Effect of Orthognathic Surgery on Pre-existing Temporomandibular Disorders.

The management of patients with pre-existing temporomandibular disorders (TMDs) undergoing orthognathic surgery remains a subject of ongoing debate. This study aimed to profile these individuals and evaluate the correlation between orthognathic surgery and alterations in TMD indicators and symptoms. We conducted a retrospective cohort investigation involving patients with skeletal malocclusion and established TMDs. Variables of interest encompassed the performance of orthognathic surgery, documented TMDs (including temporomandibular joint (TMJ) sounds, TMJ pain, muscle discomfort, and jaw locking), and patients' self-assessments of TMJ and muscle pain using a visual analog scale (VAS). The primary outcome measures focused on changes in TMD indicators and symptoms. Among the study cohort, 73.4% exhibited skeletal class III malocclusion, while 26.6% presented with skeletal class II malocclusion. Notably, patients classified as skeletal class III were significantly younger than their skeletal class II counterparts (mean age: 23.06±5.37 vs. 26.71±7.33; P=0.034). The most prevalent pre-existing TMD complaint was TMJ sounds (65.5%), followed by TMJ pain (39.1%), muscle discomfort (23.4%), and jaw locking (12.5%). Skeletal class II patients were more likely to experience TMJ sounds compared to skeletal class III patients (88.2% vs. 57.4%; P=0.022). Statistically significant improvements were observed in the VAS assessments among class III patients following surgery. A majority of patients with pre-existing TMDs seeking orthognathic surgery exhibited skeletal class III malocclusion and were younger than those with skeletal class II malocclusion. Importantly, orthognathic surgery was associated with positive changes in TMD indicators and symptoms in these patients.

Increased Prevalence of Generalized Joint Hypermobility Observed in Patients With Recurrent Temporomandibular Joint Dislocation.

BACKGROUND: Generalized joint hypermobility (GJH), determined by the Beighton score, is a fundamental part of diagnosing benign joint hypermobility syndrome (BJHS), which may also present extra-articular manifestations, and is determined by the Brighton criteria. PURPOSE: This study was designed to investigate whether there is an association between recurrent temporomandibular joint (TMJ) dislocation and these disorders. STUDY DESIGN, SETTING, AND SAMPLE: A retrospective cross-sectional study was conducted. Hospital-based patients with a history of recurrent TMJ dislocation were compared to population-based patients that did not experience TMJ dislocations or any other TMJ disorders. Age and sex matching were performed between the study groups. All subjects reached the age of skeletal maturity. PREDICTOR VARIABLE: A history of recurrent TMJ dislocations. MAIN OUTCOME VARIABLES: Measurements of Beighton score (range from 0 to 9 with a score of ≥ 4 indicating GJH) and correspondence to the Brighton criteria (with at least two "major" criteria or one "major" criterion plus two "minor" criteria or four "minor" criteria indicating BJHS). COVARIATES: Included age and sex. ANALYSES: Mann-Whitney U-test for continuous variables and the χ2 test or Fisher's exact test for categorical variables. Statistical significance was set at P < .05. RESULTS: A total of 68 participants were included, of whom 34 patients presented with recurrent TMJ dislocations compared with a control population of 34. The Mean participants were 31.35 ± 8.06 years, and 29.4% (n = 20) were males. Of the dislocation group, 16 (47.0%) patients had a Beighton score of 4 or higher. The Beighton sum score was significantly higher, with a TMJ dislocation group mean score of 3.06 ± 2.8, compared with a control score of 0.82 ± 1.1 (P = .001). A total of 58.8% (n = 20) of the TMJ dislocation group participants met the Brighton criteria versus none (0.0%) of the control group (P = .001). CONCLUSION: We found an association between recurrent TMJ dislocation and GJH. An association with BJHS was also found, based mainly on articular manifestations. Early detection of these disorders in patients suffering from recurrent TMJ dislocation may help identify individuals at increased risk for joint instabilities and allow the implementation of appropriate preventive management strategies.

