Mandibular reconstruction may be indicated for the following:
- Segmental defect of mandible following tumor ablation.
- Chronic osteomyelitis of the mandible or comminuted nonhealing mandible fracture.
- Acquired or congenital malformation of the mandible.
Among the most exciting advances in modern surgery has been an improved ability to reconstruct surgical defects and areas of tissue loss. Reconstruction of an area implies recreating not only the shape and appearance of the missing or injured tissues, but also the function. That is, ideally, the reconstructed region would look, move, feel, and sense precisely the way the native tissues once did when they were in good health.
It is in the head and neck where the need for accuracy in both functional and aesthetic reconstruction becomes the most evident. In general, it is a person's face that identifies him or her to others, and the face is the interface through which a person both detects the feelings and sentiments of others and conveys his or her own emotions.
Several disease processes may result in significant injury to the mandible. Severe trauma (eg, a gunshot wound) can result in a comminuted nonhealing fracture or tissue loss. Similarly, a neoplastic process (most commonly squamous cell carcinoma) can invade the mandible. Regrettably, the current state of medicine is such that the surgical removal of some disease processes (eg, certain malignant conditions) still provides the best chance of curing these otherwise fatally progressive disorders. Thus, the ability to reconstruct the mandible retains significance.
Aesthetically, the mandible provides the shape for the lower third of the face, defines the border between the face and the neck, and positions the mentum and lower lip (with the mandibular dentition). Functionally, the mandible supports the masticatory forces and the mandibular dentition. The mandible helps support the tongue in both position and function—a fact easily remembered when one recognizes the significant role a small mandible with a large tongue can play in creating obstructive sleep disturbance. Masticatory bite forces can be significant, with an average of 726 N and maximal forces at the molar occlusal surfaces of 4346 N. Thus, the mandible must be strong and rigid.
To choose an appropriate reconstruction method, the following factors should be considered in reconstructing the mandible: (1) the length and location of the mandibular defect, (2) associated soft tissue loss, (3) the overall health and well-being of the patient, (4) the patient's potential prognosis, (5) potential donor sites, (6) primary versus delayed repair, and (7) the patient's dental health and potential for dental rehabilitation.
The easiest form of mandibular reconstruction is no reconstruction. That is, when faced with a segmental defect, simply close the surrounding soft tissues over the defect, leaving one or two “free-swinging” mandibular segments. This leaves the patient with a significant cosmetic and functional deficit, although for a small lateral defect in an edentulous ...