Complications associated with local anesthesia in dentistry: Review and considerations for a classification proposal

Commonly occurring and known complications associated with local anesthesia and possible treatment modalities have been discussed. The dentist should recognize the symptoms and know that there may be more serious complications. This study aimed to review the literature on accidents and complications associated with dental local anesthetics and propose a classification based on anatomical depth and clinical presentation.

A systematic search was conducted in PubMed, Web of Science and Scopus until June 2025. The keywords were based on MeSH and DeCS terms related to dental anesthesia and its complications. In vivo studies, case reports, and case series in oral surgery were included. After reviewing 364 records, 28 studies met the inclusion criteria. Data on study characteristics, type of anesthesia, complications, and treatment were extracted.

Complications were more frequent with inferior alveolar nerve blocks. Local events included puncture fractures, paresthesia, hematoma, ischemia, infections, and trismus. Systemic complications included syncope, toxicity, vasoconstrictive reactions, and allergies. While many resolved spontaneously, others required surgical or pharmacological intervention. A new classification based on the anatomical planes affected (superficial, deep, neurological, and orbitoocular) and systemic categories is proposed, facilitating recognition and treatment.

Local anesthetics, although widely used and generally safe, can cause various complications in oral surgery. The proposed classification systematizes these events and may improve diagnostic clarity, prevention strategies, and clinical decision-making.