Magneto-dynamic tool for full arch immediate loading in post-traumatic restoration with narrow implants: A case report.

New surgical techniques using narrow, tilted implants positioned through a magneto-dynamic tool in guided surgery for a Toronto restoration. A 69-year-old woman wanted fixed rehabilitation to replace her removable complete dentures. A cone-beam computed tomography showed significant bone resorption in both the maxillary and mandibular regions. The plan was to load the entire upper arch with six implants immediately, while removable partial dentures were recommended for the lower jaw. The guided surgery project was aligned with the new dentures, and the laboratory created a printed cast with dental implant analogues in planned positions. A metal-reinforced denture was constructed, and surgery was performed to place six narrow implants using the magneto-dynamic instrument. The denture was directly screwed onto multi-unit abutments. Final rehabilitation was completed after 6 months. Narrow implants can be a good option for fixed, full-arch rehabilitations. Further research is needed to confirm these findings on a larger scale.

Clinical Spectrum and Treatment of Odontogenic Myxoma: Analysis of 37 Cases.

Background: Odontogenic myxoma is one of the benign mesenchymal odontogenic tumours with aggressive behaviour and showed slow and asymptomatic expansion, the second until the third decade of life is the most targeted age group. With high female preponderance, about the management, surgical management is the only option concerning this odontogenic pathology with a variety of treatment options. This study aims to analyse a series of 37 patients with odontogenic myxoma treated in a single institution. Materials and method: In total, 37 patients with odontogenic myxoma were treated at KTDH in Sudan and were retrospectively reviewed. With the analysis of medical records of all patients diagnosed with odontogenic myxoma and the related variables, data were analysed using the SPSS statistical program (version 23). Results: Most of the cases were females (26 patients 70.27%), and males were about (11 patients 29.73%). In most of the cases maxilla was affected more than the mandible (25 cases, 67.57%) mostly in its posterior segment (32 cases, 86.49). The most age group affected was the group of cases (0-20) which were about 18 cases (48.65%). In total, 35 of the cases noticed swelling (94.59%), while 14 noticed tooth mobility (37.84%) and paraesthesia was a positive finding in just one case (2.70%). In total, 12 patients (32.43%) had a positive history of tooth extraction related to the lesion, and recurrence was positive in (64, 86%). Conclusion: Odontogenic myxoma is locally aggressive. There is no gold standard protocol for surgical treatment so choosing the most suitable and reliable treatment option relay on the operator taking into consideration the characteristic of each case and the recurrence rate with the associated postoperative impairments.

The study of dental status through determination of the degree of preservation of paleoanthropological material.

OBJECTIVE: Aim: To introduce a simple classification system for the degree of preservation and quality of the dentoalveolar apparatus into scientific circulation to further investigate dental diseases in ancestral populations.. PATIENTS AND METHODS: Materials and Methods: The sample analyzed consisted of the remains of 499 individuals from the human populations that existed in the territories of Ukraine from the Copper Age to the Bronze Age. Teeth and jaws were examined macroscopically under bright light; dental changes were evaluated by probing. Dental radiographic examinations were performed using retroalveolar and panoramic X-ray films in adult individuals. RESULTS: Results: The authors divide the dentoalveolar apparatus of fossil and subfossil skeletons into ten levels for further medical investigation of dental diseases. These levels depend on the preservation degree and changes in jaws and teeth. CONCLUSION: Conclusions: The study of bone and tooth preservation, determination of skeletal sex, and age characteristics is a separate section and stage in reconstructing the physical type of individuals and the health status of a community. Studying the taphonomic features of odontologic anthropological material should be a mandatory prerequisite preceding its analysis in paleopathology. The condition of the dentoalveolar system can be classified into ten levels for paleopathological conclusions. This classification will be helpful to doctors specializing in forensic medicine and anthropologists.

The effectiveness of autologous platelet concentrates in prevention and treatment of medication-related osteonecrosis of the jaws: A systematic review.

