Three-Dimensional Printing Bioceramic Scaffolds Using Direct-Ink-Writing for Craniomaxillofacial Bone Regeneration.

Defects characterized as large osseous voids in bone, in certain circumstances, are difficult to treat, requiring extensive treatments which lead to an increased financial burden, pain, and prolonged hospital stays. Grafts exist to aid in bone tissue regeneration (BTR), among which ceramic-based grafts have become increasingly popular due to their biocompatibility and resorbability. BTR using bioceramic materials such as ß-tricalcium phosphate has seen tremendous progress and has been extensively used in the fabrication of biomimetic scaffolds through the three-dimensional printing (3DP) workflow. 3DP has hence revolutionized BTR by offering unparalleled potential for the creation of complex, patient, and anatomic location-specific structures. More importantly, it has enabled the production of biomimetic scaffolds with porous structures that mimic the natural extracellular matrix while allowing for cell growth-a critical factor in determining the overall success of the BTR modality. While the concept of 3DP bioceramic bone tissue scaffolds for human applications is nascent, numerous studies have highlighted its potential in restoring both form and function of critically sized defects in a wide variety of translational models. In this review, we summarize these recent advancements and present a review of the engineering principles and methodologies that are vital for using 3DP technology for craniomaxillofacial reconstructive applications. Moreover, we highlight future advances in the field of dynamic 3D printed constructs via shape-memory effect, and comment on pharmacological manipulation and bioactive molecules required to treat a wider range of boney defects.

Effect of Material and Pad Abrasion on Shear Bond Strength of 3D-Printed Orthodontic Brackets.

OBJECTIVE: To investigate the effect of printing material and air abrasion of bracket pads on the shear bond strength of 3D-printed plastic orthodontic brackets when bonded to the enamel of extracted human teeth. MATERIALS AND METHODS: Premolar brackets were 3D-printed using the design of a commercially available plastic bracket in two biocompatible resins: Dental LT Resin and Dental SG Resin (n = 40/material). 3D-printed brackets and commercially manufactured plastic brackets were divided into two groups (n = 20/group), one of which was air abraded. All brackets were bonded to extracted human premolars, and shear bond strength tests were performed. The failure types of each sample were classified using a 5-category modified adhesive remnant index (ARI) scoring system. RESULTS: Bracket material and bracket pad surface treatment presented statistically significant effects for shear bond strengths, and a significant interaction effect between bracket material and bracket pad surface treatment was observed. The non-air abraded (NAA) SG group (8.87 ± 0.64 MPa) had a statistically significantly lower shear bond strength than the air abraded (AA) SG group (12.09 ± 1.23 MPa). In the manufactured brackets and LT Resin groups, the NAA and AA groups were not statistically significantly different within each resin. A significant effect of bracket material and bracket pad surface treatment on ARI score was observed, but no significant interaction effect between bracket material and pad treatment was found. CONCLUSION: 3D-printed orthodontic brackets presented clinically sufficient shear bond strengths both with and without AA prior to bonding. The effect of bracket pad AA on shear bond strength depends on the bracket material.

Colour stability of 3D-Printed orthodontic brackets using filled resins.

OBJECTIVE: To determine the effect of common beverages and accelerated aging on the colour stability of filled resins, which could potentially be used for fabrication of 3D-printed orthodontic brackets. MATERIALS AND METHODS: GR-17.1 (shades A1, A2, and A3), and GR-10 Guide resins (pro3dure medical, Eden Prairie, MN) were printed on an Asiga MAX UV printer into discs 2 mm thick, with a diameter of 10 mm, and then post-print processed as per manufacturer's instructions. Discs were immersed in 5 mL of coffee, tea, red wine, or distilled water for 7 days. Another group was subjected to accelerated aging in accordance with ISO Standard 4892-2. Ten samples were produced per resin, per treatment condition. Colour measurements were taken on the discs before and after treatment using a spectrophotometer against white and black reference tiles to assess colour and translucency differences with the CIEDE2000 colour difference formula. RESULTS: While initial colour of the printed resin discs was acceptable, all resin groups underwent significant colour change during the experiment. Red wine and coffee produced the greatest colour and translucency change, followed by tea, with accelerated aging producing the least change in colour and translucency. CONCLUSION: The 3D-printed resins tested underwent significant changes in colour and translucency following exposure to endogenous and exogenous sources of staining, which may affect their acceptability for fabrication of aesthetic orthodontic brackets.

