Development and validation of OMIs: a device for orthodontic mini implant stability measurement using the osstell ISQ system

Orthodontic mini-implants (OMIs) provide reliable skeletal anchorage, but their clinical success depends on achieving optimal primary stability. Although Resonance Frequency Analysis (RFA) using the Osstell ISQ system is well-established in implantology, its application to OMIs is limited by structural incompatibility and the absence of standardised adaptors. This study aimed to develop and evaluate the Orthodontic Mini-Implant SmartPeg (OMIS), a reusable and universal adaptor for assessing OMI stability using the Osstell ISQ system. A mixed-methods study was conducted in two phases: laboratory validation using goat jawbone models and SICace® implants, and clinical usability testing among orthodontic lecturers and postgraduate trainees. OMIS was developed using aluminium alloy 6061 with a claw- end magnetic coupling design. Its performance was compared to standard Osstell SmartPegs, and its compatibility was tested with four commercial OMI brands. User perception was assessed using a validated 17-item questionnaire. OMIS demonstrated good inter-device reproducibility but exhibited poor test-retest reliability (ICC < 0.5) and weak, non-significant correlations with SmartPeg ISQ values (Spearman’s r = 0.21– 0.36, p > 0.05). The OMIS attached securely to all four OMI systems and produced consistent intra-brand ISQ measurements despite inter-brand differences. Usability feedback indicated high agreement (>80%) on instruction clarity, perceived usefulness, and educational potential, with moderate ratings for intraoral comfort and ease of handling. In conclusion, OMIS shows promising potential as a standardised, reusable tool for OMI stability assessment. Further refinement in calibration accuracy, ergonomic design, and multi-centre clinical validation is recommended to optimise its clinical application.