title: Evaluation of the maxillary sinus in panoramic radiography-a comparative study.
abstract: BACKGROUND
  The aim of this study was to evaluate the validity and the inter- and intra-examiner reliability of panoramic-radiograph-driven findings of different maxillary sinus anatomic variations and pathologies, which had initially been prediagnosed by cone beam computed tomography (CBCT).
  
  
  METHODS
  After pairs of two-dimensional (2D) panoramic and three-dimensional (3D) CBCT images of patients having received treatment at the outpatient department had been screened, the predefinition of 54 selected maxillary sinus conditions was initially performed on CBCT images by two blinded consultants individually using a questionnaire that defined ten different clinically relevant findings. Using the identic questionnaire, these consultants performed the evaluation of the panoramic radiographs at a later time point. The results were analyzed for inter-imaging differences in the evaluation of the maxillary sinus between 2D and 3D imaging methods. Additionally, two resident groups (first year and last year of training) performed two diagnostic runs of the panoramic radiographs and results were analyzed for inter- and intra-observer reliability.
  
  
  RESULTS
  There is a moderate risk for false diagnosis of findings of the maxillary sinus if only panoramic radiography is used. Based on the ten predefined conditions, solely maxillary bone cysts penetrating into the sinus were frequently detected differently comparing 2D to 3D diagnostics. Additionally, on panoramic radiographs, the inter-observer comparison demonstrated that basal septa were significantly often rated differently and the intra-observer comparison showed a significant lack in reliability in detecting maxillary bone cysts penetrating into the sinus.
  
  
  CONCLUSIONS
  Panoramic radiography provides the most information on the maxillary sinus, and it may be an adequate imaging method. However, particular findings of the maxillary sinus in panoramic imaging may be based on a rather examiner-dependent assessment. Therefore, a persistent and precise evaluation of specific conditions of the maxillary sinus may only be possible using CBCT because it provides additional information compared to panoramic radiography. This might be relevant for consecutive surgical procedures; consequently, we recommend CBCT if a precise preoperative evaluation is mandatory. However, higher radiation dose and costs of 3D imaging need to be considered.
authors.affiliation: Clinic of Cranio-Maxillofacial Surgery, University Hospital of Bern, Freiburgstrasse 4, 3010, Bern, Switzerland. Johann.malina-altzinger@insel.ch.
authors.forename: Johann
authors.identifier: http://orcid.org/0000-0003-4226-586X
authors.initials: J
authors.lastname: Malina-Altzinger
authors.affiliation: Clinic of Oral Surgery, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland.
authors.forename: Georg
authors.initials: G
authors.lastname: Damerau
authors.affiliation: Former Head of the Department of Cranio-Maxillofacial and Oral Surgery, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland.
authors.forename: Klaus W
authors.initials: KW
authors.lastname: Grätz
authors.affiliation: Clinic of Oral Surgery, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland.
authors.forename: P D Bernd
authors.initials: PD
authors.lastname: Stadlinger
keywords: Cone beam computed tomography; Inter-examiner reliability; Inter-imaging method differences; Intra-examiner reliability; Maxillary sinus; Panoramic radiography