Incidence of Trismus in Fascial Space Infections: An Insight from Odontogenic Causes

Background: Trismus or lockjaw characterized by limited mouth opening presents as complication associated with odontogenic infections commonly involving mandibular teeth. Due to limited literature providing insight to probable odontogenic causes of trismus, this study is oriented to determine the incidence of Trismus severity in association with fascial space infection resulting from odontogenic causes, i.e., pericoronitis, pulp infection, or periodontal infection. Methods: This study was conducted at the Department of Oral and Maxillofacial Surgery, Azra Naheed Dental College/ Chaudhry Muhammad Akram Dental Hospital from July 2024 to December 2024. In this descriptive cross-sectional study, following non-probability purposive sampling, 87 patients who had trismus secondary to fascial space infections were enrolled. All required demographic and clinical data were recorded in a purpose-designed form. The collected data were analyzed by the Chi-square test, using SPSS version 25. A p-value of ≤ 0.005 was considered significant. Results: The average mean value of Trismus was 23.5±5.5mm. Submandibular space infection most frequently involved the fascial space 42 (48.2%), and the mandibular third molar was frequently involved, offending tooth 43 (49.4%) in this study. The most common cause of odontogenic infection was Pulp infection/caries 58 (66.6%), followed by pericoronitis 27 (31.3%) and periodontal infection 2 (2.3%). Conclusion: Mandibular third molars are the most involved teeth, leading to fascial space infection and associated with increased severity of Trismus. The submandibular space is the most affected fascial space, and pulp infection is the major cause of odontogenic infection, leading to fascial space involvement.