Bringing hydrogel-based craniofacial therapies to the clinic.

This review explores the evolution of the use of hydrogels for craniofacial soft tissue engineering, ranging in complexity from acellular injectable fillers to fabricated, cell-laden constructs with complex compositions and architectures. Addressing both in situ and ex vivo approaches, tissue restoration secondary to trauma or tumor resection is discussed. Beginning with relatively simple epithelia of oral mucosa and gingiva, then moving to more functional units like vocal cords or soft tissues with multilayer branched structures, such as salivary glands, various approaches are presented toward the design of function-driven architectures, inspired by native tissue organization. Multiple tissue replacement paradigms are presented here, including the application of hydrogels as structural materials and as delivery platforms for cells and/or therapeutics. A practical hierarchy is proposed for hydrogel systems in craniofacial applications, based on their material and cellular complexity, spatial order, and biological cargo(s). This hierarchy reflects the regulatory complexity dictated by the Food and Drug Administration (FDA) in the United States prior to commercialization of these systems for use in humans. The wide array of available biofabrication methods, ranging from simple syringe extrusion of a biomaterial to light-based spatial patterning for complex architectures, is considered within the history of FDA-approved commercial therapies. Lastly, the review assesses the impact of these regulatory pathways on the translational potential of promising pre-clinical technologies for craniofacial applications. STATEMENT OF SIGNIFICANCE: While many commercially available hydrogel-based products are in use for the craniofacial region, most are simple formulations that either are applied topically or injected into tissue for aesthetic purposes. The academic literature previews many exciting applications that harness the versatility of hydrogels for craniofacial soft tissue engineering. One of the most exciting developments in the field is the emergence of advanced biofabrication methods to design complex hydrogel systems that can promote the functional or structural repair of tissues. To date, no clinically available hydrogel-based therapy takes full advantage of current pre-clinical advances. This review surveys the increasing complexity of the current landscape of available clinical therapies and presents a framework for future expanded use of hydrogels with an eye toward translatability and U.S. regulatory approval for craniofacial applications.

Effect of print orientation on the dimensional accuracy of orthodontic aligners printed 3-dimensionally.

INTRODUCTION: Fabrication of orthodontic aligners directly via 3-dimensional (3D) printing presents the potential to increase the efficiency of aligner production relative to traditional workflows; however tunable aspects of the 3D-printing process might affect the dimensional fidelity of the fabricated appliances. This study aimed to investigate the effect of print orientation on the dimensional accuracy of orthodontic aligners printed directly with a 3D printer. METHODS: A digitally designed aligner of 500 µm thickness was printed in 3D in Grey V4 (Formlabs, Somerville, Mass) resin at 8 angulations at 45° intervals (n = 10 per angulation) using a stereolithography 3D printer. Each aligner was scanned with an optical scanner, and all but the intaglio surface of each scan was digitally removed. Each resultant scan file was superimposed onto the isolated intaglio of the designed master aligner file. The dimensional deviation was quantified with Geomagic Control software (3D Systems, Rock Hill, SC), and data were analyzed using R statistical software (version 2018; R Core Team, Vienna, Austria) (P <0.05). RESULTS: Print angle showed a statistically significant effect on standard deviation, average positive deviation, absolute average negative deviation, and percentage of points out of bounds (tolerance bounds defined as ±250 µm) (P <0.05). Qualitative analysis of the 3D surface deviation maps indicated that the 0° and 90° groups showed less deviation and appeared to be the most accurate in the anterior regions. Overall, the majority of the print angle groups studied were not printed within clinically acceptable tolerance ranges, with the major exception being the 90° group, which printed nominally within clinically acceptable tolerance ranges. CONCLUSIONS: With the workflow applied, print orientation significantly affects the dimensional accuracy of directly 3D-printed orthodontic aligners. Within the limitations of this study, printing at the 90° angulation would be advised as it is the group with the most accurate prints relative to the 7 other orientations investigated, although not all differences were statistically significant.

Evaluation of current additive manufacturing systems for orthodontic 3-dimensional printing.

