Evaluation of Peri-Implant Soft Tissue after Osteocutaneous Free Flap Reconstruction of Mandibular Defects: A Case Series

Abstract

The use of osteocutaneous free flaps has been a long-standing, predictable method of reconstruction for mandibular defects that has allowed patients to regain form and function. Placement of dental implants into the osteocutaneous free flap has been a significant advancement that has improved mastication, retention, and stability of dental prostheses. However, several challenges have been noted, such as peri-implant mucositis and gingival tissue overgrowth, that have limited implant longevity due to lack of adequate peri-implant hygiene. Other contributors to this problem may be inherent to skin itself as a peri-implant tissue, flap thickness, and skin mobility. The aim of our study was to analyze soft tissue challenges and their effect on implant success after dental implant placement into osteocutaneous free flaps. A case series identified 6 patients who underwent dental implant placement in microvascular mandibular reconstructions between 2012-2019 in an academic institution. Patient-specific information, such as indication for osteocutaneous fibula free flap reconstruction and history of radiation to the head and neck region, were evaluated. Furthermore, implant-specific information, such as implant longevity, radiographic changes of surrounding peri-implant bone, and implant success as defined by the Albrektsson criteria, were examined. Tissue-specific factors, such as type and number of tissue modification procedures performed, were collected. We also analyzed the type of dental restoration each patient obtained. A total of 20 (16 BioHorizons Laser-Lok and 4 NobelActive TiUnite) dental implants were placed into osteocutaneous fibula free flaps. One patient in the cohort received radiation therapy to the head and neck. Based on the Albrektsson criteria, 3 of the 20 (15%) implants failed due to severe peri-implant bone loss and implant mobility. Secondary gingival debridement, flap debulking, and vestibuloplasty procedures were performed in 4 patients. Two patients underwent simultaneous implant placement and flap debulking; however, both required additional flap debulking prior to dental rehabilitation. Two patients obtained soft tissue debulking, vestibuloplasty, or gingival debridement after implant placement. Of the patients with post-implant placement soft tissue modifications, 1 patient required serial gingival debridements. Of the 5 patients with restorative data, 1 patient had implants restored with a fixed partial denture, and 4 patients are being restored with an implant retained mandibular partial overdenture (3 loaded and 1 awaiting final restoration). Endosseous dental implant placement into osteocutaneous fibula free flaps continues to be an acceptable treatment option for dental reconstruction. Even though dental implants allowed for a stable dental rehabilitation, significant soft tissue challenges exist that require multiple pre-prosthetic and maintenance surgeries to maintain implant function.