A Comparative Study of Maximum Mouth Opening amongst Postoperative Oral Cancer Patients with or without Radiotherapy

Introduction: Restricted mouth opening is a long-term sequelae of head neck cancer treatment. This is a major concern as it leads to multiple problems in maintenance of oral hygiene, speech, chewing, swallowing, prosthetic rehabilitation, and follow-up intra-oral examination. In this study, our aim was to assess maximum mouth opening (MMO) amongst postoperative oral cancer patients with or without conventional radiotherapy over a period of one year. Material and methods: A prospective longitudinal study was done in oral cancer patients, within three years, to compare effect of post-operative radiotherapy (PORT) on MMO over a follow-up period of one year with control of post-operative cases without radiation. Level of significance was set at alpha level 0.05. Results: Among 18 patients of PORT and 19 patients of control group, repeated measure ANOVA were significant for the following parameters: within subject effect in each group; between subject effect and interaction effect of month and radiation. Multiple pairwise comparison showed MMO at 3rd, 6th, 9th and 12th month were significantly different in PORT group, in comparison to preoperative MMO. In the control group however, only postoperative MMO at 1st month was significantly different. After one-year, mean MMO, in PORT and control was 32.56±4.29mm and 46.37±4.65mm, respectively and total trismus in radiotherapy group was 66.67% and that of control group was nil. Conclusion: Conventional radiotherapy in oral cancer patients can lead to high rate of trismus as a late effect. Strict exercise protocol along with close monitoring is recommended to have beneficial effect to the patients.