Mental nerve neuropathy: patient characteristics and neurosensory changes.
OBJECTIVE
The objective of this study was to analyze the etiological factors and neurosensory signatures of patients attending with a primary complaint of numb chin.


METHODS
Charts of 27 patients referred to Hadassah School of Dental Medicine, Jerusalem, Israel, with a complaint of unilateral numbness or paresthesias of the chin were reviewed. Demographic and etiologic data and special tests, including imaging, that were prescribed as necessary for the treatment protocol were evaluated. The neurosensory evaluation protocol included assessment of detection thresholds to electrical stimulation (assessing large myelinated nerve fibers) and heat (assessing thin unmyelinated nerve fibers) in the mental and infraorbital nerves regions bilaterally. Data from 8 healthy, age and sex-matched subjects who underwent similar sensory testing served as the control group.


RESULTS
Invasive dental procedures (eg, extractions, implants) were the etiologic factor in 63% of the cases. Inflammatory pathoses (15%) (eg, periapical periodontitis or infection), and malignant lesions (22%) were identified as causative in the remaining patients. Frank nerve injury due to advanced malignant processes was characterized by significantly elevated heat and electrical thresholds (hyposensitivity). Inflammatory process was accompanied by reduced electrical detection thresholds (hypersensitivity).


CONCLUSIONS
This study concurs with previous studies that sensory hyposensitivity accompanies nerve damage. Accordingly, quantitative sensory testing may contribute to the diagnostic process of patients with mental nerve neuropathy. In this sample of patients, the most common cause for mental nerve neuropathy was dental treatment followed by malignant metastasis.
Vydehi Institute of Dental Sciences and Research Center, Bangalore, India. dolanmaz@hotmail.com
Mythili
M
Kalladka
Noam
N
Proter
Rafael
R
Benoliel
Rakefet
R
Czerninski
Eli
E
Eliav
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002680:Chin / Q000294:innervation*; D003389:Cranial Nerve Diseases / Q000175:diagnosis / Q000209:etiology*; D004558:Electric Stimulation; D005260:Female; D006358:Hot Temperature; D006801:Humans; D006987:Hypesthesia / Q000175:diagnosis / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000150:complications*; D009412:Nerve Fibers / Q000473:pathology; D019647:Oral Surgical Procedures / Q000009:adverse effects*; D009915:Orbit / Q000294:innervation; D010485:Periapical Periodontitis / Q000150:complications*; D012189:Retrospective Studies; D012684:Sensory Thresholds; D061221:Trigeminal Nerve Injuries