Evaluation of sensitivity of teeth after mandibular fractures.

The sensitivity of teeth anterior to a fracture between the mental and mandibular foramina has been tested and followed up until reinnervation or 3 years has passed. This study assessed the reinnervation period, the number of denervated teeth, and their clinical importance. Fifty patients and 459 teeth were examined. Two hundred and seventy-three teeth were affected and had potentially impaired innervation. Tests after injury showed non-responsive teeth in 81% of affected teeth. Six weeks after injury, 19% of teeth were reinnervated; by 1 year after injury, 92% of initially non-responsive teeth were reinnervated. Most teeth (34%) were reinnervated from 6 weeks to 3 months. All 23/186 initially non-responsive, unaffected, contralateral corresponding teeth were reinnervated within 6 weeks. A year after injury, 95% of incisors, 91% of canines, 94% of premolars, and 82% of molars were reinnervated. Three years after injury, 8% of teeth remain denervated. During the second and third years, no reinnervation occurred, but clinical signs of pulp devitalisation of denervated teeth occurred in 18% or 1% of the initially non-responsive affected teeth. The results revealed the stability of pulp 1 year after injury. Denervated teeth should not be treated if no clinical or radiological signs of devitalisation exist.