Smart Functional Appliance - A New Approach to Improve Patient Compliance

Introduction

Ideal orthodontic treatment outcome is influenced by at least two factors: the orthodontist's expertise and the patient's compliance. Patient compliance is one of the most tricky and potentially challenging area in the orthodontic treatment.

For correction of the malocclusion or retaining the treatment outcomes, removable orthodontic appliances have been commonly used.¹ Active patient compliance is essential for favourable outcome of orthodontic treatment, especially in therapy using detachable appliances.²

In the last century and even at the start of the present, an entirely accurate calculation of patient compliance treated with various removable devices was nearly impossible. This has influenced the clinical procedures and the reliability of different studies conducted on this form of therapy.³

Essentially, the struggle in assessing compliance has been the variation between what the subject says about appliance usage and what the orthodontist finds on clinical examination.⁴ Hence, a system that can objectively evaluate patient compliance must be developed. Different gadgets were launched to calculate the accurate wear time of removable appliances.^4,5

The proposal of measuring wear time in appliance wear originated roughly 40 years ago.⁶ The initial recorders that assessed appliance wear time were used only for a short time because of their bulkiness and intricacy. Precision and feasibility presented as the main obstacles inhibited measuring devices from being utilised in orthodontic practice.⁷

Recently developed electronic microsensors seem quite assuring since they are user-friendly and have shown consistency and accuracy in calculating the wear time of removable orthodontic appliances.^4,5,8 These microsensors can measure the temperature and give detailed wear time information by embedding them in the primary construction material.

The microsensors are approximately 12x8x4 mm in dimensions and 0.4 g in weight. They use Radio-Frequency IDentification (RFID) technology as a read-out procedure.⁹ These are compact-sized hightech microsensors containing an application-specific integrated circuit (ASIC), which measures and stores the sensor data in adjustable intervals. A small rechargeable Li-Ion dry cell battery powers the sensor. Stored data is transferred wirelessly via an onboard antenna (RFID) to a dedicated reader device.¹⁰

In orthodontics, microsensors are used in removable retainers and functional appliances. In recent studies, they have been used with facemasks to improve patient compliance.¹¹ They can also be used with aligners for better tracking. In patients with obstructive sleep apnea, microsensors are inserted in the removable appliances. This monitor indirectly calculates the therapeutic effectiveness of oral mandibular advancement device therapy.¹² Ophthalmologists also used microsensors in the medical field to track how long children with vision impairments wear their glasses and ocular patches.¹³ In this research, patients were asked to wear a detachable functional device that was equipped with a microsensor. The wear time was then measured again after the patients were aware of the microsensor's existence.

Materials & Methods

Study population and ethical approval

The data required for the study was collected from the patients treated at the Orthodontics and Dentofacial Orthopaedics Department. Approval was obtained from the Research Sustenance and Institutional Review Board Committee (IRB) of the institution. All carers gave written consent. Fifteen patients who required a removable functional appliance were chosen. TheraMon® microsensors were embedded in each of the appliances. Prepubertal patients having good oral hygiene, and not related to one another were included in the study. Subjects with cleft lip & palate and other syndromes, subjects with multiple dental and medical issues, and adult patients were excluded from the study.

Sample size calculation

The GPower software version 3.1.9.4 was used to estimate the sample size. The total sample size required was estimated as 15, taking into account the two-tailed hypothesis, 80 percent effect size (dz), 80 percent power, and five percent margin of error.

Procedure

This study sample included 15 patients who needed removable functional appliances. Parents’ consent was taken before the start of the study.

TheraMon® Microsensor was embedded in each of them (Figure 1).

Removable appliances embedded with TheraMon® microsensors were delivered to patients. Three weeks after the delivery, microsensor were activated. Patients were not made aware of their monitoring at the time of microsensor activation (T0). After the activation of microsensor, patients were assessed at intervals of T1 and T2, which corresponded to follow-up visits three and six weeks, respectively. During the T1 appointment, objective wear time was noted, and subjects were made aware that their functional appliance was equipped with TheraMon® Microsensor. The microsensors were once again scanned at the T2 session to learn more about the study subjects' ongoing compliance after they were made aware of the sensor (during the T1 appointment) (Figure 2).

