Evaluation of the effects of hall technique on temporomandibular joint, masseter muscle and occlusion in children

Objective: This study aims to determine the mechanism of occlusal change in primary molars treated with the Hall Technique in children and evaluate its impact on the temporomandibular joint and masseter muscle. Methods: Materials and Methods: Children between the ages of 5 and 9, who had primary molars with dentin caries not associated with the pulp and had not been treated with the Hall Technique (HT) before, were included in the study. At the first visit, patients' complaints about the Temporomandibular Joint (TMJ) and masseter muscle were recorded according to the American Pediatric Dentistry Criteria, and the examination findings were recorded according to the Helkimo Clinical Dysfunction Index. Occlusal Vertical Dimension (OVD) was determined with a digital caliper by taking the primary canine teeth as reference. Before HT, intraoral impressions were taken, plaster models were obtained and transferred to the digital platform in STL. Then, HT was applied, and all measurements and documentations were repeated at immediately after HT, at the 1st and 3rd month. Rapidform2006 software was used to analyze digital models taken at different times and to measure changes of the teeth's volumes over time. A survey was conducted on the children participating in the study at the 3rd month regarding their perceptions about the Hall Technique. Frequency, percentage, mean and standard deviation analyzes were used to explain demographic and clinical findings in data analysis. In continuous data analysis, ANOVA Test and independent sample t-test were used for repeated measures. Type-1 error level was taken as p<0.05. Results: The average age of the 28 participating patients was determined as 6.4±1.1 years. Mild temporomandibular dysfunction was detected in 10.7% (n=3) of the patients at 1-month. No TMJ dysfunction was detected in any child at 3-month. A statistically significant difference was found between the baseline OVB mean (3.3±0.9 mm), the 1-month OVB mean (2.9±1 mm) and 3-month OVB mean (3.1±1 mm) (p<0.001). Mean volumes of HT and antagonist teeth at 1 month and 3 months were significantly lower than their mean volumes at immediately after (p<0.001). Following HT application, a volume decreased of 14.5±9.0 mm3 occurred in HT-treated teeth within 3 months; a volume difference of 7.3±6.9 mm3 was detected in the antagonist teeth (p<0.001). While there is no significant difference between maxillary and mandibular teeth in terms of volume mean in HT-treated teeth (p=0.92), there is a significant difference in antagonist teeth (p=0.04). 92.9% of the patients stated that they were satisfied or very satisfied with their teeth treated with HT. Conclusion: The reduction in occlusal vertical dimension observed over time following the HT is primarily associated with intrusion in both opposing teeth, with a more notable impact in HT-teeth. In our study, the majority of children stated satisfaction with the HT and no moderate or severe Temporomandibular dysfunction was observed within the 3-month follow-up period. The absence of adverse effects on patients during the occlusal changes suggests that HT application may be considered an acceptable treatment option. Key Words: Dental occlusion, digital technology, pediatric dentistry, temporomandibular disorders, vertical dimension.