Oral Submucous Fibrosis (OSMF) is a chronic, progressive, and irreversible disorder of the oral cavity with a well-documented potential for malignant transformation.1 It predominantly affects populations in South and Southeast Asia, where areca nut chewing, either alone or in combination with tobacco, is deeply ingrained in social and cultural practices.2 The disease is characterized by progressive fibrosis of the oral mucosa, leading to loss of tissue elasticity, blanching, burning sensation, and ultimately restricted mouth opening.3 Among these clinical manifestations, trismus remains the most functionally debilitating and clinically significant symptom, often prompting patients to seek treatment.1

The pathogenesis of OSMF involves complex interactions between chronic irritation, inflammatory mediators, and altered collagen metabolism. Increased collagen synthesis coupled with reduced degradation results in excessive fibrotic tissue deposition in the lamina propria and deeper connective tissues.4 Over time, this fibrosis extends to involve the muscles of mastication, significantly compromising mandibular movements. As the disease progresses, patients experience difficulty in eating, speaking, swallowing, and maintaining oral hygiene, which adversely affects nutritional status and overall quality of life.5 The clinical severity of OSMF is commonly assessed based on the degree of mouth opening restriction. Mild cases may remain asymptomatic or respond adequately to conservative management, including habit cessation, intralesional injections, and physiotherapy.6 However, in moderate to severe cases, conservative approaches often fail to provide sustained improvement, making surgical intervention the treatment of choice. Surgical management aims to release fibrotic bands and restore mouth opening, frequently supplemented by reconstructive procedures such as buccal fat pad grafts or skin grafts to prevent contracture.7

Despite the widespread use of surgical techniques, outcomes vary considerably among patients. One of the key factors influencing surgical success is the severity of the disease at the time of intervention. Advanced OSMF presents with dense fibrosis, compromised vascularity, and reduced tissue compliance, all of which negatively impact surgical release and postoperative healing. Therefore, evaluating the relationship between disease severity and surgical mouth opening outcomes is essential for prognosis estimation and treatment planning.8

Although several studies have reported postoperative improvement in mouth opening following surgical management of OSMF, limited literature focuses on correlating disease severity with functional surgical outcomes. Understanding this relationship can aid clinicians in counseling patients, selecting appropriate surgical techniques, and emphasizing the importance of early intervention. The present study was undertaken to clinically evaluate OSMF severity and assess its impact on preoperative and postoperative mouth opening in patients undergoing surgical management.

This clinical observational study was conducted in the Department of Oral and Maxillofacial Surgery over a period of 12 months. A total of 60 patients clinically diagnosed with Oral Submucous Fibrosis were included after obtaining informed consent. Patients aged between 18 and 60 years who were willing to undergo surgical intervention were enrolled in the study. Patients with systemic diseases affecting wound healing, previously treated OSMF cases, and those with evidence of oral malignancy were excluded. Clinical assessment included detailed history taking, habit evaluation, and measurement of interincisal mouth opening using a calibrated Vernier caliper. Based on mouth opening, patients were categorized into Grade I (>30 mm), Grade II (20–30 mm), and Grade III (<20 mm). All patients underwent surgical release of fibrotic bands under standard protocols. Depending on the severity, adjunctive procedures such as buccal fat pad grafting were performed. Postoperative mouth opening was recorded, and all patients were advised physiotherapy exercises to maintain surgical gains.

Statistical Analysis

Data were analysed using descriptive statistics. Mean values, percentages, and standard deviations were calculated. Comparison between preoperative and postoperative mouth opening was performed.

Postoperative improvement in mouth opening was observed in all groups. Maximum gain was noted in Grade II patients, while Grade III patients showed comparatively lesser improvement (Table1,2,3).

Table 1: Distribution of Patients According to OSMF Severity (n = 60)

Table 2: Mean Preoperative Mouth Opening by Severity Grade

Table 3: Comparison of Preoperative and Postoperative Mouth Opening

The present study evaluated the impact of Oral Submucous Fibrosis severity on surgical mouth opening outcomes and demonstrated that disease stage plays a pivotal role in determining both preoperative limitation and postoperative improvement. A clear inverse relationship was observed between OSMF severity and baseline mouth opening, which aligns with the progressive fibrotic nature of the disease.

In this study, patients with Grade III OSMF exhibited the lowest preoperative mouth opening, reflecting extensive fibrosis and muscular involvement. Similar findings have been reported in previous studies, where severe OSMF cases consistently demonstrated mouth opening below 20 mm due to dense collagen deposition and reduced tissue elasticity. The restricted improvement observed postoperatively in severe cases further highlights the irreversible nature of advanced fibrosis. Moderate OSMF (Grade II) patients showed the maximum postoperative gain in mouth opening. This finding is consistent with earlier research suggesting that surgical intervention during the moderate stage yields optimal functional outcomes. The relatively preserved tissue elasticity and vascularity in Grade II cases allow more effective fibrotic band release and improved postoperative healing. Studies by various authors have reported comparable improvements ranging from 10 to 15 mm in moderate OSMF cases following surgical management, supporting the results of the present study.

