Boosting clear aligners at home could prove to be the most efficient method for teeth straightening (The assistant orthodontist at home) 4D aligners

Image for post
Image for post

Moving teeth effectively and shortening treatment durations has been the sweet spot of orthodontics since modern orthodontics has evolved over a century ago.
So many trials throughout history have been recorded. The most effective empirical methods to monitor tooth movement efficiency with clear aligners were either the biological methods or the clinical trials. Since clear aligners are clearly a removable orthodontic device and can't be fixed to teeth, the forces applied on teeth are basically intermittent in nature.

Clinical data and biological findings on the reactivation rhythm of orthodontic appliances are extremely important to improving the efficiency and safety of the orthodontic treatment. Here I want to give a glimpse of a new technology that might change the way we think about clear aligner treatments or even whole orthodontics. The method uses the analogy of activating orthodontic appliances with clear aligners that are in the normal sense static plastic splints.

Because most orthodontic appliances are slowly dissipating, clinical treatment can be viewed as a series of intermittent force applications. Experimental data from animal models suggest that reactivating an orthodontic appliance over longer intervals stimulates more efficient tooth movement than reactivations over very short periods. Biochemical analysis of known markers of active bone metabolism have demonstrated that significant amounts of alveolar bone turnover continue for an indeterminate period following appliance decay. 57 Studies of tooth movement and tissue responses following reactivations indicate that linear tooth movement and rapid recruitment of osteoclasts can be achieved if reactivation is timed to coincide with the latter part of the bone remodeling cycle initiated by the first activation.

In the light of this scientific finding the method, an aligner booster uses to activate clear aligners could prove very promising. An aligner booster is a device used by patients at home to heat up or activate aligners made out of shape memory polymers. Activation of clear aligners in this context means shifting its shape from one form to another in the sequence of treatment. The boosting is done throughout a period of 7-10 days. So the same aligner could be worn for 3 weeks or more and has different forms or shapes.

Image for post
Image for post

Orthodontic tooth movement curves following short (1 day) and long (10 days) interval reactivation schedules. Note the greater overall tooth movement without a delay period.

Image for post
Image for post
Esthetics and Biomechanics in orthodontics by Dr.Ravindra Nanda

On the other hand, the desirable goal of expediting tooth movement remains a perplexing and complex issue to resolve. Several historical approaches and some novel ones have recently been proposed to facilitate this goal.

physical or mechanical stimulation (vibrations — Acceledent, electrical current, low IR light- Orthopulse and pulsed electromagnetic fields) and surgically facilitated orthodontic therapy (SFOT) (corticotomy, dentoalveolar distraction, periodontal distraction). Most of these have yet to be shown to expedite orthodontic tooth movement or, as in the case of corticotomies, appear to do so only transiently.

All of these approaches in principle attempt to modulate or hack biological processes nonspecifically rather than to rationally use knowledge of bone biology to achieve the desired expedited tooth movement. Thus, for example, corticotomies result in short-term acceleration of tooth movement, which may be related to its modulation of a transient increase in RANKL61 then fades quickly. In contrast, a more logical approach to achieving the goal of faster tooth movement would entail directly harnessing the biological regulation of bone turnover without large surgical procedures.

When patients use an aligner booster they use it to place an aligner inside it for almost 5 minutes. During those couple of minutes the clear aligner is subjected to the stimulation necessary to change the aligner shape. The shape change is minimal and corresponds to changing an aligner to the next one in sequence in standard clear aligner therapies.

The aligner booster reminds patients to boost their aligners during day light hours better than at night. This improves the teeth movements according to several studies. (Add photo)

Related to the concept of reactivation timing is how the circadian rhythm factors into the biology of tooth movement. Since there is a decreased metabolism at night during sleep, the question arises as to whether this becomes more favorable or less desirable for tooth movement. A research study was carried out on subjects divided into three groups: appliances were activated over 21 days either continuously throughout the experimental period, only during the light (0700 to 1900 hours) period, or only during the dark (1900 to 0700 hours) period. 59 Results demonstrated that the tooth movement in the whole-day and light-period groups was about twice that in the dark-period group.

Histological evaluation of the periodontal tissues confirmed that there was greater new bone formation on the tension side in the whole-day and light-period groups and more osteoclastic activity on the pressure side compared to the dark-period group. Overall, the light-period group exhibited decreased hyalinization of the PDL compared to the whole-day group.

An aligner booster could be used by patients to boost aligners or activate them at home on a weekly or 10-day basis. This could be great news for direct to consumer methods (DIY) for teeth straightening in the market. They could provide a cutting edge orthodontic treatment while replacing the orthodontist's function.
The aligner boosting cycles are even monitored by asking the patient questions related to pressure on teeth, aligner fit and aligner tightness. Patient answers to these questions after one week of wearing an aligner help the software to either amend the 7-week aligner boosting or keep as is, accordingly alternating the schedule of aligner wearing and adapting it to possible biological responses.

This level of intelligence not could only prove to replace the orthodontists but also improve the orthodontic treatment process many folds.

Image for post
Image for post

References: Esthetics and Biomechanics book for Dr.Ravindra Nanda

Written by

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store