title: Odontomas: a clinicopathologic study in a Portuguese population.
abstract: OBJECTIVE
  Odontoma is a tumorlike malformation (hamartoma) that contains odontogenic epithelium with odontogenicectomesenchyme. Frequency and distribution of odontogenic tumor among a Portuguese population were analyzed and compared with previous reports.
  
  
  METHODS
  A total of 65 odontogenic tumor cases were collected from the files of the Department of Pathology of Hospital Sao Joao,Porto,Portugal, and the Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), from January 1993 to December 2006. Of these cases, 48 were retrieved and analyzed. The final diagnosis of each case was based on the 2005 WHO histopathologic classification of odontogenictumors, and to the authors' best knowledge, the present series represents the first study on odontomas in a northern Portuguese population.
  
  
  RESULTS
  Of the 65 odontogenic tumors cases, 64 (98.5%) were benign and 1 (1.5%), an ameloblasticcarcinoma, was malignant. Odontoma was the most frequent odontogenic tumor (73.9%), followed by unicysticameloblastoma(7.7%) and calcifying cystic odontogenic tumor (7.7%). Of the 48 odontomas(26 males and 22 females), 34 (70.8%) were compound and 14 (29.2%) were complex. Most odontomas(72.9%) occurred in patients under the age of 30, with a peak incidence in the second decade of life. Twenty-eight (58.3%)odontomas were in the maxilla and 20 (41.7%) in the mandible (P<.05). Twenty-eight (58.3%) of the 48 odontomas were associated with 33 impacted teeth, including 31 permanent teeth, 1 primary tooth, and 1 supernumerary tooth. The maxillary central incisor (n= 6; 19.4%) and the maxillary canine (n= 6; 19.4%) were most commonly associated with odontoma, followed by the mandibular canine (n= 5; 16.0%) and maxillary third molar (n= 4; 12.9%).
  
  
  CONCLUSIONS
  This study provides clinical and pathological information on odotogenic tumors in a nothern Portuguese population
authors.forename: Liliana Faria
authors.initials: LF
authors.lastname: da Silva
authors.forename: Leonor
authors.initials: L
authors.lastname: David
authors.forename: Diana
authors.initials: D
authors.lastname: Ribeiro
authors.forename: António
authors.initials: A
authors.lastname: Felino
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D005260:Female; D006801:Humans; D007573:Jaw Neoplasms / Q000150:complications / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009810:Odontoma / Q000150:complications / Q000473:pathology*; D011174:Portugal; D012189:Retrospective Studies; D014095:Tooth, Impacted / Q000150:complications; D055815:Young Adult