"Proportional Condylectomy" for Vertical Condylar Hyperplasia Without Intermaxillary Elastics: Clinical Results and Patient Satisfaction.

OBJECTIVES: First, to investigate the clinical outcome of 'proportional condylectomy' for patients with active unilateral condylar hyperplasia without complementary treatment by intermaxillary elastics and, second, to examine their level of satisfaction regarding function and esthetics. STUDY DESIGN: A retrospective observational descriptive study was conducted. All patients included in the study suffered from active unilateral condylar hyperplasia with a vertical component. The length of the condylar-ramus unit was measured on both sides by an multidetector computed tomography scan. The difference was calculated and resected from the hyperplastic condyle during the operation. Facial, occlusal, and skeletal changes were evaluated using photographic and radiologic records, and a satisfaction questionnaire regarding function and esthetics was completed. P <0.05 was considered significant. RESULTS: Fifteen patients were included in the study. The mean participants' age was 27.93±13.06 years, and the mean follow-up duration was 12.40±6.55 months. The mean chin deviation improved by 58.47% ( P =0.001). Mean lip commissure plane tilt was improved by 61.31% ( P =0.001). Six months postoperatively, all patients exhibited centered dental midlines ( P =0.001). Occlusal plane tilt was significantly improved by 70.02% ( P =0.001), and high patient satisfaction was recorded. Twenty-six percent (4/15) of patients did not require the complementary orthodontic treatment, and none of them required complementary orthognathic surgery. CONCLUSIONS: 'Proportional condylectomy' for patients with active unilateral vertical condylar hyperplasia without complementary treatment by intermaxillary elastics is a predictable procedure in terms of function and esthetics.

Are There Cephalometric Measurements Associated With Recurrent Temporomandibular Joint Dislocation?

PURPOSE: Several theories have been proposed for the etiology of recurrent temporomandibular joint (TMJ) dislocation. The purpose of the present study was to determine whether there are cephalometric measurements associated with this phenomenon. METHODS: A retrospective case-control study was performed, which included individuals who suffered from recurrent TMJ dislocation and a control group composed of patients who suffered from unrelated odontogenic infections and did not have any TMJ disorder. All the patients were referred to the Department of Oral and Maxillofacial Surgery at the Hadassah Medical Center between 2010 and 2021 and underwent multidetector computed tomography of the jaws. The main predictor variable was a history of recurrent TMJ dislocations. Covariates included age and gender. The primary outcome variable was a set of 11 cephalometric measurements. A statistical analysis was performed with the Mann-Whitney U-test for continuous variables and the Chi-squared test or Fisher's exact test for categorical variables, followed by a logistic regression model. Multiple comparisons were made by using the Benjamini-Hochberg method. RESULTS: The total 32 subjects included in the analysis consisted of 16 patients presenting with bilateral recurrent TMJ dislocation and a control population of 16 patients. The mean age was 34.19 ± 12.7 years, 40.6% (n = 13) were males, with no statistically significant differences between the groups. An increased overbite was detected in the TMJ dislocation group, whereas over-jet was greater among the control group, although not statistically significant. Skeletal ratio analysis showed that the TMJ dislocation group had a statistically significantly greater Articulare-Gonion length (46.96 mm ± 5.2 mm vs 43.01 mm ± 5.3 mm; P = .043) and a lower angle of occlusal plane to Frankfort horizontal (4.56o ± 5.7o vs 9.60o ± 3.9o; P = .007), Y-axis (58.01o ± 4.9o vs 61.72o ± 3.3o; P = .019), and Frankfurt mandibular plane (24.10o ± 6.1o vs 30.14o ± 4.7o; P = .004). CONCLUSIONS: Specific cephalometric measurements are associated with recurrent TMJ dislocation. The high Articulare-Gonion length and the low rates of occlusal plane to Frankfort horizontal angle, Y-axis, and Frankfurt mandibular plane found in the study population suggest that the resultant vertically oriented elevator muscles may be considered a predisposing factor for this phenomenon.

