Severe Complications of Odontogenic and Deep Neck Infections: An Umbrella Review of Risk Factors, Prognostic Determinants, and Evidence Credibility

Umbrella review of systematic reviews and meta-analyses on risk factors and prognostic determinants of severe complications of odontogenic and deep neck infections (descending necrotizing mediastinitis, cervical necrotizing fasciitis, airway compromise, sepsis, intracranial or orbital spread, death). The review separates evidence by time zero, appraises reviews with AMSTAR-PF and ROBIS, assesses primary-study overlap, and grades statistical credibility. Registration: DOI 10.17605/OSF.IO/TM8RU. This project holds the current protocol (v1.2.3) and appendices (A–E, v1.2.3), earlier versions (v1.2.1 and v1.2.2, retained), and the search records (Scopus, PubMed, Web of Science Core Collection and Epistemonikos, searched 13 October 2026).