Safe and rapid contouring of fibro-osseous lesions in the orbital area using navigation with minimally invasive cranial bone registration

Background: Bone contouring is currently the best treatment for fibro-osseous lesions after bone growth arrest. Navigation systems available for this surgery allow intra-operative visualisation with improved cosmetic outcomes. However, conventional navigation systems using superficial skin registration cannot prevent subtle discrepancies. Method: To address this problem, we used a non-invasive cranial bone registration that uses patient-specific dental templates to maintain exact registration. We created the preset goal using the mirror image of the unaffected side for unilateral lesions, and using images obtained before the onset of symptoms for bilateral lesions. This system achieved precise pre-operative simulation. A sound aid in the navigation system provided information regarding proximity to critical structures and to the preset goal. Results: We used this system to contour fibro-osseous lesions in three patients. All patients achieved good facial contours and improvement in symptoms. Conclusions: This method offers a safe, rapid surgical aid in treating orbital fibro-osseous lesions.