Lower Molar Research Articles

Exploring morphometric transformations in temperature-sensitive NiTi instruments alongside real-time intracanal temperature dynamics.

This study was twofold: (i) it aimed to investigate the morphometric changes of three temperature-sensitive nickel-titanium (NiTi) instruments at different temperatures, and (ii) to conduct an invivo real-time analysis of intracanal temperature changes. Changes in the shape and length of XP-Endo Shaper, XP-Endo Finisher, and XP-Endo Finisher-R were evaluated in real time whilst heated in a temperature-controlled water bath from 22 to 45°C. Instruments were fixed to a laminated water-resistant 1 mm graph paper attached to a stone block. Instruments were imaged whilst subjected to increasing temperature using a digital camera attached to an operating microscope. From recorded videos, still frames were extracted at 10-s intervals and changes in the length and shape of each instrument were measured and changes were plotted against time. Moreover, the intracanal temperature of distal roots of lower molars was measured invivo for patients attending the clinic for non-surgical root canal treatments. The temperature was measured using a K-type thermocouple probe inserted into the mid-root level after irrigating the canal with a solution set at room temperature (22°C) or heated to 45°C. The intraoral and intracanal temperatures were recorded using a video camera for 180 s at 5-s intervals to plot the change in the intraoral and intracanal temperature, after both irrigation solution temperatures, with time. The shape transformation of XP-Endo Shaper began at 31.5 ± 2.0°C and reached its optimal transformation at 35.1 ± 1.0°C. For the Finisher and Finisher-R, shape transformations began at 29.2 ± 1.9 and 26.9 ± 2.2°C reaching the optimal transformation at 33.9 ± 1.4 and 32.7 ± 1.7°C, respectively. The average decreases in lengths of XP-Endo Shaper, Finisher, and Finisher-R after full transformation were 0.43 ± 0.23, 1.07 ± 0.22, and 1.15 ± 0.22 mm, respectively. The intracanal temperature reached 32.9 ± 0.8 and 33.2 ± 1.0°C after 3 min of application of irrigation solutions set at 22 or 45°C, respectively. The tested instruments exhibited diverse changes in their shapes and lengths at varying temperatures. Despite the temperature of the irrigation solution, the intracanal temperature consistently remained lower than the intracanal temperature once equilibrium was reached. This highlights the importance of considering the temperature of irrigation solution during invitro testing of endodontic instruments.

Prognostic risk factors for apical root resorption in orthodontic patients – Are the Kjær’s morphologic characteristics of clinical relevance?

BackgroundPatients undergoing orthodontic treatment (OT) face an increased risk of developing external apical root resorption (EARR). A prognostic risk assessment prior to OT can potentially be conducted through anatomical features in panoramic radiography. This retrospective study aimed to assess the significance of Kjær's morphological characteristics in analyzing the risk of EARR. MethodsPanoramic radiographs of 1,156 patients (624 females, 532 males) were retrospectively analyzed. Anamnestic and treatment-related data were extracted from patient records. The mean age at the start of OT was 12.8 ± 2.2 years (min. 6.4 years, max. 22.3 years) and at the end of OT 15.9 years (min. 8.5 years, max. 24.1 years). The mean treatment duration was 3.1 ± 1.6 years. Panoramic radiographs with a minimum of two per patient were examined for the presence of Kjær’s characteristics. The degree of EARR was registered defining resorption in four degrees of severity. Bivariate analysis and multivariate Poisson regression were performed to assess the association between Kjær’s characteristics and EARR patient- and tooth- related (α = 0.05). ResultsIn total, 72.8% of the patients showed EARR at the end of OT with lateral maxillary incisors most frequently affected. Short roots (p < 0.001) were significantly associated with EARR in patients. Tooth-related microdontia (#12, #22, lower second premolars), narrow crowns (#11, #21, lower incisors), short roots (upper incisors, lower first molars) and ectopia (#11, #21, #13), such as shorter distal roots of the mandibular first molar showed a significant association with EARR depending on severity degree. The type of orthodontic appliance (fixed: p < 0.001, fixed and removeable: p = 0.008), as well as treatment duration (p < 0.001) were also identified as risk factors for EARR. ConclusionsAlthough the risk assessment for EARR development through panoramic radiography analysis is limited, predisposition appears to be present in specific dental characteristics and treatment-related factors.

