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Comparative Efficacy of Laser Acupuncture and Direct Photobiomodulation for Inferior Alveolar Nerve Hypoesthesia
Yongqing Ma1, Miaomiao Yang2, Jiang Sun3
1Department of Oral Surgery, Stomatological Hospital of Dalian University (Dalian Stomatological Hospital), Dalian, P.R. China.
Background:
Inferior alveolar nerve (IAN) sensory disturbance after mandibular third molar extraction can persist and affect speech, mastication, and quality of life. Photobiomodulation (PBM) has been used to promote peripheral nerve recovery, but the most suitable irradiation strategy remains unclear. Laser acupuncture (LA) delivers PBM to predefined acupoints and may provide both local and central neuromodulatory effects.
Objective:
To compare standardized LA with direct nerve-trajectory PBM for post-extraction IAN hypoesthesia in a randomized, double-blind, sham-controlled trial.
Methods:
Adults aged 18-60 years with unilateral IAN hypoesthesia lasting ≥7 days and ≤12 weeks were randomized (1:1:1) to LA, direct PBM along the external IAN projection, or sham treatment. All participants received mecobalamin (0.5 mg, three times daily) for 30 days. PBM was delivered using an 808-nm diode laser (continuous wave, 100 mW; beam area 1.0 cm2), 90 s/site (9 J; 9 J/cm2), every other day for 15 sessions. LA used a fixed 5 + 2 prescription: ST4, ST6, ST7, CV24, Jiachengjiang (EX-HN19), plus LI4 and PC6. Primary outcomes were two-point discrimination (TPD) and Semmes-Weinstein monofilament examination (SWME) at day 30. Secondary outcomes included Visual Analog Scale (VAS) numbness, additional sensory tests, and day-60 follow-up.
Results:
Sixty participants completed the intervention. Both active groups improved more than sham for TPD and SWME (group × time p < 0.01). Mean TPD change at day 30 was -3.2 ± 1.8 mm (LA) and -2.6 ± 1.7 mm (direct PBM) versus -0.8 ± 1.1 mm (sham). SWME improved by ≥1 grade in 85%, 80%, and 25%, respectively. VAS numbness decreased by 60%, 48%, and 12%, respectively, and the improvement was largely maintained at day 60. No treatment-related adverse events occurred.
Conclusions:
Under matched PBM dosimetry, both irradiation strategies improved sensory recovery compared with sham. LA produced comparable results and was associated with greater improvement in patient-reported numbness.