The effect of irradiation on developing teeth

Effects of therapy on dentofacial development in long-term survivors of head and neck rhabdomyosarcoma: the memorial sloan-kettering cancer center experience

PURPOSE

To describe potential effects of multimodality therapy on dental and facial development in long-term survivors of head and neck rhabdomyosarcoma.

PATIENTS AND METHODS

The medical records of all patients aged 20 years or less presenting between 1985 and 1996 with a diagnosis of rhabdomyosarcoma and treated by protocol were reviewed. Head and neck rhabdomyosarcoma patients who were followed in the Dental Service and were alive and free of disease with at least a 5-year follow-up were included in the review. Ten patients satisfied the inclusion criteria and form the basis of this report. The median age at diagnosis of the 10 patients was 4.3 years (range 10 months to 19.5 years). All patients were treated with chemotherapy, two patients underwent surgery, and all but one patient received external beam radiation therapy.

RESULTS

Clinical or radiographic dentofacial abnormalities were observed in 8 of the 10 (80%) patients. Abnormalities included enamel defects, bony hypoplasia/facial asymmetry, trismus, velopharyngeal incompetency, tooth/root agenesis, and disturbance in root development. Bony hypoplasia and disturbance in root formation were the most common findings.

CONCLUSIONS

Multimodality therapy for head and neck rhabdomyosarcoma can result in dentofacial abnormalities that affect the patient's quality of life. The care of the long-term survivor requires a multidisciplinary approach, including early involvement of the dental team.

Dento-maxillofacial sequelae in a child treated for a rhabdomyosarcoma in the head and neck. A case report

This case report describes severe dento-maxillofacial defects after chemoradiation therapy in a child aged 9 years 6 months with a parameningeal rhabdomyosarcoma. A clinical and radiologic (apical dental radiographs, orthopantograph, lateral skull roentgenogram) dental follow-up over 4 years showed such dental abnormalities as root blunting, mild to severe root shortening, premature closure of the root apices, and severe radiation caries. Craniofacial morphology evaluated by cephalometric analysis and dental models showed deficiency with mandibular and maxillary hypoplasia.

Autogenous transplantation of third molars in irradiated jaws--a preliminary report

Our experience with third molar autotransplants in 2 patients, into an area irradiated at an early age, is described and discussed. It is shown that such autotransplantations are possible.

Multiple external root resorption

Presented is an unusual case of multiple external root resorption. Although the cause of this resorption was not determined, several possibilities are presented. Trauma from occlusion, periodontal and pulpal inflammation, and resorption of idiopathic origin are all discussed as possible causes.

Disturbances in dental development after total body irradiation in bone marrow transplant recipients

The dental status of 16 children who had been treated with bone marrow transplantation (BMT) for serious bone marrow diseases was followed for up to 6 years. Several types of disturbances in dental development were observed in children who had been conditioned with total body irradiation (TBI) at 10 Gy before BMT. Thus, impaired root development that caused short V-shaped roots was found in all patients, a complete failure of root development and premature apical closure were found in five patients, enamel hypoplasia was observed in four patients, and microdontia was observed in three patients conditioned with TBI. Patients younger than 6 years of age at BMT exhibited the most severe and extensive dental aberrations. The TBI at 10 Gy appeared to be the major cause of the disturbances found.

Failure of root development of human permanent teeth following irradiation

Complete absence of root formation of the upper incisors, canine and first premolar was reported in a 27-year-old female who had received radiation therapy for a retinal glioma of the right eye at age of 3 years 1 month. Ground and decalcified sections showed no remarkable changes in enamel and dentin of the crowns, but the pulp floor was closed by irregular dentin deposit despite the absence of root formation. The outer surface of the irregular dentin was covered by acellular cementum, and the periodontal membrane was undeveloped. A slight degree of fibrosis was seen in the pulp, but the coronal part of the dentin was lined by odontoblasts. The theory that tooth eruption is caused by the growth of the root is not substantiated by the observation in this case.

Mandibular third molar development after mantle radiation in long-term survivors of childhood Hodgkin's disease

Sequential panoramic radiographs were assessed for mandibular third molar development in 47 long-term survivors of childhood Hodgkin's disease after treatment with 37 Gy mantle field radiation. To make a comparison, panoramic radiographs of 149 healthy, nonirradiated children were reviewed for the presence of mandibular third molars. In children between the ages of 7 and 12 years, bilateral agenesis of mandibular third molars was more frequent in patients who had been treated with mantle radiation than in nonirradiated patients. Unilateral agenesis, crown hypoplasia, and root growth impairment of mandibular third molars were also found. Similar, apparent, radiation-induced developmental anomalies were noted in maxillary third molars of the irradiated patients.

Tooth root growth impairment after mantle radiation in long-term survivors of Hodgkin's disease

The tooth root growth impairment that resulted from 35 to 37 Gy mantle port radiation in 47 long-term survivors of childhood Hodgkin's disease was quantified and related to specific age groups and categories of teeth. Root measurements of the mandibular permanent canines, first and second premolars, and first and second molars were made from sequential panoramic radiographs taken at the time of radiation therapy and after the closure of root apexes. The severity of root growth impairment was greatest in patients who received radiation during the early stages of odontogenesis. With later stages of odontogenesis, and as the age increased at the time of treatment, less impairment occurred. The potential difficulties of using repeated panoramic radiographs to assess tooth lengths in longitudinal studies also were discussed.

The effect of radiation on teeth. A clinical, histologic and microradiographic study

54 teeth from 20 patients irradiated for treatment of malignant tumors of the head and neck region were examined clinically, histologically and microradiographically. 18 teeth from 8 patients were used as controls. A significantly higher degree of hyposialia, radiation mucositis and atypical caries was found in the original group as compared to the control material. Occurrence of narrow gaps between dentin and cementum was also higher in the former group as compared with the latter.

Effects of radiation on the developing dentition and supporting bone

Underdevelopment of teeth after exposure to radiation has been observed since the early experiments with X rays. Two patients had been irradiated at young ages for embryonal rhabdomyosarcomas. For the patient treated with radiation at age 4 for a lesion in the submandibular area, root development of the mandibular teeth stopped, but the teeth nevertheless erupted. In the patient treated with radiation at age 9 for a tumor in the left cheek, bone apposition in the left side of the mandible failed to continue at the same rate as on the right side. Although new megavoltage radiation machines have reduced the chances of bone complications in adults, developing bone and structures are still significantly affected by radiation.