Assessment of Changes in the Outcome of Autogenous Tooth Grafts Over Time: A Clinical Study Evaluating Periodontal Healing in Bone Defects After Lower Third Molar Removal

BackgroundThe removal of impacted lower third molars (ILTM) is associated with bone defects in the distal area of second molars. Different methods have been described to minimize these defects. PurposeThe primary objective was to assess changes in probing depth (PD) over time (up to 36 months) between test (grafted) and control (ungrafted) groups; the graft was obtained from the extracted ILTM. Study design, setting, sampleThis split-mouth randomized clinical trial was conducted at the Postgraduate Course in Oral Surgery of the Faculty of Dentistry of the Complutense University of Madrid. Adult patients requiring bilateral ILTM extraction with adjacent second molars were recruited, excluding pregnant/lactating women, patients in treatment with nonsteroidal anti-inflammatory drugs and patients with periodontal diseases. Predictor/exposure/independent variableThe predictor variable was the graft technique. The bone defect after ILTM removal was treated with autogenous tooth graft (ATG) in the test group, leaving the control group ungrafted. Main outcome variablePD on the distobuccal, distomedial and distolingual surfaces was recorded in both groups and averaged at baseline (T0), 3 (T1), 6 (T2) and 36 months (T3) postoperatively. CovariatesSex, age, surgical time, ILTM situation and position between groups were assessed. AnalysesANOVA repeated measures for comparisons between groups and the Friedman test for comparisons within the groups over time were applied. Statistical significance was established with a confidence interval (CI) of 95% (p<0.05). ResultsThe sample comprised 22 patients (6 males, 16 females) with a mean age of 21.68±2.19 years; 44 ILTM extractions were performed. Statistically significant differences in PD average were found between groups (p<0.001, 95% CI) at 3 (1.63 ± 0.29), 6 (1.76 ± 0.3) and 36 months (1.74 ± 0.36). Reductions from T0 to T3 of 2.74±0.28 (p<0.001) and 0.54 ± 0.3 (p=0.43) were observed in test and control groups, respectively. Conclusions and relevanceATG placed on the distal surface of lower second molars and almost completely filling the extraction socket improved PD 3, 6 and 36 months after ILTM. Furthermore, no significant changes in PD were observed over time; no major complications occurred. ATG appears to be a viable alternative graft material for this procedure.

ANALYZING DEVICES AND METHODS FOR ASSESSING THE PRIMARY STABILITY OF ORTHODONTIC MINI-IMPLANTS

When disruptions occur in the mechanisms regulating the eruption of lower jaw molars, it becomes necessary to artificially extract and reposition them within the dentition. Various treatment methods are employed for this purpose, with the primary approach involving traction fixed to teeth or other anchorage elements and bone supports. Skeletal support is preferred to minimize resistance from orthodontic appliances when applying force to the patient's teeth. The utilization of mini-implants for anchorage demonstrates a relatively high success rate, though instances of failures and complications are not unheard of. Potential issues such as stability loss and mini-implant displacement may necessitate relocation or adjustments to treatment strategies, posing challenges for both practitioners and patients. Unlike dental implants, where secondary stability often dictates treatment success, primary stability holds paramount importance for orthodontic mini-implants. Investigating primary stability parameters can significantly impact treatment strategy selection and orthodontic mini-implant loading timelines. Focusing solely on mini-implant torque during placement is inadequate, as it fails to comprehensively gauge real stability. Moreover, the available range of torque indicators for orthodontic mini-implant placement is limited, typically ranging from 5ncm to 10 ncm. Furthermore, the selection of specialized devices for measuring primary stability is limited and necessitates meticulous evaluation.

