Strategies for Development of a Next-Generation Protein Sequencing Platform.

Proteomic analysis can be a critical bottleneck in cellular characterization. The current paradigm relies primarily on mass spectrometry of peptides and affinity reagents (i.e., antibodies), both of which require a priori knowledge of the sample. An unbiased protein sequencing method, with a dynamic range that covers the full range of protein concentrations in proteomes, would revolutionize the field of proteomics, allowing a more facile characterization of novel gene products and subcellular complexes. To this end, several new platforms based on single-molecule protein-sequencing approaches have been proposed. This review summarizes four of these approaches, highlighting advantages, limitations, and challenges for each method towards advancing as a core technology for next-generation protein sequencing.

Immediate Inferior Alveolar Nerve Reconstruction With Ablative Mandibular Resection Results in Functional Sensory Recovery.

BACKGROUND: Ablative mandibular resection with sacrifice of the inferior alveolar nerve (IAN) results in loss of sensation and decreased quality of life. PURPOSE: The purpose of this study is to evaluate functional sensory recovery (FSR) of immediate IAN allograft reconstruction performed during ablative mandibular resection at 1 year following surgery. STUDY DESIGN, SETTING, SAMPLE: This is a single-center retrospective cohort study that included consecutive subjects who underwent mandibular resection with IAN discontinuity and used a nerve allograft of ≥40 mm. PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE: The primary predictor variable is the use of an immediate nerve allograft in mandibular reconstruction. MAIN OUTCOME VARIABLE(S): The main outcome variable is FSR at 1 year using the Medical Research Council Scale. COVARIATES: Covariates include subject age, sex, specific pathology, nerve gap length, and development of neuropathic pain. ANALYSES: Statistical analysis of comparison of neurosensory outcomes was measured by bivariate statistics, weighted values, repeated measures, analysis of variance, and McNemar test. RESULTS: The study sample was composed of 164 subjects, of whom 55 (33.5%) underwent nerve allograft reconstruction and 30 (18.3%) did not have nerve reconstruction. Seventy-nine subjects (48.2%) did not meet the inclusion criteria. In the entire nerve allograft group of 55 subjects, FSR was achieved in 80% at 1 year; however, in benign disease alone, 31 of 33 (94%) achieved FSR at 1 year. In the nonallograft group (all benign disease), only 2 of 30 (7%) achieved FSR at 1 year. The significant covariates were age and pathology. Benign pathologic resections were 5.2 times more likely to achieve FSR than malignancies, and all subjects ≤ 18 years of age achieved FSR. After adjusting for age, sex, pathology, nerve gap length, nerve allograft was significantly associated with achieving FSR at 1 year (adjusted odds ratio = 5.52, 95% confidence interval = (1.03, 29.51), P value = .045 < .05). CONCLUSION AND RELEVANCE: Immediate long-span IAN allograft reconstruction is effective in restoration of sensation with an overall 80% of subjects achieving FSR at 1 year, while benign disease resulted in 94% FSR at 1 year. Immediate IAN reconstruction should be considered with mandibular resection involving the IAN, especially for children and benign disease.

Which Factors Affect the Reduction Quality of Open Reduction Internal Fixation of Mandibular Subcondylar Fractures?

BACKGROUND: Open reduction internal fixation (ORIF) of mandibular subcondylar fractures (MSF) involves several variables that could affect decision making. There is insufficient data regarding factors influencing the outcomes of MSF ORIF. PURPOSE: The purpose of this study was to investigate factors associated with quality of bony reduction of MSF and occlusion, after ORIF. STUDY DESIGN, SETTING, AND SAMPLE: We designed a retrospective cohort study of consecutively treated subjects for MSF ORIF, ages 18 to 64 years, by University of Illinois' Department of Oral and Maxillofacial Surgery, between January 1, 2013, and January 26, 2021. PREDICTOR VARIABLE: The primary predictor variable was the vertical level of MSF from the gonial angle. Secondary predictor variables included surgeon, fixation scheme (number and configuration of miniplate), surgical approach, time to surgery, mechanism of injury, vertical fragment overlap, overlying soft tissue thickness, presence of other mandibular fractures, and severity and direction of displacement. MAIN OUTCOME VARIABLES: The primary outcome variable was the mean radiographic reduction score (RRS), rated by 2 blinded observers on a 1 to 5 scale. The secondary outcome variable was presence of postoperative malocclusion as documented in the medical records. COVARIATES: Covariates were age and sex. ANALYSES: Descriptive statistics were computed. To investigate the influence of the predictor variables on reduction quality, multifactorial analysis of variance with post hoc Tukey test was performed. For malocclusion, χ2 test was performed. The level of significance was set at P < .05. RESULTS: Thirty-eight MSF in 37 subjects were included. Mean age was 32.7 years (range 18 to 64), and 83.8% were male. Mean RRS was 4.38 (standard deviation 0.77). Fixation scheme was the only variable that showed significant impact on RRS: single-straight miniplate had lower scores than double-straight (-1.50, P = .011), rhomboid (-1.29, P = .036), and ladder miniplates (-1.38, P = .048). There was 1 incidence of malocclusion (2.7%) which resolved without intervention. CONCLUSIONS AND RELEVANCE: Favorable reduction (anatomic reduction to mild discrepancies) can be achieved without malocclusion using double-straight, or rhomboid-shaped or ladder-shaped miniplates, without influences from patient or injury-related factors. In contrast, single-straight miniplate fixation resulted in moderate discrepancies in reduction, although it did not lead to malocclusion.