The efficacy of a protective protocol for oral and maxillofacial surgery procedures in a COVID-19 pandemic area-results from 1471 patients.

OBJECTIVE: To examine the effectiveness of an empiric protection protocol during oral surgical treatments in a COVID-19 pandemic area and to evaluate the potential effect of postponed dental procedures on the frequency of facial infections during a lockdown period. METHODS: We performed a retrospective analysis of a case series of a broad-spectrum of oral surgeries in a COVID-19 pandemic area. Data collection included patient age, type of procedure performed, and COVID-19 status of staff and patients. Data were analyzed using descriptive statistics. RESULTS: Between February 21 and April 23, 2020, 1471 patients were treated in the outpatient clinic (n=1404) and under general anesthesia (n=67). All procedures were carried out under a strict empiric protective protocol that included patient screening, personal protective equipment allocation protocol, frequent staff testing, and patient testing before general anesthesia. Treatments included emergency and urgent elective procedures. Only one staff member was confirmed positive for COVID-19 during routine weekly testing, and an independent epidemiologic investigation suggested he was likely infected outside of hospital facilities. CONCLUSIONS: Our empiric protective protocol was found to be effective in preventing staff cross-infection with COVID-19 in an oral and maxillofacial surgery setting. CLINICAL RELEVANCE: To the best of our knowledge, this is the first report that provides data regarding oral surgical activity in a COVID-19 pandemic area. Our suggested protective protocol may assist oral surgeons in continuing dental services in a safe manner.

Indirect Bactericidal Properties of Recombinant Human Bone Morphogenetic Protein 2 In Vitro.

PURPOSE: Bone morphogenetic proteins (BMPs) are secreted cytokines and are involved in various metabolic functions and inflammatory processes in different organs. The purpose of this study was to investigate whether BMPs also possess antimicrobial properties in direct or indirect ways. MATERIALS AND METHODS: Antibacterial properties of recombinant human BMP2 (rhBMP2) were tested on 4 bacteria species (Staphylococcus aureus, Escherichia coli, Streptococcus mitis, Streptococcus constellatus) to examine the potential synergism of rhBMP2 with antibiotics. Indirect antibacterial properties were tested by infecting neutrophils with rhBMP2 and bacteria to investigate bacterial survival. Reactive oxidative species (ROS) production in neutrophils in the presence of rhBMP2 also was tested. RESULTS: RhBMP2 in cardboard disks or sponge collagen as carriers did not show antibacterial activity against all tested bacteria. Further, synergism of rhBMP2 with antibiotics was not evident. Survival of bacteria inoculated with neutrophils and rhBMP2 led to a marked decrease in bacterial survival compared with neutrophils without rhBMP2. Although rhBMP2 inoculation of neutrophils alone did not induce ROS, its presence with the bacterial infection showed augmented ROS production for all tested bacteria. CONCLUSIONS: RhBMP2 did not show direct antibacterial properties but did exhibit an indirect bactericidal effect in the presence of neutrophils. ROS production indicated that rhBMP2 has a role as a priming agent for neutrophils by augmenting their bactericidal capabilities and suggests the importance of its presence in contaminated surgical bone augmentation sites.

Successful Mandibular Mucormycosis Treatment in the Severely Neutropenic Patient.

PURPOSE: Mucormycosis is a rare opportunistic and aggressive deep fungal infection that predominantly affects immunocompromised patients, and its mortality rate has been reported as up to 80%. Typing of the infection is based mainly on clinical and anatomic presentations, with the most common being the rhinocerebral type. MATERIALS AND METHODS: This report presents 3 patients with cancer who had successful treatment of mandibular mucormycosis. Chemotherapy was administered 13 to 30 days before diagnosis of the infection, resulting in neutropenia in all patients. Each case is thoroughly presented from initial admission through its diagnosis and treatment sequence. RESULTS: Early surgical ablative treatment and antifungal treatment resulted in the resolution of infection in all patients. Absolute neutrophil count increased 7 to 8 days after surgical debridement. CONCLUSIONS: Bringing patients to the post-neutropenic state tremendously increases their odds for survival.