The systematic review aims to answer the PICOS question: "Are the autologous platelet concentrates (APCs) an effective strategy in prevention and/or treatment of patients at risk of/affected by medication-related osteonecrosis of the jaws (MRONJ)?". A literature search was conducted via PubMed, MEDLINE, EMBASE, and CINAHL (January 2006 - September 2023). 30 articles were included, evaluating preventive (n = 8*) and treatment strategies (n = 23*). The risk of bias and quality of studies were assessed utilising ROB-2, ROBIN-1 and GRADE criteria. Meta-analysis was undertaken for eligible studies. The application of APCs demonstrated a statistically significant effectiveness in prevention of MRONJ in 86.13% (p < 0.001) but failed to achieve the same level of certainty in treatment of established MRONJ in 83.4% (p = 0.08). High levels of bias were identified; thus, the results should be interpreted with caution. More high quality prospective randomised controlled trials are needed to further evaluate the effectiveness of APCs in management of MRONJ.

Central giant cell granuloma of the jaws-long-term clinical and radiological outcomes of surgical and pharmacological management.

OBJECTIVES: To compare long-term results of different treatment modalities in central giant cell granuloma of the maxillofacial-skeleton. Primary resection may result in major defects. Alternative treatments include pharmacological agents. As yet there has been no consensus on the use of the variety of treatment options, and few studies have reported clarifying long-term results. MATERIALS AND METHODS: This retrospective study on 22 patients with 25 lesions evaluated clinical, radiological and histological features, treatment preformed and lesion recurrence. Success was defined as regression/calcification and failure as recurrence, progression or un-responsiveness. RESULTS: Of the presenting patients, 77% were under age 40. Lesion prevalence was higher in the anterior mandible and left posterior maxilla. Most cases exhibited pain, tooth-mobility or mucosal-expansion. The appearance was predominantly unilocular in the maxilla and multilocular in the mandible, which also exhibited higher prevalence of cortical perforation. Up to 80% of lesions were classified as aggressive. Intralesional steroids/calcitonin were used in 7 cases. Mean follow-up was 39.8 months. Two cases showed recurrence. In 71% of the cases treated pharmacologically, calcification/regression were observed. CONCLUSIONS: Our analysis indicates better outcomes using a combined approach, including both pharmacological and surgical treatments in large aggressive lesions. Pharmacological treatment resulted in decreased size or well-defined lesions, thus reducing the need for extensive bone resection. Dual treatment with corticosteroids and calcitonin showed no superior outcomes, but a larger cohort should be assessed. CLINICAL RELEVANCE: There are several protocols for treatment of central-giant-cell-granuloma lesions, but most are not fully established. It is important to report results that contribute to the establishment of proven protocols. This report attempts to establish the relevance of the combined approach: pharmacological treatment followed by surgical resection.

Partial Implant Rehabilitations in the Posterior Regions of the Jaws Supported by Short Dental Implants (7.0 mm): A 7-Year Clinical and 5-Year Radiographical Prospective Study.

Background: Short implants have been used in the restoration of edentulous jaws in the past several years. However, some studies have suggested that short implants are less successful than standard implants. The aim of this study is to investigate the outcome of short implants placed in the posterior maxilla or mandible following one-stage or immediate-function protocols with a follow-up of 7 years (clinically) and 5 years (radiographically). Methods: This study included 127 patients rehabilitated with 217 implants measuring 7 mm and supporting 157 fixed prostheses in the posterior segments of both jaws. Final abutments were delivered at the surgery stage and were loaded after 4 months in 116 patients (199 implants). The primary outcome measure was implant survival measured through life tables. Secondary outcome measures were marginal bone loss and the incidence of biological and mechanical complications at the patient level and implant level (evaluated through descriptive statistics). Results: Twenty-four patients (18.9%) with 45 implants (20.7%) were lost to the follow-up. In total, 32 implants failed (14.8%) in 22 patients (17.3%), resulting in a cumulative survival rate at 7 years of 81.2% for 7 mm implants in the rehabilitation of the posterior regions of the maxilla and mandible. The average (standard deviation) marginal bone loss was 1.47 mm (0.99 mm) at 5 years. The incidence rate of biological complications was 12.6% and 10.6% at the patient and implant levels, respectively. The incidence rate of mechanical complications was 21.3% for patients and 16.1% for implants. A higher failure rate was registered in smokers and in implant arrangements with a sequence of three fixtures in proximity. Conclusions: Within the limitations of this study, it can be concluded that the placement of 7 mm long implants for the partial implant-supported rehabilitation of atrophic posterior jaws is possible in the long term, judging by the survival rate and stable average marginal bone loss. Nevertheless, strict case selection should be performed, especially in smokers and with implant arrangements that provide a minimum of one unit in inter-implant distance.

