Oral Submucous Fibrosis (OSMF) is a chronic, insidious condition characterized by progressive fibrosis of the oral mucosa, leading to reduced mouth opening, burning sensation, and dysphagia. It is strongly associated with areca nut chewing and poses a significant risk for malignant transformation [1]. Management of OSMF, especially in its advanced stages, often necessitates surgical intervention to release fibrotic bands and restore oral function [2].

Nasolabial flap (NLF) is commonly used for intraoral reconstruction following fibrotomy due to its ease of harvest, rich vascularity, and versatility [3]. However, conventional NLFs have limitations, including visible scarring and tension at the pivot point, which can compromise both aesthetic and functional outcomes [4].

Recent innovations include the fishtail modification—a technique that involves bifurcating the distal end of the flap to create a wider base for intraoral coverage, reducing the chance of flap retraction and improving scar concealment [5]. While anecdotal reports support its efficacy, robust clinical evidence comparing fishtail-modified NLF with the conventional design is limited.

Objective: The aim of this study is to evaluate and compare the outcomes of conventional nasolabial flaps with fishtail-modified nasolabial flaps in the surgical management of advanced OSMF.

Study Design and Setting:

This prospective randomized clinical trial was conducted at the Department of Oral and Maxillofacial Surgery, [Institution Name], between January 2023 and December 2023.

Sample Size and Selection:

Forty patients diagnosed with grade III or IV OSMF were recruited. Inclusion criteria included restricted mouth opening (<25 mm), no prior surgical treatment for OSMF, and absence of systemic contraindications for surgery. Patients were randomly allocated to Group A (conventional NLF) or Group B (fishtail-modified NLF), with 20 patients in each group.

Surgical Procedure:

All patients underwent bilateral fibrotomy under general anesthesia. In Group A, a standard nasolabial flap was raised, while in Group B, the distal tip was split into a fishtail configuration. Flaps were rotated intraorally and sutured to the buccal mucosa. Donor sites were closed primarily in both groups.

Outcome Measures:

• Primary Outcome: Interincisal mouth opening (IMO) measured preoperatively and at 1, 3, and 6 months postoperatively.
• Secondary Outcomes: Flap viability, wound dehiscence, scar visibility (graded by two blinded observers), and patient satisfaction (assessed using a 10-point Likert scale).

Statistical Analysis:

Data were analyzed using SPSS version 25.0. Continuous variables were presented as mean ± SD. Independent t-tests and paired t-tests were used for inter- and intra-group comparisons. Categorical variables were analyzed using Chi-square tests. A p-value < 0.05 was considered statistically significant.

Demographics
The study comprised 40 patients, of which 28 were male and 12 were female. The mean age across the study population was 36.2 ± 6.7 years. Both groups were comparable at baseline with no statistically significant differences in demographic characteristics or preoperative mouth opening.

Interincisal Mouth Opening (IMO)

Improvement in mouth opening was observed in both groups postoperatively. Group A (conventional nasolabial flap) showed an increase in mean interincisal mouth opening from 18.3 ± 2.7 mm preoperatively to 33.6 ± 3.1 mm at six months. Group B (fishtail-modified flap) demonstrated a greater improvement from 17.9 ± 3.0 mm to 36.2 ± 2.9 mm over the same period. Statistically significant differences were observed between the groups at 1 month (p = 0.04), 3 months (p = 0.02), and 6 months (p = 0.03) postoperatively (Table 1).

Complications and Flap Viability

All flaps remained viable throughout the follow-up period. One case of wound dehiscence was recorded in Group A. No instances of infection or flap necrosis were reported in either group, indicating high procedural safety.

Scar Visibility and Patient Satisfaction

Aesthetic outcomes favored the fishtail-modified flap. Low scar visibility was reported in 80% of patients in Group B compared to 40% in Group A (p = 0.02). Additionally, 90% of Group B patients reported high satisfaction levels versus 55% in Group A, showing a significant difference in patient-perceived outcomes (p = 0.01) (Table 2).