INTRODUCTION: The objective of this research was to evaluate and compare linear and surface accuracy of dental models fabricated using 3 different vat photopolymerization printing units: digital light synthesis (M2 Printer; Carbon, Redwood City, Calif), digital light processing (Juell 3D Flash OC; Park Dental Research, New York, NY), and stereolithography apparatus (Form 2; Formlabs Inc, Somerville, Mass), and a material jetting printing unit: PolyJet (Objet Eden 260VS; Stratasys, Eden Prairie, Minn). METHODS: Maxillary and mandibular dental arches of 20 patients with the American Board of Orthodontics Discrepancy Index scores ranging between 10 and 30 were scanned using an intraoral scanner. Stereolithographic files of each patient were printed via the 3-dimensional (3D) printers and were digitized again using a 3D desktop scanner to enable comparisons with the original scan data. One-sample t test and linear regression analyses were performed. To further graphically examine the accuracy between the different methods, Bland-Altman plots were computed. The level of significance was set at P <0.05. RESULTS: Bland-Altman analysis showed no fixed bias of one approach vs the other, and random errors were detected in all linear accuracy comparisons. When a 0.25 mm tolerance level was deemed acceptable for any positive or negative surface changes, only the models manufactured from digital light processing and PolyJet units showed more than 97% match with the original scans. CONCLUSION: The surface area of 3D printed models did not yield an utterly identical match to the original scan data and was affected by the type of printer. The clinical relevance of the differences observed on the 3D printed dental model surfaces requires application-specific judgments.

Effect of build angle and layer height on the accuracy of 3-dimensional printed dental models.

INTRODUCTION: Three-dimensional (3D) printing technologies are profoundly changing the landscape of orthodontics. To optimize treatment-oriented applications, dimensional fidelity is required for 3D-printed orthodontic models. This study aimed to evaluate the effect of build angle and layer height on the accuracy of 3D-printed dental models and if each of their influences on print accuracy was conditional on the other. METHODS: A maxillary cast was scanned using an intraoral scanner. One hundred thirty-two study models were printed at various combinations of build angle (0°, 30°, 60°, 90°) and layer height (20 µm, 50 µm, 100 µm) with a digital light processing printer (n = 11 per group). The models were digitally scanned, and deviation analyzed using a 3D best-fit algorithm in metrology software. RESULTS: A statistically significant interaction was consistently found between build angle and layer height for each positive deviation, negative deviation, and proportion out of bounds. Average deviations of all study models were within clinically acceptable ranges, but the least accurate models were printed at 0°/20 µm. Although there was a tendency for an oblique build angle of 30° or 60° with a smaller layer height of 20 µm or 50 µm to print the most accurate models, 95 % confidence intervals overlapped with all other angles and heights except for 0°/20 µm. CONCLUSIONS: Build angle and layer height have statistically significant interactive effects on the accuracy of 3D-printed dental models. Overall, digital light processing printers produced models within clinically acceptable bounds, but the choice of build angle and layer height should be considered in conjunction with the clinical application, desired print time, and preferred efficiency of each print job.

Colour stability of 3D-printed resin orthodontic brackets.

OBJECTIVE: To evaluate the colour stability of polymeric resins that could be used to 3D-print orthodontic brackets. DESIGN: In vitro, laboratory study. MATERIALS AND METHODS: Disc-shaped specimens were fabricated via 3D printing using three resins: Dental LT; Dental SG; and Clear. Five conditions were evaluated for each resin (n = 10 per treatment per resin) to assess its corresponding effect on colour and translucency: immersion in (1) red wine, (2) coffee, (3) tea and (4) distilled water (control), and (5) exposure to accelerated aging. Colour and translucency measurements were made before and after exposure using a spectrophotometer. Mean colour differences (ΔE00) and changes in translucency parameter (ΔTP00) were calculated for each sample using the CIEDE2000 colour difference formula. RESULTS: Statistically significant effects of the resin material, the treatment condition and interactions effects of material and condition were observed for ΔE00 and ΔTP00 (P < 0.001). The most pronounced changes in colour (ΔE00) were a result of the staining effects of wine on all three resins, ranging from 14.5 ± 0.6 to 20.8 ± 1.2. Dental LT, Dental SG and Clear resins all showed changes in colour when exposed to certain staining agents. Dental SG and Clear resins exhibited changes in colour with aging, while the colour of Dental LT resin remained stable with aging. CONCLUSIONS: The colour changes of the resins investigated does not support their use in 3D-printed aesthetic bracket applications.

Evaluation of the dimensional accuracy of thermoformed appliances taken from 3D printed models with varied shell thicknesses: An in vitro study.

