title: Unilateral condylar hyperactivity: a histopathologic analysis of 47 patients.
abstract: OBJECTIVE
  To perform a histopathologic analysis of condyles that were resected because of unilateral condylar hyperactivity and compare the results of the bone scan with the histopathologic findings.
  
  
  METHODS
  A total of 47 resected condyles were histopathologically examined. In 29 cases, a single photon emission computed tomography (SPECT) bone scan was available. For all condylar specimens, a standardized histologic scoring system was used to assess the number of cartilage islands and the thickness of the cartilage layer. The SPECT scans were analyzed by calculating the difference in bone activity between the hyperactive and contralateral condyles.
  
  
  RESULTS
  The number of cartilage islands was highly variable, ranging from almost absent in 37% of the patients to abundant in 35%. Furthermore, the relative thickness of the cartilage layer exhibited considerable variation, from less than one quarter of the total thickness of the condylar articular layer in 22% of the patients to one half of the total thickness in 35%. We found no significant relationship between the number of cartilage islands and bone activity using SPECT (P = .11) or between the relative thickness of the cartilage layer and bone activity using SPECT (P = .82).
  
  
  CONCLUSIONS
  Unilateral condylar bone growth can occur without large numbers of cartilage islands and without abundant cartilage formation. The bone activity measured by bone scintigraphy was not related to the histologic results. The histopathologic findings of resected condyles in unilateral condylar hyperactivity cannot, therefore, be used as a reference standard. Nevertheless, histopathologic examination should always be performed to rule out other diseases.
authors.affiliation: Department of Oral and Maxillofacial Surgery and Oral Pathology, VU University Medical Center/Academic Center of Dentistry, Amsterdam, The Netherlands. cp.saridin@vumc.nl
authors.forename: Carrol P
authors.initials: CP
authors.lastname: Saridin
authors.forename: Pieter G H M
authors.initials: PG
authors.lastname: Raijmakers
authors.forename: Piet J
authors.initials: PJ
authors.lastname: Slootweg
authors.forename: Dirk B
authors.initials: DB
authors.lastname: Tuinzing
authors.forename: Alfred G
authors.initials: AG
authors.lastname: Becking
authors.forename: Isaäc
authors.initials: I
authors.lastname: van der Waal
mesh_terms: D000328:Adult; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008335:Mandibular Condyle / Q000000981:diagnostic imaging* / Q000254:growth & development / Q000473:pathology; D013705:Temporomandibular Joint Disorders / Q000000981:diagnostic imaging* / Q000473:pathology; D015899:Tomography, Emission-Computed, Single-Photon; D055815:Young Adult