A Twin Block is a removable functional appliance commonly used in growing patients to
correct a Class II malocclusion due to a combination of accelerated mandibular growth and
dento-alveolar change. The Twin Block consists of two separate intersecting appliances
that hold the lower jaw in a forward-postured position to correct anterior-posterior
skeletal and dental relationships, thereby improving the facial profile and reducing the
projection of the upper front teeth (overjet). In order to achieve these desired changes,
Twin Blocks need to be worn for at least 12 hours per day. Due to the removable nature of
the appliance, treatment success is reliant on patient compliance.
Compliance with twin block wear is known to be suboptimal, with non-compliance rates of
up to 34% recorded in the literature. This may be attributed to several factors
associated with Twin Block wear, such as lack of self-motivation, physical impairment,
social concerns and forgetfulness. Virtual appointments could potentially help to address
some of these issues.
Previously explored interventions to improve compliance with removable appliances include
the use of calendars, known monitoring, conscious hypnosis and establishing
implementation intentions. Patients have also recommended the use of visual aids,
effective communication tools, positive reinforcement and reminders, all of which may be
incorporated within virtual appointments, in improving compliance with Twin Block wear.
The effectiveness of virtual appointments in improving Twin Block wear is yet to be
assessed.
The use of remote consultation in healthcare offers potential advantages to patients,
reducing travel costs and improving convenience, while also potentially enhancing
cost-effectiveness and efficiency. Patients report high levels of satisfaction with
virtual dental appointments related to ease of use, effectiveness and reliability. Remote
communications have been employed successfully to deliver oral health advice, diagnose,
monitor development, and provide behaviour guidance for paediatric patients.
'Teledentistry' has been adopted in orthodontics for remote consultations and monitoring,
owing to advancements in technology, the need for social distancing during the COVID-19
pandemic, demand and convenience. Notwithstanding this, there is limited evidence
available concerning its effectiveness either as a substitute to or an adjunct to
conventional in-person visits.
As patients tend to over-report wear time of removable appliances, compliance is better
measured objectively through the use of temperature-sensitive microsensors embedded
within Twin Block appliances. These devices work by taking frequent readings of the
surrounding temperature. When the temperature falls to below that of the intra-oral
environment, it suggests the appliance is no longer being worn. The data collected from
the sensor is interpreted through dedicated software and can be translated to the number
of hours of wear per day. TheraMon® microsensors have been placed in various removable
appliances to provide acceptable accuracy in measuring wear-time, with mean
under-reporting of 4% and a mean difference of approximately one hour between actual and
recorded wear described.
