Assessment of lingual nerve functions after smoking cessation.

OBJECTIVE: Cigarette smoking is associated with a variety of oral diseases. A previous study showed a reduction of thermal sensitivity in the innervation area of the lingual nerve in smokers possibly caused by a degeneration of thermosensitive receptors as a consequence of smoking. The current study investigates somatosensory changes in ex-smokers. MATERIALS AND METHODS: Sensory functions in innervation areas of lingual nerve were investigated in 40 ex-smokers by psychophysical means. Functions of lingual nerve in 40 ex-smokers were compared to those in 40 smokers and 40 non-smokers. Subjects were investigated using quantitative sensory testing (QST, cold and warm detection, thermal sensory limen, heat and cold pain, and mechanical detection). RESULTS: Significant differences were found in both groups, ex-smokers and smokers compared to non-smokers. Cold (p < .001), warm (ex-smokers: p < .01; smokers: p < .001) detection thresholds and thermal sensory limen (p < .001) showed significantly lower sensitivity in ex-smokers and smokers in comparison to non-smokers. CONCLUSIONS: The lower temperature sensitivity of ex-smokers compared to that in non-smokers indicates a reduction of somatosensory function of the tongue, possibly caused by irreversible nerve degeneration associated with smoking. Influencing factors leading to sensory changes could be modulation of thermo-receptors, demyelination as well as a change of the epithelial structure.

Simplifying the assessment of the recovery from surgical injury to the lingual nerve.

OBJECTIVE: To determine the sensitivity of conventional sensory assessment in monitoring lingual nerve recovery subsequent to third molar surgery and to evaluate if the assessment methods can be predictive of injury outcome. METHOD: A prospective case series of 94 patients presenting with lingual nerve injuries evaluated using objective mechanosensory and subjective methods during the recovery period of up to 12 months. RESULTS: The conventional tests were often unable to diagnose the presence of injury due to variability and they were not predictive of outcome. As a result of this study, we are able to identify patients more likely to have permanent rather than temporary lingual nerve injury at four to eight weeks post injury, using patient reported subjective function. The subjective function test also minimises the requirements for specialist training or equipment providing an ideal method for general dental practice. CONCLUSIONS: The development of these simple subjective tests may enable us to identify which patients are at risk of permanent lingual nerve injuries in the early post injury phase, thus allowing expeditious therapy when indicated.

A comparison of patient satisfaction and objective assessment of neurosensory function after trigeminal nerve repair.

PURPOSE: The purpose of this study was to compare objective and subjective assessments of neurosensory function after trigeminal nerve repair. METHODS: This was a retrospective cohort study using a sample of patients who underwent surgical repair of trigeminal nerve injuries. The primary study variables were categorized as objective or subjective. The objective variable was the change in neurosensory examination between preoperative and 1-year postoperative visits. Neurosensory status was measured using an ordinal scale ranging from anesthetic (0) to normal (4). Subjective variables included patient satisfaction with the nerve repair and patient assessment of injury-related oral dysfunction. Demographic, anatomic, and operative variables were also collected. Appropriate univariate and bivariate statistics were computed. RESULTS: The sample was composed of 19 patients (14 female, 17 Caucasian) who had trigeminal nerve repair (17 lingual, 2 inferior alveolar). The mean duration between injury and repair was 4.5 +/- 2.3 months; between repair and postoperative assessment was 11.9 +/- 0.9 months. The mean change in neurosensory status was 1.3 +/- 1.0 levels. The majority of patients (63.1%) rated their satisfaction with the outcome of treatment as "good" to "excellent." There was a statistically significant correlation between change in neurosensory status and patient satisfaction (rho = 0.86; P < .01). CONCLUSION: There is evidence of a strong correlation between improvement in the neurosensory examination following trigeminal nerve repair and patient satisfaction with the surgical outcome 1-year postoperatively. Patients who experience greater neurosensory improvement also report lower frequencies of related oral dysfunction.

Long-term outcome assessment for lingual nerve microsurgery.

