Heterogeneity in mouth opening function among patients with oral cancer following surgery: A latent profile analysis

Objective This study aimed to identify heterogeneous subtypes of mouth opening function in patients after oral cancer surgery and explore factors associated with mouth opening function profiles. Methods We recruited 305 patients who underwent oral cancer surgery at the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China, between April and September 2025. Data were collected using a general information questionnaire, measurements of maximum interincisal opening, the Gothenburg Trismus Questionnaire, and the Tampa Scale of Kinesiophobia for Temporomandibular Disorders. Latent profile analysis (LPA) was used to identify subtypes of mouth opening function, followed by multinomial logistic regression to determine the associated factors. Results Three subtypes were identified through LPA among included postoperative patients with oral cancer: well-functioning with mild symptoms (28%, n = 86), moderate dysfunction with pain (50%, n = 153), and severe dysfunction with severe symptoms (22%, n = 66). Compared with the first subtype, preoperative mouth opening restriction (odds ratio [OR] = 2.830, P = 0.018) and a higher level of mandibular movement avoidance behavior (OR = 1.394, P = 0.001) were associated with the second subtype. Preoperative mouth opening restriction (OR = 5.624, P = 0.001), a higher level of mandibular movement avoidance behavior (OR = 1.304, P = 0.020), and receipt of flap reconstruction (OR = 13.144, P = 0.002) were associated with the third subtype. Of note, only a small number of patients in Class 3 did not receive flap reconstruction, which resulted in a wide confidence interval. This association should therefore be interpreted cautiously. Conclusions Using a subjective–objective combined assessment method, this study identified three distinct mouth opening function subgroups in postoperative oral cancer patients. Each subgroup exhibited distinct characteristics and was associated with a combination of factors. These findings may provide a useful basis for early identification and for developing future targeted intervention strategies according to the characteristics of each subtype.