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immobilization. Other causes include infection, inaccurate reduction,

and lack of contact between fragments, traumatic ischemia, and

periosteal stripping.

Alcoholism is a major contributor to both delayed union and nonunion,

combined with poor compliance, poor nutrition, poor oral hygiene, and

tobacco abuse.

Treatment of delayed union and nonuntion includes identifying the

cause, controlling infection, surgically debriding devitalized tissues,

removing existing hardware, refreshing the bone at fracture ends,

reestablishing correct occlusion, stabilizing segments with a 2.4 locking

plate, and grafting autogenous bone.

D. Malunion

Malunion is the improper alignment of the healed bony segments. It is

caused by improper reduction, inadequate occlusal alignment during

surgery, imprecise internal fixation, or inadequate stability of the

fracture site.

Not all malunions are clinically significant. When teeth are involved in

the malunion, a malocclusion may result.

Treatment of malunion often requires identification of the cause, and

then orthodontics for small discrepancies or an open surgical approach

with standard osteotomies, refracturing, or both.

E. TMJ Ankylosis

Ankylosis is a process where the mandibular condyle fuses to the

glenoid fossa. It results from intra-articular hemorrhage, which leads to

joint fibrosis and eventual ankylosis. Ankylosis may also cause underde-

velopment due to injury of the mandibular growth center.

Ankylosis can be prevented by using shorter periods of MMF (2–3

weeks) and physiotherapy. Treatment may require additional surgery

in the form of a gap arthroplasty or total alloplastic joint replacement.

F. Trigeminal (Fifth) Nerve Injury

The fifth nerve, or inferior alveolar nerve and its branches, is the most

commonly injured nerve in mandibular fracture. The deficit is numbness

or other sensory changes in the lower lip and chin. Most of the sensory

and motor functions of these nerves improve and return to normal with

time. Iatrogenic injury must be avoided when treating fifth nerve injury.

G. Facial (seventh) Nerve Injury

Seventh nerve assessment in the severely traumatized patient may be

difficult if the patient is obtunded and facial nerve testing is limited to