Imperforate titanium shell enclosing recombinant human bone morphogenetic protein-2-induced bone formation for high-profile dental implants in rabbit tibia.

PURPOSE: To evaluate the use of a nonperforated titanium occlusive device over high-profile dental implants in rabbit tibia using recombinant human bone morphogenetic protein-2 (rhBMP-2) in an absorbable collagen sponge (ACS) for augmentation grafting. MATERIALS AND METHODS: Eight New Zealand white rabbits were used for the experiment. All rabbits underwent computed tomography of the right tibia. A custom titanium shell was manufactured for each rabbit using a computer-assisted design to confine the graft. Three high-profile implants were placed in the right tibia of each rabbit; the middle implant was placed 8 mm in supracrestal fashion and the adjacent implants were placed 5 mm in supracrestal fashion. There were 4 groups (n = 2 per group): non-shell control, titanium shell only, titanium shell over buffered collagen, and titanium shell over the ACS enriched with rhBMP-2. The animals were sacrificed after 6 or 12 weeks. Histologic preparation was carried out to evaluate bone formation. RESULTS: After 6 weeks, negligible bone growth was found around the implants. After 12 weeks, there was minimal bone formation around the implants in the control group, whereas in the group treated with ACS enriched with rhBMP-2, the titanium shell was filled with mature bone, which was expressed at the implant surface, the shell's interior, and the exterior surfaces. CONCLUSION: The placement of ACS enriched with rhBMP-2 beneath an occlusive nonperforated titanium shell confining high-profile dental implants resulted in visibly more formation of mature bone.

Alveolar sandwich osteotomy in resorbed alveolar ridge for dental implants: a 4-year prospective study.

PURPOSE: To answer whether severe vertical alveolar defects can be resolved using the sandwich osteotomy technique with xenograft material as filler and to evaluate the predictability of this procedure. MATERIALS AND METHODS: Ten graft sites (5 mandibular and 5 maxillary) in 9 patients treated at the Department of Oral and Maxillofacial Surgery, Hadassah Medical Center, were included in the present study. The patients underwent vertical bone augmentation using the sandwich osteotomy technique filled with xenograft material. The degree of bone augmentation was analyzed clinically at surgery and 4 to 6 months later from the computed tomography images taken just before the sites had been rehabilitated using dental implant insertion. A trephine histologic analysis was performed during implantation at 1 maxillary site. RESULTS: The mean vertical bone gain in the interval between the sandwich osteotomy and implementation was 6 mm (range 4 to 10), and it remained stable after 4 to 6 months. In 2 cases, additional horizontal bone augmentation was needed. All graft sites were rehabilitated using dental implants with satisfactory results. In 3 cases, gingival porcelain was required for the final prosthesis. Histologic examination revealed vital segmentized bone and remodeling of the filled gap. CONCLUSIONS: The interpositional alveolar bone graft using xenograft filler appears to be a viable and predictable alternative to block grafting or guided bone regeneration, resulting in good final results, with substantial vertical bone gain, even for challenging cases.

Enigma of missing teeth in maxillofacial trauma.

