[Glossopharyngeal, Vagus, Accessory, and Hypoglossal Nerves in Head and Neck Practice]

This review presents a concise, practice-focused overview of the glossopharyngeal (IX), vagus (X), accessory (XI), and hypoglossal (XII) nerves, with particular emphasis on head and neck practice. We outline clinically relevant anatomy and surgical landmarks from the skull base to the cervical field, including constant planes, vascular and osseous reference points, and danger zones encountered during neck dissection, thyroid surgery, and parapharyngeal surgery. We then summarize each nerve's major functions and characteristic deficits, linking sentinel symptoms with bedside and endoscopic findings to expedite localization. Representative cases illustrate intraoperative and imaging appearances and demonstrate how nerve injury manifests on laryngoscopy, swallowing assessment, and shoulder evaluation. By integrating structure, function, and practical signs, this concise overview aims to support safer surgery, clearer differential diagnosis, and targeted rehabilitation in everyday head and neck care.