Abstract
I-cell disease or Mucolipidosis II is thought to be an inherited disorder of the glycoprotein metabolism. Clinically it is characterized by coarse facial features, growth failure, psychomotor retardation and severe skeletal changes. These clinical characteristics resemble those of mucopolysaccharidosis such as the Hurler syndrome. There is, however, no excessive excretion of glycosaminoglycan in the urine. In cultured skin fibroblasts from patients with this disease, there are many cytoplasmic inclusions from which the name of I-cell disease originated. The medical character of this disease has been fairly well elucidated in many reports, however few papers have described the dental features of the patient.
The present paper concerns the dental findings of a 12-year-old male patient with I-cell disease who first visited the Pedodontic Clinic of Tokyo Medical and Dental University Dental Hospital when he was 3 years 2 month old. The patient had grown poorly, having a gargoyl face, dorsolumber kyphosis with lumber gibbus, joint contraction of limbs and slight mental retardation. There was severe skeltal malformation in the whole body of the patient, and the carpus bone age was about two or three years younger than his own chronological age. The patient has spaced dental arches and open bite with a large tongue. The dental radiographs reveal that the primary molars had tortuous roots, and the alveolar bone surrounding them had resorbed horizontally. Several permanent teeth had not yet erupted and their formation had also been delayed. The histological examination of the extracted primary molars demonstrated that the teethhad much interglobular dentin and that the secondary cementum was very noticeably deposited at the root apex region. The dentinal tubules ran partialy in a disordered manner. In the Knoop hardness test, the dentin from the patient had a decreased value. Thermal analysis of the dentin indicated that the overall composition had not changed, but the differential thermal analysis curve was slightly different from that of normal dentin. Considering that the pathogenesis of I-cell disease is related to the metabolism of glycoprotein, these findings suggest that there may be some qualitative alterration in the organic matrix of the dentin taken from the patient.
