title: Upper spine morphology in hypophosphatemic rickets and healthy controls: a radiographic study.
abstract: OBJECTIVE
  The aim of this study was to describe upper spine morphology in adult patients with hypophosphatemic rickets (HR) compared with controls to assess differences in spine morphology in terms of severity of skeletal impact and to study associations between spine morphology and craniofacial morphology.
  
  
  METHODS
  The study population comprised 36 HR patients and 49 controls. The atlas and axis dimensions were measured on cephalograms, and the differences between the groups were estimated by regression analysis. The upper spine morphology was visually assessed to estimate the prevalence of cervical vertebral anomalies.
  
  
  RESULTS
  The dimensions of the atlas and the axis were larger in HR patients than in controls (P ≤ 0.001), and fusions (FUS) occurred more often in HR patients (39%) than in controls (6%; P ≤ 0.001). In HR patients, the length of the atlas correlated positively (P = 0.008) and the height of the dens correlated negatively (P = 0.043) with the severity of skeletal impact. The height of the posterior arch of the atlas and the length of the axis correlated negatively with the cranial base angle (P ≤ 0.017), and the vertical dimensions of the atlas correlated positively with the thickness of the occipital skull (P ≤ 0.015). The length of the atlas correlated positively with mandibular prognathism (P = 0.042). FUS correlated positively with the frontal and parietal thickness (P = 0.034 and P = 0.003, respectively).
  
  
  CONCLUSIONS
  The dimension of the atlas and the axis and the prevalence of the FUS were increased in HR patients compared with controls. Upper spine dimensions were associated with craniofacial dimensions, primarily in relation to the posterior cranial fossa.
authors.affiliation: Section of Oral Health in Rare Diseases, Department of Maxillofacial Surgery, Aarhus University Hospital.
authors.forename: Hans
authors.initials: H
authors.lastname: Gjørup
authors.forename: Liselotte
authors.initials: L
authors.lastname: Sonnesen
authors.forename: Signe S
authors.initials: SS
authors.lastname: Beck-Nielsen
authors.forename: Dorte
authors.initials: D
authors.lastname: Haubek
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D001270:Cervical Atlas / Q000000981:diagnostic imaging / Q000473:pathology; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008313:Malocclusion, Angle Class III; D008875:Middle Aged; D011378:Prognathism / Q000209:etiology / Q000473:pathology; D011859:Radiography; D012044:Regression Analysis; D063730:Rickets, Hypophosphatemic / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D012886:Skull / Q000000981:diagnostic imaging / Q000473:pathology; D019291:Skull Base / Q000000981:diagnostic imaging / Q000473:pathology; D014716:Vertical Dimension; D055815:Young Adult