title: Ponticulus posticus is a frequent radiographic finding on lateral cephalograms in nevoid basal cell carcinoma syndrome (Gorlin-Goltz syndrome).
abstract: Nevoid basal cell carcinoma syndrome (NBCCS) is a predisposition to a rare tumor type with a variable phenotype. Besides tumors, skeletal alterations, such as bifid ribs or frontal bossing constitute the phenotype. Recently, a variant of the first cervical vertebra, the ponticulus posticus, was reported to occur in 50% of patients with NBCCS as revealed by analysis of lateral cephalograms.
  
  
  METHODS
  Lateral cephalograms of eight patients with NBCCS were studied for the presence of ponticulus posticus.
  
  
  RESULTS
  The ponticulus posticus was present in all patients. In one case, a series of cephalograms performed during a period of 20 years allowed the slow and continuous recording of a ponticulus posticus formation.
  
  
  CONCLUSIONS
  Besides the predisposition to developing neoplasms, NBCCS also affects bone development. Some diagnostic criteria for NBCCS rely on certain osseous transformations either in hard tissues, e.g. keratocystic odontogenic tumor in jaws, or in soft tissues, e.g. calcification of the falx cerebri. Furthermore, the physiognomy can be affected by skeletal alterations, e.g. frontal bossing or hypertelorism. Given this wide spectrum of osseous involvement in NBCCS, the high prevalence rate of ponticulus posticus should be added to the relevant diagnostic findings of the skull and vertebral column. However, the onset of ponticulus posticus formation in the life of such patients is unclear and thus the relevance of this finding in early diagnosis of NBCCS remains to be elucidated.
authors.affiliation: Department of Oral and Craniomaxillofacial Surgery, Eppendorf University Hospital, University of Hamburg, Hamburg, Germany r.friedrich@uke.de.
authors.forename: Reinhard E
authors.initials: RE
authors.lastname: Friedrich
mesh_terms: D000328:Adult; D000368:Aged; D001478:Basal Cell Nevus Syndrome / Q000000981:diagnostic imaging* / Q000473:pathology; D001846:Bone Development; D002114:Calcinosis / Q000000981:diagnostic imaging / Q000473:pathology; D001270:Cervical Atlas / Q000000981:diagnostic imaging* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000000981:diagnostic imaging / Q000473:pathology*; D011859:Radiography
keywords: Gorlin–Goltz syndrome; Nevoid basal cell carcinoma syndrome; arcuate foramen; atlanto-occipital ligament; calcification; lateral cephalogram; phacomatosis; ponticulus posticus