Signatures of convergence in Neotropical cichlid fish.

Convergent evolution of similar phenotypes suggests some predictability in the evolutionary trajectories of organisms, due to strong and repeated selective pressures, and/or developmental constraints. In adaptive radiations, particularly in cichlid fish radiations, convergent phenotypes are commonly found within and across geographical settings. Cichlids show major repeated axes of morphological diversification. Recurrent changes in body patterns reveal adaption to alternative habitats, and modifications of the trophic apparatus respond to the exploitation of different food resources. Here we compare morphologically and genetically two Neotropical cichlid assemblages, the Mexican desert cichlid and the Nicaraguan Midas cichlid, with similar polymorphic body and trophic adaptations despite their independent evolution. We found a common morphological axis of differentiation in trophic structures in both cichlid radiations, but two different axes of differentiation in body shape, defining two alternative limnetic body patterns. Adaptation to limnetic habitats implied regulation of immune functions in the Midas cichlid, while morphogenesis and metabolic functions in the desert cichlid. Convergent phenotypic adaptions could be associated to divergent gene regulation.

Clinicopathological features of myofibromas and myofibromatosis affecting the oral and maxillofacial region: A systematic review.

BACKGROUND: Myofibromas are rare benign neoplasms composed of myoid cells and myofibroblasts. This study aimed to systematically review case reports and a series of myofibromas (MF) and myofibromatosis (MFT) occurring in the oral and maxillofacial regions in order to describe their main clinicopathological features. METHODS: This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Electronic searches were conducted in 2023 in four databases: MEDLINE/PubMed, Web of Science, Scopus, and EMBASE. A manual search and a search in the grey literature were also conducted. The lesions were classified as MF or MFT according to their original report. RESULTS: A total of 169 cases were included in this systematic review. Men were slightly more affected, with a painless nodule. When occurring in soft tissue, MF usually developed in the gingiva (mean age:29.23 ± 21.93 years) and when it was intra-osseous, it occurred more frequently in the posterior mandible (mean age:14.33 ± 15.62 years). MFT occurred mainly in the mandible and was predominantly described as well-circumscribed masses of spindle cells organized in fascicles with a prominent vascular activity in a hemangiopericytoma-like pattern. The lesions were mainly positive for smooth muscle actin and vimentin immunomarkers. Surgical excision was the treatment of choice in the majority of cases and recurrence was observed in only three cases. CONCLUSION: MF and MFT affect more men, with an indolent clinical course. Intra-osseous tumors and MFT seem to occur more frequently in younger individuals. These lesions seem to have a good prognosis and low recurrence.

Four-mm-short implants in the rehabilitation of posterior atrophic jaws: A retrospective study on 212 patients with a mean follow-up of 8.02 years.

OBJECTIVE: This study aimed to assess clinical efficacy of 4-mm-short implants in patients with posterior severe vertical bone atrophy in the medium- and long-term follow-up. MATERIALS AND METHODS: Patients rehabilitated with 4-mm-short implants in the posterior atrophic jaws, with a minimum follow-up of 3 years post-loading, were included in the study. Data were collected for eligible patients, and marginal bone loss (MBL) for each implant was evaluated. The research outcomes were implant failure, MBL and complications. RESULTS: A total of 212 patients with 496 implants were included, resulting in a mean follow-up of 8.02 ± 2.17 years. The implant survival rate was 95.36% (95% CI: 93.12%-97.04%). More implant failures were observed in the maxilla (p = .02) and fewer failures were observed in patients undergoing more number of hygienic sessions per year (p < .001). The average MBL after 1-year-loading was 0.47 mm, increasing to 0.59 mm after 10 years; after 3 years no statistically significant increase in MBL was observed. Maxillary implants showed greater bone loss than mandibular ones (p < .001). More frequent professional oral hygiene sessions per year resulted being related with reduced MBL (p < .001). CONCLUSIONS: Four-mm-short implants showed high survival rates with an up to 10-year follow-up. Their use can offer a fixed prosthetic solution for patients with posterior vertical bone atrophy, minimizing surgical invasiveness, rehabilitative times and costs.

Desmoplastic Fibroma of the Gnathic Bones-A Systematic Review.