PURPOSE: The initial evaluation and treatment of trauma victims should follow a planned approach, as delineated by the Advanced Trauma Life Support protocol, with the main concern securing a patent airway. When trauma has been associated with maxillofacial injury, it can complicate airway management owing to aspirated avulsed teeth or dental prosthetic devices. In such cases, endotracheal intubation can be life-threatening, if the foreign bodies are pushed into the upper respiratory tract. The objective of the present report was to illustrate the diagnostic and management problems related to foreign bodies from the oral cavity lodged in the upper airway after blunt maxillofacial trauma or emergency endotracheal intubation. We also discussed how this could be prevented. PATIENTS AND METHODS: A retrospective study was performed at the Department of Oral and Maxillofacial Surgery, Hadassah Medical Center (Jerusalem, Israel). The records of 1,411 patients admitted for treatment of facial trauma during the past 10 years were reviewed. RESULTS: Of the 1,411 patients, 7 (0.5%) had aspirated foreign bodies that had lodged in the airway because of the trauma or subsequent intubation. CONCLUSIONS: The patient's oral cavity and upper airway must be inspected thoroughly before attempting endotracheal intubation. Any foreign body should be removed from the mouth and throat. This process must be undertaken, despite the stressful and limiting conditions of emergency care.

Computerized navigation for immediate loading of dental implants with a prefabricated metal frame: a feasibility study.

PURPOSE: To study the probability of using Image Guided Implantology (IGI) for planning and execution of a dental plan of 3 implants in a geometric pattern that fits a prefabricated metal frame accurately, simulating provisional restoration in immediate loading. MATERIAL AND METHODS: Ten mandible models were imaged by standard computed tomography. Three implants, two in the premolar and one in the molar area on each side of the jaws, were planned by use of the IGI system (Image Navigation Ltd, Moshav Ora, Israel). Two millimeter drilling and subsequent 3 millimeter widening drilling was performed with the real-time computerized navigation technology in the 120 sampling sites. In each step, parallel pins were inserted, and metal gauging frames with preplanned holes of incremental diameters and in the predefined geometric pattern were placed on the pins to evaluate the precision of fit. RESULTS: Full success was obtained in fitting all three 3-mm pins, with frames having clearance of 0.5 or 1 mm, and in matching pairs of pins 2 or 3 mm in diameter at clearances of 0.5 mm or greater. With more constrained clearances, matching of all 3 pins was 80% and 95% successful with 2-mm pins (clearance of 0.25 and 0.5 mm, respectively) and 60% and 95% successful with 3-mm pins (clearance of 0 and 0.25 mm, respectively). Some laterality bias was observed. CONCLUSIONS: This preliminary study shows that the IGI system enables accurate planning of implant number and location to be achieved together with planning for a prefabricated metal frame for immediate loading.

Island osteoperiosteal flaps with interpositional bone grafting in rabbit tibia: preliminary study for development of new bone augmentation technique.

PURPOSE: Loss of alveolar vertical height is one of the most challenging conditions in the field of implantology. A few augmentation techniques have been proposed to address this challenge, including guided bone regeneration, alveolar distraction osteogenesis, sandwich osteotomies and autogenous block grafting. This is a pre-clinical study of lengthening the alveolar bone height using a thin osteoperiosteal bone flap, the "island bone flap" or i-flap, to establish vitality, stability and incorporation of the augmentation material after healing. MATERIALS AND METHODS: A rabbit tibia model was designed for this study and included 8 rabbits. An osteoperiosteal osteotomy was performed through the periosteum cutting 1 mm of the outer cortex of the bone in order to elevate a bone flap. The bone flap was detached, and remained attached to the periosteum as a free floating osteoperiosteal flap, and the resultant defect was filled with xenograft. RESULTS: The histological analysis demonstrates formation of maturing trabeculae in the site of the i-flap. In cases of trauma to the bone marrow during the surgical procedure, a centripetal gradient of bone remodeling from the surgical site toward the periphery was evident, while the bony component of the i-flap maintained vital. CONCLUSIONS: Creating a free floating osteoperiosteal flap, used here with interpositional grafting in a rabbit tibia, appears to heal by both appositional modeling and creeping substitution remodeling. Volumetric augmentation persisted despite exuberant bone turnover in this animal model. This technique holds promise as a possible augmentation bone grafting approach for use in alveolar reconstruction.

Evaluation of a navigation system for dental implantation as a tool to train novice dental practitioners.