Anti-resorptive therapy and MRONJ. A survey of the Italian Society of Periodontology and Implantology.

OBJECTIVES: Anti-resorptive agents have been linked to the development of MRONJ in patients undergoing dental surgical procedures. This survey aims to explore the level of knowledge and experience of Italian Society of Periodontology and Implantology members in the management of patients treated with anti-resorptive agents and with the risk of developing MRONJ. MATERIALS AND METHODS: An 18-item questionnaire was submitted by e-mail to the SIdP members. Statistical analyses were carried out. Continuous variables were described as mean ± standard deviation (SD) or median, and first and third quartile according to distribution's normality. Normality of data was checked with Shapiro-Wilk test. RESULTS: Four hundred and fifty-one questionnaires were returned by e-mail (32%). Most of the respondents were private practitioners (81.8%). Only 47.7% declared to be highly confident in managing patients on anti-resorptive therapy while 92.5% reported to have performed tooth extractions and 52.3% implant surgery in patients under anti-resorptive therapy for osteometabolic disorders. One or more MRONJ-affected patients were encountered by 63.2% of the respondents. CONCLUSIONS: This survey highlights the need to develop a "dedicated" program both for dentists and prescribers to improve the level of cooperation and to increase the level of awareness of patients treated with anti-resorptive agents.

Awareness of Medication-Related Osteonecrosis of the Jaws Amongst Patients on Antiresorptive and Antiangiogenic Medications.

Background Medication-related osteonecrosis of the jaws (MRONJ) is a rare but severe condition that has garnered increasing attention in recent years. It primarily affects individuals undergoing treatment with antiresorptive and antiangiogenic medications, such as bisphosphonates and denosumab, commonly prescribed for osteoporosis and cancer-related bone metastases. Therefore, the present study aimed to assess awareness and understanding of MRONJ among patients receiving antiresorptive and antiangiogenic medications. Methods A cross-sectional survey was conducted among 110 patients receiving antiresorptive and antiangiogenic medications in a clinical setting. Participants were given a structured questionnaire to assess their awareness of MRONJ. The questionnaire covered aspects such as MRONJ, bisphosphonate usage, and awareness of the condition's potential complications. Demographic information was also collected. Chi-square and Fisher's tests were performed using SPSS statistical software. Results In terms of gender distribution, 63.6% of the participants were female. Concerning age distribution, the majority (43.6%) fell within the 21 to 40 age group, whereas only 5.5% were aged over 60. Regarding educational attainment, a substantial majority (58.2%) of the participants held a bachelor's degree. The study findings reveal that a considerable proportion (35.5%) of participants possess awareness regarding jaw osteonecrosis, and this association is statistically significant (p=0.002). A substantial number of participants administered the medication orally (30.9%), while others utilized various administration routes, including injection (IV and others) (40%), and this difference was also statistically significant (p=0.001). Most participants took bisphosphonates for osteoporosis (41.8%) or cancer (13.6%), both statistically significant (p<0.01). Gender had no significant impact (p>0.01), but age showed potential associations (p=0.07 for awareness, p=0.003 for medication use). Educational backgrounds had no significant link, except for bisphosphonate usage (p<0.01) and side effects reporting (p<0.01). Conclusion Notably, a small percentage of participants demonstrated awareness of this condition, indicating a need for continued education and awareness campaigns. Further research and interventions may be warranted to address the specific needs of different age groups and educational backgrounds in promoting safe and effective medication management.

