title: Current concepts in pediatric temporomandibular joint disorders: Part 1. Etiology, epidemiology, and classification.
abstract: BACKGROUND
  Pediatric temporomandibular joint dysfunction, resulting from either soft-tissue or skeletal disorders, may be congenital or acquired. Congenital temporomandibular joint disorders are uncommon. The authors review their experience with pediatric temporomandibular joint disorders and propose a new classification system.
  
  
  METHODS
  Clinical records, cephalograms, computed tomographic scans, magnetic resonance images, and pathologic specimens of all pediatric patients (younger than 18 years) with trismus or restricted mandibular excursion from 1976 to 2008 were reviewed. Cases were stratified according to soft-tissue or skeletal pathologic findings; skeletal abnormalities were further characterized as intracapsular or extracapsular.
  
  
  RESULTS
  Thirty-eight patients, ranging in age from 1 day to 18 years at diagnosis, were identified with temporomandibular joint disorders. Ten cases (26.3 percent) were attributable to soft-tissue abnormality. The remaining 28 cases (73.7 percent) were attributable to skeletal abnormality, consisting of 14 congenital and 14 acquired cases (50 percent each). Acquired skeletal deformities included 12 intracapsular ankyloses (85.7 percent) and two extracapsular ankylosis (14.3 percent) (extraarticular bone blocks). Congenital skeletal deformities accounted for five intracapsular ankyloses (35.7 percent) and nine extracapsular ankyloses (64.3 percent).
  
  
  CONCLUSIONS
  On initial survey, the data are consistent with published reports that attribute temporomandibular joint dysfunction to acquired abnormality (i.e., trauma and infection). However, the authors observed a significantly higher percentage (50 percent) of congenital temporomandibular joint skeletal disorders than previously reported. Most congenital cases involved extracapsular abnormality (i.e., coronoid hypertrophy); only a minority of cases had glenoid-condylar fibro-osseous fusion (i.e., intracapsular ankyloses). Because the diagnosis and classification of temporomandibular joint disorders determine treatment options, the authors provide a new classification that characterizes the extent of capsular involvement.
authors.affiliation: New York, N.Y.; and Santiago, Chile From the Institute of Reconstructive Plastic Surgery, New York University School of Medicine, and the Department of Maxillofacial Surgery, Hospital de Salvadór, Children's Hospital Exequiel González Cortés, Universidad Mayor.
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Allori
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Chang
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Fariña
authors.forename: Barry H
authors.initials: BH
authors.lastname: Grayson
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Warren
authors.forename: Joseph G
authors.initials: JG
authors.lastname: McCarthy
mesh_terms: D000293:Adolescent; D000367:Age Factors; D017668:Age of Onset; D000844:Ankylosis / Q000175:diagnosis; D002508:Cephalometry; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D008499:Medical Records; D009139:Musculoskeletal Abnormalities / Q000175:diagnosis; D012189:Retrospective Studies; D013704:Temporomandibular Joint / Q000473:pathology* / Q000503:physiopathology*; D013705:Temporomandibular Joint Disorders / Q000150:complications / Q000151:congenital / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D014057:Tomography, X-Ray Computed