Radiographic Evaluation of the Craniofacial Skeletal Structures in Pediatric Patients with Neurofibromatosis Type 1

Abstract

Introduction: Neurofibromatosis Type I (NF1), also known as von Recklinghausen disease, is an autosomal dominant disorder that affects one in every 3000 births. There is no gender or race predilection seen in NF1 patients. Common clinical features include neurofibromas, cafe-au-lait spots, axillary and inguinal freckling, optic glioma, Lisch nodules and some form of bone lesions. NF1 causes a mutation in the gene that produces neurofibromin protein, which thus increases the activation of the Ras protein. This leads to rapid, radical growth of cells in the skin, skeletal and neural tissues. The craniofacial morphology of NF1 adult patients has been studied, however there have been few studies done on pediatric NF1 patients. The purpose of this study was to analyze and compare craniofacial regions, including the morphology of the cranial base and the sphenoid bone, using cephalometric radiographs of NF1 pediatric patients and age and gender matched healthy controls. Methods: A total of 28 pediatric NF1 patients and their age and gender matched healthy controls were used in this study. Cephalometric radiographs of the NF1 group were obtained from the NIH, and the cephalometric radiographs of their matched healthy controls were collected from The University of Maryland Dental School, orthodontic department. Sixteen cephalometric linear and angular measurements that reflected the cranial base, vertical heights, maxilla and mandible were measured to the nearest tenth of a millimeter or degree utilizing Dolphin Software. The groups were analyzed based on the total sample, pre-pubertal and post-pubertal status, and gender. Results: The results showed that there were very few statistically significant differences found between the NF1 pediatric group and their matched healthy controls. The NF1 pediatric patients in the total group, pre-pubertal and post-pubertal groups were all found to have larger cranial base flexure angles compared to their matched healthy controls. It was also found that male NF1 patients had larger measurements compared to their female NF1 patients, which was also seen in the healthy control group. Conclusion: In conclusion, there were very few statistically significant differences found between the NF1 pediatric group and their matched controls. These differences are unlikely to have an effect on the orthodontic and orthopedic treatments performed on NF1 pediatric patients by their clinicians. Therefore, pediatric NF1 patients should be offered the same type of orthodontic and orthopedic treatment options as their matched healthy controls.