title: [Occipitalization of the atlas. Radiological diagnosis and clinical significance].
abstract: BACKGROUND
  Occipitalization of the atlas is the most common malformation of the craniovertebral junction. It can be diagnosed on lateral teleradiography and its finding imposes screening for associated atlantoaxial instability. In case of instability, brisk movements of the cervical spine during surgery may result in compression and distortion of the spinal chord and vertebro-basilar vascular system.
  
  
  METHODS
  An 18 year-old female patient was referred to our department for facial dysmorphosis and extraction of the third molars. A lateral teleradiography revealed an occipitalization of the atlas and the fusion of the second and third cervical vertebral body. Further pre-operative investigations allowed ruling out any joint instability or associated craniovertebral junction malformations.
  
  
  CONCLUSIONS
  Occipitalization of the atlas is not usually well-known by maxillofacial surgeons. It may be diagnosed with a lateral teleradiography. Its diagnosis imposes screening for other spinal malformations (spinal fusion, hemivertebra, spina bifida occulta). The major risk is compression and distortion of the spinal chord and vertebro-basilar vascular system, during surgery or anesthesia.
authors.affiliation: Clinique de chirurgie maxillofaciale et de stomatologie, centre hospitalier universitaire de Nantes, 1 place Alexis-Ricordeau, Nantes, France.
authors.forename: E
authors.initials: E
authors.lastname: Kahouadji
authors.forename: O
authors.initials: O
authors.lastname: Lucas
authors.forename: R H
authors.initials: RH
authors.lastname: Khonsari
authors.forename: J
authors.initials: J
authors.lastname: Longis
authors.forename: O
authors.initials: O
authors.lastname: Hamel
authors.forename: P
authors.initials: P
authors.lastname: Corre
mesh_terms: D000293:Adolescent; D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging / Q000601:surgery; D001269:Atlanto-Occipital Joint / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery; D001270:Cervical Atlas / Q000002:abnormalities* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007714:Klippel-Feil Syndrome / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery; D009777:Occipital Bone / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000601:surgery; D057909:Orthognathic Surgery; D011859:Radiography; D014081:Tooth Extraction