Effect of metakaolin content and shape design on strength performance of lightweight rubberized geopolymer mortars incorporated slag-waste glass powders

Lightweight rubberized geopolymer (LRGP) has gained attention due to its economic, engineering, and environmental benefits. With the rising human demands, the need for alternative materials to meet the requirements of infrastructural expansion, and global industrialization required. Based on those facts, this study aimed to develop of lightweight geopolymer mortars using wastes rubber as fine aggregate (WRA) to replace the natural aggregates, which metakaolin (MK), wastes bottle glass (WBG) and granulated blast furnace slag (GBFS) used as precursor materials with alkaline activator contained low molarity of sodium hydroxide solution and sodium silicate and cured at ambient temperatures. The effect of WRA on physical, mechanical, and microstructural properties of metakaolin-based rubberized geopolymer has been evaluated by using several tests such as compressive, flexural and tensile strength. As well as morphology and chemical reaction on LRGP by using AFM, FESEM, EDX, FTIR and XRD tests. In addition, a sustainable shape design has been cast and subjected to compressive strength to obtain the strength performance of the proposed LRGP mortar. At optimal mixture, the SEM images exhibited improvement in the interfacial transition zone (ITZ) among WRA and binder, leading rubberized geopolymer with 15% WRA to achieve a strength of 27.47 MPa after 28 days and with a reduction in density by 7.2%. The findings of this study can provide valuable insights on utilizing WRA in the shape design and formulation of geopolymer mortar, a key ingredient in the development of functional environmentally friendly building materials.

Synergistically constructed lamination-like network of redox-active polyimide and MXene via π-π interactions for aqueous [formula omitted] storage

As a nonmetallic charge carrier, ammonium ion (NH4+) has garnered significant attention in the construction of aqueous batteries due to its advantages of low molar mass, small hydration size and rapid diffusion in aqueous solutions. Polymers are a kind of potential electro-active materials for aqueous NH4+ storage. However, traditional polymer electrodes are typically created by covering the bulky collectors with excessive additives, which could lead to low volume capacity and unsatisfactory stability. Herein, a nanoparticle-like polyimide (PI) was synthesized and then combined with MXene nanosheets to synergistically construct an additive-free and self-standing PI@MXene composite electrode. Significantly, the redox-active PI nanoparticles are enclosed between conductive MXene flakes to create a 3D lamination-like network that promotes electron transmission, while the π-π interactions existing between PI and MXene contribute to the enhanced structural integrity and stability within the composite electrode. As such, it delivers superior aqueous NH4+ storage behaviors in terms of a notable specific capacity of 110.7 mA·h·cm–3 and a long lifespan with only 0.0064% drop each cycle. Furthermore, in-situ Raman and UV–Vis examinations provide evidence of reversible and stable redox mechanism of the PI@MXene composite electrode during NH4+ uptake/removal, highlighting its significance in the area of electrochemical energy storage.

Evaluation of the Effect of Primary and Secondary Closure on the Use of Leukocyte and Platelet-Rich Fibrin in Impacted Lower Third Molar Surgery

The aim of this study was to compare the effect of using L-PRF in patients undergoing impacted lower third molar surgery with either primary or secondary closure techniques. Methods: This prospective, randomized, double-blind, split-mouth clinical trial was conducted on patients with bilateral impacted lower third molars of a similar position. Primary closure was performed in group 1 and secondary closure in group 2. The group 1 closure technique was applied to one side of the patients, and the group 2 closure technique was applied to the other side at different times. Of the 45 patients evaluated, 9 patients were excluded from the study because of alveolitis and failure to attend regular control visits out. Results: Of the 36 patients included in the study, 23 were female and 13 were male, with a mean age of 22.42 ± 3.36 years. The secondary closure group had lower VAS scores at hour 6 (p &lt; 0.05). Pain decreased more in the primary closure group when comparing changes between the VAS scores at 6 hours and 7 days (p &lt; 0.05). Conclusions: The results of this study, showing that both secondary and primary closure are effective, with similar outcomes in terms of pain, swelling, and trismus, should be supported by future clinical trials.

Risk Factors Associated With Inferior Alveolar Nerve Injury After Extraction of Impacted Lower Mandibular Third Molars: A Prospective Cohort Study