OBJECTIVE: To summarize published information about the desmoplastic fibroma of the gnathic bones into a descriptive analysis of the main features of this condition. MATERIAL AND METHODS: A systematic review according to the PRISMA guidelines was conducted. Electronic search was performed in four databases and in the gray literature. Case reports and case series were included. Frequencies were obtained for descriptive analysis. RESULTS: We identified 66 articles, for a total of 96 cases. Female patients (55.8%) in the first decade of life (40.6%) with a mean age of 18.2 years were more affected. The mandible was the most affected bone with 81.2% of the cases. The main clinical feature was painless swelling (54.2%). Most of the imaging examinations (radiological, computed tomography, and magnetic resonance) showed well-defined radiolucencies (65.4%) lesions. The treatment was surgical removal in all cases. The recurrence rate was 10.8% and all in the posterior mandible. Spindle cell fibroblasts in a collagenized stroma were often described in the histopathological features. Vimentin, smooth muscle actin, and ß-catenin were common immunohistochemical markers. CONCLUSION: Desmoplastic fibroma is a locally aggressive lesion that commonly affects the jaws in children. Histopathology is essential for diagnosis, and the pathogenesis of this tumor should be further investigated.

Epidemiological Features of 4777 Cysts and Odontogenic Tumors Based on the 2022 WHO Classification.

OBJECTIVE: The epidemiology of cysts and odontogenic tumors is important for differential diagnosis and treatment strategies. We aimed to describe the epidemiological features of cysts and odontogenic tumors in the Chilean population using the current WHO classification. MATERIALS AND METHODS: We reviewed 22,914 biopsy requests received between January 1984 and September 2023 at the oral pathology department, School of Dentistry, Universidad Mayor, Santiago, Chile. Patients diagnosed with cysts of the jaws and odontogenic tumors were selected and information regarding age, sex, and location was recorded. RESULTS: 4226 (18.4%) were cysts, and 551 (2.4%) were odontogenic tumors, ranging from 2 to 97 years old. Males represented 54.4% and females 45.7% of the total sample. The most prevalent cysts were radicular cysts (58.6%), dentigerous cysts (17.9%), and odontogenic keratocysts (13.3%). The most prevalent odontogenic tumors were odontomas (40.1%) and conventional ameloblastoma (17.6%). CONCLUSIONS: Our study was the first retrospective analysis to determine the epidemiological features of both cysts and odontogenic tumors together, based on the 2022 WHO classification. This is relevant as it offers a potential basis for comprehensive comparisons of the epidemiological features of these entities, which could contribute to an accurate differential diagnosis, therefore, leading to more effective therapeutic interventions.

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.

Nonfamilial cherubism in a 6-month-old infant: a case report.

BACKGROUND: Cherubism is known as a very rare autosomal dominant familial disorder of childhood caused by a mutation in the SH3BP2 gene on 4p16.3. It has not yet been observed at birth and is usually diagnosed in children aged 2-7. Here, we present a non-hereditary case of cherubism at a very early age. CASE PRESENTATION: A 6-month-old girl presented with bilateral progressive jaw enlargement. On physical examination, bilateral asymmetrical jaw enlargement, predominantly on the left side, and some enlarged, non-tender, mobile submandibular lymph nodes were detected. No other abnormality was observed. Further investigations with radiology suggested cherubism and Burkitt's lymphoma as differential diagnoses. Later on, histopathologic evaluations were suggestive of cherubism. No surgical interventions were indicated, and the child is on regular follow-ups. CONCLUSION: Non-hereditary Cherubism, despite scarcity, can present in children below two years of age, even as early as the beginning of primary dentition. Accurate and swift diagnosis is essential to avert physical and psychological complications. Our case report shows the importance of keeping cherubism in mind as a differential diagnosis of bone disease, even in children under a year old, and the value of interdisciplinary collaboration in dealing with rare genetic disorders.

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.

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.

Glandular odontogenic cyst misdiagnosed and treated as a periapical inflammatory lesion for 6 years in an older adult.

OBJECTIVES: To document the case of a patient who underwent several endodontic treatments due to a glandular odontogenic cyst misdiagnosed as an inflammatory periapical lesion. BACKGROUND: Glandular odontogenic cysts behave more aggressively, while others have an indolent course. There is limited information on this cyst in the gerodontologic literature. MATERIALS AND METHODS: A 76-year-old male patient presented with an asymptomatic expansive lesion in the anterior mandible resistant to several endodontic treatments. Cone-beam computed tomography revealed a multilocular osteolytic lesion measuring 6.0 × 4.0 cm, with cortical bone perforation. RESULTS: Histopathological analysis of a biopsy specimen was consistent with glandular odontogenic cyst. The patient underwent marginal mandibulectomy with preservation of the base of the mandible. CONCLUSION: A strict diagnostic process is important to avoid unwanted consequences, particularly in the geriatric population.

Comparison of quantitative radiomorphometric predictors of healthy and MRONJ-affected bone using panoramic radiography and cone-beam CT.

