Horner's syndrome associated with local anesthesia techniques in dentistry

Literature review

Abstract

Introduction: Local anesthesia in dentistry, although safe and fast-acting, can cause rare complications such as Horner’s Syndrome (HS), characterized by ptosis, miosis, and facial anhidrosis, due to interruption of the oculosympathetic pathway. Furthermore, this condition, although infrequent, can result from the inadvertent diffusion of the anesthetic into the cervical sympathetic chain during deep regional anesthetic techniques. Objective: To analyze the relationship between Horner’s Syndrome and local anesthesia techniques in dentistry, evaluating pathophysiological mechanisms, risk factors, clinical manifestations, diagnosis, immediate management, and preventive strategies. Materials and methods: A systematic review was conducted following the PRISMA guidelines, searching PubMed, SciELO, and Google Scholar between 2020 and 2025. Twenty-three articles addressing the association between dental local anesthesia and HS were selected, excluding unrelated studies or those without direct clinical application. Results: Horner’s syndrome (HS) occurs primarily after deep regional blocks, especially of the inferior alveolar nerve, due to diffusion of the anesthetic to cervical sympathetic fibers. Therefore, clinical manifestations include ptosis, miosis, and anhidrosis, which are generally transient. Predisposing anatomical factors were also identified, highlighting the importance of anatomical knowledge and precise technique in preventing this complication. Conclusion: This study demonstrated the relationship between Horner’s syndrome and local anesthesia in dentistry, emphasizing the need for early diagnosis and the application of preventive techniques to minimize risks, thus ensuring safer clinical practice.