Virtually planned and CAD/CAM-guided secondary reconstruction of the mandibular condyle after malunion: from "unpredictable" to precise? -accuracy and outcomes.

BACKGROUND

In patients with malunited condylar fractures of the mandible surgical intervention is preferred when malocclusion and compromised masticatory function occur. This study evaluated the accuracy and clinical utility of virtual surgical planning (VSP) and CAD/CAM fabricated patient-specific implants (PSIs) for the secondary correction of post-traumatic mandibular condyle deformities.

METHODS

Accuracy of condylar segment repositioning was quantified by comparing the virtually planned joint surface with the actual postoperative same surface of the condylar head using Mimics and 3-Matic software (Materialise, Leuven, Belgium). Deviation was calculated by two methods: the Part Comparison Analysis (PCA) function of the analysis software and by measuring distances between four corresponding reference points on the planned and final segments.

RESULTS

The mean deviation between planned and final joint surfaces was 2.27 mm (range 4.69) with the PCA method and 2.56 mm (range: 8.99) with the reference-point method. No significant difference was observed between high and low condylar osteotomies. Accuracy was greatest along the lateromedial axis (1.83 mm; range: 6.98 mm) and lowest in the craniocaudal axis (3.30 mm; range: 6.75 mm). A good postoperative mandibular mobility was assessed in most cases with an average active mouth opening of 37 mm and no permanent sensory impairment was reported.

CONCLUSION

Virtual surgical planning combined with CAD/CAM PSIs provides a reliable option for secondary reduction and fixation of condylar fragments, achieving high positional accuracy, good postoperative mandibular mobility, and a low rate of major complications.