PURPOSE: This study evaluated the benefits of a virtual reality navigation system for teaching the surgical stage of dental implantation to final-year dental students. The study aimed to assess the students' performance in dental implantation assignments by comparing freehand protocols with virtual reality navigation. MATERIALS AND METHODS: Forty final-year dentistry students without previous experience in dental implantation surgery were given an implantation assignment comprising 3 tasks. Marking, drilling, and widening of implant holes were executed by a freehand protocol on the 2 mandibular sides by 1 group and by virtual reality navigation on 1 side and contralaterally with the freehand protocol by the other group. Subjective and objective assessments of the students' performance were graded. RESULTS: Marking with the navigation system was more accurate than with the standard protocol. The 2 groups performed similarly in the 2-mm drilling on the 2 mandibular sides. Widening of the 2 mesial holes to 3 mm was significantly better with the second execution in the standard protocol group, but not in the navigation group. The navigation group's second-site freehand drilling of the molar was significantly worse than the first. The execution of all assignments was significantly faster in the freehand group than in the navigation group (60.75 vs 77.25 minutes, P = .02). Self-assessment only partly matched the objective measurements and was more realistic in the standard protocol group. CONCLUSIONS: Despite the improved performance with the navigation system, the added value of training in dental implantation surgery with virtual reality navigation was minimal.

Endoscopic approach to dental implantology.

OBJECTIVE: To describe an innovative miniature visualization surgical endoscope and endoscopic techniques applicable to dental implant procedures. MATERIALS AND METHODS: A newly developed modular dental implant endoscope is introduced, and the first impressions from its use in different implant procedures are reported. RESULTS: Details of the device that combines an endoscope, irrigation cannulas, and a surgical microinstrument channel are presented. The advantages of using it in dental implant procedures are described, and examples of how miniature visualization and surgical endoscopic techniques can be applied to increase the success of implantation are outlined. The new modular implant endoscope accurately identified all microanatomical and pathological structures, and simplified dental implant procedures. CONCLUSION: Endoscopy should be considered not only for intraoperative observation and assessment of implant sites, but also should be applied for active assistance during implant placement procedures.

Short Dental Implants (5 to 7 mm) with Expandable Apex in the Posterior Maxilla-Preliminary Results.

PURPOSE: The purpose of this study was to examine whether the use of short dental implants with an expandable compressive design could be a proper alternative to the conventional sinus elevation procedure in cases of deficient alveolar ridge height in the posterior maxillary area. MATERIALS AND METHODS: Fifty patients with 73 short dental implants with an expandable compressive design who were treated for posterior maxillary alveolar ridges of 5 to 7 mm in the vertical dimension between 2012 and 2018 were included in a retrospective study. All patients had a minimum postrehabilitation period of 1 year. Patient demographics, implant properties, primary stability, and implant success and survival rates were analyzed. RESULTS: The total success rate was 97.2%, with two failed implants at implant uncovering. The mean bone loss was 1.03 mm. No difference in bone loss was found between sexes or age groups. CONCLUSION: The results of this study suggest that short dental implants with an expandable apical compressive design could be an alternative to sinus elevation procedures in selected cases of vertically deficient maxillary alveolar ridges.

The influence of articular eminence morphology on temporomandibular joint anterior dislocations.

OBJECTIVE: The aim of this study was to investigate the correlation between the bony morphology of the articular eminence and the occurrence of idiopathic anterior temporomandibular joint (TMJ) dislocation. STUDY DESIGN: A comparative retrospective study was conducted in 14 patients with idiopathic anterior dislocations (study group) and 14 patients who did not suffer from any TMJ disorders (control group). All patients underwent multidetector computed tomography (MDCT), which demonstrated the full extent of their joints. The scans of 56 joints were reconstructed and analyzed by using the tools available in Dolphin 3 software. Gross morphology characteristics and fine morphologic characteristics were defined by measuring the articular eminence inclination and height on the lateral, middle, and medial aspects of the articular eminence. RESULTS: Gross and fine morphologic characteristics of the articular eminence did not differ statistically between the study group and the control group. CONCLUSIONS: Articular eminence morphology does not affect TMJ idiopathic anterior dislocation.

