Evaluation of Normal Range of Mouth Opening Using Three-finger Index and Its Impact on Age, Gender, and Body Mass Index of an Individual

Introduction: Mouth opening, or the maximum distance that the jaws can be separated, is an important parameter in clinical practice as it determines the access and visibility of the oral cavity. Previous studies have reported that mouth opening may be influenced by various factors such as age, gender, and body mass index (BMI). Objective: This study aimed to evaluate the normal range of mouth opening using the three-finger width method and to investigate the impact of age, gender, and BMI on this parameter. Materials and Methods: A cross-sectional study involved 500 individuals, comprising 250 males and 250 females aged between 15 and 60 years. Mouth opening was measured using the three-finger width method, and the participants' age, gender, and BMI were recorded. A statistical analysis was conducted to assess the impact of age, gender, and BMI on mouth opening. Results: The study's results demonstrated a significant correlation between mouth opening and age and an association with gender and BMI about mouth opening (P < 0.001). Conclusion: This study provides normative data on the normal range of mouth opening using the three-finger width method and demonstrates that mouth opening is influenced by gender, age, and BMI. These outcomes hold significant value for clinicians seeking to assess and compare mouth opening in their patients.