Analysis of the effects of mandibular reconstruction based on microvascular free flaps after oncological resections in 21 patients, using 3D planning, surgical templates and individual implants.

Introduction: Post- resection defects in the area of the head and neck frequently result in functional impairment of the masticatory system and unaesthetic outcome in the facial appearance. In pediatric population they exert a devastating effect on speech development, breathing and facial growth leading to secondary deformations which are extremely challenging in reconstruction by means of conventional surgery protocols.

Material And Methods: 21 patients (14 males/ 7 females) aged 4-17 years old, treated between 2015 and 2019 due to malignant/benign tumors or congenital deformities requiring mandible resection were enrolled in the study. All patients underwent Virtual Surgical Planning (VSP), mandible tumor resection with use surgery guides and defect reconstruction with microvascular bone graft supported with custom implants. Postoperatively, 3D models used for the planning and postoperative 3D model of the reconstructed mandible were compared using authors method based on easily measurable morphometric measurements (3 angles, 3 linear dimensions), allowing a three-dimensional quantitative assessment of postoperative outcomes of the surgery. Linear regression analysis and one-way analysis of variance were used to evaluate the clinical material. The difference was considered significant if p < 0.05.

Results: Free fibula flap (FFF) was most commonly used type of the reconstruction of the pediatric mandible. The average maximum deviation for the analyzed cases was 7.7 mm, and the average minimum deviation was -6.09 mm, however without significant differences and the postoperative position of the mandible condyle was comparable to the position designed in the 3DVSP preoperatively. Position of the whole reconstructed mandible by means of individually planned grafts and plates provided comparable position of the ramus and mandible body and no chin deviation as the differences between the pre-operative axial and sagittal angles and their post-operative equivalents were insignificant (p > 0,05).

Conclusions: This study confirms applicability of the 3DVSP in pediatric craniomaxillofacial surgery. Preoperative planning of the osteotomies, grafting technique and production of the individualized guides and implants provides precise tumor resection and immediate reconstruction adjusted to the specific anatomy of the pediatric patients.