BackgroundInferior alveolar nerve (IAN) injury is one of the complications of impacted lower mandibular third molar (LM3) extraction. Given the unknown prognosis of IAN injuries and limited treatment options, it is critical to understand the risk factors of IAN injury before LM3 extraction. PurposeThe study purpose was to identify risk factors associated with IAN injury after LM3 extraction. Study design, setting, sampleThis was a prospective cohort study including patients who underwent LM3 extraction from May to December in 2021 at authors’ institution. Patients with systemic diseases, previous maxillofacial surgeries or sensory abnormalities were excluded. Predictor variable(s)The predictor variable is composed of several risk factors. The variables were grouped into four categories: demographic, radiographic, procedure-related, and surgeon experience. Main outcome variable(s)The outcome variable was postoperative neurosensory disturbance coded as present or absent and was measured as one-month (transient) and one-year (permanent). CovariatesNot applicable. AnalysesThe measurement data were represented by mean and standard deviation (SD). The association of each variable with the presence of IAN injury was tested by the chi-square test. Statistical significance was accepted at p < 0.05. ResultsThe study sample was consisted of 705 patients (37.0% male) with an average age of 28.51 ± 6.51 years. A total of 17/705 (2.4%) and 4/705 (0.57%) patients developed transient and permanent IAN injury. The results demonstrated that the following factors were associated with higher rates of transient injury: use of chisels during surgeries (6.4%; 95% CI: 2.7-12.3; p=0.02; RR=11.4), LM3s located below the IAN canal (8.7%; 95% CI: 4.3-15.7; p<0.01; RR=7.3), compressed contact between LM3s and the IAN canal (36.4%; 95% CI: 12.3-78.2; p<0.001; RR=25.4), and not using corticosteroids after surgeries (3.8%; 95% CI: 1.9-6.5; p=0.03; RR=3.1). The only factor associated with permanent injury was compressed contact between LM3s and the IAN canal (18.2%; 95% CI: 2.2-62.3; p<0.001; RR=48.2). Conclusions and RelevanceClose proximity between LM3s and IAN canal, and the use of chisels, increase the risk of transient IAN injury. Corticosteroid treatment may promote nerve recovery. Compressed contact between LM3s and IAN canal is the only risk factor for permanent injury.

Dental sculpting and compensatory shearing crests demonstrated in a WEAR series of Presbytis rubicunda (Cercopithecoidea, Colobidae) with dental topography analysis.

Maintaining effective and efficient occlusal morphology presents adaptive challenges for mammals, particularly because mastication produces interactions with foods and other materials that alters the geometry of occlusal surfaces through macrowear and/or catastrophic failure (i.e. "chipping"). Altered occlusal morphologies are often less effective for masticating materials of given diet-but not always-some species exhibit dental sculpting, meaning their dentitions are set up to harness macrowear to hone their occlusal surfaces into more effective morphologies (i.e. secondary morphologies). Here we show that dental sculpting is present in the folivorous Presbytis rubicunda of Borneo. Thirty-one undamaged lower second molars of P. rubicunda exhibiting various stages of macroscopic wear were micro-CT scanned and processed into digital surfaces. The surfaces were measured for convex Dirichlet normal energy (vDNE, a measure of surface sharpness), and degree of surface wear. Regression analyses compared surface sharpness with several measures of wear to test for the presence and magnitude of dental sculpting. Positive correlations between the wear proxies and vDNE reveal that P. rubicunda wear in such a way as to become sharper, and therefore more effective chewing surfaces by exposing enamel-dentine junctions on their occlusal surfaces and then honing these junctions into sharpened edges. Compared to another primate folivore in which increasing surface sharpness with macrowear has been demonstrated (i.e., Alouatta palliata), the worn surfaces are similarly sharp, but the dental sculpting process appears to be different. The results presented here suggest that not only do some primates exhibit dental sculpting and the attendant secondary morphology, but that there appear to be multiple different morphological configurations that can achieve this result. P. rubicunda has thicker enamel and a more stereotyped wear pattern than A. palliata, although both show positive correlations of occlusal surface sharpness (vDNE) with various wear proxies. These findings shed light on the varied approaches for the maintenance of effective and efficient occlusal surfaces in primates.

Management of class III malocclusion in adult patient using buccal shelf bone screw: A case report

A skeletal Class III malocclusion can be treated with orthopaedic camouflage either with Face mask or Chin cup therapy or extraction of premolar, and orthognathic surgical method depending on the complexity of skeletal and dental manifestation that Class III malocclusion had. Skeletal Class III malocclusion can be treated with Accurate treatment planning since malocclusion having lot off aesthetic as well as functional problem depending on the severity of the discrepancy.Here we presenting a case reports of Angle's Class III malocclusion which has been treated effectively with distalisation of lower arch Using 2 buccal shelf screws (2x12mm) with elastic chains following lower third molars extraction. In addition, improvement was observed in the soft tissue profile of the case. After 16 months of treatment, the case achieved an aesthetic and functional occlusion. A non-surgical approach of a 23-year-old male with skeletal and dental Class III malocclusion, concave profile, anterior crossbite, and a negative overjet of 5 mm while retaining the patient's profile was achieved. At the conclusion of the procedure, positive improvement with functional and aesthetic result were attained.

