No Evidence of Reduction in Mouth Opening After Biopsy in Oral Submucous Fibrosis-A Prospective Cohort Study.

Background: Reluctancy to perform biopsy in oral submucous fibrosis (OSF) is usually observed among clinicians due to the common assumption that maximum mouth opening (MMO) is reduced after biopsy as wound healing occurs by an exaggerated pathological fibrotic response.

Purpose: The study purpose was to evaluate and compare MMO in OSF subjects before and after biopsy against baseline MMO of healthy controls.

Study design, setting, sample: This was a prospective institutional cohort study including subjects with OSF and healthy controls reporting at Nair Hospital Dental College, Mumbai, India from January to December 2023. Subjects less than 12 years of age, edentulous subjects, missing permanent incisors, subjects having temporomandibular joint disorders like ankylosis, OSF undergoing malignant transformation and previously treated OSF were excluded.

Predictor variable: The predictor variable was disease status, and subjects were grouped into healthy controls and OSF subjects.

Main outcome variable(s): The outcome variable was jaw function measured using MMO. In healthy controls, baseline MMO was assessed. In study group MMO was evaluated at 4 intervals: 1) before biopsy and 2) after biopsy at (a) 15th day, (b) 1-month, and (c) 6-month follow-up.

Covariates: The covariates were age and sex.

Analyses: A repeated measures analysis of variance test was employed to find statistical differences between MMO recorded in both groups. P < .05 was considered as statistically significant.

Results: The study composed of 200 (100%) subjects with mean age of 45.94 ± 17.29 years and 100 (50%) males. Each group comprised of 100 subjects with healthy controls having mean age of 47.49 ± 21.45 years and OSF group 44.39 ± 11.67 years. A statistically significant difference (P < .001) was observed between MMO in healthy controls (mean = 47.49 ± 4.87 mm, range 35 to 56 mm), and OSF subjects before biopsy (mean = 20.73 ± 5.79 mm, range 9 to 29 mm). MMO of OSF subjects at 4 intervals were 20.73 ± 5.78 mm, 20.92 ± 5.52 mm, 20.98 ± 5.51 mm and 21.01 ± 5.52 mm respectively, showing no statistical significance (P = .3).

Conclusion and relevance: No decrease in MMO in OSF subjects after biopsy was observed thus encouraging clinicians to take biopsy to rule out epithelial dysplasia and malignancy.