TheraMon® sensor is a device with a polyurethane covering. It makes use of an application-specific integrated circuit with inbuilt EEPROM memory of 16 kilobytes (EEPROM-Memory). For up to 18 months, the sensor's accuracy in determining oral temperature is +/- 0.1°C. Every five minutes after the appliance is turned on, the temperature is measured. The microsensor uses RFID technology (Radio Frequency Identification) to send and receive the data via a reading station.

The embedded microsensor is positioned parallel to the reading station's antenna. The reading procedure begins as soon as a microsensor is subjected to the reading station's magnetic field since the programme recognises it at that point. The resultant information will be automatically displayed as a wearing-time curve for each patient on the computer screen (Figure 3). 

Statistical analysis

Student paired t test was used to compare the mean wear time of the functional appliance (in hrs/day) between T0 & T1 and T1 & T2 time intervals. The level of significance was set at P <0.05.

Results

In the present study, the compliance of 15 subjects (7 females and 8 males with an age group of 11+/-2 years) was checked using microsensors embedded in the removable functional appliances. Recommended wear time was 18 h/day.

Table 1 illustrates that the mean wear time of the aware period on day 1 was significantly higher (11.765±4.575) compared to the non-aware period (5.781±3.356), and the mean variation was statistically considerable. 

Table 2 shows the mean overall wear time of the aware period for 21 days duration to be significantly higher (239.568±74.79) as compared to the non-aware period (145.03±58.69), and the average variation was statistically considerable (P=0.001) (Figure 4).

The average wear time on day 1 during the non-aware period among males was relatively higher (7.021±3.275) compared to female patients (4.364±3.062). However, the mean difference between the gender was statistically insignificant (P=0.16).

The mean wear time during the aware period on day 1 among females was relatively higher (11.921±5.032) compared to male patients (11.629±4.485). However, the mean difference between the genders was statistically insignificant (P=0.64).

Table 3 shows that the overall mean wear time during the non-aware period for 21 days was relatively higher among females (157.370±56.004) compared to male patients (134.241±62.574). However, the mean difference between both the genders was statistically insignificant (P=0.91). Similarly, the overall mean wear time during the aware period for 21 days among females was relatively higher compared to male patients.  

However, the mean difference between the genders was statistically insignificant (P=0.25) (Figure 5).

Discussion

In the current study, compliance with detachable functional equipment was objectively evaluated over an extended length of time in a sample size of 15 patients. The null hypothesis was rejected since there was a statistically considerable time variation between the non-aware period and the aware period in terms of patient's compliance. This result is consistent with the findings of the study by Thornton and Ackerman, which showed that the appliance wear time was 2.3 hours longer per day in the aware group than in the non-aware group.¹⁴ This outcome is comparable to the Hawthorne phenomenon when participants perform better while being monitored.¹⁵

Regarding overall compliance, there was no substantial distinction between male and female patients. This could be a result of the sample size being quite small, which prevented a significant difference from emerging. With the removable appliance, it is essential to have time-sensitive patient compliance. Compliance has a variable pattern which can be increased by clinical intervention.¹⁶

The wear time of removable functional appliances is a particularly challenging aspect of orthodontic treatment and is the most influential factor for an orthopedic effect and successful treatment outcome. Patients must have internal motivation to wear these appliances.¹⁷

Usually, patients claim that the wear time of detachable gadgets is as per the schedule suggested by an orthodontist; however, they truly do not reach the prescribed wear time.¹⁷ Children and younger patients, in particular, often overestimate the wear time of their devices. Disinterest and forgetfulness are commonly found in this patient group. Younger patients often need help understanding the link between wear time and treatment success, and they must be aware of the effect of poor compliance on treatment success.²

Measuring the removable appliance's wear time can help orthodontist manage patient compliance. The objective wear time of detachable devices may be determined with the use of TheraMon® microsensors and thus they were used in this study.

In a prior trial, the wear time of the patients was tracked using the Smart Retainer. It showed that individuals who were aware of the wear time tracking were more compliant compared to those who were unaware.¹⁴

Based on the wear-time record, the orthodontist can examine and, if necessary, modify their treatment idea. Better compliance can be expected if the prescribed wear time conforms to the patient's regime. When dealing with younger patients, consideration must be given to school and leisure activities. While keeping the patient's expectations in mind, the treating dentist has access to the continuous monitoring of wear time.²

The recording of wear time could serve as a means for improving compliance and motivation. Young patients should not perceive the wear time measurement as an unwanted supervision but should rather consider as a prospect for the dentist to customize the wear time based on patient's specific situations. Electronic wear time measurement might become the foundation for treatment planning in orthodontics. Patients may determine if their compliance results in therapeutic success or whether modifications are required.² 

Since this study aimed to determine the patient's compliance, the presence of microsensors was not informed to the patients in the earlier stages of the study.

