A radiographic dental examination was performed in 16 children conditioned with total body irradiation (TBI) and cyclophosphamide (CY) prior to bone marrow transplantation (BMT), and in 52 children treated with multiagent chemotherapy. For each child, three age- and sex-matched healthy controls were selected. Evaluation of disturbances in dental development and tooth size was based on planimetric measurements of mandibular teeth on panoramic radiographs. Short V-shaped roots were diagnosed in 94 per cent of the children treated with TBI/CY compared with 19 per cent in the chemotherapy group (P < 0.001). Children receiving TBI/CY also exhibited a pronounced reduction in tooth size compared with the controls. Reductions varied from 19 per cent in incisors to 39 per cent in the second molars. In the chemotherapy group the corresponding values were 7 and 15 per cent respectively. When comparing crown/root ratios, the indices for incisors, canines (P < 0.05) and molars (P < 0.01) in the BMT group were significantly higher than the corresponding values in the control group. This indicates that the reduction in root size was more pronounced than the reduction in crown size. The premolars in the BMT group exhibited a similar reduction in crown and root size. All developing teeth were affected by multiagent chemotherapy and radiation therapy. The most severe disturbances were found in children treated with TBI/CY at a young age.

A roentgen cephalometric investigation was used to study facial growth and morphology in 17 children who had undergone bone marrow transplantation (BMT) because of acute leukaemia and aplastic anaemia. The ages at BMT varied from 1.0 to 12.9 years. Preoperative treatment included high doses of cyclophosphamide and in children with acute leukaemia also 10 Gy total body irradiation (TBI). The median observation period following BMT was 3.9 years. The control group comprised 85 age and sex matched healthy children. In comparison to the controls, all linear measurements studied were found to be significantly diminished in children conditioned with TBI. For variables describing vertical dimensions, the degree of reduction appeared to be associated with the patients' ages at the time of irradiation. It was concluded that the disturbance in dental development, which is also a consequence of TBI, could be partly responsible for this association. Children who were not conditioned with TBI exhibited no significant differences when compared to controls in respect of the variables studied.

The effect of cyclophosphamide (Cy) on tooth development was studied in molars of 18 young Sprague-Dawley rats. Doses of 30 mg/kg body weight of Cy dissolved in 1 ml 0.9% NaCl were administered to 18 experimental rats and 1 ml 0.9% NaCl to 18 control rats at 10 and 13 days of age. The most obvious changes in the experimental teeth could be seen in the developing pulp of the third molar and developing roots of the first and second molars. Wide cell-free areas appeared in the third molar 2 days after the last injection; later these areas turned into mineralized osteodentin. Similar areas could be observed also in the roots of the first and second molars. These changes were related to the developmental stage of the area.

Scanning electron microscopy was used to study the effect of cyclophosphamide (Cy) on molar development in 18 Sprague-Dawley rats from 15 to 48 days of age after birth. Doses of 30 mg/kg body weight of Cy dissolved in 1 ml 0.9% NaCl were given to the rats at 10 and 13 days of age. Eighteen control rats had injections of 1 ml 0.9% NaCl at the same ages. The most obvious changes in the experimental teeth were found in the developing roots of the first and second molars and in both the crown and roots of the third molar. The roots of the first and second molars were short and showed apical closure in the experimental rats. In addition to the disturbances in crown and root formation, the third molars were also significantly reduced in total size as compared with the third molars in the control rats.

Abstract— The effect of growth hormone (GH) treatment on craniofacial development was studied in five children exhibiting growth retardation following bone marrow transplantation. Linear and angular measurements were made on lateral radiographic cephalograms taken prior to the start of GH treatment and after an average treatment time of 1.2 yr. The results showed that the mean growth increments of mandibular length in the GH treated children, exceeded the corresponding values of the control group by 150% during the period of investigation. It is suggested that this dimensional increase in the patients was due to GH stimulation on the chondral growth process in the mandibular condyles.