X‐linked hypophosphatemic rickets: Enamel abnormalities and oral clinical findings

Abstract

X-linked hypophosphatemia (XLH) is a genetic disorder related to alterations in bones and teeth formation, due to low levels of phosphate in blood. Oral findings in XLH have been enamel and dentine abnormalities, high pulp horns, large pulp chambers, and some cases of periapical abscesses related to teeth without caries or traumatic injuries. The aim of our study was to assess the presence of enamel alterations, such as microclefts and/or structure defects in patients with XLH and give guidelines of prevention of XLH dental complications. History taking, oral clinical and radiological examination in 10 young patients affected by XLH (average age of 9) and in 6 patients without XLH (average age of 8). Impressions were performed on the vestibular surfaces of teeth in order to obtain replicas. The replicas were analyzed using scanning electron microscope (SEM) and compared to replicas of control group. The images of replicas of XLH patients showed deep microclefts and irregular enamel surface structure compared to replicas of control group. The replica of a patient with spontaneous periapical abscesses showed numerous enamel crater-shaped depressions and deep microcleavages penetrating into the enamel thickness. In absence of caries or fractures, the abscesses pathogenesis may be related to microcleavages of the enamel and dentin, which allow bacterial invasion of the pulp. There could be a relationship between XLH disease and enamel abnormalities.

Long-term dental intervention and laboratory examination in a patient with Vitamin D-dependent rickets type I

“…[ 2 ] Additionally, enamel defects, periodontal disease, and malocclusion occur in XLH. [ 5 ] Previously, it was reported that patients with VDDR-I exhibit hypoplastic enamels, large pulp chambers, short roots, and chronic periodontal disease. [ 1 , 14 ] However, there is still a lack of morphologic and histologic evidence regarding VDDR-I.…”

“…Vitamin D-dependent rickets type I (VDDR-I) is a rare type of rickets caused by mutation of the CYP27B1 gene, which leads to 1-α-hydroxylase enzyme deficiency and conversion disorder of 25-OH vitamin D to 1,25-(OH) 2 vitamin D. [ 1 ] Laboratory findings include hypocalcemia, hypophosphatemia, elevated serum parathyroid hormone (PTH), low serum 1,25-(OH) 2 vitamin D, and normal or increased 25(OH) vitamin D. [ 2 ] Clinical manifestations of VDDR-I display the typical characteristics of rickets, including bowleg, growth retardation and ectodermal dysplasia. [ 3 ] Although dental abnormalities have been reported in many types of rickets such as vitamin D-dependent rickets type II (VDDR- II), [ 4 ] X-linked hypophosphatemia (XLH) [ 5 ] and vitamin D–resistant rickets (VDRR), [ 6 ] the dental manifestation of VDDR-I and its long-term dental intervention remain largely unclear. Considering that dental abnormalities in children affect chewing ability, pronunciation, facial appearance, and mental health, it is important to provide information on diseases with dental problems for pediatricians and dentists to effectively manage these patients.…”

Endodontic Management of Patients With X Linked Hypophosphatemic Rickets: Case Series Report

“…Some clinical studies reported the absence of enamel alterations in subjects affected by XLH [11]. However, Cremonesi et al, have shown by scanning electron microscopy, an irregular structured, slightly hypoplastic enamel in XLH teeth when compared to the images of control group [12]. In both deciduous and permanent teeth, pulp chambers could be enlarged, resembling taurodontism and prominent pulp horns extend up to the dentino-enamel junction [13].…”

Dental Management of Hypophosphatemic Vitamin D Resistant Rickets

“…Dental findings of this condition are enlarged pulp chambers, pulp horns which spread outside the dentino-enamel junction, enamel and dentine defects, poorly defined lamina-dura, short roots and hypoplastic alveolar ridge (4,(9)(10)(11).…”

“…The combination of all these factors contribute to recurrent dental abscesses in VDRR cases. Bacteria and their toxins which come from the oral cavity to the pulp cause pulpitis, pulp necrosis, periapical recurrent abscess or periapical complications without dental caries (1,2,4,5,7,(9)(10)(11)(12)(13)(14).…”