The relative accuracy of dynamic navigation-guided and conventional coronectomy for mandibular third molars: A randomized controlled trial.

OBJECTIVES

This study aimed to evaluate and compare the surgical precision of coronectomy for mandibular third molars (M3Ms) performed with the aid of a dynamic navigation system (DNS) versus the conventional freehand technique.

METHODS

A single-blind randomized controlled trial was conducted in 110 patients undergoing M3M coronectomy. After withdrawal of three patients, 107 patients (teeth, N = 117) were included in the final analysis. Teeth were randomly allocated to the DNS-assisted group (patients, n = 52; teeth, N = 57) or the freehand group (patients, n = 55; teeth, N = 60). The primary outcome measure was the root mean square (RMS) deviation between the achieved osteotomy plane and the preoperative virtual plan, assessed for the entire resection surface as well as the mesial and distal subregions. Secondary outcomes included: (i) maximum and mean positive and negative deviations in all regions; (ii) curvature parameters (RMS, maximum, and minimum) for the complete osteotomy plane and its subregions; and (iii) total procedure duration and active operative time. Postoperative cone-beam computed tomography (CBCT) scans were processed with Geomagic software for three-dimensional deviation analysis.

RESULTS

The DNS-assisted group showed significantly reduced RMS deviations (overall: 1.02 ± 0.50 mm; mesial: 1.06 ± 0.58 mm; distal: 0.92 ± 0.54 mm) compared with the freehand group (overall: 1.44 ± 0.90 mm; mesial: 1.46 ± 1.07 mm; distal: 1.48 ± 1.25 mm; P < 0.05). Consistent advantages of DNS were also observed in maximum and mean positive deviations, RMS curvature, and minimum curvature values. However, operative duration was significantly longer with DNS than with the freehand method (28 min vs. 14 min, P < 0.05).

CONCLUSIONS

Dynamic navigation significantly improves the accuracy of M3M coronectomy, achieving millimeter-level precision that surpasses that of the freehand technique.

CLINICAL SIGNIFICANCE: These findings highlight the value of a fully digital workflow from preoperative planning through postoperative validation in DNS-guided coronectomy, underscoring its potential to improve safety and precision in complex M3M surgeries.