Assessing tooth mobility before and after miniscrew implantation for diagnosing root contact: a cadaveric animal study.

Objective: To determine whether miniscrew-root contact can be diagnosed by assessing tooth mobility before and after miniscrew implantation.

Materials and methods: Cadaveric pig mandibles were used, with 80 miniscrews placed mesial to the first premolars and distal to the fourth premolars. Maximum insertion torque (MIT) was measured for the first premolar miniscrews. Tooth mobility was assessed before and after implantation, and the Periotest Value difference (PTV-Diff) was calculated. Miniscrew-root distance (MS-R Dist) was measured using computed tomography. Spearman's rank correlations were analysed between MS-R Dist and PTV-Diff, and between MS-R Dist and MIT. Diagnostic efficacy was assessed using receiver-operating characteristic (ROC) curve analysis.

Results: PTV-Diff exhibited a positive correlation with MS-R Dist (rs > 0.7, P < 0.001), confirming reduced tooth mobility when miniscrews contacted tooth roots. PTV-Diff demonstrated high diagnostic accuracy, with an area under the ROC curve > 0.9, outperforming MIT. Three observed root fractures influenced the correlation between MS-R Dist and PTV-Diff.

Limitations: The primary limitation is the use of cadaveric mandibles, allowing ideal perpendicular percussion with the Periotest system, which may be challenging to replicate in humans due to anatomical constraints.

Conclusion: Our results suggested that PTV-Diff effectively diagnoses miniscrew-root contact, outperforming MIT. Differences between first and fourth premolars emphasize the need for tooth-specific cut-off values in clinical applications. Root fractures significantly affected diagnostic accuracy, underscoring the importance of multiple PTV measurements during miniscrew placement. Measuring tooth mobility before and after miniscrew implantation may hold promise as a diagnostic approach for detecting miniscrew-root contact.