Could MRONJ Be Related to Osimertinib Monotherapy in Lung Cancer Patients after Denosumab Suspension?

BACKGROUND: Medication-related osteonecrosis of the jaws is the most frequent complication in patients treated or in therapy with antiresorptive/antiangiogenetic drugs. The list of medications possibly related to MRONJ onset is constantly growing; we aimed to report on a third-generation epidermal growth factor receptor tyrosine kinase inhibitor (Osimertinib) as possibly responsible for bilateral maxillary necrosis onset in the herein-described case. METHODS: In June 2023, an oncologic patient with two different maxillary bone exposures was referred to our attention. His medical history revealed a two-year Denosumab regimen along with Osimertinib, the latter not suspended before teeth extractions. The clinicians performed a sequestrum removal and bone debridement after three cycles of antibiotic therapy. RESULTS: Histologic examinations confirmed the clinical diagnosis of MRONJ excluding a metastatic occurrence, while complete mucosal healing was achieved after 15 days. CONCLUSIONS: The patient suspended Denosumab for more than six months before teeth extraction for MRONJ prevention; hence, failure to discontinue Osimertinib led us to consider it a possible etiological factor. From a literature analysis, only one case has already been published reporting a possible Osimertinib-related occurrence of MRONJ in lung cancer patients. Our case is a further report that could be intended as an alert both for oncologists and dentists to share decisions about the oral management of such patients together, also informing them about this possible risk. Also, this report could trigger in the scientific community the necessity to evaluate further guidelines for similar doubtful cases in which the drug interaction, the mono-suspension, and the possible removable prosthesis-related additional trauma should be considered causes or con-causes.

Implant presence-triggered osteonecrosis: A scoping review.

Unlike medication-related osteonecrosis of the jaw (MRONJ), implant presence-triggered osteonecrosis of the jaw (IPTO) is not well appreciated. Recent reports have suggested a mechanical aetiology unique to osseointegrated dental implants that may be responsible for this phenomenon. A scoping review was performed to consolidate the available evidence. Two reviewers independently searched the PubMed, EMBASE, CINAHL, and Cochrane Library databases. The study was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) extension for scoping reviews. Studies that described or evaluated the development of IPTO in osseointegrated implants, which were placed prior to the commencement of anti-resorptive or anti-angiogenic agents, were included. Twenty-three (23) articles were included in this study. Patient characteristics, aetiopathogenesis, presentation, and treatment of the disease were evaluated. Most studies suggested a 6-month period between dental implant insertion and the commencement of anti-resorptive therapy as a criterion for IPTO. Both infective and mechanical processes were reported to be involved in the pathogenesis of IPTO. Most patients required surgical intervention to achieve resolution. While there are several knowledge gaps regarding IPTO, the evidence points towards a continuum in the pathogenesis of the disease, whereby there is a mechanical cause followed by secondary infection. Similar to typical MRONJ, the severity and treatment required also vary. Persistent peri­implantitis features around a dental implant should alert the clinician to the possibility of IPTO in patients taking anti-resorptive or anti-angiogenic agents. Prompt identification of the disease may play a role in timely management or appropriate referrals.

Investigation on the accuracy of field widths and the quantitative relationship with energy variations for dynamic jaws helical tomotherapy.

