Tissue Engineering: Current Technology for Facial Reconstruction.

Facial reconstruction is a complex surgical process that requires intricate three-dimensional (3D) concepts for optimal functional and aesthetic outcomes. Conventional reconstruction of structural facial anomalies, such as those including cartilage or bony defects, typically rely on hand-carving autologous constructs harvested from a separate donor site, and shaping that cartilage or bone into a new structural framework. Tissue engineering has emerged in recent decades as a potential approach to mitigate the need for donor site morbidity while improving precision in the design of reconstructive construct. Computer-aided design and computer-aided manufacturing have allowed for a digital 3D workflow to digitally execute the planned reconstruction in virtual space. 3D printing and other manufacturing techniques can then be utilized to create custom-fabricated scaffolds and guides to improve the reconstructive efficiency. Tissue engineering can be paired with custom 3D-manufactured scaffolds to theoretically create an ideal framework for structural reconstruction. In the past decade, there have been several compelling preclinical studies demonstrating the capacity to induce chondrogenesis or osteogenesis in a custom scaffold. However, to date, these preclinical data have not yet translated into significant clinical experience. This translation has been hindered by a lack of consensus on the ideal materials and cellular progenitors to be utilized in these constructs and a lack of regulatory guidance and control to enable clinical application. In this review, we highlight the current state of tissue engineering in facial reconstruction and exciting potential for future applications as the field continues to advance.

Higher Computed Tomography (CT) Scan Resolution Improves Accuracy of Patient-specific Mandibular Models When Compared to Cadaveric Gold Standard.

BACKGROUND: 3D-printed patient-specific anatomical models are becoming an increasingly popular tool for planning reconstructive surgeries to treat oral cancer. Currently there is a lack of information regarding model accuracy, and how the resolution of the computed tomography (CT) scan affects the accuracy of the final model. PURPOSE: The primary objective of this study was to determine the CT z-axis resolution necessary in creating a patient specific mandibular model with clinically acceptable accuracy for global bony reconstruction. This study also sought to evaluate the effect of the digital sculpting and 3D printing process on model accuracy. STUDY DESIGN: This was a cross-sectional study using cadaveric heads obtained from the Ohio State University Body Donation Program. INDEPENDENT VARIABLES: The first independent variable is CT scan slice thickness of either 0.675 , 1.25, 3.00, or 5.00 mm. The second independent variable is the three produced models for analysis (unsculpted, digitally sculpted, 3D printed). MAIN OUTCOME VARIABLE: The degree of accuracy of a model as defined by the root mean square (RMS) value, a measure of a model's discrepancy from its respective cadaveric anatomy. ANALYSES: All models were digitally compared to their cadaveric bony anatomy using a metrology surface scan of the dissected mandible. The RMS value of each comparison evaluates the level of discrepancy. One-way ANOVA tests (P < .05) were used to determine statistically significant differences between CT scan resolutions. Two-way ANOVA tests (P < .05) were used to determine statistically significant differences between groups. RESULTS: CT scans acquired for 8 formalin-fixed cadaver heads were processed and analyzed. The RMS for digitally sculpted models decreased as slice thickness decreased, confirming that higher resolution CT scans resulted in statistically more accurate model production when compared to the cadaveric gold standard. Furthermore, digitally sculpted models were significantly more accurate than unsculpted models (P < .05) at each slice thickness. CONCLUSIONS: Our study demonstrated that CT scans with slice thicknesses of 3.00 mm or smaller created statistically significantly more accurate models than models created from slice thicknesses of 5.00 mm. The digital sculpting process statistically significantly increased the accuracy of models and no loss of accuracy through the 3D printing process was observed.

Response to induction chemotherapy in sinonasal malignancies: A single-institutional experience.

BACKGROUND: Sinonasal malignancy (SNM) is a heterogeneous group of diseases for which induction chemotherapy (IC) may reduce tumor burden. The purpose of this study was to characterize the response to IC in SNM as a prognostic factor through its effect on survival. METHODS: Retrospective cohort of patients undergoing IC for SNM between 2010 and 2019 at our quaternary referral center. RESULTS: Forty-two patients with advanced SNM were included in the analysis. Patients with a favorable response to IC had higher survival rates than those who had an unfavorable response (5-year OS: 66.8% vs. 9.7%; p < 0.001; PFS: 56.8% vs. 0%; p < 0.001). CONCLUSIONS: Response to IC in our patient cohort was a prognostic indicator of overall response to treatment. Further elucidation of predictors of response is needed for appropriate patient selection.

Central Skull Base Osteomyelitis: A Case Series from a Tertiary Care Center Over 5 Years.

OBJECTIVE: Skull base osteomyelitis may rarely present in the sphenoid bone or clivus without an otologic source. This is referred to as central skull base osteomyelitis (CSBO). Knowledge regarding CSBO is limited to case reports and small case series. Here we present a case series to further describe typical patient characteristics, clinical presentation, and clinical course associated with this rare infection. METHODS: All patients treated at a single academic tertiary care institution for CSBO from 2016 through 2020 were identified. Inclusion criteria included culture proven CSBO without an otologic or iatrogenic source. Data were extracted via patient chart review and qualitatively analyzed. RESULTS: Seven patients were identified with CSBO, 5 male and 2 female. Age ranged from 63 to 87 (average 76). Risk factors included advanced age, diabetes, and history of radiation. The most common presenting symptom was headache (6), followed by otalgia (4). Two patients presented with cranial neuropathies. Diagnosis was facilitated by history and exam (including flexible laryngoscope exam), imaging (MRI), and labs (ESR). All patients received endoscopic biopsy and culture (most commonly polymicrobial, with diverse species). Treatment involved IV antibiotics, with a limited role for surgery. All patients survived and achieved resolution of infection. CONCLUSIONS: CSBO remains a diagnostic challenge due to its rarity and vague presenting symptoms that overlap with presentation of sinonasal malignancies. A high index of suspicion is required by the evaluating provider to ensure a timely diagnosis with early treatment in order to limit the significant morbidity which can be associated with this infection. LEVEL OF EVIDENCE: 4.