 for 36.8% of patients and 24.3% of sinuses, grade 3 for 6.0% of patients and 3.7% of sinuses, and grade 4 for 3.6% of patients and 2.2% of sinuses. Unilateral sinus disease was more common than bilateral disease. Of those sinuses with thickening, 80.6% were grade 2, 12.2% were grade 3, and 7.2% were grade 4. Of the 469 sinuses with membrane thickening, 210 were adjacent to unhealthy teeth, 233 were adjacent to healthy teeth, and 26 were in edentulous maxillas. Of the 210 unhealthy teeth, 30 had postextraction CBCT scans available for evaluation. Grade 2 sinus membrane thickening showed a 75% resolution to grade 1 after adjacent tooth removal. Grade 3 sinuses resolved in 25% to grade 1 and grade 2, with 50% remaining at grade 3. There were 2 grade 4 sinuses with follow-up scans, with 1 resolving to grade 2 and the other remaining at grade 4.
  
  
  CONCLUSIONS
  Sinus membrane thickening is present in 46.7% of patients presenting to an oral and maxillofacial surgical practice. The prevalence of sinus membrane thickening was almost equal in association with unhealthy and healthy teeth. The removal of unhealthy teeth decreased, but did not completely resolve sinus membrane thickening.
authors.affiliation: Private Practice, Metairie, LA. Electronic address: drblock@cdrnola.com.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Block
authors.affiliation: Resident, Department of Oral and Maxillofacial Surgery, Louisiana State Univeristy School of Dentistry, New Orleans, LA.
authors.forename: Kamran
authors.initials: K
authors.lastname: Dastoury
mesh_terms: D054893:Cone-Beam Computed Tomography; D006801:Humans; D010256:Paranasal Sinuses / Q000473:pathology*; D012189:Retrospective Studies; D014070:Tooth / Q000473:pathology*