Rehabilitation of a Patient with a Post Radiotherapy Trismus with an Obturator and a Maxillary Denture Using Magnet Attachments

Construction of an obturator is necessary to restore normal function and aesthetics in patients who had a resection of a tumor in the soft and hard palates. The design of the prosthesis is affected by the remaining supporting structures of the oral cavity, presence and extent of reconstructed tissue and the severity and location of the lesion. Many adverse forces act on an obturator and these can be minimized by maximizing palatal coverage, selecting the proper occlusal scheme and utilizing direct retention to name a few methods. Maximizing the lateral peripheral contour can increase retention and reduce vertical displacement by facilitating the skin grafted lateral wall of the defect. This procedure can however, be more challenging when the patient suffers from trismus and the access is severely restricted. A combination of surgery and radiotherapy is one of the methods for managing a head and neck cancer patient For the patients undergoing radiotherapy, numerous short and long term side effects are expected. One of the well known complications is trismus, which may have been caused by inflammation and insults to muscles of mastication and other surrounding tissues. Wang reported that the degree of trismus has been reported to increase continuously over time. In patients treated for nasopharyngeal carcinoma with radiotherapy, the maximum interincisal distance was reported to be reduced to 97% of its original distance in the first nine weeks after radiotherapy. Further reduction to 73%, 69%, 68% and 67% were observed in 12, 24, 36, 48 months, respectively. Clinical applications of magnetic attachments in maxillofacial prostheses have been used as overdenture abutments and for attachments between components of the prostheses. With improvements in magnetic attachments, the issues regarding corrosion have been overcame and an improved retentive force in a smaller device has been developed. The magnetic attachments are self limiting in transmitting forces vertically and horizontally, where no greater than the retention force of the attachment can be transferred to the other component. In a large defect area where a single insertion path for a stable prosthesis was not possible, use of magnetic attachments to connect several pieces of a prosthesis have been reported to achieve stability and retention. This accommodates maximum use of anatomical features and undercuts. The aim of this clinical report is to describe prosthetic management in a patient with post-radiotherapy trismus.