Case Report: Reconstruction of a Large Maxillary Defect With an Engineered, Vascularized, Prefabricated Bone Graft.

The reconstruction of complex midface defects is a challenging clinical scenario considering the high anatomical, functional, and aesthetic requirements. In this study, we proposed a surgical treatment to achieve improved oral rehabilitation and anatomical and functional reconstruction of a complex defect of the maxilla with a vascularized, engineered composite graft. The patient was a 39-year-old female, postoperative after left hemimaxillectomy for ameloblastic carcinoma in 2010 and tumor-free at the 5-year oncological follow-up. The left hemimaxillary defect was restored in a two-step approach. First, a composite graft was ectopically engineered using autologous stromal vascular fraction (SVF) cells seeded on an allogenic devitalized bone matrix. The resulting construct was further loaded with bone morphogenic protein-2 (BMP-2), wrapped within the latissimus dorsi muscle, and pedicled with an arteriovenous (AV) bundle. Subsequently, the prefabricated graft was orthotopically transferred into the defect site and revascularized through microvascular surgical techniques. The prefabricated graft contained vascularized bone tissue embedded within muscular tissue. Despite unexpected resorption, its orthotopic transfer enabled restoration of the orbital floor, separation of the oral and nasal cavities, and midface symmetry and allowed the patient to return to normal diet as well as to restore normal speech and swallowing function. These results remained stable for the entire follow-up period of 2 years. This clinical case demonstrates the safety and the feasibility of composite graft engineering for the treatment of complex maxillary defects. As compared to the current gold standard of autologous tissue transfer, this patient's benefits included decreased donor site morbidity and improved oral rehabilitation. Bone resorption of the construct at the ectopic prefabrication site still needs to be further addressed to preserve the designed graft size and shape.

The need for overcorrection: evaluation of computer-assisted, virtually planned, fronto-orbital advancement using postoperative 3D photography.

OBJECTIVE: The main indication for craniofacial remodeling of craniosynostosis is to correct the deformity, but potential increased intracranial pressure resulting in neurocognitive damage and neuropsychological disadvantages cannot be neglected. The relapse rate after fronto-orbital advancement (FOA) seems to be high; however, to date, objective measurement techniques do not exist. The aim of this study was to quantify the outcome of FOA using computer-assisted design (CAD) and computer-assisted manufacturing (CAM) to create individualized 3D-printed templates for correction of craniosynostosis, using postoperative 3D photographic head and face surface scans during follow-up. METHODS: The authors included all patients who underwent FOA between 2014 and 2020 with individualized, CAD/CAM-based, 3D-printed templates and received postoperative 3D photographic face and head scans at follow-up. Since 2016, the authors have routinely planned an additional "overcorrection" of 3 mm to the CAD-based FOA correction of the affected side(s). The virtually planned supraorbital angle for FOA correction was compared with the postoperative supraorbital angle measured on postoperative 3D photographic head and face surface scans. The primary outcome was the delta between the planned CAD/CAM FOA correction and that achieved based on 3D photographs. Secondary outcomes included outcomes with and those without "overcorrection," time of surgery, blood loss, and morbidity. RESULTS: Short-term follow-up (mean 9 months after surgery; 14 patients) showed a delta of 12° between the planned and achieved supraorbital angle. Long-term follow-up (mean 23 months; 8 patients) showed stagnant supraorbital angles without a significant increase in relapse. Postsurgical supraorbital angles after an additionally planned overcorrection (of 3 mm) of the affected side showed a mean delta of 11° versus 14° without overcorrection. The perioperative and postoperative complication rates of the whole cohort (n = 36) were very low, and the mean (SD) intraoperative blood loss was 128 (60) ml with a mean (SD) transfused red blood cell volume of 133 (67) ml. CONCLUSIONS: Postoperative measurement of the applied FOA on 3D photographs is a feasible and objective method for assessment of surgical results. The delta between the FOA correction planned with CAD/CAM and the achieved correction can be analyzed on postoperative 3D photographs. In the future, calculation of the amount of "overcorrection" needed to avoid relapse of the affected side(s) after FOA may be possible with the aid of these techniques.

Evaluating Preoperative Models: A Methodologic Contribution.

BACKGROUND: Three-dimensional (3D) printed models of the human skull and parts of it are being increasingly used for surgical education and customized preoperative planning. OBJECTIVE: This study, using the calvaria as a model, provides a methodologic analysis with regard to future investigations aimed at evaluating patient-specific skull replicas. METHODS: Postmortem computed tomography was used for 3D reconstruction of a skull. The digital model obtained was converted to a physical replica by 3D printing. This copy was compared qualitatively and quantitatively with the original, using both a classical anthropometric and a 3D surface scanning approach. RESULTS: Qualitatively, the replica and the original displayed good qualitative concordance. The quantitative deviations, as measured by osteometric tools, lay partly in the submillimetric area, partly between 1 and 2 mm. The maximum difference was 3.7 mm. On the basis of the surface scans, a mean deviation of 0.2930 mm (±0.2677 mm) and a median difference of 0.2125 mm (0.0000-1.5509 mm) were observed for the inner surface. For the whole object, corresponding figures amounted to 0.9101 mm (±0.5390 mm) and 0.8851 mm (0.000-3.2647 mm). CONCLUSIONS: Qualitatively flawless replicas of the skull region investigated are feasible, subject to extensive manual CT image editing. However, neurosurgeons should be aware that models of one and the same patient will vary according to the production chain used by the 3D printing laboratory in charge. Methodologically, both classic anthropological and light-stripe-based comparisons are justified for use in future studies. For trials aimed at assessing mean deviations and topographic distribution patterns, optical 3D scanning technologies can be recommended.

Computer-assisted virtual planning and surgical template fabrication for frontoorbital advancement.

OBJECT The authors describe a novel technique using computer-assisted design (CAD) and computed-assisted manufacturing (CAM) for the fabrication of individualized 3D printed surgical templates for frontoorbital advancement surgery. METHODS Two patients underwent frontoorbital advancement surgery for unilateral coronal synostosis. Virtual surgical planning (SurgiCase-CMF, version 5.0, Materialise) was done by virtual mirroring techniques and superposition of an age-matched normative 3D pediatric skull model. Based on these measurements, surgical templates were fabricated using a 3D printer. Bifrontal craniotomy and the osteotomies for the orbital bandeau were performed based on the sterilized 3D templates. The remodeling was then done placing the bone plates within the negative 3D templates and fixing them using absorbable poly-dl-lactic acid plates and screws. RESULTS Both patients exhibited a satisfying head shape postoperatively and at follow-up. No surgery-related complications occurred. The cutting and positioning of the 3D surgical templates proved to be very accurate and easy to use as well as reproducible and efficient. CONCLUSIONS Computer-assisted virtual planning and 3D template fabrication for frontoorbital advancement surgery leads to reconstructions based on standardizedmeasurements, precludes subjective remodeling, and seems to be overall safe and feasible. A larger series of patients with long-term follow-up is needed for further evaluation of this novel technique.