Comparison of objective wear time between monoblock and twin-block appliances measured by microsensor

Objectives: To assess the objective compliance levels in skeletal Class II patients with mandibular retrognathia wearing monoblock and twin-block appliances. Materials and Methods: A prospective clinical study was conducted with 30 patients between 10 and 15 years old who were equally divided into two study groups. Group 1 was treated with monoblock, and group 2 was treated with twin-block appliances. The patients were instructed to wear their appliance for 15 hours per day. Wear times were monitored by a microsensor. (TheraMon; MCTechnology, Hargelsberg, Austria) for an average of six appointments. Patients were also instructed to record their wear times on a chart, and this record was admitted as subjective wear time. Statistical analysis was performed with the data derived from both the patients' charts and the monitoring records. Results: The mean wear time by the patients was 10.67 6 3.93 hours, which was less than the 15 hours prescribed by the orthodontist, with no difference between the two appliances (P . .05). The regular use rate, which included the days with a wear time of 8 hours or more per day, was 75%. Compliance levels decreased by 35% throughout the six control appointments. Patients declared that their wear time was more than their objective wear time by an average of 3.76 hours. Conclusions: Despite their different designs, there was no significant difference between the monoblock and twin-block appliances in terms of compliance. (Angle Orthod. 2021;91:749-755.)

Automated summary

The study evaluated the objective compliance levels in skeletal Class II patients with mandibular retrognathia wearing monoblock and twin-block appliances. Results showed that patients' wear times were generally less than the prescribed time by orthodontists, with a regular use rate of 75%, and compliance levels decreased throughout the follow-up appointments.