Factors influencing on masticatory ability in mandibulectomy and glossectomy patients

Objective:

Japan has about 9,000 oral cancer patients per year which was 1.7% of all cancer patients. In cases of mandibular area surgical reconstruction as well as prosthetic treatment was required after the resection of tongue or mandibular bone. Therefore it is speculated that post-operative recovery of masticatory ability of such patients was intricately influenced by surgical resection, reconstruction, prosthodontic treatment and passage of time after surgery. The purpose of this study was to analyze the factors influencing the recovery of masticatory ability in post-operative cancer patients in mandibular region.

Methods:

The subjects in this study consisted of 44 mandible, tongue, oral floor tumor patients(32 men and 12 women; average age 61.6+/- years). Masticatory performance was measured using a testing gummy jelly and 30ml water swallowing time at five stage: before surgery, and 1, 3, 6, 12 months after surgery. Multiple linear regression analysis for searching factors influencing the recovery of masticatory ability after surgery(p<0.10).

Results:

Masticatory performance and swallowing time before surgery were found to be predictive factors at each stage, suggesting need for preoperative examinations. Among items on cancer treatment, resection of tongue base, neck dissection, resection of mandibular bone and radiotherapy were chosen as negative factors for the recovery of masticatory ability, in contrast chemotherapy was chosen as a positive factor. Contribution of early prosthodontic intervention was suggested because number of posterior remaining teeth in the mandible was positive factor until 3 months after surgery, and occlusal support including prosthesis was that over 6 month after surgery.

Conclusions:

These results would enable us to predict the recovery of post-operative masticatory ability which might be useful for the informed consent before surgery as well as for developing effective rehabilitation strategy.