A meta-analysis of prevalence of mouth opening restriction in patients with oral cancer

Objective·To study the prevalence of mouth opening restriction in oral cancer patients by meta-analysis.Methods·China National Knowledge Infrastructure (CNKI), Chinese Science and Technology Journal Database (VIP), Wanfang Data (Wanfang), Chinese BioMedical Literature Database (CBM), PubMed, Ovid, EMbase, Cochrane Library, Web of Science/SciSearch, and ClinicalTrials.gov were searched for observational studies about the prevalence rate of restricted mouth opening in oral cancer patients (including prospective, retrospective, and cross-sectional studies). The time limit for retrieval was from the database establishment to April 30th, 2022. The obtained documents were independently screened and extracted according to the inclusion and exclusion criteria, and the literature quality evaluation was performed by using methodological index for non-randomized studies (MINORS). The data were combined with the mouth-opening-restricted prevalence rate as the outcome indicator, the meta-analysis was performed by using Stata 15.0 software, and the subgroup analysis was performed based on the detection time, tumor site, and tumor stage. The evidence quality of outcome indicators was evaluated by using GRADE profiler 3.6 software according to GRADE (Grading of Recommendations Assessment, Development, and Evaluation) system.Results·A total of 3 719 documents were obtained during the initial examination, and 18 documents were finally included, including 2 701 objects. The meta-analysis results showed that the total prevalence rate of mouth opening restriction in oral cancer patients was 42.7% (95%CI 27.0%‒59.1%). The results of subgroup analysis showed that the prevalence rates of mouth opening restriction in patients with oral cancer before surgery, and 3 months, 6 months and 1 year or more after surgery were 29.6% (95%CI 9.0%‒55.8%), 75.2% (95%CI 68.3%‒81.5%), 59.1% (95%CI 38.8%‒77.9%) and 22.3% (95%CI 2.0%‒54.3%), respectively. The prevalence rates of mouth opening restriction in patients with oral cancer at T1‒T2 stage and T3‒T4 stage were 38.6% (95%CI 26.0%‒52.0%) and 99.6% (95%CI 93.9%‒100.0%) respectively. The prevalence rates of mouth opening restriction in patients with oral cancer in the retromolar triangle, the gingiva, the tongue, the salivary gland, the floor of mouth and the lip were 93.1% (95%CI 68.5%‒100.0%), 68.1% (95%CI 52.9%‒81.7%), 46.1% (95%CI 11.6%‒82.7%), 26.1% (95%CI 15.9%‒37.5%), 21.9% (95%CI 0.7%‒54.0%), and 3.1% (95%CI 0‒9.3%), respectively. The GRADE system for evidence quality grading indicated that the quality of evidence for outcome indicator was extremely low.Conclusion·The total prevalence rate of mouth opening restriction in patients with oral cancer is high, nearly 50%; the patients at 3 months after surgery, at 6 months after surgery, at T3‒T4 stage or whose tumor located in the retromolar triangle have higher prevalence rates.