Facial paralysis after intraoral anesthetic injection: A systematic review.

Many complications can occur after the injection of local intraoral anesthetics (ILIA) before dental intervention. Facial paralysis (FP) is one of these complications. The purpose of this study was to systematically analyze the association between ILIA and FP. A systematic review was carried out taking into account the methodology of the Cochrane Handbook for Systematic Reviews of Interventions and the PRISMA statement. The search strategy used "Palsy AND Facial" and "Paralysis AND Facial" as search terms. The ScienceDirect, PubMed and Scopus databases were searched using the "dentistry journal" filter. The inclusion criteria included studies describing FP after or during ILIA that were published in dental journals. The CAse REports (CARE) checklist was applied in evaluating the methodological quality of case reports. A total of 2,462 articles (algorithm) were identified. After reviewing titles and abstracts, 18 articles were deemed relevant taking into account the objectives of this study. Only 13 of them, after reading the full text, met the inclusion criteria and were analyzed. Case reports on 18 cases of FP were analyzed, 12 of which described the early development of FP (onset within 24 h) and 6 the late development (onset after 24 h). Acceptable compliance with CARE guidelines was observed in the included studies . Early FP CRs presented the effect of the administered anesthetic on the facial nerve, and the vascular effect of the vasoconstrictor included in the anesthetic formula, while more recent FP CRs focused on the reactivation of herpes simplex virus type 1 (HSV-1), human herpesvirus 6 (HHV-6) or varicella-zoster virus (VZV).