Craniofacial morphology in patients with hypophosphataemic vitamin-D-resistant rickets: a cephalometric study.

Hypophosphataemic vitamin-D-resistant rickets (HVDRR) is a hereditary disease mainly transmitted as an X-linked dominant trait and characterized by certain general clinical signs (Filho HM, de Castro LC, Damiani D. Arq Bras Endocrinol Metab. 2006;50:802). In literature, only one study had been published in 1965 on the cephalometric findings in patients with HVDRR (Marks SC, Lindahl RL, Bawden JW. J Dent Child. 1965;32:259). This is the first detailed study on craniofacial characteristics of patients with HVDRR in the dental literature. The aim of this study was to determine the effect of HVDRR on the parameters of the craniofacial skeleton of young Jordanian patients using cephalometric analysis. Lateral cephalometric radiographs were made for 22 Jordanian children (aged 2-16 years) diagnosed with HVDRR. The cephalometeric parameters of HVDRR group were compared with those of normal control group matched for gender and chronological age using paired t-test. The HVDRR group had a significant increase in the SNBa angle (P < 0.01); as well as reduced anterior cranial base length (P = 0.01), reduced maxillary length, corpus mandibular length and mandibular height (P = 0.01, 0.04 and 0.008 respectively). The cranial base and gonial angles were significantly increased in diseased individual, but the SNA and ANB angles were significantly reduced (P = 0.018 and 0.000 respectively). The angulation of the lower incisor to mandibular plane was also significantly reduced in the diseased group compared with Jordanian norm (P = 0.004). Patients with HVDRR have deficiency in the anterior cranial base length, ramus height and cranial base angle. Patients with HVDRR also have class III skeletal relationship.