Anionic Conjugate Addition Oligomerization of Carbon Dioxide/Butadiene Derived Lactones.

Nucleophilic and non-nucleophilic bases have been employed in anionic oligomerization of unsaturated δ-valerolactone (3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one) (1). Compared to the seminal findings with 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), the unsaturated lactone reacts with guanidines, disilazanes, and phosphazenes both in bulk and in solution with higher productivities and activities, reaching full conversion with turnover frequencies up to 382 h-1. Additionally, reactions using phosphazenes and NaHMDS were active at 1 mol % catalyst loadings both in solvent and in bulk monomer at room temperature. Characterization of the reaction products by 1H, 13C, FTIR, MALDI-MS, tandem mass spectrometry (MS/MS), and ion mobility mass spectrometry (IM-MS) revealed microstructural differences dependent on the nucleophilicity of the organocatalytic base and reaction conditions. The products from phosphazene-catalyzed reactions are consistent with selective vinylogous 1,4-conjugate addition, whereas both conjugate addition and ring-opening mechanisms are observed in TBD. DSC reveals that these microstructures can be tuned to have a Tg range between -18 and 80 °C, while SEC and MALDI-MS reveal that only low molar mass oligomers are formed (748-5949 g/mol). From these results, an approach for selectively favoring the vinylogous 1,4-conjugate addition pathway is obtained over ring-opening reactivity.

Management of a solitary bone cyst using a custom-made surgical guide for a minimally invasive approach: technical note and case report

BackgroundSolitary Bone Cyst (SBC), also known as a simple bone cyst, hemorrhagic cyst, or traumatic cyst is classified by the WHO among non-odontogenic benign lesions of the jaw. The article explores the use of a static 3D-printed surgical guide to treat mandibular SBC, emphasizing a minimally surgical approach for this lesion.Case PresentationA 20-year-old woman was referred for a persistent mandibular SBC lacuna, without specific complaints. Her medical history included a previous bone trepanation for a SBC in the same area, radiologically and surgically confirmed. X-ray assessment showed a well-defined unilocular radiolucency surrounding the root of the first left lower molar (tooth #36), measuring 10 × 10 mm. Pulp sensitivity was normal. CBCT data and STL files of dental cast were obtained preoperatively and registered. A 3D-printed surgical guide was used for minimally invasive trepanation of the buccal cortical. The simulation used a targeted endodontic microsurgery approach in order to determine axis and diameter of the trephine. Surgery was performed under local anesthesia. The guide was tooth supported integrating tubes and a fork for guiding precise trepanation. A 3.5 mm round bone window was created, leaving an empty cavity confirming SBC diagnosis and permitting bone curettage. A blood clot was obtained to promote bone healing. Complete reossification was observed after 6 months. The follow-up at 2 years confirmed a complete bone healing with normal pulp sensitivity.DiscussionThe 3D-printed windowed surgical guide with dental support offers big advantages, including improved visibility and reduced errors. Compared to traditional guides, it eliminates visual hindrance and allows easier and quick access to confined areas as well as an improved irrigation during drilling process. The article also highlights the importance of preoperative planning while acknowledging potential limitations and errors and surgical complications.ConclusionThe use of the 3D-printed surgical guide could be used in routine for minimally invasive intervention of SBC. This case also demonstrates the potential utility of this approach in various procedures in oral and maxillofacial surgery. The technique provides precise localization, reducing complications and enhances operative efficiency.