An Unusual Case of Severe Trismus After Craniotomy.

Myositis ossificans Traumatica (MOT) is a non-neoplastic, heterotrophic ossifying disease process in muscle and soft tissue rarely involving the craniofacial area. Treatment depends on the extent of ossification and functional limitations. We present the first case of MOT of the temporalis muscle following neurosurgical intervention. This is the case of a 28-year-old male patient who underwent numerous neurosurgical interventions and reported progressive trismus following these interventions. Imaging demonstrated a right temporal region radio-opacity consistent with ossification of the temporalis muscle. The patient underwent coronoidectomy with excision of the ossified right temporalis muscle and reconstruction with an anterolateral thigh adipofascial vascular free flap. Postoperatively, he maintained intact function with increased incisal opening and no cosmetic defects. Limited mouth opening after the neurological procedure has a wide differential, and MOT must be considered. Surgical repair and reconstruction are multifaceted problems. Free flap reconstruction should be considered in multiple operated patients.

Predictability of single versus double-barrel vascularized fibula flaps and dental implants in mandibular reconstructions: A systematic review and meta-analysis of prospective studies.

STATEMENT OF PROBLEM: Patients with vascularized bone flaps from the fibula have reduced bone height, in which case a higher prosthetic abutment is needed for their implant-supported prosthesis. Although the double-flap technique seems promising, systematic reviews and meta-analyses of prospective studies are lacking. PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate the grafted areas of single barrel fibular flaps (SBFF) and double-barrel fibular flaps (DBFF) by considering failure rates, dental implant complications, and bone union at the osteotomy sites. MATERIAL AND METHODS: A systematic review and meta-analysis was performed in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement, population, intervention, control, and outcomes (PICO) question, and the National Health and Medical Research Council scales. The event rate of complications and failures was calculated with a confidence interval (CI) of 95%. RESULTS: A total of 13 prospective studies with 441 participants and 330 graft sites were identified. A total of 235 participants had SBFF with 445 implants, and 95 had DBFF with 164 implants. The overall combined graft failure rates were 4.2% for SBFF and 3.2% for DBFF. The complication rate was 10% for SBFF and 1.9% for DBFF. Implant failure was at 4.7% in the SBFF group and 3.4% in the DBFF group. CONCLUSIONS: Complication rates and implant failures were similar for SBFF and DBFF. Therefore, for long-term oral rehabilitation, both SBFF and DBFF are suitable procedures for mandibular reconstruction.

Comparison of CT, MRI, and F-18 FDG PET/CT for initial N-staging of oral squamous cell carcinoma: a cost-effectiveness analysis.

