title: Quantitative analysis of planar bone scintigraphy in patients with unilateral condylar hyperplasia.
abstract: OBJECTIVE
  This study compares quantitative analysis of planar bone scintigrams with visual interpretation in patients having unilateral condylar hyperplasia (UCH) and normal control subjects. The possibility of using a bony structure in a region near the condyle as an objective measurement of bone activity is assessed.
  
  
  METHODS
  Planar bone scintigrams from 20 subjects suspected of having active UCH were analyzed both qualitatively and quantitatively. Bone activity was assessed in both condyles as well as in reference sites in the cervical spine and the skull. Percentile activities for both condyle regions and ratios using condyle activity versus reference regions were assessed.
  
  
  RESULTS
  All UCH patients had unilateral increased activity on qualitative visual interpretation of the bone scan. The mean percentile activities of the affected and unaffected condyles in the UCH group were significantly different at 55.3% and 44.7%, respectively (P < .001). No significant difference was found in the control group, with the ratios between left and right condyle being 49.5% and 50.5%, respectively (P = .46). In the ratios between the region of interest (ROI) in the condyles versus the ROIs selected for the cervical spine and the skull, a significant difference was noticed in the UCH group; however, there was a considerable overlap between condyle and reference ROI ratios. Symmetrical uptake of diphosphonate reliably excluded continued asymmetrical growth of the condyles.
  
  
  CONCLUSIONS
  Quantitative analysis of planar scintigrams in unilateral condylar hyperplasia patients was not found to be superior to qualitative visual interpretation of the scans. Because of a considerable overlap in condyle/reference ROI ratios, quantified ratios did not seem to be clinically helpful in the differentiation of a hyperplastic condyle from a normal condyle. In the case of unilateral increased condylar uptake of diphosphonate, clinical assessment is mandatory.
authors.affiliation: Department of Oral and Maxillofacial Surgery and Oral Pathology, VU Medical Centre Amsterdam, Amsterdam, The Netherlands. cp.saridin@vumc.nl
authors.forename: Carrol P
authors.initials: CP
authors.lastname: Saridin
authors.forename: Pieter
authors.initials: P
authors.lastname: Raijmakers
authors.forename: Alfred G
authors.initials: AG
authors.lastname: Becking
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging; D005146:Facial Asymmetry / Q000209:etiology; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000000981:diagnostic imaging; D008297:Male; D008335:Mandibular Condyle / Q000000981:diagnostic imaging* / Q000473:pathology; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012886:Skull / Q000000981:diagnostic imaging; D013669:Technetium Tc 99m Medronate / Q000031:analogs & derivatives; D013705:Temporomandibular Joint Disorders / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology
chemical_list: D019275:Radiopharmaceuticals; C024226:technetium Tc 99m hydroxymethylene diphosphonate; D013669:Technetium Tc 99m Medronate