Is Facial Artery Musculomucosal Flap a Viable Option for Reconstruction of Intraoral Defects Resulting from Osteonecrosis?

Osteonecrosis of the jaw can be caused by multiple etiologies, such as radiation, infection, and bisphosphonate use¹. In many cases, small area defects can be managed with superficial debridement and soft tissue closure. However, moderate size defects pose a significant challenge in terms of providing adequate soft tissue coverage. Such coverage is paramount due to the avascular nature of the disease. However, the soft tissue surrounding the lesions is usually inflamed and fibrotic. Unfortunately, the availability of vascularized soft tissue donor sites in this group of patients is limited. Distant donor sites may carry excessive morbidity and they provide an unnecessary bulk of tissue to cover a moderate-size defect. This study reports the use of a facial arterial musculomucosal (FAMM) flap to  provide soft tissue coverage for patients who have moderate bony involvement caused by osteoradionecrosis (ORN), Bisphosphonate related osteonecrosis (BRONJ), and osteomyelitis; as these patients often develop intraoral defects that require reconstruction.

This retrospective study involved patients with a diagnosis of ORN, BRONJ, or  osteomylitis.  Demographic data, etiology of the osteonecrosis, size and location of the defect, ASA status, disease progression during the follow-up period, donor site morbidity, and flap survival were documented. There was a minimum of six months follow-up. Clinical outcome was classified as: [1] complete closure, [2] partial closure, and [3] complete open defect.

Six patients were identified that met our criteria to be included in the following study. The average defect size was 10 mm x 30 mm. The age of the patients ranged from 36 to 71 years, and there were an equal number of males and females. Three of the patients were diagnosed with ORN, two with osteomyelitis, and one with BRONJ. All defects were located at the mandibular alveolar crest. Post- operatively, there were no complications or flap failures. The donor sites were well healed without excessive scarring that can lead to trismus. Five patients had complete closure of their defects, however one patient with BRONJ had partial closure. The success rate was the same in patients who had previous neck dissection or radiation as in non radiated individuals. In all three ORN patients, facial arteries were identified intra-operatively with Doppler ultrasound. This finding is consistent with that of  Perrett et al.²on the existence of the facial artery in radiated patients with previous neck dissection.

Based on these findings, the FAMM flap appears to be the desired flap to reconstruct moderate-size intraoral defects resulting from BRONJ, ORN, and osteomyelitis.  The partial wound dehiscence in one patient was most likely a result of harvesting an inadequately sized flap. The advantages of the FAMM flap include reliability, ease of harvest, close proximity to the defect, similar mucosal lining, no visible scarring, and no major complications. Its major disadvantage is significant flap shrinkage during the post-operative period. Therefore, the flap should be harvested at a size 20% larger than the size of the defect to prevent wound dehiscence. Although this study is limited by its small sample size and retrospective nature, it serves as a pilot study for subsequent research involving this flap in managing these types of patients.

1. Cozin M, Pinker BM, Solemani K, Zuniga JM, Dadaian SC, Cremers S, Landesberg R, Raghavan S. Novel therapy to reverse the cellular effects of bisphosphonates on primary human oral fibroblasts. J Oral Maxillofac Surg. 2011 Oct; 69(10):2564-78.
2. Parrett B, Przylecki WH, Singer MI. Reliability of the Facial Artery Musculomucosal Flap for Intraoral reconstruction in Patients who Have Undergone Previous Neck Dissection and Radiation Therapy, Plastic and Reconstructive Surgery 2012; 130(6): 910e-911e