BACKGROUND AND PURPOSE: TomoEDGE is an advanced technology for TomoTherapy treatment delivery by introducing a sliding-window dynamic jaw motion. The front and back jaws move independently at the start and end of a target volume along the longitudinal couch direction to reduce the undesired dose to the normal tissues. The accuracy of field width is essential to treatment delivery in this regard. The purpose of this work was to analyze the performance of dynamic jaws on helical tomotherapy and investigate the relationship with energy variation. METHODS: The Tomotherapy-Quality-Assurance (TQA) Dynamic Field Width procedure was performed monthly across three tomotherapy machines. All field widths were analyzed, especially the FWHM of the 10 mm field width. Field width measurements were compared with the ratio of Percentage Depth Dose at 20 and 10 cm to render the value of correlation. Changes in beam FWHM and energy were further discussed. Two-year data were collected for this purpose. RESULTS: On average, measured field widths in each unit agreed within 1% tolerance recommendation stated. The average absolute difference between reference and measured FWs in each unit was approximately 0.07 mm. An increase of 1.5% in the FW of the 10 mm nominal beam width was correlated with a 1% increase in PDD20,10 ratio, implying a positive correlation between the two factors (p < 0.002). CONCLUSIONS: A positive correlation between nominal 10 mm FW and PDD20,10 was observed. In the case that the PDD20,10 marginally passes the QA tests, users are recommended to consider further verification on Dynamic Jaws to ensure the smallest field width to be within tolerance, which is essential to maintain effective treatment in TomoEDGE system. Since the regression of this study was a single-factor model, other confounding factors such as the focal spot size of linear accelerator should also be considered when evaluating the machine status.

Clínica, epidemiología e imagenología del fibroma osificante y la displasia fibrosa del territorio cráneo-maxilofacial: revisión narrativa / Clinical, epidemiology and imaging of ossifiying fibroma and fibrous dysplasia of the cranio-maxillofacial territory: narrative review

Introducción: El fibroma osificante (FO) y la displasia fibrosa (DF) tienen características imagenológicas e histopatológicas similares que dificultan el diagnóstico diferencial. El propósito de la presente revisión narrativa es analizar las características clínicas, epidemiológicas e imagenológicas del FO y la DF, y evaluar la relación entre las características imagenológicas y las variantes histopatológicas del FO, en reportes y series de casos publicados.Materiales y métodos:Se realizó una búsqueda de reportes y series de casos de FO y DF entre 2017-2021 en PubMed, Scopus y Web of Science. Los casos debían tener suficiente información clínica, epidemiológica, histopatológica e imagenológica.Resultados:Se incluyeron 23 artículos con 25 lesiones: 17 FO y 8 DF. El tiempo de evolución de DF es más prolongado que FO. FO se ubica con mayor tendencia en complejo osteomeatal en comparación con DF. Sólo FO presentó alteraciones en piel, radiolucidez/hipodensidad periférica, perforación ósea y rizalisis externa, además, tuvo mayor tendencia al avance a espacios anatómicos adyacentes y a generar asimetría facial y/o craneal. FO psammomatoide y FO trabecular comparten patrones imagenológicos y tienen límites definidos corticalizados. FO convencional tuvo mayor tendencia a perforar corticales. DF puede tener límites mal definidos y definidos corticalizados. El FO mostró características imagenológicas de mayor agresividad que la DF.Conclusiones:La histología e imagenología por sí solas no son decisivas en el diagnóstico de FO y DF. Es imprescindible considerar conjuntamente clínica, imagenología e histopatología, enfatizando en las características que orienten el diagnóstico diferencial.(AU)

Introduction: Ossifying fibroma (OF) and fibrous dysplasia (FD) have similar imaging and histopathological characteristics, which make differential diagnosis difficult. The aim of this narrative review was to analyze the clinical, epidemiological and imaging characteristics of OF and FD, as well as to evaluate the relationship between imaging characteristics and histopathologic variants of OF, in reports and case series published.Materials and methods:A search of reports and case series of OF and FD between 2017-2021 in PubMed, Scopus and Web of Science was performed. The cases had to have enough clinical, epidemiological, histopathological and imaging information.Results:23 articles with 25 lesions were included: 17 OF and 8 FD. FD had a longer time of evolution than OF. OF is more likely to be in osteomeatal complex compared to FD. Only OF had skin alterations, peripheral radiolucency/hypodensity, bone perforation and external root resorption, in addition, it had a greater tendency to advance to adjacent anatomical spaces and generate facial and/or cranial asymmetry. Psammomatoid OF and trabecular OF share imaging patterns and have defined and corticated margins. Conventional OF had a greater tendency to cortical perforation. DF can have ill-defined and defined and corticated margins. OF has imaging characteristics of greater aggressiveness than FD.Conclusion:Histology and imaging alone are not decisive in OF and FD diagnosis. It is essential to consider clinical, imaging and histopathological evaluations as a whole, emphasizing in the characteristics that guide the differential diagnosis.(AU)