OBJECTIVE: Clinicians make numerous decisions when 3D printing models for fabrication of thermoformed appliances, including printing solid or hollow models. While hollow models can reduce resin use, models intended for thermoformed appliance fabrication must be printed with sufficient thickness to withstand thermoforming. The aim of the study was to determine for hollow 3D printed orthodontic models if there is an effect of shell thickness on the dimensional accuracy of retainers thermoformed upon them as compared with solid models and, if so, to identify the minimum shell thickness that ensures dimensional accuracy of the thermoformed retainer under the conditions investigated. MATERIAL AND METHODS: Thermoformed appliances were fabricated on 3D printed models of six shell thicknesses: 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, and solid (n=10/group). The models were scanned before and after thermoforming. Thermoformed appliances were captured by two methods: scanning a polyvinylsiloxane casting of the appliance and scanning the appliance interior surface (intaglio surface). Each model-appliance pair was compared using superimposition software. A generalized linear model and post-hoc Tukey contrasts (α=0.05) were applied to compare each thickness. RESULTS: Model thickness has a statistically significant effect on dimensional accuracy of thermoformed appliances. Appliances fabricated on 1.0mm and 1.5mm models displayed poor accuracy, with a statistically significantly lower percentage of data points within tolerance (±0.250mm) than appliances fabricated on models printed at 2.0mm thickness and greater. CONCLUSIONS: 3D printed model thickness affects the dimensional accuracy of a thermoformed retainer. To ensure minimal deformation and promote clinical utility of the thermoformed appliance, models should be printed with a minimum shell thickness of 2.0mm for the materials investigated.

Wear Resistance of 3D Printed and Prefabricated Denture Teeth Opposing Zirconia.

PURPOSE: To evaluate the wear resistance of a recently developed three-dimensional (3D) printed denture teeth resin compared to three commercially available prefabricated denture teeth. MATERIALS AND METHODS: A total of 88 maxillary first molar denture teeth were evaluated: C (Classic; Dentsply Sirona, York, PA), DCL (SR Postaris DCL; Ivoclar Vivadent, Schaan, Liechtenstein), IPN (Portrait IPN; Dentsply Sirona, York, PA), and F (Denture Teeth A2 Resin 1 L; Formlabs, Somerville, MA). The 3D printed denture tooth specimens were fabricated from a methacrylate-based photopolymerizing resin using stereolithography (SLA). Denture teeth were subjected to a three-body wear test with a poly(methylmethacrylate) (PMMA) abrasive slurry. A Leinfelder-style four station wear apparatus with custom bullet-shaped milled zirconia styli was utilized with a load force of 36-40 N at 1.7 Hz for 200,000 cycles. Maximum depth of wear was measured using a lab grade scanner and analyzing software program. Data were analyzed using a one-way ANOVA followed by the Tukey's Multiple Comparisons post hoc test (α = 0.05). RESULTS: A statistically significant difference in depth of wear was found between denture tooth materials (p < 0.001). The mean vertical depth of wear for the 3D printed denture teeth (0.016 ± 0.010 mm) was statistically significantly less than the prefabricated denture teeth. The highly cross-linked denture teeth, DCL (0.036 ± 0.011 mm) and IPN (0.035 ± 0.014 mm), exhibited statistically significantly less wear than the conventional acrylic denture teeth. The conventional acrylic denture teeth demonstrated the greatest wear (0.058 ± 0.014 mm). No significant difference in depth of wear was found between DCL and IPN (p > 0.001). CONCLUSIONS: Denture tooth material significantly influences the depth of wear. The 3D printed denture teeth demonstrated superior wear resistance compared to the commercially available prefabricated denture teeth when opposed to zirconia. Denture teeth fabricated with SLA technology may have a promising future in prosthetic dentistry.

Analysis of the thickness of 3-dimensional-printed orthodontic aligners.

