This presentation will focus on the importance of adequate dimensioning of the forces and moments applied during orthodontic therapy and summarize the development of telemetric smart brackets over the last 15 years. Measuring the three-dimensional (3D) force-moment (F/M) systems exerted on individual teeth during orthodontic therapy is highly desirable for accurate spatial control of tooth movement and for reducing traumatic side effects such as irreversible root resorption. To date, suitable tools for monitoring the applied F/M system during clinical therapy have been lacking. A true-scale orthodontic bracket with an integrated microelectronic stress sensor system for 3D F/M measurements on individual teeth has previously been introduced. The underlying theoretical concept assumes a linear correlation between externally applied F/M systems and mechanical stresses induced within the smart bracket. The validity of this methodological approach has been theoretically proven using finite element simulations, and also experimentally demonstrated by measurements with real true-scale smart brackets with wire-mediated data transmission. Recently, the technical challenge of incorporating a telemetric system for energy and data transmission within a true-scale smart bracket has been overcome. This major step was realized by assembling a sensor chip and a microcoil (both with a surface size of only 2 × 2.5 mm2) with a standard ceramic bracket slot with reduced thickness. This first telemetric smart bracket was monitored over a distance which was sufficient to allow a contactless operation. Telemetrically extracted sensor data are demodulated, digitized and decoded by a reader unit. The readout tool is connected to a graphical user interface which allows the orthodontist to select F/M values relevant for the specific clinical situation. F/M values were successfully acquired by the telemetric smart bracket with resolutions better than 60 mN and 0.14 Nmm, respectively, which might be considered as clinically sufficient. Hence, clinical application of wireless smart brackets stands on the verge of a breakthrough.

This lecture will analyze patient-related factors that can help the clinician to improve the efficacy and efficiency of functional jaw orthopaedics (FJO) for the treatment of Class II malocclusions independently from the type of appliance. Two such factors are timing of treatment and individual patient responsiveness. The role of treatment timing on mandibular growth stimulation produced by removable functional appliances will be illustrated through a meta-analysis and a long-term study. The results of both indicate that if the aim of treatment is to try to stimulate effectively mandibular growth and that it is prudent to include the pubertal growth spurt in the active treatment period (one-phase treatment). In particular, if the aim of treatment is to produce short- and long-term favourable skeletal mandibular changes (effective mandibular growth stimulation and chin advancement), the start of treatment with removable functional appliances should be postponed until puberty (one-phase treatment). On the other hand, if correction of the Class II problem requires mainly dentoalveolar modifications, treatment timing can be initiated before puberty with a two-phase approach. Besides treatment timing, individual patient responsiveness should be taken into account to identify either good or poor candidates to FJO. Good responders to FJO for the treatment of Class II malocclusions associated with mandibular retrusion are characterized by a small mandibular angle (Co-Go-Me). In other words, pubertal Class II patients who present with a small mandibular angle are characterized by a favourable mandibular growth potential.