Mild OSMF (Grade I) patients demonstrated satisfactory postoperative mouth opening; however, the mean gain was lower compared to moderate cases.9 This can be attributed to higher baseline mouth opening values, leaving limited scope for dramatic improvement. Nonetheless, early surgical or conservative intervention in such cases helps prevent disease progression and long-term functional impairment.10 The role of postoperative physiotherapy cannot be overstated. Several studies emphasize that sustained mouth opening improvement depends not only on surgical release but also on patient compliance with physiotherapy. Inadequate physiotherapy has been identified as a major cause of relapse and reduced long-term outcomes. In the present study, all patients were advised regular physiotherapy, which contributed to the overall improvement observed across all severity grades.11

Comparing surgical outcomes across severity grades reinforces the importance of early diagnosis and timely intervention. Studies have shown that delayed presentation often results in advanced disease, where surgical management becomes technically challenging and outcomes are less predictable. The limited postoperative improvement in severe cases observed in this study corroborates these findings.12 Furthermore, advanced OSMF carries a higher risk of malignant transformation, emphasizing the need for early therapeutic intervention not only to improve function but also to reduce long-term morbidity. Surgical management in earlier stages may thus offer dual benefits functional rehabilitation and disease control.13

The severity of Oral Submucous Fibrosis significantly affects surgical mouth opening outcomes. Moderate OSMF cases achieve the best functional improvement, while severe cases show limited gains. Early diagnosis and timely surgical management, combined with postoperative physiotherapy, are essential for optimal results.

1. Prakash O, Mahuli SA, Rai A, Shamsi S, Paswan KK, Shree P. Surgical Management of Oral Submucous Fibrosis: A Scoping Review. Indian Journal of Otolaryngology and Head & Neck Surgery. 2025 Oct;77(10):4626-41.
2. Raha S, Desai RS, Bansal SP, Shirsat PM, Prasad PS. No evidence of reduction in mouth opening after biopsy in oral submucous fibrosis-A prospective cohort study. Journal of Oral and Maxillofacial Surgery. 2025 Sep 16.
3. Kaur A, Rustagi N, Ganesan A, Pm N, Kumar P, Chaudhry K. Minimal clinically important difference of mouth opening in oral submucous fibrosis patients: a retrospective study. Journal of the Korean Association of Oral and Maxillofacial Surgeons. 2022 Jun 30;48(3):167-73.
4. Dasukil S, Jena AK, Boyina KK, Grover S, Arora G, Ahmed ZU. Functional outcome of two different grafting techniques in the surgical management of oral submucous fibrosis: A comparative evaluation. Oral and Maxillofacial Surgery. 2022 Sep;26(3):477-83.
5. Chaudhry K, Khatana S, Bali R, Kaur A, Dutt N. Quality of life in oral submucous fibrosis: a systematic review. Journal of Maxillofacial and Oral Surgery. 2022 Mar;21(1):14-24.
6. Memon AB, Rahman AA, Channar KA, Zafar MS, Kumar N. Evaluating the oral-health-related quality of life of oral submucous fibrosis patients before and after treatment using the OHIP-14 tool. International Journal of Environmental Research and Public Health. 2022 Feb 5;19(3):1821.
7. Naik V, Kumar M, Solomon MC, Chandrashekhar C, Guddattu V. Clinical and histological indicators for malignant transformation of oral submucous fibrosis: an analysis of cases from a tertiary care center. BMC Oral Health. 2025 Jul 2;25(1):1053.
8. Mohandoss AA, Thavarajah R, Joshua E, Rao UK. Mitigation of mouth opening in oral submucous fibrosis with nutraceutical products: A network meta-analysis. Indian Journal of Dental Research. 2025 Jul 1;36(3):353-60.
9. Lahiri J, Bansod S. IMPLANT PLACEMENT IN ORAL SUBMUCOUS FIBROSIS (OSMF) AND TRISMUS PATIENTS WITH RESTRICTED MOUTH OPENING. Egyptian Journal of Oral and Maxillofacial Surgery. 2024 Oct 1;15(4):202-6.
10. Ullah H, Maqsood A, Faheem S, Khan ZA, Ganji KK, Bashir O, Ahmed N, Heboyan A. Nasolabial Flap in the Management of Oral Sub Mucous Fibrosis: A Series of Cases. Clinical Medicine Insights: Case Reports. 2023 Aug;16:11795476231191030.
11. Al-Madhoon HW, Elkhateb A, Asla MM, Jaber M. Comparative evaluation of nasolabial flap and buccal fat pad flap in the surgical management of oral submucous fibrosis: a systematic review and meta-analysis. Oral and Maxillofacial Surgery. 2024 Mar;28(1):91-100.
12. Nanavati S, Nanavati P, Nanavati M. Split-Thickness Skin Grafts in the Surgical Management of Oral Submucous Fibrosis. Sciences. 2025;7:61-80.
13. Nanavati S, Nanavati P, Nanavati M. Split-Thickness Skin Grafts in the Surgical Management of Oral Submucous Fibrosis. Sciences. 2025;7:61-80.