The Effectiveness of Photobiomodulation Therapy on Inferior Alveolar Nerve Injury: A Systematic Review and Meta-Analysis

Yongqing Ma, Miaomiao Yang, Xiaodong Chen, Weiguo Qu, Xiaofu Qu, Ping He


The aim of this META-analysis was to evaluate the efficacy of photobiomodulation (PBM) therapy in the treatment of inferior alveolar nerve (IAN) injury due to orthognathic surgeries, extraction of impacted third molars and mandibular fractures.


However, there are few reports about low-intensity laser treatment of IAN injury, and the high-quality RCT is even less, and the evaluation methods are different and the sample size is generally small. In addition, previous systematic reviews and META-analyses have either outdated or focused on a specific cause of injury. To our knowledge, the main factor affecting the repair outcome is the extent of the injury [21–23]. Therefore, a more comprehensive and updated meta-analysis is needed to explore the effectiveness of PBM therapy on IAN injury.

Materials and methods

This review was performed in accordance with both the recommendations from the Cochrane’s Handbook for Systematic Reviews and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Protocols (PRISMA guidelines), aim to evaluate whether the low intensive laser or LED therapies could be an available treatment modality for the sensory recovery after lower alveolar injures [24, 25].


There was no difference in the recovery of direction discrimination between the experimental and control groups one day after therapy (Fig 13, SMD 0.1, 95% CI: −0.54 ∼ 0.75, I 2 = 30%, no obvious heterogeneity), but after 60 days, the experimental group was significantly better than the control group (Fig 14, SMD 1.17, 95% CI: 0.59 ∼ 1.74, I 2 = 0, no heterogeneity). As for pain discrimination, although this test was mentioned in many articles, but only two of them could extract valid data, which proved that there was significant relief of pain after 30 days post-treatment [11, 12]. 


In the included studies, the etiologies of IAN damage were mostly sagittal split ramus osteotomy, only two studies for wisdom tooth extraction and two for mandibular fractures. Lesions due to impacted third molars extraction were mostly excluded because they were not RCTs or could not isolated from data mixed with lingual injuries [16, 17, 40–43]. In addition, Qi W et al’s article was the only one that used medicine therapy as a control (mecobalamin) instead of placebo.


The results of this META-analysis show that PBM therapy is effective in the treatment of IAN dysfunction caused by orthognathic surgeries, teeth extraction and mandibular fractures no matter it begins early or later. However, due to the limitations number of well-designed RCTs and small number of patients in each study, it would be necessary to conduct randomized controlled trials with large sample size, long follow-up time and more standardized treatment and evaluation methods in the future to provide more accurate and clinically meaningful experimental results.


We would like to thank Professor Xiaodong Chen, Professor Xiaofu Qu, Professor Weiguo Qu and Professor Ping He for their valuable advice and selfless help in the design and revision of the study.

Citation: Ma Y, Yang M, Chen X, Qu W, Qu X, He P (2023) The effectiveness of photobiomodulation therapy on inferior alveolar nerve injury: A systematic review and META-analysis. PLoS ONE 18(8): e0287833.

Editor: Sompop Bencharit, Medical University of South Carolina, UNITED STATES

Received: March 21, 2023; Accepted: June 14, 2023; Published: August 10, 2023

Copyright: © 2023 Ma et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the manuscript and its Supporting Information files.

Funding: The author(s) received no specific funding for this work

Competing interests: The authors have declared that no competing interests exist.

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