Occlusal Bite Force Changes in Skeletal Class-II Patients during Functional and Fixed Mechanotherapy: A Prospective Study

Introduction: Orthodontic treatment in skeletal Class II malocclusion initially leads to transient disturbances in bite force, occlusal contacts and fluctuations in Body Mass Index (BMI) due to functional adaptation and altered eating patterns. As the treatment progresses, occlusal stability and masticatory efficiency are progressively restored, leading to normalisation of masticatory efficiency and BMI. Aim: To assess maximum occlusal bite force changes and its effects on BMI in skeletal Class II patients following functional and fixed mechanotherapy using TekscanFlexiforce sensors with extreme low frequency system (T-scan). Materials and Methods: The present prospective study was conducted in the Department of Orthodontics, Faculty of Dental Sciences, SGT University, Gurugram, Haryana, India, from March 2021 to September 2022. A total sample of 45 patients (age 10-15 years) having Cervical Vertebrae Maturation Index (CVMI) 2, 3, and 4 were divided into three equal groups. Group I and group II consisted of skeletal Class II individuals who were treated using myofunctional therapy and fixed orthodontic mechanotherapy, respectively. Group III with Class I skeletal Malocclusion was used as control group. Occlusal contacts bite force and BMI were evaluated at the beginning of treatment (T0), first week (T1), first month (T2), third month (T3), sixth month (T4) and at the end of therapy or eight months (T5). Statistical methods like the unpaired t-test was used to analyse the quantitative variables. Statistical significance is considered for p-values<0.05. Results: The maximum bite forces started decreasing as the treatment progressed in group I (271.20 N at T0 to 82.9 N at T4) and group II (348.27 N at T0 to 262.13 N at T2) which was more significant in group I, There was a reduction in the BMI in both group I and II but it showed a gradual recovery towards the end of the treatment. The maximum bite force for control group III was 287.73 N. Conclusion: There was significant reduction of maximum bite force in the functional appliance therapy group as compared to fixed mechanotherapy. In the initial stages of the treatment, there was a reduction in the BMI and occlusal contacts in both the groups which gradual recovered towards the end of the treatment.