BACKGROUND AND PURPOSE: Treatment of oral squamous cell carcinoma (OSCC) is based on clinical exam, biopsy, and a precise imaging-based TNM-evaluation. A high sensitivity and specificity for magnetic resonance imaging (MRI) and F-18 FDG PET/CT are reported for N-staging. Nevertheless, staging of oral squamous cell carcinoma is most often based on computed tomography (CT) scans. This study aims to evaluate cost-effectiveness of MRI and PET/CT compared to standard of care imaging in initial staging of OSCC within the US Healthcare System. METHODS: A decision model was constructed using quality-adjusted life years (QALYs) and overall costs of different imaging strategies including a CT of the head, neck, and the thorax, MRI of the neck with CT of the thorax, and whole body F-18 FDG PET/CT using Markov transition simulations for different disease states. Input parameters were derived from literature and willingness to pay (WTP) was set to US $100,000/QALY. Deterministic sensitivity analysis of diagnostic parameters and costs was performed. Monte Carlo modeling was used for probabilistic sensitivity analysis. RESULTS: In the base-case scenario, total costs were at US $239,628 for CT, US $240,001 for MRI, and US $239,131 for F-18 FDG PET/CT whereas the model yielded an effectiveness of 5.29 QALYs for CT, 5.30 QALYs for MRI, and 5.32 QALYs for F-18 FDG PET/CT respectively. F-18 FDG PET/CT was the most cost-effective strategy over MRI as well as CT, and MRI was the cost-effective strategy over CT. Deterministic and probabilistic sensitivity analysis showed high robustness of the model with incremental cost effectiveness ratio remaining below US $100,000/QALY for a wide range of variability of input parameters. CONCLUSION: F-18 FDG PET/CT is the most cost-effective strategy in the initial N-staging of OSCC when compared to MRI and CT. Despite less routine use, both whole body PET/CT and MRI are cost-effective modalities in the N-staging of OSCC. Based on these findings, the implementation of PET/CT for initial staging could be suggested to help reduce costs while increasing effectiveness in OSCC.

Selective C-Terminal Conjugation of Protease-Derived Native Peptides for Proteomic Measurements.

Bottom-up proteomic experiments often require selective conjugation or labeling of the N- and/or C-termini of peptides resulting from proteolytic digestion. For example, techniques based on surface fluorescence imaging are emerging as a promising route to high-throughput protein sequencing but require the generation of peptide surface arrays immobilized through single C-terminal point attachment while leaving the N-terminus free. While several robust approaches are available for selective N-terminal conjugation, it has proven to be much more challenging to implement methods for selective labeling or conjugation of the C-termini that can discriminate between the C-terminal carboxyl group and other carboxyl groups on aspartate and glutamate residues. Further, many approaches based on conjugation through amide bond formation require protection of the N-terminus to avoid unwanted cross-linking reactions. To overcome these challenges, herein, we describe a new strategy for single-point selective immobilization of peptides generated by protease digestion via the C-terminus. The method involves immobilization of peptides via lysine amino acids which are found naturally at the C-terminal end of cleaved peptides from digestions of certain serine endoproteinases, like LysC. This lysine and the N-terminus, the sole two primary amines in the peptide fragments, are chemically reacted with a custom phenyl isothiocyanate (EPITC) that contains an alkyne handle. Subsequent exposure of the double-modified peptides to acid selectively cleaves the N-terminal amino acid, while the modified C-terminus lysine remains unchanged. The alkyne-modified peptides with free N-termini can then be immobilized on an azide surface through standard click chemistry. Using this general approach, surface functionalization is demonstrated using a combination of X-ray photoelectron spectroscopy (XPS), ellipsometry, and atomic force microscopy (AFM).

DANG (Depth-Adjusted Nerve Guide) - A Technical Note.

Traditional surgical approaches to the inferior alveolar nerve (IAN) pose a technical challenge and risk iatrogenic damage to healthy, uninvolved nerve tissue. The use of computer-assisted virtual surgical planning and fabrication of surgical guides has shown efficacy in various craniomaxillofacial surgical procedures, and may provide greater precision in accessing the inferior alveolar canal and allow for a more conservative approach. The addition of a depth control feature to a tooth-borne and bone-borne surgical guide, with the use of a standard contra-angle handpiece, provides safe and efficient access for IAN repair. This report describes this novel technique involving a guided transoral approach to the IAN for excision of a neurofibroma of the inferior alveolar nerve, with immediate peripheral nerve allograft IAN reconstruction.

The Incidence of COVID-19 Patients in Oral and Maxillofacial Surgery.

