Vibratory stimulus and accelerated tooth movement: A critical appraisal

Human Interleukin-1β Profile and Self-Reported Pain Monitoring Using Clear Aligners with or without Acceleration Techniques: A Case Report and Investigational Study

INTRODUCTION

There is a growing demand for more aesthetic, comfortable, and faster orthodontic treatments, and clear aligners emerged as a solution to fulfill this need. However, the effectiveness of clear aligners to treat complex malocclusions is yet contentious. The use of acceleration methods could improve the efficacy of clear aligners by stimulating cells' mechanobiology through numerous pathways, but this hypothesis is still poorly explored.

OBJECTIVE

We aimed to monitor the release profile of an inflammatory marker-the interleukin-1β-and to evaluate its relationship with self-reported pain scores with and without the use of acceleration techniques during an orthodontic treatment requiring difficult tooth movements with clear aligners. Case Report. Here, we report a case of a 46-year-old female patient who presented functional and aesthetic complaints. Intraoral examination revealed a diminished overjet and overbite, rotation of teeth 45 and 24, absence of teeth 25, 35, and 36, buccolingual dislocation of tooth 21, a tendency to a Class III malocclusion, and a 2 mm left deviation of the lower midline. This study is divided into three stimulation phases: no stimulation, mechanical vibration stimulation, and photobiomodulation. Interleukin-1β levels in gingival crevicular fluid samples from the pressure side of six selected teeth were evaluated at four time points after the orthodontic treatment onset. Pain monitoring in those teeth was performed using a visual analogue scale at the same time points.

RESULTS

Interleukin-1β protein production peaked 24 h after treatment onset. Complex movements were associated with increased self-reported pain.

CONCLUSION

Clear aligners show limitations in solving complex tooth movements, even when combined with acceleration. The development of customized and programmable stimulation microdevices integrated into "smart aligners," which could be designed to specifically stimulate the direction of movement and stimulation parameters and could constitute a solution to optimize the orthodontic tooth movement with clear aligners.

The Effect of Mechanical Vibration on Osteogenesis of Periodontal Ligament Stem Cells

INTRODUCTION

Appropriate occlusal forces can prevent ankylosis after tooth replantation or transplantation. However, the "proper occlusal forces" on periodontal ligament (PDL) healing have not yet been defined due to insufficient in vitro studies and uncertain in vitro models. Herein, we presented a mechanical vibration device as an in vitro model to determine such favorable occlusal forces.

METHODS

Human periodontal ligament stem cells (hPDLSCs) were exposed to mechanical vibration force with 4 frequencies (30, 90, 150, and 210 rpm). Cell viability and the expression of osteogenic differentiation-related genes and proteins were tested in vitro. The calvarial transplantation experiment was performed to assess the bone formation ability of 150 rpm mechanical vibration stimulation (MVS).

RESULTS

MVS at 150 and 210 rpm significantly reduced cell viability in the early stages. The 150-rpm MVS decreased osteogenic marker expression at the early time point (3 days) but had no harmful effects at the late time point (14 days). Furthermore, hPDLSC cell sheets treated with 150-rpm MVS had potential to decrease bone formation in rat calvarial defects serendipitously and facilitated functional PDL-like tissue formation.

CONCLUSIONS

We found that MVS at a frequency of 150 rpm could provide a strategy for a transient reduction in the osteogenic potential of hPDLSCs and promote PDL-like tissue formation. Thus, 150-rpm MVS could be used as a controllable proper occlusal force to prevent ankylosis and promote PDL healing after tooth replantation or transplantation.

Young Adults' Preferences and Willingness to Pay for Invasive and Non-invasive Accelerated Orthodontic Treatment: A Comparative Study

To evaluate the preference of young adult patients and their willingness to pay for the different approaches accessible to accelerate orthodontic tooth movement. A cross-sectional survey was conducted in Jeddah, Saudi Arabia from September to December 2019. Young adult orthodontic patients from 18 to 45 years old were interviewed via online survey regarding their perception to the extent of treatment, acceptability of non-invasive (customized appliances and medications) and invasive (surgery) approaches accessible to accelerate orthodontic treatment and increase in fees they were willing to pay. Statistical analyses were performed, and gender difference was calculated at P < .05. There are 100 respondents: 70% aged between 18 to 25, 50% male, and 56% with annual income <10 000 SR. About 72% of the respondents decided that treatment takes longer period and 51% wished it would last for less than 6 months. Customized appliances were reported to be the most convenient to use (58%) and to pay (44%), followed by medications (48%). On the other hand, surgery was reported to be the most inconvenient to use (58%) and to pay for (55%). About 70% of the respondents were unwilling to pay more than 10% to 20% for all procedures assessed; considerable variation was not observed in responses between gender at 95% confidence level. Majority of the respondents believed that orthodontic treatment is taking lengthy duration. Less invasive, nonsurgical techniques and procedures were more preferred. Likewise, financial factors play vital role in the selection of their preferred approach. Most of them agrees to provide up to 20% increment of the fee for additional procedures.