The role of sensory input of the chorda tympani nerve and the number of fungiform papillae in burning mouth syndrome.

OBJECTIVE: The aim of this study was to evaluate patients suffering from burning mouth syndrome (BMS) and control subjects by means of sensory testing and fungiform papillae count. STUDY DESIGN: The left and right anterior two-thirds of the tongue of of 25 BMS subjects and 20 healthy control subjects were evaluated for electric taste and electric detection threshold. The number of fungiform papillae/cm(2) was evaluated by using close-up digital photography. RESULTS: The electric taste/tingling detection threshold ratio was significantly higher in BMS compared with control subjects (P = .041). No difference was found between the number of fungiform papillae/cm(2) in the BMS compared with the control subjects (P = .277). Patients suffering from BMS for a prolonged period of time presented with a significantly elevated electric taste/tingling detection threshold ratio (P = .031). CONCLUSIONS: BMS may be a neurodegenerative process with chorda tympani nerve hypofunction potentially playing a role in the pathophysiology of this disorder.

Physical neurosensory testing versus current perception threshold assessment in trigeminal nerve injuries related to dental treatment: a retrospective study.

OBJECTIVE: To provide a preliminary comparison of traditional clinical neurosensory examination (CNE) and current perception threshold (CPT). METHOD AND MATERIALS: This is a retrospective chart audit of patients with trigeminal nerve injuries related to dental treatment who were evaluated with both CNE and CPT assessments (electrical stimulus tests) after presenting with altered sensation involving either the inferior alveolar nerve (IAN) or lingual nerve (LN) distributions. The tests were performed on the anterior two-thirds of the tongue for LN injuries and the lower lip and chin for IAN injuries. Results were defined as hyper-, hypo-, or normal sensory response. RESULTS: Twelve charts were reviewed; 10 of the 12 nerve injuries occurred secondary to mandibular third molar extraction affecting 7 LN and 5 IAN branches. Following LN injuries, the C, and A-delta fibers assessment demonstrated hyposensitivity in the affected nerve territory in CPT and the CNE tests with the exception of 1 normal nerve response in 5-Hz CPT. Within the LN injury group, good correlation was observed between the CNE and CPT tests with the exception of brush stroke and 250-Hz CPT stimuli. Following IAN injuries, sensory testing results were more varied. A-beta fiber evaluation demonstrated hyposensitivity to VF in all patients and in 4 of 5 for brush test. One patient was hypersensitive for the brush test. The response to 2,000-Hz electrical stimulus demonstrated hyposensitivity in 3 patients, hypersensitivity in 1 (the same patient that was hypersensitive for brush), and normal sensitivity in 1 patient. Good correlations were found only between the CPT 5-Hz and heat and cold tests. Only 1 patient (IAN injury) reported pain that was hypersensitive for heat, cold, pinprick, brush, and 250-Hz and 2,000-Hz stimuli. CONCLUSION: Following LN injuries, CNE and CPT tests provided similar findings. More disparity was observed between the CNE and CPT methods in the IAN injury evaluation. For LN injury assessments, CNE alone appears to be adequate for assessing nerve injuries.

Comparison of lingual and inferior alveolar nerve microsurgery outcomes.

OBJECTIVE: To evaluate the outcomes of published studies involving lingual nerve (LN) and inferior alveolar nerve (IAN) microsurgery and reviewing differences in sensory recovery and timing to repair for both groups. METHOD AND MATERIALS: A total of 29 patient charts referred to the principal investigator were reviewed (15 IAN and 14 LN). Age, gender, mechanism of injury, and time from injury to surgical repair were assessed. Two-point discrimination and tactile detection threshold (via von Frey monofilaments) were the utilized measured variables because both are quantifiable and repeatable data points. RESULTS: There was a predominance of female patients (10 IAN, 12 LN), and the mean age of the patients in the IAN group (37.40 +/- 9.61 years) was significantly higher than in the LN group (28.86 +/- 7.99 years). The time from injury to microsurgery was longer in the LN group (234.10 +/- 166.13 days) than the IAN group (137.80 +/- 83.80 days). Four patients from the IAN group and 7 from the LN group were operated on more than 6 months after the injury. Of the 15 patients who underwent IAN microsurgery, 1 patient had no change in either von Frey or 2-point discrimination results after the procedure, and 2 patients had no changes in only von Frey results. For the 14 patients undergoing LN repair, 1 patient demonstrated no change in the 2-point discrimination test and 1 patient had a reduced postoperative von Frey result compared to the preoperative measurement. CONCLUSION: Patients undergoing LN and IAN microsurgery benefit from trigeminal nerve microsurgery. No statistically significant differences overall were observed when comparing the outcomes of LN and IAN microsurgery. Patients undergoing trigeminal nerve microsurgery for LN and IAN injuries 6 months after injury derived less sensory recovery; however, significant improvement was still observed, warranting consideration for microsurgery in those patients who might present later for initial surgical consultation.

Use of topical medication in orofacial neuropathic pain: a retrospective study.

OBJECTIVE: The objective of this study was to evaluate the effect of topical medications as a single treatment or in combination with systemic medications in the treatment of orofacial neuropathic pain conditions. STUDY DESIGN: A retrospective chart review of 39 patients treated for orofacial neuropathic pain at the Orofacial Pain Clinic in the New Jersey Dental School was performed. In line with the treatment selection, the subjects were divided into 3 groups: topical medications only (n = 12), systemic medications only (n = 10), and a combination of both (n = 17). RESULTS: The starting pain level as expressed in pain Visual Analog Scale for the 3 groups was significantly different. The combined treatment group baseline pain level (7.5 +/- 0.403 SEM; P = .0015) and the systemic treatment only group pain level (8.6 +/- 0.611 SEM; P = .0375) was significantly elevated compared to the topical only group (6.1 +/- 0.716 SEM; P = .1057). Following treatment, pain level was significantly reduced in all 3 groups. The combined group had the highest pain relief (52.0 +/- 6.676 SEM % reduction; P < .0001) followed by the systemic-only group (40.6 +/- 9.727 SEM % reduction; P = .0029) and the topicals-only group (40.9 +/- 10.775 SEM% reduction; P = .0048). The time taken for the topical treatment only to act was significantly shorter (3 weeks +/- 0.479 SEM; P = .0015) when compared with the systemic-only (4 weeks +/- 0.772 SEM; P = .3629) and the combined group (5.5 weeks +/- 0.912 SEM; P = .1738). CONCLUSION: Topical medication as single treatment or in combination with systemic medications can reduce orofacial neuropathic pain severity. Further prospective research should be performed to validate this treatment option.

Trigeminal nerve injury following accidental airbag deployment and assessment with quantitative sensory testing.

High velocity motor vehicle accidents are associated with an increase in mortality rates and a significant number of facial injuries. Accidental deployment of airbags and the associated release of hot gases can result in both thermal and mechanical injuries. The more commonly reported maxillofacial injuries include temporomandibular joint fractures and dislocations, dental trauma, facial nerve paralysis, and other orofacial pain complaints. The following case report describes a patient with facial trauma from the accidental deployment of an airbag resulting in complaints consistent with a neurological injury for which quantitative sensory testing was used in confirming the diagnosis.