Facial Artery Musculo-Mucosal (FAMM) Flap

Julian J. Pribaz

Simon G. Talbot

ANATOMY

The FAMM flap is an axial flap containing the facial artery with its accompanying venous plexus, with a small amount of surrounding buccal fat, buccinator muscle, submucosa, and mucosa. It can be thought of as an intraoral and mirrorimage version of an axial nasolabial flap.
Arterial anatomy
- The facial artery provides a rich blood supply to the lower central part of the face and neck.
- It is a branch of the external carotid artery, and after giving off several cervical branches, it enters the face by hooking around the lower border of the mandible at the anterior edge of the masseter muscle (FIGS 1 and 2).
- It follows a tortuous course through the cheek, passing upward and medially toward the oral commissure.
- It traverses deep to the superficial muscles of facial expression— the risorius, the zygomaticus major and minor, and the superficial lamina of the orbicularis oris muscles.
- It lies superficial to the buccinator, the levator angulioris muscle, and the lateral edge of the deep lamina of the orbicularis oris muscle, and it has a variable relationship to the levator labii superioris muscle.
  
  FIG 1 • Anatomy of facial artery.
- It gives off the inferior and superior labial arteries (through which it connects with the contralateral side), as well as multiple perforators to the cheek skin and mucosa. In the cheek, it also anastomoses with the buccal and transverse facial vessels.
- It continues superiorly as the angular artery, giving multiple perforators to the nasal alar and sidewall, and terminates near the medial canthus where it anastomoses with branches from the dorsal nasal, infratrochlear, and infraorbital vessels.²
Venous Anatomy
- The main facial vein does not run with the artery but is located more laterally in the cheek and approaches the facial artery near the angle of the mandible.
- Nonetheless, the FAMM flap has an excellent venous outflow and rarely becomes congested due to a “syncytial” type of venous plexus within the submucosa, which connects not only to the facial vein but also to pterygoid plexus and maxillary vein.
Due to its intraoral design, the FAMM flap spares the superficial and most important muscles of facial expression and their nerve supply, as well as the overlying skin, thus minimizing deformity.³

The FAMM flap is usually 1.5 to 2 cm in width and can be 8 cm in length, but it is key that the facial artery traverses
the entire flap. Although from the vascular point of view the flap could certainly be made wider, this would create too large an intraoral defect, leading to contracture.

FIG 2 • Schematic of the course of the left facial artery through the cheek passing between the superficial muscles of facial expression and buccinators. Contralateral intraoral view of proposed right FAMM flap.

The flap is designed anterior to Stensen duct.
The FAMM flap can be based superiorly (where the blood flow is retrograde) or inferiorly (where the blood flow is antegrade), thereby increasing its versatility.

PATIENT HISTORY AND PHYSICAL FINDINGS

The FAMM flap may be indicated in patients with a wide array of relatively small (yet difficult to repair) defects and deformities within the oral cavity, including small defects in hard and soft palate, alveolus, buccal sulcus, floor of mouth, tongue, and tonsillar fossa. It can also be used to reconstruct defects of the upper and lower lip vermilion. In addition, the flap has been used to reconstruct intranasal mucosal defects.⁴^,⁵
The patient needs to be carefully evaluated and the problem in question accurately assessed according to its location and size to determine if a pedicled FAMM flap (with maximum size 2 × 8 cm) can be used for the reconstruction.
An intact facial artery, detected by Doppler examination, is crucial, as is the lack of scars from previous procedures along the course of the flap.

Superiorly or Inferiorly Based FAMM Flap?