In this study, most patients failed to wear the removable appliance for the prescribed time (18 h/day), even after being informed about the microsensor in the later stages of the study.

Even though the wear period was shorter than the fulltime schedule (22-24 hours), the effect of the detachable functional gadget was still evident.18 According to Proffit, the external forces were influential even though the duration of wearing removable appliances was nearly half.¹⁹ No skeletal or dental variations were seen between the full- or part-time usage schedules of functional appliances as reported by Parekh et al. ¹⁸ As a result, it was decided that an average of 18 hours would be considered for this study.

It is known that skeletal growth follows circadian rhythm. One can take advantage of skeletal growth for better results if the appliance is worn during these hours. Growth hormones are released in the evenings during which the majority of growth takes place, usually between the hours of 8 pm and midnight or 1 am. It is advised that children wear their functional gadgets from after dinner until they wake up in the morning, roughly 12 hours each day to benefit from this period. An active growth period can be missed if the wearing of the appliance is delayed until bedtime.²⁰ The appliances used in the study were made by the same technician, and the clinical applications were executed by a single clinician for all patients. All microsensors were embedded in the palatal region of the appliances. All patients received a uniform clinical motivation to avoid any bias in compliance levels.

Most orthodontic appliances included the TheraMon® microsensor, which measured 9x13x4 mm. Compared to the prototype, the sensor has an extra polymer capsule covering, enhancing its protection.² Each appliance took around five minutes to integrate the sensor, read the data, and analyze it. Processing the data of the micro-sensor and preparing a report took less than a minute.

When the microsensor was placed in the functional appliance, an increase in the acrylic width in the palatal region was seen (approximately 7-11 mm). TheraMon® wear-time sensors are not detrimental to the therapeutic function of orthodontic appliances, and therapeutic goals may be met just as well with equivalent appliances without wear-time sensors.⁵ The patients in this study did not report any discomfort caused by the thickness of the appliance.

TheraMon® sensor software was developed to ensure that possible manipulation efforts are brought to the practitioner's notice. TheraMon® sensor's temperature calculation algorithm takes into account the small temperature fluctuations that can be anticipated to develop in a patient's oral cavity.⁵

An in vitro study was conducted where the oral cavity’s natural temperature differences were simulated with a thermostatic water bath. The wear time graph displayed "suspicion of manipulation" when the sensor software identified temperature variations in the water bath as "unnatural".⁵

In earlier in vitro studies, Schott and Göz discovered that the TheraMon® had more adaptability and accurate wear time records than the SMART microsensor.^2,5

Microsensors may assist to obtain quicker and more patient-friendly treatment outcomes by measuring the actual wear time of detachable devices. Numerous studies have shown the clinical importance of the TheraMon® microsensor. Our study recorded a significant change in the wear time of the patients once they were aware of the presence of microsensor.

TheraMon® microsensor is manufactured by an Austrian company and is currently unavailable in India. To make it more geographically and economically accessible, an attempt can be made to manufacture the sensor locally.

Future studies can be done to test the connection between wear time and various other parameters like age, type of removable appliance and treatment outcomes. A larger sample size will help in attaining a more accurate result.

Conclusion

In this study, we have concluded the following:

1. Patients wore the functional appliance more often during the aware phase compared to the non-aware period, and this difference was statistically significant.

2. Regarding overall compliance, there was no substantial distinction between male and female patients. 

3. The clinical importance of a microsensor has been proven in this study. To make it more geographically and economically accessible, an attempt can be made to manufacture the sensor locally.

Conflict of interest

No conflict of interest is associated with this publication, and there has been no financial support for this work that could have influenced its outcome.

Ethical Approval: Approval was obtained from Research Sustenance and Institutional Review Board Committee (IRB), DAPM RV Dental College. IRB NO.: 392/VOL2/2021. Parent Consent Statement: All carers gave written consent.