INTRODUCTION: This study aimed to investigate the effect of digitally designed aligner thickness on the thickness of the corresponding 3-dimensional (3D)-printed aligner. METHODS: Digitally designed aligners of 3 different thicknesses (0.500 mm, 0.750 mm, and 1.000 mm) were 3D printed in 2 different resins-Dental LT (n = 10 per group) and Grey V4 (n = 10 per group)-using a stereolithography format 3D printer. The Dental LT aligners were coated with a contrast spray and scanned with an optical scanner. The Grey V4 aligners were scanned before and after the application of the spray. Aligner scans were superimposed onto the corresponding digital design file. Average wall thickness across the aligner for each specimen was measured with metrology software. RESULTS: Superimpositions showed that 3D-printed aligners were thicker overall than the corresponding design file. The Dental LT aligners had the largest thickness deviation, whereas the Grey V4 without spray had the smallest. For the 0.500-mm, 0.750-mm, and 1.000-mm groups, Dental LT average thickness deviation from the input file was 0.254 ± 0.061 mm, 0.267 ± 0.052 mm, and 0.274 ± 0.034 mm, respectively, and average thickness differences between the Grey V4 with and without spray was 0.076 ± 0.016 mm, 0.070 ± 0.036 mm, and 0.080 ± 0.017 mm, respectively. These results indicate that the excess thickness in the Dental LT groups could not be attributed to spray alone. CONCLUSIONS: Fabrication of clear aligners directly by 3D printing with the workflow applied resulted in an increased thickness that may deleteriously affect the clinical utility of the aligners.

Three-Dimensional Printing for Craniofacial Bone Tissue Engineering.

The basic concepts from the fields of biology and engineering are integrated into tissue engineering to develop constructs for the repair of damaged and/or absent tissues, respectively. The field has grown substantially over the past two decades, with particular interest in bone tissue engineering (BTE). Clinically, there are circumstances in which the quantity of bone that is necessary to restore form and function either exceeds the patient's healing capacity or bone's intrinsic regenerative capabilities. Vascularized osseous or osteocutaneous free flaps are the standard of care with autologous bone remaining the gold standard, but is commonly associated with donor site morbidity, graft resorption, increased operating time, and cost. Regardless of the size of a craniofacial defect, from trauma, pathology, and osteonecrosis, surgeons and engineers involved with reconstruction need to consider the complex three-dimensional (3D) geometry of the defect and its relationship to local structures. Three-dimensional printing has garnered significant attention and presents opportunities to use craniofacial BTE as a technology that offers a personalized approach to bony reconstruction. Clinicians and engineers are able to work together to produce patient-specific space-maintaining scaffolds tailored to site-specific defects, which are osteogenic, osseoconductive, osseoinductive, encourage angiogenesis/vasculogenesis, and mechanically stable upon implantation to prevent immediate failure. In this work, we review biological and engineering principles important in applying 3D printing technology to BTE for craniofacial reconstruction as well as present recent translational advancements in 3D printed bioactive ceramic scaffold technology.

Effect of Radiation on DCE-MRI Pharmacokinetic Parameters in a Rabbit Model of Compromised Maxillofacial Wound Healing: A Pilot Study.

PURPOSE: Osteoradionecrosis (ORN), a potentially debilitating complication of maxillofacial radiation, continues to present a challenging clinical scenario, with limited treatment options that often fail. Translational animal models that can accurately mimic the human characteristics of the condition are lacking. In the present pilot study, we aimed to characterize the effects of radiation on the dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) pharmacokinetic parameters in a rabbit model of compromised maxillofacial wound healing to determine its potential as a translational model of ORN. MATERIALS AND METHODS: An experimental group underwent fractionated radiation of the mandible totaling 36 Gy. At 4 weeks after irradiation, the experimental and control groups (n = 8 rabbits each) underwent a surgical procedure to create a critical size defect in the mandibular bone. DCE-MRI scans were acquired 1 week after arrival (baseline; time point 1), 4 weeks after completion of irradiation in the experimental group (just before surgery, time point 2), and 4 weeks after surgery (time point 3). RESULTS: No differences in the analyzed DCE-MRI parameters were noted within the experimental or control group between the baseline values (time point 1) and those after irradiation (time point 2). The whole blood volume fraction (vb) in the experimental group was increased compared with that in the control group after irradiation (time point 2; P < .05). After surgery (time point 3), both the forward flux rate of contrast from blood plasma and the extracellular extravascular space and the vb were increased in the control group compared with the experimental group (P < .05). CONCLUSIONS: The results of the present study suggest that DCE-MRI of a rabbit model of compromised maxillofacial wound healing could reflect the DCE-MRI characteristics of human patients with ORN and those at risk of developing the condition. Future studies will focus on further characterization of this rabbit model as a translational preclinical model of ORN.

Effect of print layer height on the assessment of 3D-printed models.