OBJECTIVES: To determine the most distinctive quantitative radiomorphometric parameter(s) for the detection of MRONJ-affected bone changes in panoramic radiography (PR) and cone-beam CT (CBCT). METHODS: PR and sagittal CBCT slices of 24 MRONJ patients and 22 healthy controls were used for the measurements of mandibular cortical thickness (MCT), fractal dimension (FD), lacunarity, mean gray value (MGV), bone area fraction (BA/TA), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular number (Tb.N). MCT was measured in the mental foramen region. While FD and lacunarity were measured on mandibular trabecular and cortical regions-of-interest (ROIs), the remaining parameters were measured on trabecular ROIs. The independent samples t-test was used to compare the measurements between the MRONJ and control groups for both imaging modalities (P = .05). RESULTS: MCT was the only parameter that differentiated MRONJ-affected bone in both PR and CBCT (P < .05). None of the remaining parameters revealed any difference for MRONJ-affected bone in CBCT (P > .05). FD, lacunarity, MGV, BA/TA, and Tb.Sp could distinguish MRONJ-affected trabecular bone in PR (P < .05). The correspondent ROI for both imaging methods that was reliable for detecting MRONJ-affected bone was the trabecular bone distal to the mental foramen above the inferior alveolar canal (ROI-3). CONCLUSIONS: MCT is a reliable parameter for the discrimination of MRONJ-affected bone in both PR and CBCT images. PR may be used to detect MRONJ-affected trabecular bone using FD, lacunarity, MGV, BA/TA, and Tb.Sp measurements as well.

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.

Fitting fangs in a finite face: A novel fang accommodation strategy in a 280-million-year-old ray-finned fish.

Though Paleozoic ray-finned fishes are considered to be morphologically conservative, we report a novel mode of fang accommodation (i.e., the fitting of fangs inside the jaw) in the Permian actinopterygian †Brazilichthys macrognathus, whereby the teeth of the lower jaw insert into fenestrae of the upper jaw. To better understand how fishes have accommodated lower jaw fangs through geologic time, we synthesize the multitude of ways living and extinct osteichthyans have housed large mandibular dentition. While the precise structure of fang accommodation seen in †Brazilichthys has not been reported in any other osteichthyans, alternate strategies of upper jaw fenestration to fit mandibular fangs are present in some extant ray-finned fishes-the needlejaws Acestrorhynchus and the gars of the genus Lepisosteus. Notably, out of our survey, only the two aforementioned neopterygians bear upper jaw fenestration for the accommodation of mandibular fangs. We implicate the kinetic jaws of neopterygians in this trend, whereby large mandibular fangs are more easily fit between the multitude of upper jaw and palatal bones. The restricted space available in early osteichthyan jaws may have led to a proliferation of novel ways to accommodate large dentition. We recommend a greater survey of Paleozoic actinopterygian jaw morphology, in light of these results and other recent reevaluations of jaw structure in early fossil ray-fins.

Upper beak depression instead of elevation dominates cranial kinesis in woodpeckers.

The value of birds' ability to move the upper beak relative to the braincase has been shown in vital tasks like feeding and singing. In woodpeckers, such cranial kinesis has been thought to hinder pecking as delivering forceful blows calls for a head functioning as a rigid unit. Here, we tested whether cranial kinesis is constrained in woodpeckers by comparing upper beak rotation during their daily activities such as food handling, calling and gaping with those from closely related species that also have a largely insectivorous diet but do not peck at wood. Both woodpeckers and non-woodpecker insectivores displayed upper beak rotations of up to 8 degrees. However, the direction of upper beak rotation differed significantly between the two groups, with woodpeckers displaying primarily depressions and non-woodpeckers displaying elevations. The divergent upper beak rotation of woodpeckers may be caused either by anatomical modifications to the craniofacial hinge that reduce elevation, by the caudal orientation of the mandible depressor muscle forcing beak depressions, or by both. Our results suggest that pecking does not result in plain rigidification at the upper beak's basis of woodpeckers, but it nevertheless significantly influences the way cranial kinesis is manifested.

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.

Synchronous odontogenic tumors: A systematic review.