PURPOSE: The SARS-CoV-2 global pandemic has resulted in widespread changes to healthcare practices across the United States. The purpose of this study is to examine the incidence of COVID-19 patients in the oral-maxillofacial surgery setting in order to help guide perioperative protocols during the pandemic. METHODS: In this retrospective cohort study, predictor variables (presence of preoperative symptoms on presentation, patient age, patient gender, patient race, hospital location, and presence of statewide stay-at-home orders) were examined with outcome variables (SARS-CoV-2 test results) over 10 months between March 2020 and December 2020 for patients undergoing surgical procedures in the operating room by the following Oral-Maxillofacial Surgery Departments: - Louisiana State University Health Sciences Center (Baton Rouge, LA) - University of Illinois at Chicago (Chicago, IL) - University of Texas Health Science Center at Houston (Houston, TX) Data analysis included Fisher exact tests to compare categorical variables across COVID test groups and Wilcoxon rank sum tests to compare continuous covariates. Two-sample tests of proportions were used to compare observed COVID-19 positivity rates to other study results. RESULTS: Out of 684 patients in 3 institutions, 17 patients (2.5%, 95% CI = 1.5 to 4.0%) tested positive for COVID-19 over a 10 month interval (March 1, 2020- December 31, 2020). The majority of patients that tested positive were asymptomatic in the preoperative setting (P-value = .09). They were significantly more likely to be African-American (P-value = .015) and less likely to have a stay-at-home order present at the time of surgery (P-value = .033). Age, gender, and hospital location did not play a statistically significant role. CONCLUSION: Our results demonstrate a 2.5% incidence of COVID-19 infection in the total population of patients undergoing scheduled oral-maxillofacial surgeries in 3 major healthcare systems across the United States. This data may help inform perioperative protocols and infection control measures during the COVID-19 pandemic.

Does the Use of Computer-Assisted Surgery Affect the Margin Status in Resections of Ameloblastoma?

PURPOSE: Computer-assisted surgery (CAS) was implemented rapidly, and recent concerns have been raised regarding its safety and its effect on surgical outcomes. We wanted to understand the impact CAS has on the surgical margin status when used for the resection of ameloblastoma. MATERIALS AND METHODS: We performed a 10-year retrospective cohort study at a single institution. Subjects were identified by surgical logs and chart query. Histopathologic reports were examined for margin status. We compared surgical technique (CAS and non-CAS) with the surgical margin (≤5 mm vs >5 mm). Other variable outcomes included previous treatment, histologic type, time from imaging to surgery, and recurrence. Bivariate analysis was performed to determine significance. RESULTS: A total of 31 subjects were identified (12 females; 19 males) with a mean age of 34.5 (standard deviation [SD] ± 19.1) years. Fifteen subjects were included in the CAS group and 16 subjects in the non-CAS group. No statistically significant difference was identified between the CAS and non-CAS group when surgical margins were defined as less than or equal to 5 mm and greater than 5 mm (P = .5368). The average distance from surgical margin to lesion was 9.6 mm (SD ± 5.1) in the CAS group and 8.5 mm (SD ± 5.6) in the non-CAS group (P = .2590). However, the non-CAS group had 1 positive margin and a total of 6 margins of less than or equal to 2 mm compared with zero margins of less than or equal to 2 mm in the CAS group (closest margin 3 mm). CONCLUSIONS: The use of CAS and cutting guides based on predetermined surgical margins did not compromise the margin status in surgical resections of ameloblastoma. The use of CAS could potentially decrease the occurrence of close or positive margins.

The Quality of the Evidence in Craniomaxillofacial Trauma: Are We Making Progress?

PURPOSE: The purpose of this study is to evaluate the level of evidence in the craniomaxillofacial trauma literature. The secondary purpose is to determine if improvement in the quality of evidence has been made over the past 2 decades. MATERIALS AND METHODS: This retrospective cohort study analyzed clinical articles published in select craniomaxillofacial surgery journals. Patient-focused articles were selected. The year of publication (1999, 2009, 2019) was the primary predictor variable. Secondary predictor variables included study funding status, anatomical facial region (eg maxilla, mandible, and so on), specific journal, and journal impact factor. The level of evidence was determined using the Center of Evidence-Based Medicine criteria, which served as the outcome variable. The statistical analysis included descriptive, bivariate, and regression analysis. RESULTS: The sample consisted of 469 craniomaxillofacial trauma articles, with 13.2% being published in 1999, 44.1% in 2009, and 42.6% in 2019. The majority of the studies (77.5%) were published in 4 journals. The impact factor varied among the journals with a significant improvement in the mean impact factor from (0.89 ± 0.29) in 1999 to (1.4 ± 0.47) in 2009 and a slight decline in 2019 (1.26 ± 0.71). Mandibular fractures (31.6%) and orbital trauma (26%) were the most investigated topics. Level 4 studies accounted for 67.4% of the sample, with level 3 evidence of 4.7%, level 2 of 22.6%, and level 1 of 5.3% of the included studies. Significant progress in the level of evidence has been made from 1999 but not since that time (P = .002). It is unclear why this may be but sheds light on the need for further development of high quality studies. Finally, a higher quality of evidence is associated with journal impact factor (odds ratio  = 1.9; P < .01) and funded research (odds ratio = 4.69; P = .02). CONCLUSIONS: While there has been some improvement in the level of evidence in the craniomaxillofacial trauma literature over the past 2 decades, the current quality remains low, and further progress is needed to support the practice of evidence-based medicine.

