Maxillofacial prosthetic treatment aims to recover esthetics, mastication, swallowing and speech dysfunction using maxillofacial prostheses. For this purpose, reconstruction of the maxillofacial configuration and functional rehabilitation are important. In particular, combined use of surgical reconstruction and rehabilitation for defects, deformities and displacements of the maxillofacial configuration are essential for functional recovery. At the 36th Annual Meeting of the Japanese Academy of Maxillofacial Prosthetics Society, the symposium “Liaison for Maxillofacial Reconstructive Treatment” was held by Prof. Keiichi Sasaki of Tohoku University （June 2019）. This article comments on the meanings of “liaison,” which is the key word for understanding the symposium articles that follow, such as 1） meaning, necessity, and results, 2） management method, 3） issues and prospects.
Because the head and neck region harbors indispensable sensory organs such as the eyes, nose, and tongue, it is very important to take into consideration the patients’ quality of survival （QOS） in addition to the goal of better disease prognosis. Recently, cancer boards have become a valuable tool in the treatment of many kinds of cancer. Cancer boards are discussion groups where all the disciplines involved in the treatment of a patient are brought together to determine the best course of treatment for that patient. The head and neck cancer board plays an important role in these discussions because of the important issues surrounding QOS such as dysphagia, dysphonia, visual and hearing impairment, dysosmia, dysgeusia and disturbance of movement of extremities after treatment. At Tohoku University Hospital, the head and neck cancer board has met every week since July 2014 and has discussed over 1,200 cases involving head and neck cancer. New treatment options are also discussed such as robotic surgery, proton and carbon beam radiotherapy, and immune checkpoint inhibitors. These detailed discussions by the head and neck cancer board result in tailor-made treatment plans for our patients.
For head and neck reconstruction at Tohoku University Hospital, the Department of Medicine and the Department of Dentistry cooperate to draw up a surgical plan, jointly perform surgery, and perform postoperative treatment. Mandibular reconstruction is an example of a surgical procedure that has improved significantly since the start of collaboration between the medical and dental departments. Reconstruction after segmental resection of the mandible requires consideration of both esthetics and occlusal reproduction. Through cooperation, stable and good results have been achieved, and the denture placement rate has greatly improved. As collaboration has progressed, the scope of surgery has expanded, and the technology and knowledge of each department have been used also for management of complications and double-barrel reconstruction with fibula in mandibular reconstruction.
In patients with advanced oral cancer, treatments against cancer often significantly impair life functions such as appearance, speech, chewing, and swallowing. To minimize post-treatment dysphagia in patients with advanced oral cancer, functional reconstructive surgery, rehabilitation, and prosthetic treatment must be comprehensively planned. We have formed a multidisciplinary team for dysphagia consisting of doctors, dentists, rehabilitation physicians, speech therapists, nurses and dental hygienists. Our team becomes involved with patients with advanced oral cancer before the surgery. This allows for comprehensive treatment and maximal maintenance of swallowing function after surgery. For over a decade our swallowing team has been formed and has achieved good results. In order for multidisciplinary members to collaborate and form a team, it is necessary to meet continuously and regularly to deepen mutual understanding, and to respect each other’s expertise. However, the team has grown and is now at a stage where enthusiasm alone cannot keep up the team. Therefore, in July 2019 we established the “Center for Dysphagia of Tohoku University Hospital” as an official organization of our hospital.
Background: In cases with defective mandibular jaw, functional recovery with a prosthesis is considered, but the rehabilitation outcome varies widely depending on the anatomical and functional state after surgery. Therefore, this paper reviews the outcome of rehabilitation by wearing a prosthesis for defective mandibular jaw. Methods: The literature was systematically searched by presenting key words to the Japan Medical Library Association in addition to Clinical Guidelines for Maxillofacial Prosthetics 2009. Then, we selected 16 reports related to this review paper. Results: The treatment outcomes for 44 cases of mandibular bone reconstruction and 55 non-reconstruction cases after wearing a prosthesis for defective mandibular jaw were assessed in terms of masticatory and articulatory functions and esthetic satisfaction. Overall, a prosthesis for defective mandibular jaw stabilizes the mandibular movement over time, and reduces difficulty of chewing. The combined use of a palatal lump for guiding mandibular movement was effective for improving speech intelligibility by stabilizing the mandibular position in phonation. Patients’ impaired esthetics might be improved by restoring defective teeth and mandibular structures. Conclusions: For patients with mandibular jaw defects, a prosthesis can be effective for improving functional and esthetic problems. Standardized assessment procedures should be used for establishing evidence of treatment outcomes
Malnutrition degrades activities of daily living （ADL） for the elderly. In order to maintain their ADL, it is important to prevent the frailty cycle from developing by activating nutrient absorption. Nutrient absorption is affected by the degree of food digestion, and so mastication function should be maintained at a level that allows foods with various textures to be taken. For aged persons suffering from mastication disorders due to general muscle weakness in association with aging, food may be softened to a texture that does not require mastication. Over time, mastication function might degrade through disuse. Therefore, the bite force essential for mastication should be strengthened up to the normal level. A 15-week program of exercise by clenching with the maximum possible force using a specially fabricated elastic plate was designed and applied to six residents wearing dentures in a nursing home. Chronological changes in bite force and masseter muscle activity were investigated periodically. Before the exercise, none of the subjects exhibited vertical force during clenching, but force in either the anteroposterior or lateral direction was observed for all subjects. EMG did not exhibit continuous activity but spastic activity for all subjects. Four weeks later, bite force in the vertical dimension as well as the horizontal dimension appeared for all subjects. The continuous aspect of EMG activity was observed instead of the spastic aspect for all subjects. It is concluded that the designed biting exercise strengthened the bite force and thus improved mastication ability.
A 79-year-old female underwent partial maxillectomy due to squamous cell carcinoma. The patient used a maxillary denture for a defective jaw, however, masticatory dysfunction was caused by denture instability. A new maxillary denture for the defective jaw was fabricated because an implant prosthesis was not selected in consideration of the risk of systemic disease and the patient’s wishes. A hollow obturator was attached to the maxillary denture for the defective jaw. The obturator was formed by applying the tissue undercut in the defect to improve retention and bracing of the denture. Furthermore, beading operation was performed at the margin of the defect in the anterior division of the hard palate in order to seal the denture. Five years after the maxillary denture for the defective jaw was reproduced, the score of initial self-assessed masticatory ability of 10 increased to 35, and the score of masticatory performance using test gummy jelly increased from 0 to 2, in comparison with the old denture. Although edentulous patients have maxillary defects such as in the present case, using the limited remaining alveolar ridge and tissue undercut effectively can provide high retention and stability for the maxillary prosthesis, thus improving oral functions.