Use of Phototherapy and Er-YAG Laser in the Management of Mandible Osteoradionecrosis: A Case Report.

Introduction: Osteoradionecrosis (ORN) is a secondary complication from radiotherapy, which is difficult to manage and significantly reduces the life quality of the affected patients. Case Report: A 59-year-old female patient, diagnosed with infiltration by squamous cell carcinoma in the left cervical region, underwent adjuvant cervical-facial radiotherapy with a total dose of 66.6 Gy of radiation. Eight years after the diagnosis, the patient underwent multiple extractions and, subsequently, the installation of osseointegrated implants, evolving to extensive intraoral bone exposure associated with oral cutaneous fistula. The patient was initially exposed to photobiomodulation therapy (PBMT), with a low-power laser at wavelengths of 660 nm and 808 nm, and thereafter to antimicrobial photodynamic therapy (aPDT). After an improvement in the clinical condition and resolution of the oral cutaneous fistula, a surgical procedure with the Er: YAG laser was performed to remove the remaining necrotic bone. Once the ORN condition was completely treated, the patient's oral rehabilitation was implemented by the installation of an upper mucous-supported total prosthesis and a lower implant-supported prosthesis. Conclusion: The patient is in a clinical follow-up and has no signs of bone necrosis recurrence, suggesting that low and high-power laser treatment can be an effective therapeutic alternative to resolve this condition.

Bisphosphonates and Their Connection to Dental Procedures: Exploring Bisphosphonate-Related Osteonecrosis of the Jaws.

Bisphosphonates are widely used to treat osteoporosis and malignant tumors due to their effectiveness in increasing bone density and inhibiting bone resorption. However, their association with bisphosphonate-related osteonecrosis of the jaws (BRONJ) following invasive dental procedures poses a significant challenge. This review explores the functions, mechanisms, and side effects of bisphosphonates, emphasizing their impact on dental procedures. Dental patients receiving bisphosphonate treatment are at higher risk of BRONJ, necessitating dentists' awareness of these risks. Topical bisphosphonate applications enhance dental implant success, by promoting osseointegration and preventing osteoclast apoptosis, and is effective in periodontal treatment. Yet, systemic administration (intravenous or intraoral) significantly increases the risk of BRONJ following dental procedures, particularly in inflamed conditions. Prevention and management of BRONJ involve maintaining oral health, considering alternative treatments, and careful pre-operative and post-operative follow-ups. Future research could focus on finding bisphosphonate alternatives with fewer side effects or developing combinations that reduce BRONJ risk. This review underscores the need for further exploration of bisphosphonates and their implications in dental procedures.

Clinicopathological Features of Metastasis to the Oral and Maxillofacial Region-Multicenter Study.

BACKGROUND: This study aimed to investigate the clinicopathological features of metastases in the oral and maxillofacial regions. METHODS: In this retrospective study, biopsy records were obtained from referral centers for oral and maxillofacial diagnosis in Brazil, Guatemala, Mexico, and South Africa. RESULTS: A total of 120 cases were evaluated. Of these, 53.78% affected female patients, with a mean age of 57.64 years. Intraosseous lesions were more frequent, particularly in the posterior region of the mandible (49.58%). Clinically, most cases presented with symptomatic swelling, with an average evolution time of 25 months. The clinical diagnostic hypothesis in most instances was that of a malignant lesion. Breast cancer was the most common primary tumor location in females, while lung origin was most common in males. In most cases, the primary cancer was an adenocarcinoma (44.73%). The follow-up period was available for 29 cases, and out of these, 20 had died due to the disease. CONCLUSION: Although this is a rare condition, clinicians should be aware that any oral lesions have the possibility of being metastatic, particularly in individuals with a previous history of cancer. The findings from this study could assist clinicians in prompt diagnosing these lesions and subsequent conducting oncologic assessments and treatment.