Comparing the Surgical Response of Bisphosphonate-Related Versus Denosumab-Related Osteonecrosis of the Jaws.

PURPOSE: The pathophysiology and treatment of medication-related osteonecrosis of the jaws (MRONJ) remain unclear after nearly two decades of recorded observation and discussion. The purpose of this study was to assess outcomes of surgical resection of MRONJ in patients exposed to denosumab. MATERIALS AND METHODS: A literature review was performed in conjunction with experts at the University of Illinois at Chicago Library. The primary outcome of interest was surgical success defined by maintenance of complete mucosal closure without bone exposure and infection after surgical resection. Secondary interests included demographics, MRONJ stage, location of the focus of osteonecrosis, and the primary underlying disease necessitating antiresorptive treatment. Statistical analysis was performed by χ2, analysis of variance, or t test (P < .05 and b = 0.2 or a power of 0.8). RESULTS: A total of 70 articles were identified and 14 met inclusion criteria. Twenty patients were included (13 women; 7 men); age 61.8 years ± 12.9 (range 19 to 77); and MRONJ stage I (40.0%), II (35.0%), and III (25.0%). Most cases occurred in the mandible (65.0%), followed by the maxilla (30.0%). The success rate of surgical intervention for MRONJ secondary to denosumab was in 16 of 20 (80.0%) patients. Stage I MRONJ lesions achieved mucosal closure in 100% of patients, stage II in 71.4%, and stage III in 60.0%. The surgical success rate was 83.3% in the maxilla and 76.9% in the mandible. CONCLUSIONS: The surgical success rate for MRONJ secondary to denosumab was 80.0%, similar to that reported in bisphosphonates of 85 to 95%; however, more evidence must be reported and analyzed.

Old age and other factors associated with salivary microbiome variation.

BACKGROUND: Many factors can contribute to the exact makeup of the salivary microbiome. Differences in the oral microbiome occur with old age, which may be due to oral conditions and diseases associated with old age, such as edentulism, as well as other unknown causes. METHODS: The salivary microbiome was sampled in patients from a large urban clinic. For all subjects age, gender, periodontal status, caries status, presence of edentulism, medications, and tobacco usage were recorded. Multifactor analysis was used to study variation in salivary microbiome profiles linked to these factors. RESULTS: In the population sampled, there were significantly higher numbers of edentulous subjects, and increased levels of polypharmacy found with aging. Large differences in alpha diversity and beta diversity of the salivary microbiome in the old age group were largely linked to edentulism. However, multivariable analysis revealed, even after adjusting for differences in edentulism, polypharmacy, tobacco usage, periodontal disease, caries level, and gender, that old age itself was associated with lower levels of taxa Porphyromonas endodontalis, Alloprevotella tannerae, Filifactor alocis, Treponema, Lautropia Mirabilis and Pseudopropionibacterium sp._HMT_194. Surprisingly, of these taxa, most were ones known to reside on or near tooth surfaces. CONCLUSIONS: Another factor or factors beyond edentulism, polypharmacy and periodontal disease play a role in the differences seen in oral microbiome with old age. The nature of this factor(s) is not known.

Immediate Reconstruction of the Infraorbital Nerve After Maxillectomy: Is it Feasible?

PURPOSE: Ablative procedures of the midface may require sacrifice of the infraorbital nerve (ION) resulting in permanent paresthesia of its dermatome. Because the ION is not commonly reconstructed, the goal of this study was to determine the feasibility of nerve allograft reconstruction. PATIENTS AND METHODS: A retrospective cohort of patients underwent immediate ION allograft reconstruction, during August 2018 to August 2019 at a single academic medical center by a single surgeon (M.M.). Demographic and clinical variables were collected. The outcome of interest was clinical neurosensory testing using the Medical Research Council Scale and subjective recovery, which was recorded using a visual analog scale at 3, 6, and 12 months after surgery. RESULTS: This cohort series consisted of 3 consecutive patients who underwent immediate ION allograft reconstruction. At 6 months, all patients achieved functional sensory recovery (S3, S3+, and S4) and acceptable subjective improvement. CONCLUSIONS: Immediate nerve allograft reconstruction of the ION is a viable option to achieve functional sensory recovery.