UNRAVELING THE OUTCOMES: A RETROSPECTIVE ANALYSIS OF ABERRANTLY POSITIONED IMPACTED THIRD MOLAR EXTRACTIONS

In the realm of dentistry, the extraction of third molars occupying abnormal positions poses a formidable challenge. These enigmatic teeth, deviating from their anticipated anatomical location, demand meticulous evaluation and specialized approaches to ensure their successful removal. Intriguingly, the evaluation of such cases has remained unexplored in the context of Kazakhstan until now. Aim: The objective of this study is to examine the occurrence of mandibular third molar impaction and its correlation with factors such as impaction type, impaction side, age, and gender among patients. Methods: A retrospective review was conducted on the medical records of 2351 patients who underwent surgical extraction of impacted mandibular third molars. Results: The findings revealed a remarkable prevalence of mesioangular impaction (56.15%) in the lower third molars. The highest number of patients were observed in the age group of 18–30 years (25.05%), and a majority of cases involved the left side (75.75%). A notable female predominance (66.35%) was also observed. The most frequent indication for surgical removal was recurrent pericoronitis (24.25%). Conclusion: This pioneering study in Kazakhstan provides insights into extraction success for impacted third molars. It reveals a remarkable prevalence of mesioangular impaction in the lower molars, predominantly on the left side with a notable female predominance. Recurrent pericoronitis is the primary reason for surgical removal. Early removal of symptomatic impacted molars prevents future complications, but careful patient selection is crucial. Further research is needed to understand these findings in the Kazakhstani population.

EXPLORING CYTOLOGICAL ASPECTS OF SOCKET HEALING OPTIMIZATION AFTER ATYPICALREMOVAL OF THE THIRD LOWER MOLAR

This study aims to investigate the cytological characteristics of socket healing after atypical removal of the lower third molar, utilizing osteoplastic synthetic material in conjunction with platelet-rich gel and plasma enriched with thrombocyte factors, to enhance local osteogenesis. Materials and Methods For this comparative clinical study, smears of alveolar content were collected following atypical extraction of the lower third molar. Cell elements were quantified for cytological analysis. Data collection utilized a template developed in Microsoft Excel version 16.34. Statistical processing was performed using RStudio 2023.03.1 Build 446 (Posit Software, PBC). Smears were air-dried, fixed in a 1:1 mixture of alcohol and acetone for 5 minutes, stained first with May-Grünwald’s methylene blue (15 minutes), followed by Romanowsky-Giemsa’s azure-eosin stain (30 minutes). Smear images were captured with the Leica morpho densitometric complex: DM 1000 microscope, DFC-320 camera, images were obtained in jpg format at 400x magnification. Results The study encompassed 30 patients divided into control and experimental groups. Cytological analysis was conducted on the 2nd, 5th, and 10th days of post- operation. In both groups, on the 2nd day, alveolar smears showed the presence of erythrocytes (n = 6) and neutrophils (n = 2). On the 5th day, the experimental group exhibited neutrophils (n = 3) and abundant cocci microflora (n = 6). On the 10th day, epitheliocytes (n = 8) primarily indicated proliferation. Conclusions The obtained results underscore the effectiveness of employing osteoplastic synthetic material in combination with plateletrich gel and plasma enriched with thrombocyte factors for enhancing local osteogenesis following atypical removal of the third molar. This approach demonstrates significant elevation in epithelialization activity, fibroblastic activity, and other markers of the reparative process in comparison to the control group.

Como o uso de fibrina rica em plaquetas pode beneficiar as exodontias de terceiros molares mandibulares?

Surgery for the removal of third molars is a surgical procedure commonly performed in Dentistry. It is associated with inflammatory events and possible complications, being more evident after the removal of lower molars, since in most cases there is a need for more invasive approaches. It is essential for the dentist to minimize such effects, providing a more peaceful postoperative period with less morbidity for the patient. In this context, platelet-rich fibrin (PRF) was developed, which is considered a platelet aggregate obtained by centrifugation of the patient's own blood and proposes to minimize inflammatory effects, accelerate healing and repair processes, and reduce postoperative complications. A literature review on the effect of L-PRF in sockets after the removal of mandibular third molars was conducted, evaluating its efficacy on pain, swelling, trismus, and healing. A bibliographic survey was performed on the PubMed, Web of Science, and Elsevier databases, using the following descriptors: 'platelet rich fibrin', 'third molar', and 'surgery', limiting to articles written in English published from 2013 to 2023. Thus, we have a current scientific overview of the real effect of using this platelet aggregate in the extraction of lower third molars. The studies reviewed, for the most part, showed positive results in improving pain, swelling, trismus, and healing.

Mitigating jaw osteonecrosis: bioactive glass and pericardial membrane combination in a rat model.