Accuracy of Intraoral Scanner for Recording Completely Edentulous Arches-A Systematic Review.

Scanning edentulous arches during complete denture fabrication is a crucial step; however, the quality of the resulting digital scan is still questionable. The purpose of this study is to systematically review studies (both clinical and in vitro) and determine whether intraoral scanners have clinically acceptable accuracy when recording completely edentulous arches for the fabrication of removable complete dentures. An electronic search in medical databases like PubMed, Scopus, and Web of Science (WOS), using a combination of relevant keywords, retrieved 334 articles. After full-text evaluation, twelve articles fulfilled the inclusion criteria for this review (eight clinical studies and four in vitro studies). A quality analysis of the included studies was carried out using the QUADAS-2 tool. The accuracy values varied between different intraoral scanners. Different regions of the edentulous arches showed differences in trueness and precision values in both in vitro and clinical studies. Peripheral borders, the inner seal, and poorly traceable structures like the soft palate showed maximum discrepancies. The accuracy of intraoral scanners in recording clear anatomic landmarks like hard tissues with attached mucosa was comparable to conventional edentulous arch impressions. However, higher discrepancies were recorded when digitizing mobile and poorly traceable structures. Intraoral scanners can be used to digitize denture-bearing areas, but the interpretation of the peripheral border and the soft palate should be carefully carried out.

Three-dimensional kinematics of leaf-cutter ant mandibles: not all dicondylic joints are simple hinges.

Insects use their mandibles for a variety of tasks, including food processing, material transport, nest building, brood care, and fighting. Despite this functional diversity, mandible motion is typically thought to be constrained to rotation about a single fixed axis. Here, we conduct a direct quantitative test of this 'hinge joint hypothesis' in a species that uses its mandibles for a wide range of tasks: Atta vollenweideri leaf-cutter ants. Mandible movements from live restrained ants were reconstructed in three dimensions using a multi-camera rig. Rigid body kinematic analyses revealed strong evidence that mandible movement occupies a kinematic space that requires more than one rotational degree of freedom: at large opening angles, mandible motion is dominated by yaw. But at small opening angles, mandibles both yaw and pitch. The combination of yaw and pitch allows mandibles to 'criss-cross': either mandible can be on top when mandibles are closed. We observed criss-crossing in freely cutting ants, suggesting that it is functionally important. Combined with recent reports on the diversity of joint articulations in other insects, our results show that insect mandible kinematics are more diverse than traditionally assumed, and thus worthy of further detailed investigation. This article is part of the theme issue 'Food processing and nutritional assimilation in animals'.

Mandibular small cell osteosarcoma: a case report and review of literature.

BACKGROUND: Small cell osteosarcoma is an extremely rare histopathological variant of conventional osteosarcoma. Due to nonspecific symptoms, most osteosarcomas of the jaws are misdiagnosed as periapical abscesses and mistreated by teeth extraction and drainage. CASE PRESENTATION: We report, to our knowledge, the seventh case of small cell osteosarcoma in gnathic sites affecting the mandible of an old female with history of a large painful swelling related to the right mandibular molar area for 2 months. Cone-beam computed tomography scan showed an osteolytic lesion related to the lower molar area with involvement of the inferior alveolar nerve. An incisional biopsy was taken, and after histopathological examination and immunohistochemical staining, a diagnosis of small cell osteosarcoma was reached. Hemi-mandibulectomy was performed by a maxillofacial surgeon. No clinical evidence for recurrence was noted until manuscript writing. CONCLUSION: Accurate diagnosis is very important, and general practitioners should be aware of this entity considering that small cell osteosarcoma has a poor prognosis when compared to conventional osteosarcoma.