Engineering ClpS for selective and enhanced N-terminal amino acid binding.

One of the central challenges in the development of single-molecule protein sequencing technologies is achieving high-fidelity sequential recognition and detection of specific amino acids that comprise the peptide sequence. An approach towards achieving this goal is to leverage naturally occurring proteins that function through recognition of amino (N)-terminal amino acids (NAAs). One such protein, the N-end rule pathway adaptor protein ClpS, natively recognizes NAAs on a peptide chain. The native ClpS protein has a high specificity albeit modest affinity for the amino acid Phe at the N-terminus but also recognizes the residues Trp, Tyr, and Leu at the N-terminal position. Here, we employed directed evolution methods to select for ClpS variants with enhanced affinity and selectivity for two NAAs (Phe and Trp). Using this approach, we identified two promising variants of the Agrobacterium tumefaciens ClpS protein with native residues 34-36 ProArgGlu mutated to ProMetSer and CysProSer. In vitro surface binding assays indicate that the ProMetSer variant has enhanced affinity for Phe at the N-terminus with sevenfold tighter binding relative to wild-type ClpS, and that the CysProSer variant binds selectively to Trp over Phe at the N-terminus while having a greater affinity for both Trp and Phe. Taken together, this work demonstrates the utility of engineering ClpS to make it more effective for potential use in peptide sequencing applications.

Addressing the unmet need for visualizing conditional random fields in biological data.

BACKGROUND: The biological world is replete with phenomena that appear to be ideally modeled and analyzed by one archetypal statistical framework - the Graphical Probabilistic Model (GPM). The structure of GPMs is a uniquely good match for biological problems that range from aligning sequences to modeling the genome-to-phenome relationship. The fundamental questions that GPMs address involve making decisions based on a complex web of interacting factors. Unfortunately, while GPMs ideally fit many questions in biology, they are not an easy solution to apply. Building a GPM is not a simple task for an end user. Moreover, applying GPMs is also impeded by the insidious fact that the "complex web of interacting factors" inherent to a problem might be easy to define and also intractable to compute upon. DISCUSSION: We propose that the visualization sciences can contribute to many domains of the bio-sciences, by developing tools to address archetypal representation and user interaction issues in GPMs, and in particular a variety of GPM called a Conditional Random Field(CRF). CRFs bring additional power, and additional complexity, because the CRF dependency network can be conditioned on the query data. CONCLUSIONS: In this manuscript we examine the shared features of several biological problems that are amenable to modeling with CRFs, highlight the challenges that existing visualization and visual analytics paradigms induce for these data, and document an experimental solution called StickWRLD which, while leaving room for improvement, has been successfully applied in several biological research projects. Software and tutorials are available at http://www.stickwrld.org/.

Cutting guides in mandibular tumor ablation: Are we as accurate as we think?

Purpose: Tumor margin status is critical in local tumor recurrence and is a significant prognostic factor in head and neck cancer survival. With the introduction of computer-assisted surgical planning, one of the main challenges is the accurate positioning of the surgical cutting guide but there is limited evidence of the accuracy of the 3D cutting guides in mimicking virtually planned osteotomy. This study evaluates the accuracy of osteotomy lines produced by 3D-printed cutting guides and assesses the overall accuracy of mandibular reconstruction. Material and Methods: The pre and postoperative 3D models were aligned using an automated surface registration feature based on the iterative closest point algorithm. The differences in osteotomy line deviation, linear and angle measurements, and 3D volume quantification of the pre and post models were measured. Results: We included 14 patients (8 men and 6 women with ages ranging from 13 to 75 years) with a segmental mandibular resection who met all of the inclusion criteria. The smallest defect size was 4.4 cm, the largest defect was 12.2 cm, and the average was 7.30 cm +/- 2.80 cm. The average deviation between virtually planned osteotomy and actual surgical osteotomy was 1.52 +/-1.02 mm. No covariates were associated with increased inaccuracy of the 3D-printed cutting guides. Conclusion: The finding of this study suggests that virtual surgical planning is an unambiguous paradigm shift in the predictability of the surgical plan and achievement of the reconstruction goals. The 3D-printed cutting guides are a very accurate and reliable tool in translating virtual ablation plans to an actual surgical resection margin.