Targeted Injection Therapies for Temporomandibular Joint Disorders: A Comparative Review of Hyaluronic Acid and Botox Techniques

Purpose: This study aimed to evaluate the effectiveness of different injection therapies for temporomandibular joint disorders (TMD) and answer the research question: how do botulinum toxin (onabotulinumtoxinA, Botox) and hyaluronic acid (HA) injections affect symptoms of temporomandibular joint disorder (TMD)? Methods: An electronic search of three databases was performed using the search terms “Treatment of TMD or TMJ” and one of the following: 1) “Hyaluronic Acid Injection” or 2) “Intramuscular Botox Injection”. Based on studies done with human patients, the effects of both hyaluronic acid and Botox injections as treatments for TMD were observed and analyzed. Inclusion criteria were: full articles in English, studies conducted in North America or Europe, and articles published from 2015 to the present. Review articles and abstract-only articles were excluded. Results: A total of 20 sources were found and analyzed; eight related to Botox and 12 related to HA. Of the eight Botox articles, six showed a reduction of pain based on the visual analogue scale (VAS) score, and two showed an increased range of motion. Out of the 12 articles related to HA, 12 showed a reduction in pain based on the VAS scores, and 11 showed an increased range of motion. Conclusions: About half of the studies indicate that Botox can reduce pain and increase joint range of motion. Compared to HA, almost all studies showed decreased pain and increased range of motion. This indicates that both treatment methods were associated with successful treatment of TMD symptoms. However, HA was most effective in treating symptoms of TMD.