INTRODUCTION: Many variables can affect the accuracy of 3D-printed orthodontic models, and the effects of different printing parameters on the clinical utility of the printed models are just beginning to be understood. The objective of this study was to investigate the effect of print layer height on the assessment of 3D-printed orthodontic models with the use of the American Board of Orthodontics Cast-Radiograph Evaluation grading system. METHODS: Twelve cases were scanned using a desktop model scanner and 3D-printed using a stereolithography-based printer at three different layer heights (25, 50, and 100-µm; n = 12 per group). All models were scored by eleven graders using the Cast-Radiograph Evaluation grading system. All models were scored a second time, at least two weeks later. RESULTS: No statistically significant effects of print layer height were found on the scoring of the models for any of the grading metrics or total score. 3D-printed models of each layer height were highly positively correlated with stone models for the total score, with the strongest correlation found with models printed at 100-µm. CONCLUSIONS: 100-µm layer height 3D-printed models are potentially clinically acceptable for the purposes of evaluation of treatment outcomes, diagnosis and treatment planning, and residency training.

Efficacy of the mini tooth positioner in improving orthodontic finishes.

INTRODUCTION: The primary objective of this study was to assess the effectiveness of the mini tooth positioner in improving the quality of orthodontic treatment outcomes, as measured by the American Board of Orthodontics (ABO) cast-radiograph evaluation (CRE). METHODS: Thirty patients were treated prospectively with a minipositioner for 4-6 weeks immediately after debond. Sixteen patients who had received a maxillary vacuum-formed retainer (VFR) and fixed mandibular canine-to-canine retainer at time of debond were enrolled retrospectively as control subjects. Models from time of debond (T1) were graded with the use of the ABO CRE and compared with models obtained 4-6 weeks after debond (T2) for each group. RESULTS: For the minipositioner group, the overall CRE score improved significantly by an average of 6.77 points. Significant improvements were noted in the categories of alignment and rotations (-0.68), marginal ridges (-1.40), buccolingual inclination (-0.45), overjet (-0.97), and occlusal contacts (-3.00). For the control group, overall CRE score improved significantly by an average of 1.16 points. Only the categories of overjet (-0.38) and occlusal contacts (-1.22) showed significant improvements. CONCLUSIONS: The minipositioner is an effective tool in improving the overall finish of orthodontic treatment. In the 4-6 weeks after debond evaluated in this study, the minipositioner significantly outperformed the maxillary VFR/mandibular fixed canine-to-canine retainer in improving final treatment outcomes.

Comparison of automated grading of digital orthodontic models and hand grading of 3-dimensionally printed models.

INTRODUCTION: Emerging workflows in orthodontics enable automated analysis of digital models and production of physical study models from digital files for the evaluation of treatment outcomes. The objective of this study was to compare the automated assessment of digital orthodontic models and the hand grading of 3D-printed models with the use of the American Board of Orthodontics cast-radiograph evaluation (ABO CRE) system. METHODS: Plaster models from 15 cases were scanned with the use of a desktop model scanner to create digital models from which physical models were produced with the use of a stereolithography-based 3D printer. All digital models from each case were graded with the use of an automated software tool (SureSmile), and 3D-printed models were scored by hand with the use of the ABO CRE grading system. All hand-graded models were scored a second time at least 2 weeks later. RESULTS: SureSmile gave statistically significantly higher scores to alignment and rotations (P < 0.001), overjet (P < 0.001), occlusal contacts (P < 0.001), and total score (P < 0.001). Hand grading scored higher in buccolingual inclination (P < 0.001). No significant differences were found in marginal ridges, occlusal relationships, and interproximal contacts. CONCLUSIONS: Scores assessed in an automated manner by SureSmile are generally significantly greater than those assessed by hand grading.

Development and Characterization of a Rabbit Model of Compromised Maxillofacial Wound Healing.

IMPACT STATEMENT: Maxillofacial defects often present the clinical challenge of a compromised wound bed. Preclinical evaluation of tissue engineering techniques developed to facilitate healing and reconstruction typically involves animal models with ideal wound beds. The healthy wound bed scenario does not fully mimic the complex clinical environment in patients, which can lead to technology failure when translating from preclinical in vivo research to clinical use. The reported preclinical animal model of compromised wound healing enables investigation of tissue engineering technologies in a more clinically relevant scenario, potentially fostering translation of promising results in preclinical research to patients.