Lingual nerve damage due to inferior alveolar nerve blocks: a possible explanation.

BACKGROUND: An explanation for the predominance of injuries to lingual nerves over those to inferior alveolar nerves as a result of inferior alveolar nerve blocks may be due to the nerves' fascicular pattern. A unifascicular nerve may be injured more easily than a multifascicular nerve. METHODS: The authors unilaterally dissected lingual and inferior alveolar nerves from 12 cadavers. They cut the specimens 2 millimeters above the lingula for both the lingual nerve and inferior alveolar nerve and opposite the site of the middle of the third molar for the lingual nerve, and they counted the number of fascicles at each site. RESULTS: For the lingual nerve at the lingula, the mean number of fascicles was three (range, one to eight). Four of the 12 nerves (33 percent) were unifascicular at this point. Opposite the third molar, the lingual nerve had a mean of 20 fascicles (range, six to 39). In every case, there were more fascicles in the third molar region than above the lingula in the same nerve. At the lingula, the inferior alveolar nerve had a mean of 7.2 fascicles (range, three to 14). CONCLUSION: This study may explain the observation that when an inferior alveolar nerve block causes permanent nerve impairment, the lingual nerve is affected about 70 percent of the time and the inferior alveolar nerve is affected only 30 percent of the time. In 33 percent of cases, the lingual nerve had only one fascicle at the lingula; a unifascicular nerve may be injured more easily than a multifascicular one. CLINICAL IMPLICATIONS: There is no known way to avoid the remote possibility of nerve damage resulting from an inferior alveolar nerve block. The lingual nerve may be predominantly affected because of its fascicular pattern.

Management of avulsive injuries of the nasal bones: review of the literature and three case reports.

Blunt contusions, lacerations, and avulsion-type trauma are the most often reported nasal injuries sustained in motor vehicle accidents. The nasal skeleton and soft tissues are frequently involved and may require surgical repair of the injuries. The primary reconstruction often requires the use of autogenous grafts, and secondary revision surgery may be necessary. The treatment may require a multidisciplinary surgical team or a single surgeon who knows how to manage the injury. Optimally, the reconstruction of nasal bone avulsions is performed primarily, using autogenous graft materials. This article presents reconstruction of the nasal deformities in 3 patients involved in motor vehicle accidents. The authors describe and evaluate the various graft materials and surgical techniques utilized. The advantages and disadvantages of autogenous and alloplastic materials are discussed. Studies with more patients and long-term follow-up are required for a definitive evaluation.