OBJECTIVE: A retrospective study was undertaken to investigate the clinical outcomes resulting from the microsurgical repair of lingual nerve injuries. The study was based on patient chart review. PATIENTS AND METHODS: A total of 20 patients referred to the principal investigator (V.B.Z.), with a diagnosis of lingual nerve injury who underwent trigeminal nerve microsurgery during a 3-year period (1999 to 2002), were entered in this study. All patients received a complete history and physical examination, and thorough preoperative and postoperative neurosensory testing to evaluate clinical response to hot, cold, cotton wisp, vibration, 2-point discrimination, directional stroke, and fine touch as determined by Von-Frey filaments. RESULTS: All patients underwent an external neurolysis procedure in combination with an internal neurolysis, neuroma excision, or primary neurorrhaphy under microscopic guidance depending on the intraoperative findings. The average time from injury to surgery was 8 months. The patients were followed for an average of 9 months after surgery, and assessment was based on the patients subjective experience as well as standardized neurosensory testing. Eighteen patients (90%) had some improvement in neurosensory function and 2 patients (10%) reported no improvement. One of the patients exhibiting no clinical improvement had a prolonged delay in seeking treatment, and the distal nerve could not be localized intraoperatively. Most patients were operated on between 2.5 and 7 months after injury, and there was no statistical difference in outcome as a function of the time from injury to repair in this group of patients. This subgroup of responding patients averaged at least 50% improvement in neurosensory function. CONCLUSION: Microsurgical repair of lingual nerves provides moderate to significant improvements in clinical sensory function and is a useful option in treating affected individuals, especially when implemented soon after injury.

Assessment of trigeminal somatosensory evoked potentials in burning mouth syndrome.

OBJECTIVE: The measurement of pain threshold (PT) and the assessment of trigeminal somatosensory evoked potentials (TSEPs) were performed. These experiments indicated the pathological conditions of nerve afferent and efferent pathways in patients with burning mouth syndrome (BMS). This study also explored the probable pathophysiological mechanisms in BMS. MATERIALS AND METHODS: The dorsum linguae of 38 samples in 19 subjects (22 BMS with pain, 10 BMS with numbness, and 6 controls) were stimulated by electroneuromyography. PT was measured as the lowest stimulation intensity the subjects could detect. N3, P4 latency, and spike potential latency of TSEP were recorded by stimulating the lingual nerve. RESULTS: Pain thresholds were significantly lower, N3, P4 latencies were significantly shorter, and the spike potential appeared earlier in the BMS with pain group (P < 0.01). The opposite tendency of these values presented in the BMS with numbness group (P > 0.05). CONCLUSIONS: The results indicated that the nerve sensitivity was elevated in the BMS with pain group, and that these patients were easily affected by etiological factors. In the BMS with numbness group, partial or complete nerve blockage may have been indicated. This study suggested that selfreports of BMS pain appeared to be of value, and that there were pathological conditions in nerve transmission. It supported the theory that peripheral or central nervous system involvement might play an important role in BMS. It was possible to show the pathogenesis of BMS. All of these objectively explain the clinical understanding of BMS, and may be of assistance in the treatment of BMS.

Assessment of inferior alveolar and lingual nerve disturbances after dentoalveolar surgery, and of recovery of sensitivity.

In a follow-up of 1107 dentoalveolar operations in the postcanine region, 24 (2.2%) temporary sensitivity disturbances of the inferior alveolar nerve and 16 (1.4%) of the lingual nerve were found. Permanent disturbances were not present. Complete recovery had occurred by 6 months in all cases. The incidence of temporary sensitivity disturbances depended on the different surgical interventions performed. For evaluation and follow-up purposes, a computer-aided pain and thermal sensitivity (PATH) tester was used. By PATH testing, spontaneous recovery can already be ascertained at the third or fourth postoperative month.

A method of assessment in cases of lingual nerve injury.

A method for assessing lingual sensation is described, comprising sensory testing, using touch and moving two-point discrimination and patient subjective reporting. The clinical application is seen to be the evaluation of lingual nerve injury consequent upon lower third molar surgery. Using this method it is considered possible to identify many of those patients unlikely to make full spontaneous recovery at the stage of 3 months following injury, with a view to achieving an earlier timing of surgical repair than that which prevails at present.