Head and Neck Reconstruction

Which muscles close the mouth?

• Masseter

• Temporalis

• Medial pterygoid

Which muscles open the mouth?

• Digastric muscles

• Mylohyoid muscles

• Geniohyoid muscles

• Genioglossus muscles

Which muscles protract the mandible?

• Lateral pterygoid muscles

• Digastric muscles

• Mylohyoid muscles

What are the goals of mandible reconstruction?

• Restore shape of the lower third of the face.

• Preserve occlusion (if dentition).

• Allow for potential dental implants.

• Heal in a timely fashion—do not delay adjuvant therapy.

When can nonvascularized bone grafts be used in mandible reconstruction?

• Isolated small defects in favorable locations for soft-tissue coverage (ramus, body).

• No radiation history or plan for radiation therapy.

In the medically compromised patient, what can be done to reconstruct a segmental defect at the time of mandibular resection?

• Reconstruction plate and regional tissue (pectoralis major, latissimus dorsi).

• Avoid plate reconstruction with anterior defects.

What are the disadvantages of plate reconstruction?

• Plate fatigue and fracture

• Screw loosening

• Plate exposure—beware with anterior defects and/or radiation therapy

• Osteoradionecrosis

What common microvascular flaps are available for mandible reconstruction?

• Fibula flap

• Iliac crest flap

• Scapula flap

• Radial forearm osseous flap

What is the blood supply to the iliac crest free flap?

Deep circumflex iliac artery.

What are the advantages of the iliac crest free flap?

• Good length of bone.

• Tall bone stock—good for implants. Abundant soft tissue—good for large-volume defects.

What are the disadvantages of the iliac crest free flap?

• Short pedicle, small vessels.

• Poor skin paddle mobility.

• Protracted gait pain, risk of abdominal hernia.

• Potential for meralgia paresthetica (lateral femoral cutaneous nerve injury/entrapment).

What are the advantages of the fibula free flap?

• Reliable skin paddle for closure/monitoring.

• Long, sturdy bone.

• Long pedicle, large caliber vessels.

• Supports osseointegrated implants.

• Allows for simultaneous dissection while tumor is being resected.

• Can make two skin islands based on separate perforators and include a portion of soleus muscle.

What are the disadvantages of the fibula free flap?

• Contraindicated with severe peripheral vascular disease.

• Donor-site healing can be difficult and prolonged in some patients.

What options exist for reconstruction of the mandibular condyle?

• Reinsert condylar process as a nonvascularized bone graft if disease free—viability may be unpredictable, especially with radiation therapy.

• Neocondyle—rounding off of the fibula flap transfer.

• Prosthetic reconstruction—not recommended if postoperative radiotherapy is planned.

• No reconstruction—mandible will rotate obliquely with opening.

What is the typical dose to a tumor bed after resection of an oral cavity tumor?

Typical dose is between 60 and 80 Gy.

What effect does radiation therapy have on normal tissue?

• Acute: dermatitis, mucositis, dysphagia, odynophagia, xerostomia, altered taste, fatigue.

• Late: xerostomia, hyperpigmentation, dental decay, osteoradionecrosis, dysphagia, strictures, cataracts, sensorineural hearing loss, soft-tissue fibrosis, neck lymphedema.

What are the implications of xerostomia on oral function?

• Accelerated tooth decay.

• Chewing, swallowing difficulties.

• Speech problems.

Why is the mandible vulnerable to osteoradionecrosis?

• Radiation therapy–induced obliteration of inferior alveolar artery without adequate redundant blood supply is believed to contribute.

• Histologically, scarcity of osteoblasts leads to fragile bone, susceptible to minimal injury.

When does osteoradionecrosis manifest?

• 1 to 3 years after radiation therapy, with an overall risk of 3% with current radiation techniques.

• Risk is present for the patient’s entire life.

How does radiation therapy complicate dental extractions?

• The incidence of osteoradionecrosis increases significantly if dental extraction is performed after radiotherapy. Therefore, it should be done before radiotherapy.

• Should wait 10 to 14 days between extractions and radiation therapy.

• Atraumatic extraction with minimal mucoperiosteal flap undermining should be practiced if extraction is unavoidable.

• Hyperbaric oxygen and empiric antibiotic therapy have to be employed to minimize risk.

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