A Multi-Center Disclusion Time Reduction (DTR) Randomized Controlled Occlusal Adjustment Study Using Occlusal Force and Timing Sensors Synchronized with Muscle Physiology Sensors

Evaluation of occlusal bite force distribution by T-Scan in orthodontic patients with different occlusal characteristics: a cross sectional-observational study

BACKGROUND

The aim of orthodontic treatment, apart from esthetic and functional corrections, is uniform force distribution. Hence Occlusal analysis using a T scan gives scope for a precisely targeted treatment plan. The T-scan evaluation of occlusal force, time, and location of contacts from initial occlusal contact to maximum intercuspation enables the orthodontist to sequentially balance the occlusal forces on the right and left sides through specific treatment plan options.

OBJECTIVE

The current study aimed to determine the force distribution in the different individuals by using a T-Scan as well as the net discrepancies of forces generated at a maximum intercuspation position in the first molar region between the left and right sides of the mouth.

METHODS

This is a descriptive-correlational study that was carried out in Ras Al Khaimah College of Dental Sciences clinics and Ajman University clinics from January 2020 to September 2022 by using the convenience sampling technique. The T-scan III Novus was employed in this investigation to record multi-bite scans for several patients. T-scan was utilised to examine various malocclusions.

RESULTS

The present study consisted of 158 participants. Analysis of Variance (ANOVA) showed that there is a statistically significant difference in the percentage of force between the three types of malocclusions (I, II, and III) on the right molar side (B-16 and B-46) (p < 0.05). Moreover, the overall discrepancy showed a statistically significant difference in the three types of malocclusion classifications (p < 0.05). On the other hand, there was no statistically significant difference in the percentage of force between B-26 and B-36 (p > 0.05). Post hoc analysis showed a statistically significant difference in the percentage of force between malocclusion classes I and III on the right molar, with a mean difference of 4.11190 (p < 0.05). Similarly, there was a statistically significant difference in B-46 between Malocclusion Classes I and II, 4.01806 (p < 0.05). Additionally, post hoc analysis showed a statistically significant difference between malocclusion classes I and III, with a mean difference of -4.79841 (p < 0.05) on the right molar.

CONCLUSION

The T-Scan is a useful tool for assessing occlusal discrepancies and can be helpful during treatment planning and follow-up, especially for orthognathic surgery patients. A T-scan could be used in orthodontic therapy in a simple and efficient way. Also, it turned out to be a useful tool for diagnosing problems and gave us new information about how therapies work. In this study, T-Scan showed that it can measure occlusal forces in timing in an objective, accurate, and repeated manner. The current study found that T-Scan was better able to report the difference in the percentage of force on the right molar side than on the left side.

Influence of disclusion time reduction on changes in posterior implant prosthesis occlusion and its association with crestal bone loss: A clinical study

STATEMENT OF PROBLEM

A prolonged period of high magnitude occlusal contact can be associated with rapid changes of the occlusal surfaces and, in turn, may lead to overloading of an implant-supported prosthesis. Crestal bone loss may be one of the repercussions of overloading, but the influence of disclusion time (DT) reduction (DTR) is unclear.

PURPOSE

The purpose of this clinical study was to evaluate the role of DTR in preventing the occlusal changes and crestal bone loss at progressive time intervals of 1 week, 3 months, and 6 months in posterior implant-supported prostheses.

MATERIAL AND METHODS

Twelve participants with posterior implant-supported prostheses and opposing natural teeth were enrolled in the study. Occlusion time (OT) and DT were evaluated with the T-scan Novus (version 9.1). By performing immediate complete anterior guidance development (ICAGD) coronoplasty, prolonged contacts were selectively ground to achieve OT ≤0.2 seconds and DT ≤0.4 seconds in maximum intercuspal position and laterotrusion after cementation and during follow-up visits after 1 week, 3 months, and 6 months. Crestal bone levels were evaluated after cementation and at the 6-month follow-up. Repeated measures ANOVA and Bonferroni post hoc analysis were done for OT and DT. Student paired t test was done for crestal bone level evaluation (α=.05 for all tests).

RESULTS

A significant decrease in OT from 0.59 ±0.24 seconds to 0.21 ±0.06 seconds (P<.001) and in DT from 1.51 ±0.6 seconds to 0.37 ±0.06 seconds (P<.001) were detected in posterior implant-supported occlusion immediately after attaining ICAGD and at the 6-month follow-up period. The mean crestal bone levels at the mesial and distal sides of the implant from day 1 (0.4 ±0.13 mm, 0.36 ±0.20 mm) to 6 months (0.40 ±0.13 mm, 0.37 ±0.19 mm) showed no significant changes (P>.05).

CONCLUSIONS

Minimal occlusal changes in implant prosthesis and negligible crestal bone loss were observed up to 6 months by achieving DTR according to the ICAGD protocol.

Computerized dynamic occlusal analysis and its correlation with static characters in post-orthodontic patients using the T-Scan system and the ABO objective grading system

OBJECTIVES

This study was conducted to detect the overall performance of both static and dynamic occlusion in post-orthodontic patients using quantified methods, and to ascertain the correlation between the two states of occlusion.

MATERIALS AND METHODS

A total of 112 consecutive patients evaluated by ABO-OGS were included in this study. Based on the pre-treatment Angle's classification of the malocclusion, samples were divided into four groups. After removing orthodontic appliances, each patients underwent the American Board of Orthodontic objective grading system (ABO-OGS) and T-Scan evaluations. All the scores were compared within these groups. Statistical evaluation included reliability tests, multivariate ANOVA, and correlation analyses (p < 0.05 was considered significant).

RESULTS

The mean ABO-OGS score was satisfactory and did not differ by Angle classifications. The indices making substantial contributions to ABO-OGS were occlusal contacts, occlusal relationships, overjet, and alignment. Disocclusion time in post-orthodontic patients was longer than normal. Occlusion time, disocclusion time, and force distribution during dynamic motions were considerably influenced by static ABO-OGS measurements, especially occlusal contacts, buccolingual inclination, and alignment.

CONCLUSION

Post-orthodontic cases that passed the static evaluation of clinicians and ABO-OGS may nevertheless be left with dental casts interference in dynamic motions. Both static and dynamic occlusion should be extensively evaluated before ending orthodontic treatment. Further research is needed on dynamic occlusal guidelines and standards.