This systematic review aimed to incorporate published information about synchronous odontogenic tumors (SOTs) with an analysis of the demographic and clinical characteristics from the cases published in the literature. Case reports and case series of SOT were searched in PubMed, Web of Science, Scopus, and EMBASE. A descriptive statistical analysis was performed. Twenty-eight studies comprising 30 cases of SOTs were included. Considering all cases published, SOTs mostly occurred simultaneously in the maxilla and mandible (n = 19/63.3%). Lesions were bifocal in 13 (43.3% of all the 30 cases) and multifocal in 17 cases (56.7% of all the 30 cases). All SOTs available in the literature presented the same type of lesion, and two of them also involved another different SOT (n = 2/6.7% of all the 30 cases). Out of all published cases, the most frequent SOTs in the literature were odontomas (n = 10/33.3% of all the 30 cases), squamous odontogenic tumors (OTs) (n = 8/26.7% of all the 30 cases), calcifying epithelial OTs (n = 8/26.7% of all the 30 cases), and adenomatoid OTs (n = 2/6.7% of all the 30 cases). Considering all SOTs cases included, the overall recurrence was 13.3%. Inside a subgroup of the lesion, synchronous calcifying epithelial OT presented the highest (25%). Five cases (16.7% of all the 30 cases) had a previously associated syndrome, with two cases of Schimmelpenning syndrome being reported. Among published SOTs, odontomas were the most common. All SOTs available in the scientific literature showed the same type of OT and mainly affected both jaws simultaneously. Only a few of these cases were associated with a syndrome.

Cysts of the jaws: A multicentre study.

OBJECTIVES: To determine the relative frequency, demographic and pathologic profiles of patients diagnosed with cysts of the jaws. MATERIALS AND METHODS: Biopsy records of the participating institutions from 2000 to 2020 were reviewed for lesions diagnosed in the cyst category. Demographic data, the location of the cysts and pathologic diagnoses were collected. Data were analyzed by appropriate statistics using IBM SPSS software version 28.0. RESULTS: From 148,353 accessioned cases, 25,628 cases (17.28%) were diagnosed in the cyst category. Mean age of the patients ± SD = 42.62 ± 19.36 years. Paediatric patients (aged ≤ 16 years) accounted for 9.63%, while geriatric patients (aged ≥ 65) comprised 14.22% of all the patients. The male-to-female ratio was 1.27:1. The majority of the lesions were encountered in the mandible. The most prevalent cyst was radicular cyst followed by dentigerous cyst and odontogenic keratocyst. In the paediatric group, dentigerous cyst was the most prevalent, whereas in the geriatric group, radicular cyst was the most common. CONCLUSIONS: In general, the results of this study are in accordance with previous studies. This study provides an invaluable database for clinicians when formulating clinical differential diagnoses as well as for pathologists in rendering the final diagnosis.

Application of Computer-Assisted Preoperative Planning in Treating Congenital Bilateral Zygomatico-Maxillo-Mandibular Fusion: A Case Report and Literature Review.

Congenital fusion of the jaws (syngnathia) is a rare facial malformation with an unknown etiology. This disease may vary in severity with adhesion of soft tissue and bony fusion. It can be anterior fusion, unilateral or bilateral fusion, and complete fusion. The main problem of these patients is the difficulty of airway maintenance and feeding, and the most common postoperative complication is the relapse of bony fusion. Here, we report a young male patient with bony syngnathia, involving bilateral fusion of the ascending ramus and body of the mandible with the maxillary complex. We performed bone isolation by computer-assisted preoperative planning and used an insertional temporalis flap to fix the wound surface to prevent refusion of bone.

Biomechanical Analysis of Different Framework Design, Framework Material and Bone Density in the Edentulous Mandible With Fixed Implant-Supported Prostheses: A Three-Dimensional Finite Element Study.

PURPOSE: The objective of this finite element study was to investigate the effect of different framework designs, framework materials, and bone densities on the stress distribution of fixed implant-supported prostheses for edentulous mandibles. MATERIALS AND METHODS: Under the condition of 2-mm cortical bone, 16 models were created in the edentulous mandible to simulate different framework designs (1-piece or 3-piece frameworks) with different framework material (pure titanium, zirconia, polyetheretherketone, or carbon fiber-reinforced polyetheretherketone) in-high or low-density trabecular bone. Then, vertical loading and oblique loading at 75° were applied to the anterior and posterior regions. The stress distribution and stress concentration region of implant and peri-implant bone with different combinations were compared by finite element analysis. RESULTS: The use of the 1-piece zirconia framework in high-density trabecular bone improved stress distribution on implants and peri-implant bone. The region of stress concentration is located in the buccal cervix of the distal implants and the distobuccal portion of the cortical bone in all models. To improve the stress distribution on fixed implant-supported dentures for edentulous mandibles, the 1-piece framework and zirconia represent the better combination. CONCLUSION: Under the condition of 2-mm cortical bone thickness, the full-arch zirconia framework had minimum von Mises stress on implants and peri-implant bone in all models, and high trabecular bone density greatly decreased the stress on cortical bone.

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.