BACKGROUND: It has been suggested that botulinum toxin A (BONT-A) is a safe and effective treatment in relieving pain in patients with persistent idiopathic dentoalveolar pain (PIDP).

OBJECTIVES: This study aimed to systematically evaluate all the available studies investigating the pain-relieving effects of BONT-A in patients with PIDP.

METHODS: A systematic search with specific search terms was made in PubMed, Web of Science and Scopus. Two authors screened titles and abstracts and selected eligible studies for inclusion in the systematic review. The quality of the studies was evaluated by the 12 items Quality Assessment Tool for Observational studies (Pre-Post) Studies with No Control Group, and the level of evidence was assessed according to GRADE.

RESULTS: Three observational studies of 3695 identified were included (445 overlapping studies; 3247 excluded studies). All studies were uncontrolled observational studies investigating the pain-relieving effect of BONT-A in patients with PIDP. The included studies had a fair quality (moderate risk of bias) and insufficient level of evidence. The pain reducing effect by BONT-A injections was in average 50% or more in two studies, in one study 3 out of 4 patients became almost pain free.

CONCLUSIONS: This systematic review shows that presently the level of scientific evidence is insufficient to evaluate the pain-relieving effect of BONT-A injections in patients with PIDP. There are indications that BONT-A injections could be a possible management option for patients with PIDP that seems to be safe and with few adverse events. There is a need for well-designed placebo-controlled, double-blind RCTs.