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.

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.

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.

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.

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.

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.

Nonfixated inlay graft for anterior localized mandibular defect.

Localized vertical bone defects within the anterior mandibular alveolar ridge frequently pose a unique challenge for functionally and aesthetically pleasing rehabilitation of this area. Causes for significant bone loss in this region may include periodontal disease, postextraction atrophy, trauma, and orthodontic treatment. In the presence of such a defect, ridge augmentation may be obligatory before installation of dental implants. Several surgical procedures, notably bone augmentation techniques, including guided bone regeneration, onlay bone grafting, and interpositional grafts, have been described. However, loss of a single incisor or a few incisors may render these methods complicated for surgical manipulation. In this article, we aim to report the outcome of 4 cases with localized vertical osseous deficits in the anterior mandible, treated by using a technique whereby we utilized the bony defect's margins through a vestibular approach to wedge inlay grafts without additional fixation or distraction hardware, thus overcoming the surgical difficulties and achieving a favorable outcome.

Computerized Navigation for Minimal Invasive Retrieval of Displaced Dental Implants in the Lower Jaw.

Displaced dental implants in the mandible may constitute a clinical challenge for both physicians and patients. The complex anatomy of the floor of the mouth, together with its subsequent violation due to implant displacement makes implant allocation and retrieval a challenging procedure. Computerized navigation surgery (CNS) has been previously described and proved successful in various surgical modalities. In this article, the authors present a recommended protocol for the use of CNS for the retrieval of displaced dental implants in the mandible and describe the workflow through the stages of diagnosis, preoperative surgical planning, and the surgical procedure.

Vertical Alveolar Augmentation Using BMP-2/ACS/Allograft with Printed Titanium Shells to Establish an Early Vascular Scaffold.

Traditional reconstruction of major alveolar ridge deficiency has required autogenous cortical cancellous particulate bone grafts, often augmented with particulate allogeneic components. Now there is a new concept to consider, that of orthoalveolar form. This paradigm shift involves components of the tissue engineering triad of inductive growth factors combined with a matrix and stem cells, together with osteotomies or devices designed for space maintenance. Reported here is early experience with computer technology used to redesign deficient alveolar ridges deriving ideal alveolar-shaped bone-forms made from powdered titanium, sintered by laser at high temperature using rapid prototype technology.

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.

Release of Irretrievable Abutment Healing Caps Using Cooling: Proof of Concept and Clinical Recommendations.

PURPOSE: To study the relation between irretrievable abutment healing caps (AHCs), temperature, and the torque required to remove the AHCs from implants. MATERIALS AND METHODS: Twenty implants, 13 mm long and 4.2 mm in diameter, were inserted into four acrylic boxes and covered with acrylic resin. An AHC was screwed into each implant, using a 30 N/cm torque. The acrylic blocks were placed in a 37°C water bath, and subsequently, a block was removed from the bath, the AHCs were cooled, and the torque needed to release each AHC from the implant was measured using a torque wrench. The cooling methods applied were contact with an ice cube for 10 or 25 seconds or spraying of endodontic refrigerant spray for 3 seconds. The control abutments were similarly tested, but without prior cooling. RESULTS: The application of ice cubes for 10 seconds reduced the mean releasing torque from 29.60 ± 1.22 N/cm to 28.55 ± 1.96 N/cm (P = .01). Cooling the AHCs with ice cubes for 25 seconds reduced the mean required releasing torque from 29.6 N/cm to 27.85 ± 1.22 N/cm (P < .001). Cooling the same abutments using endodontic refrigerant spray for 3 seconds reduced the mean releasing torque to 27.74 ± 2.13 N/cm (P < .001). CONCLUSION: Within the limitations of this study, it is possible to conclude that cooling the AHC reduces the torque required for its release from the implant. This finding may also be relevant to the removal of prosthetic abutments with irretrievable screws.

Four-years' experience with dynamic implants with internal port for minimally invasive sinus elevation.

OBJECTIVE: The purpose of this article is to describe long-term results of the dynamic implant valve approach (DIVA) for the dental implant procedures when the implant system with internal ports was used. METHOD AND MATERIALS: During 2012 to 2015, 378 titanium-aluminum-vanadium implants (Ti6Al4V ELI; diameter 3.75 mm; length 11.5 and 13 mm) were implanted in 172 patients (one to nine implants per patient) using the DIVA technique. The DIVA implants were used in cases when sinus membrane and/or nasal floor elevation procedures were needed. The condition of the implants was assessed during the follow-up period up to 60 months. RESULTS: Out of 378 inserted implants, 257 implants were inserted in the maxilla with the bone level < 5 mm, and 121 implants were inserted in the maxilla with the bone level > 5 mm. In 357 cases (94.5%), the implantation was totally successful both from objective CBCT clinical and subjective patients' viewpoints. The comparison of complication rates between the cases with the bone level < 5 mm and the cases with the bone level > 5 mm indicated no significant difference (P = .32). CONCLUSION: Preliminary results that the DIVA simplifies the dental implantation procedure and augmentation treatment were confirmed. The implant with an inner sealing screw can be used in cases with elevation of the maxillary sinus membrane, and simplifies the surgery and secures optimal dental implant placement. This new type of implant simplifies the maintenance phase of implant dentistry and helps to overcome possible complications.

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.

Topical application of slow-release simvastatin as a bone substitute in bone defects in the rat tibia: a pilot study.

PURPOSE: It is hypothesized that local application of statins positively affects bone formation. The aim of this study was to evaluate the potential effect of topical slow-release simvastatin as a bone substitute on the healing of bone defects in rat tibia. MATERIALS AND METHODS: Granules of slow-releasing hydroxypropyl methylcellulose, with or without simvastatin, were inserted into critical-size defects in the tibiae of 16 rats (8 in the study group, 8 in the control group). Bone static and dynamic histomorphometric variables were examined at 2, 4, 6, and 8 weeks postsurgery. RESULTS: All indices examined in the study group indicated improved healing relative to the control group, although statistical significance was not demonstrated for all variables. In the static histomorphometric analysis, osteoid thickness and volume were significantly higher in the study group, but the fraction of trabecular surface covered with active osteoblasts, the fraction of trabecular surface covered with osteoid, and total calcified bone volume were not significantly higher in the experimental group. In the dynamic histomorphometric analysis, the mineral apposition rate, determined by time-repeated calcein labeling, was significantly higher in the study group than in the control group. Experimental time and dosage effects were observed for most bone values in the study group. CONCLUSION: The findings indicate that topical application of simvastatin for the treatment of bone defects enhances the process of healing. Dosage and the methodology of administration require further calibration.