Ⅰ. INTRODUCTION

Fibroma is a relatively common benign fibrous proliferative lesion in the oral cavity, usually presenting as a submucosal proliferation with various clinical and histopathologic variations. Irritation fibroma is a reactive proliferation due to chronic mechanical irritation or trauma and is among the most frequent oral fibrous lesions1). Cemento‑ossifying fibroma (COF) is characterized by a fibrous stroma containing calcified or ossified material, commonly arising in the premolar–molar region of the mandible2). In both entities, complete surgical excision is regarded as the principle of treatment. In both irritation fibroma and COF, surgical treatment with complete excision has been established in the literature as the key step to prevent recurrence. Kaur et al. (2019) showed that in COF, complete excision yields satisfactory outcomes and is considered the definitive modality. Lalchandani et al. (2020) similarly emphasized that for irritation fibroma, recurrence is rare only when excision is incomplete or the irritant persists. Reconstructive choice depends on the size/location of the residual defect and local tissue mobility. Both lesions are typically covered by normal oral mucosa, not part of the lesion itself, and exist as well‑defined submucosal nodules. Only under repetitive trauma does the overlying mucosa show erosion or ulceration. Prior literature also notes that these lesions commonly present as submucosal nodules covered by normal oral epithelium3,4). However, for irritation fibroma or COF, we found no prior studies that intentionally preserve the overlying normal epithelium or recycle it in situ as an epithelialized free mucosal graft to cover the defect. Mucosal‑preservation approaches have been reported for other encapsulated benign lesions (e.g., tongue schwannoma, oral angiolipoma) with favorable outcomes5,6), but evidence specific to fibroma/COF remains scarce.

Ⅱ. CASE REPORT

<Case 1>

The patient presented with a painless swelling on the left palatal area in the maxillary premolar region with no radiological findings(Fig.1). The lesion was a well‑defined nodule measuring approximately 2.0 × 1.5 × 1.1 cm with a base of attachment of about 1 cm(Fig.2A). Under local anesthesia, the lesion was totally excised(Fig.2B). During the procedure, the overlying mucosa was dissected and processed as a free mucosal graft of 1mm thickness. After verification of bleeding from the bone at the resection site, the graft was adapted to cover the defect and secured to the adjacent mucosa and teeth. The postoperative course was favorable, with minimal pain, epithelialization completed within about four weeks (Fig.2C), and there was no complication such as bleeding, infection, or necrosis. Histopathologic examination confirmed irritation fibroma. Microscopically, dense collagen fibers and hyperplasia of mature fibroblasts were found in connective tissue covered by stratified squamous epithelium (Fig.3).

<Case 2>

A 62‑year‑old female patient was referred from a local clinic with an abnormal soft tissue growth in the right mandibular premolar region. The patient had a medical history of controlled hypertension with no other systemic conditions. According to the history, the lesion had gradually enlarged over six months. Panoramic view showed that lateral displacement of adjacent teeth due to the lesion (Fig.4). Cone‑beam CT (CBCT) imaging demonstrated calcified material within the lesion(Fig.5). Clinical examination revealed a mass measuring approximately 30 × 17 mm and mobility of adjacent teeth was observed(Fig.6A). Under local anesthesia, the lesion was completely excised, and the overlying mucosa was processed as a free mucosal graft to cover the defect. And then, the defect was covered using the same method as in Case 1(Fig.6B). The postoperative course was uneventful, with no issues of pain, bleeding, or infection (Fig.6C).

Histopathologic examination confirmed cemento‑ossifying fibroma(Fig.6). In microscopic view, the lesion was found that consisted of fibrous stroma containing well-formed irregular trabeculae of bone. The same histopathological findings observed in Case 1 were also identified in the Case 2 specimen.

Calcified material within the material obserbed.(arrow)

Ⅲ. Discussion

These two cases presented as typical submucosal nodules covered by normal oral mucosa. Both lesions were completely excised, and the preserved overlying mucosa was recycled as a co‑site free mucosal graft to cover the defects. In Case 2, CBCT demonstrated intralesional calcifications, with lateral displacement and mobility of adjacent teeth. Early postoperative courses were uneventful in both cases.

Prior literature consistently supports complete surgical excision as the standard treatment for both entities1,2,7-10) and frequently describes them as submucosal nodules covered by normal epithelium3,4). However, systematic reports that intentionally preserve the overlying normal epithelium and reuse it as a free mucosal graft at the same site are lacking. By contrast, mucosa‑preservation strategies have been documented for other encapsulated benign lesions (e.g., tongue schwannoma, oral angiolipoma) with favorable outcomes5,6), indirectly supporting the biological and clinical plausibility of our technique.

Our rationale is twofold: first, it respects the oncologic principle of complete excision to minimize recurrence1,2,7- 10); second, it potentially avoids palatal donor‑site morbidity and improves color/texture matching by using native tissue at the same site. Traditional FGG/CTG approaches are associated with donor‑site pain, bleeding, and delayed healing11,12), while secondary intention healing of intraoral wounds may prolong recovery and increase risks of pain, bleeding, or contamination13,14,15). Immediate coverage with a preserved free mucosal graft may therefore stabilize the wound surface and enhance patient experience.

Nevertheless, this technique cannot always be applied universally. Its success depends on the condition of the recipient site. The possibility of failure can be increased by configuration and insufficient vascularity of recipient site. Therefore, careful evaluation of the recipient site is essential before selecting this method.

Limitations include early vascular vulnerability inherent to free grafts, limited size/thickness for large defects, and the prerequisite histopathologic safety of the overlying mucosa. Moreover, the present report is restricted by the small sample size, limited long‑term follow‑up for Case 1 beyond four weeks, and the lack of intraoperative and early (after 2 weeks) postoperative photographs for Case 2. Prospective cohorts and controlled comparisons (versus secondary intention or traditional FGG) are warranted.

Ⅳ. CONCLUSION

After excision of irritation fibroma and cemento‑ossifying fibroma, preserving the overlying normal oral mucosa as a free mucosal graft can provide stable coverage of the defect without an additional donor site, offering a practical reconstructive option with favorable clinical integration. The prerequisites for this technique include complete excision, histopathologic confirmation of the safety of the overlying mucosa, and secure fixation with meticulous hygiene. Limitations are the small sample size (two cases) and restricted long‑term follow‑up. Future work should comprise prospective controlled studies comparing this technique with secondary intention healing and conventional FGG, along with standardized objective endpoints (pain scores, bleeding, time to epithelialization, patient‑reported outcomes, recurrence).