Table 1: Interincisal Mouth Opening at Different Time Points

Table 2: Scar Visibility and Patient Satisfaction Outcomes

This study demonstrates that the nasolabial flap with fishtail modification offers significantly better functional rehabilitation and aesthetic satisfaction compared to the conventional nasolabial flap in patients undergoing surgical management for advanced oral submucous fibrosis (OSMF). The interincisal mouth opening (IMO) in both groups improved significantly postoperatively; however, Group B (fishtail-modified flap) showed superior results at all follow-up intervals. This improvement can be attributed to the broader and bifurcated distal end of the fishtail flap, which provides increased mucosal coverage, reduces tension at the suture lines, and allows more uniform distribution of forces during mouth opening. These factors likely enhance mucosal integration, minimize postoperative fibrosis, and contribute to sustained functional gains, consistent with earlier experimental and clinical reports [6].

In addition to functional improvements, aesthetic considerations are paramount in reconstructive oral surgery, especially in younger patients and those concerned with facial symmetry and scarring. The results from this study clearly indicate that the fishtail modification improves scar concealment, with 80% of patients in Group B reporting low scar visibility compared to only 40% in Group A. This aligns with the findings of earlier studies emphasizing the importance of strategic flap design in minimizing facial disfigurement post-surgery [7]. The modification likely allows the final scar to blend more naturally with the nasolabial fold and mimic the natural creases of the face, reducing its visual prominence.

The findings also corroborate the work of Bhandarkar et al., who emphasized the benefits of angular or fishtail extensions in improving flap adaptability and esthetic outcome [8]. Importantly, despite the altered design, there was no compromise in flap survival or vascular integrity. The absence of flap necrosis and the minimal incidence of wound dehiscence (only one case in Group A) reinforces the anatomical basis of the nasolabial flap's vascular reliability. The angular artery, a branch of the facial artery, provides a robust and consistent blood supply, making the nasolabial flap—modified or not—highly dependable for intraoral reconstruction [9].

From a surgical standpoint, the fishtail modification does not significantly increase operative time or complexity. It maintains the procedural simplicity and ease of harvest associated with the conventional flap while enhancing its versatility. Moreover, the modification allows better contouring to intraoral defects, particularly in the buccal mucosa, which is often extensively affected in OSMF. The extended base also reduces the risk of contracture, which is a known cause of relapse in OSMF surgical management.

A major strength of this study lies in its prospective, randomized design and standardized follow-up protocol. These features lend credibility to the findings and help control for biases that are often associated with retrospective or observational studies. Furthermore, patient satisfaction was objectively quantified, providing a comprehensive assessment of the psychosocial impact of both techniques.

Nonetheless, this study is not without limitations. The sample size, although adequate for preliminary comparison, remains relatively small, which may limit the generalizability of the results. Additionally, the follow-up duration of six months, while sufficient to assess short-term outcomes such as wound healing and initial functional gain, does not provide insights into long-term recurrence rates of fibrosis, sustained mouth opening, or the risk of malignant transformation. OSMF is a progressive condition with a variable clinical course, and long-term surveillance is critical to truly establish the efficacy of any surgical intervention.

Another limitation is the lack of objective assessment of fibrosis recurrence through imaging or histopathological markers. Furthermore, while patient satisfaction was measured, more detailed tools such as quality-of-life indices (e.g., OHIP-14 or FACE-Q scales) could offer deeper insights into the broader psychosocial outcomes of reconstructive surgery.

In light of these limitations, future research should aim at conducting larger, multicentric trials that include long-term follow-up (≥2 years) to evaluate the durability of surgical outcomes and the risk of relapse or carcinogenic progression. Comparative studies with other flap techniques—such as buccal fat pad flaps, radial forearm free flaps, or tongue flaps—would also be beneficial in determining the most effective reconstructive strategy in varying clinical scenarios. Incorporating imaging modalities such as ultrasonography or elastography could also help assess submucosal tissue remodeling objectively.

The fishtail-modified nasolabial flap offers a superior alternative to the conventional flap for the treatment of advanced oral submucous fibrosis. It achieves greater improvement in mouth opening and better aesthetic outcomes without compromising flap viability. The technique is simple, reliable, and suitable for routine surgical practice.

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