title: Accuracy of Schneiderian membrane thickness: a cone-beam computed tomography analysis with histological validation.
abstract: OBJECTIVE
  Cone-beam computed tomography (CBCT) has been used in the literature to evaluate Schneiderian membrane thickness (SMT), but its accuracy has never been validated. The primary aim of this study was to compare the SMT measured by CBCT to the gold standard histological assessment. The correlations between SMT and anatomical structures of the maxillary sinus and alveolar bone were also tested.
  
  
  METHODS
  Fourteen fresh cadaver heads were used for the study, and 28 sinus lift augmentation procedures were performed to obtain the membrane samples. Samples were fixed in formalin and stained with hematoxylin-eosine and Masson trichrome. Specimens were measured by optic microscope at three points, and a mean was obtained. Anatomical landmarks were used to accurately position the CBCT slice, so the SMT could be measured in predetermined locations. Wilcoxon signed-rank test was used to compare values of histological and CBCT measurements, and Spearman's correlation coefficient was calculated to examine the relationship between thickness and anatomical parameters.
  
  
  RESULTS
  A total of 597 histological measurements were performed, and the mean SMT thickness was 0.30 ± 0.17 mm. The mean CBCT membrane thickness was 0.79 ± 0.52 mm. A statistically significant difference from histological and radiological readings was observed (P = 0.000). Interestingly, 87.77% histological measurements had membrane less than 0.5 mm in thickness compared to 26.66% in CBCT assessment.
  
  
  CONCLUSIONS
  Within the limitation of this study, the median histological Schneiderian membrane thickness was 0.30 mm. Cone-beam computed tomography assessment was 2.6 times higher than the histological examination.
authors.affiliation: Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Angel
authors.initials: A
authors.lastname: Insua
authors.affiliation: Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Alberto
authors.initials: A
authors.lastname: Monje
authors.affiliation: Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Hsun-Liang
authors.initials: HL
authors.lastname: Chan
authors.affiliation: Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Nouf
authors.initials: N
authors.lastname: Zimmo
authors.affiliation: Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Lujain
authors.initials: L
authors.lastname: Shaikh
authors.affiliation: Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Hom-Lay
authors.initials: HL
authors.lastname: Wang
mesh_terms: D002102:Cadaver; D054893:Cone-Beam Computed Tomography; D006801:Humans; D008443:Maxillary Sinus / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D009297:Nasal Mucosa / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D059546:Sinus Floor Augmentation
keywords: Schneiderian membrane; cone-beam CT; dental implants; maxillary sinus; mucosal thickness; sinus floor elevation