Midface reconstruction in a Cordeiro IIIA defect secondary to maxillary osteoid osteoma using an antidromic temporalis muscle flap and calvarial graft.

Abstract

Introduction

Osteoid osteoma is a benign osteoblastic bone tumor that represents approximately 10–14% of benign bone tumors and between 2 and 3% of all bone tumors. Its location in the maxilla is exceptional and can present a diagnostic challenge due to its similarity to other benign bone lesions. When it involves the orbital floor, surgical resection generates complex defects that require restoration of eyeball support, soft tissue coverage, and the contour of the midface. In this context, the antidromic temporalis muscle flap combined with an autologous calvarial bone graft constitutes an effective regional alternative for orbital floor reconstruction. Due to the rarity of this entity and the limited number of cases described with this reconstructive strategy, we present the following case.

objective

To present the reconstructive management and functional and aesthetic results of a patient with maxillary osteoid osteoma treated with subtotal maxillectomy with orbital floor resection and reconstruction using an antidromic temporalis muscle flap and autologous calvarial bone graft.

Methodology

We present the case of a 21-year-old female patient with progressive swelling of the right side of her face over a six-month period, associated with facial deformity. Imaging studies demonstrated an expansive bone lesion of the right maxilla with involvement of the orbital floor; The definitive diagnosis of osteoid osteoma was confirmed by histopathological examination.

After multidisciplinary evaluation, a right subtotal maxillectomy with orbital floor resection was performed, resulting in a Cordeiro type IIIA defect. The reconstruction was performed during the same surgical procedure using an autologous calvarial bone graft to restore orbital support and transposition of an antidromic temporalis muscle flap to provide vascularized coverage and restore soft tissue volume. Clinical follow-up was conducted to evaluate the viability of the reconstruction, graft integration, ocular function, eyeball position, and facial symmetry.

Results

At 12-month follow-up, the patient presented with a favorable postoperative course, with complete flap viability and satisfactory integration of the calvarial bone graft. Visual acuity, ocular motility, and proper eyeball position were preserved, with non-functional alterations attributable to the reconstruction. Late sequelae included mild ectropion and slight midface asymmetry, which was corrected with autologous fat grafting, achieving better volume restoration and a satisfactory functional and aesthetic result.

Conclusions

Osteoid osteoma of the maxilla is a rare condition whose treatment can result in complex orbitomaxillary defects. Reconstruction using an antidromic temporalis muscle flap combined with an autologous calvarial bone graft is a safe, reproducible, and effective regional alternative for Cordeiro IIIA defects, allowing for the restoration of orbital support, preservation of ocular function, and recovery of the midface contour with favorable functional and aesthetic results.