The accuracy of implant placement using a combination of static and dynamic computer-assisted implant surgery in fully edentulous arches: A prospective controlled clinical study.

OBJECTIVE: To compare the accuracy of implant position, using a combination of static and dynamic computer-assisted implant surgery (CAIS), with either static, dynamic, or freehand implant placement, in fully edentulous arches. MATERIALS AND METHODS: Twenty-one patients with a total of 88 fixtures were included. Implants were divided equally into four groups: a combination of static and dynamic CAIS (SD group), static CAIS (S group), dynamic CAIS (D group), and freehand placement (FH group). Angular deviation, as well as the 3D platform and apex deviations, were measured for all groups. Furthermore, the direction of implant deviation was recorded and compared. RESULTS: The FH group showed significantly more deviation compared to all groups, considering all the aspects, and at both the implant platform and apex. A significant difference in angular deviation between the SD and S groups (p < .001), and between the SD and D groups (p < .001) was noted, favoring the SD group. When evaluating implant distribution, the FH group showed a tendency towards the buccal, apical, and distal directions at platform and apex, while in the D group, implants shifted more to the buccal. In contrast, the SD group did not show a trend toward any specific direction. The S and SD groups did not show a statistical significance considering any direction. CONCLUSIONS: The combination of static and dynamic CAIS increases the accuracy of implant placement in fully edentulous arches when compared with either static or dynamic CAIS alone, as well as freehand placement.

Awareness, perceptions and attitudes toward medication-related osteonecrosis of the jaw among physicians who treat osteoporosis.

Osteoporosis is the most common indication for antiresorptive drugs (ARDs). Medication-related osteonecrosis of the jaw (MRONJ) is a severe complication of ARDs. Multiple risk factors can increase the risk of MRONJ, one of which is the duration of ARD intake, which is usually prolonged for osteoporosis cases. Prevention of MRONJ relies on collaborative care between treating physicians and dental practitioners. Therefore, knowledge about MRONJ and its prevention strategies is crucial for both teams. Aim: This study aimed to assess the knowledge and attitudes of physicians toward MRONJ in osteoporosis patients. Another aim was to develop recommendations for the prevention of MRONJ. Materials and methods: Through an online survey, basic information such as the practice location, training, knowledge, perceptions, and attitudes of physicians regarding ARDs and MRONJ in osteoporosis patients was collected. Statistical analysis was performed for all variables, and their correlations were explored. Results: A total of 221 physicians participated in the survey: 34.8% were rheumatologists, 25.3% were endocrinologists, 8.6% were family medicine physicians, 5.9% were orthopedists, and 5.9% were internal medicine physicians. Of them, 58.0% reported more than 6 years of experience. Only 78.7% were aware of MRONJ and recognized that bisphosphonates (BPs) can contribute to MRONJ. In contrast, 56.0% recognized denosumab as a causative factor for MRONJ. Duration of ARD therapy and pre- and post-ARD dental care were known to influence the risk of MRONJ by 62% and 65.6% of the participants, respectively. Only 41.6% and 31.2% of participants informed patients about MRONJ prior to BP and denosumab therapy, respectively. Only 25.3% and 20.8% referred patients to dentists before BP and denosumab therapy, respectively. Overall, 65.6% of the participants had a negative attitude toward MRONJ, and 34.4% had a positive attitude. A positive attitude was mostly observed among rheumatologists (55.8%) compared to other specialists (p <0.001). More years of experience were associated with a higher level of knowledge and positive attitude. Conclusion: The findings of this study identified a notable gap in the awareness, knowledge and attitudes of physicians regarding MRONJ in osteoporosis patients. Continuing education programs about ARDs and MRONJ risk are highly recommended.