The influence of mandibular condyle morphology on TMJ anterior dislocations.

OBJECTIVES: The present study was designed to investigate the correlation between the bony morphology of the mandibular condyle and the occurrence of temporomandibular joint (TMJ) idiopathic anterior dislocation. STUDY DESIGN: A comparative retrospective study was conducted among 14 patients presenting idiopathic anterior dislocations (study group) and 15 patients who did not suffer from any TMJ disorders (control group). All patients underwent a multidetector computed tomography scan demonstrating the full extent of their joints. The scans of 58 joints were reconstructed and analyzed by tools available in Dolphine3 software. Mandibular condyle size and volume were measured, and its shape was characterized. RESULTS: Shape, width, length, height, and volume of the mandibular condyles did not differ statistically between the study and control groups. CONCLUSION: Mandibular condyle morphology does not affect TMJ idiopathic anterior dislocation.

Explant Modeling of the Immune Environment of Head and Neck Cancer.

Patients exhibit distinct responses to immunotherapies that are thought to be linked to their tumor immune environment. However, wide variations in outcomes are also observed in patients with matched baseline tumor environments, indicating that the biological response to treatment is not currently predictable using a snapshot analysis. To investigate the relationship between the immune environment of tumors and the biological response to immunotherapies, we characterized four murine head and neck squamous cell carcinoma (HNSCC) models on two genetic backgrounds. Using tumor explants from those models, we identified correlations between the composition of infiltrating immune cells and baseline cytokine profiles prior to treatment. Following treatment with PD-1 blockade, CTLA-4 blockade, or OX40 stimulation, we observed inter-individual variability in the response to therapy between genetically identical animals bearing the same tumor. These distinct biological responses to treatment were not linked to the initial tumor immune environment, meaning that outcome would not be predictable from a baseline analysis of the tumor infiltrates. We similarly performed the explant assay on patient HNSCC tumors and found significant variability between the baseline environment of the tumors and their response to therapy. We propose that tumor explants provide a rapid biological assay to assess response to candidate immunotherapies that may allow matching therapies to individual patient tumors. Further development of explant approaches may allow screening and monitoring of treatment responses in HNSCC.

A platform for locoregional T-cell immunotherapy to control HNSCC recurrence following tumor resection.

Surgical resection of head and neck squamous-cell carcinoma (HNSCC) is associated with high rates of local and distant recurrence, partially mitigated by adjuvant therapy. A pre-existing immune response in the patient's tumor is associated with better outcomes following treatment with conventional therapies, but improved options are needed for patients with poor anti-tumor immunity. We hypothesized that local delivery of tumor antigen-specific T-cells into the resection cavity following surgery would direct T-cells to residual antigens in the margins and draining lymphatics and present a platform for T-cell-targeted immunotherapy. We loaded T-cells into a biomaterial that conformed to the resection cavity and demonstrated that it could release T-cells that retained their functional activity in-vitro, and in a HNSCC model in-vivo. Locally delivered T-cells loaded in a biomaterial were equivalent in control of established tumors to intravenous adoptive T-cell transfer, and resulted in the systemic circulation of tumor antigen-specific T-cells as well as local accumulation in the tumor. We demonstrate that adjuvant therapy with anti-PD1 following surgical resection was ineffective unless combined with local delivery of T-cells. These data demonstrate that local delivery of tumor-specific T-cells is an efficient option to convert tumors that are unresponsive to checkpoint inhibitors to permit tumor cures.

Island osteoperiosteal flap for alveolar bone reconstruction.

The island osteoperiosteal flap (I-flap) is introduced as a modified alveolar split bone grafting technique used to gain width and modify the facial or buccal bone plate position. Three case examples are shown as well as animal histology indicating the possible development of this new surgical procedure as an adjunct for alveolar augmentation and implant therapy.