Bisphosphonates (BFs) show clinical effectiveness in managing osteoporosis and bone metastases but pose risks of bisphosphonate-related jaw osteonecrosis (BRONJ). With no established gold standard for BRONJ treatment, our focus is on symptom severity reduction. We aimed to assess the preventive effects of bioactive glass and/or pericardial membrane in a preclinical BRONJ model, evaluating their potential to prevent osteonecrosis and bone loss post-tooth extractions in zoledronic acid (ZA)-treated animals. Rats, receiving ZA or saline biweekly for four weeks, underwent 1st and 2nd lower left molar extractions. Pericardial membrane alone or with F18 bioglass was applied post-extractions. Microarchitecture analysis and bone loss assessment utilized computerized microtomography (CT) and positron emission tomography (PET) with 18F-FDG and 18F-NaF tracers. Histological analysis evaluated bone injury. Exclusive alveolar bone loss occurred post-extraction in the continuous ZA group, inducing osteonecrosis, osteolysis, osteomyelitis, and abscess formation. Concurrent pericardial membrane with F18 bioglass application prevented these outcomes. Baseline PET/CT scans showed no discernible uptake differences, but post-extraction 18F-FDG tracer imaging revealed heightened glucose metabolism at the extraction site in the ZA-treated group with membrane, contrasting the control group. These findings suggest pericardial membrane with F18 bioglass effectively prevents BRONJ in the preclinical model.

New proboscidean specimens from the Late Miocene of Romania: the huge-sized deinothere Deinotherium proavum, the rare “Mammut” cf. obliquelophus and the first description of the shovel-tusker Konobelodon from the country

In this article, we describe so far unpublished proboscidean specimens from several Late Miocene localities of Romania. A partial mandible and the complete upper/lower cheek tooth rows of a deinothere individual from the site of Gherghești 1 belong to Deinotherium proavum and comprise one of the few examples of entire cheek tooth rows of the same individual of this species. Gherghești 1 is geographically close to Mânzaţi from where the celebrated skeleton of “Deinotherium gigantissimum” was discovered at the end of the nineteenth century, and thus further highlights the importance of Romania in the study of this emblematic deinothere. Deinotherium proavum represents the last deinothere species in Europe and corresponds to the terminal stage of the size increase characterizing the evolution of European deinotheres. Two zygodont molars are attributed to the rare “Mammut” cf. obliquelophus and add to the scarce record of “Mammut” in the Miocene of Eurasia. They document the secure presence of “Mammut” in the Miocene of Romania. The small size of the studied molars compared to known specimens of the Pliocene “Mammut” borsoni and the weak development of the distal cingulum in the lower third molars may have taxonomic and biostratigraphic importance. Furthermore, the presence of an amebelodontid is documented by a large-sized and dorsoventrally flattened lower tusk fragment that shows tubular dentine in its inner part and is attributed to the tetralophodont shovel-tusker Konobelodon. This specimen marks the first record of the genus in Romania. Finally, the biostratigraphic distribution of the taxa is discussed.

Proposal and Validation of a New Index to Assess the Difficulty of Lower Third Molar Extraction.

A prospective cohort study on a sample of patients of the Master of Oral Surgery of the University of Seville in which multiple linear regression coefficients were calculated with a subsequent validation study of the results in the sample of patients operated in the Hospital Palmaplanas of Mallorca. The regression line obtained after applying the statistical methodology to the cohort of patients from the University of Seville obtained significant dependent variables such as depth, roots, and odontosection. Once applied to the cohort of patients from the Palmaplanas Hospital in Mallorca, a regression coefficient was obtained between the data received and the estimated 0.770. The formula proposed in this article presents significant validity in the prediction of the surgical time of extraction of the lower third molars included.

Solitary primary intraosseous xanthoma of the mandible in a 15-year-old boy: a case report

BackgroundA xanthoma is a rare bone condition consisting of a predominant collection of lipid-rich, foamy histiocytes. The central xanthoma of the jaws is a unique benign tumor.Case reportA 15-year-old Caucasian male has been presented to our department. He had radiological changes in the area of the left mandibular angle, with an area of diffuse osteolysis of 3.0 cm by 2.0 cm. Computed tomography reveals an area of diffuse osteolysis that starts from the distal root of the lower second molar and reaches the ascending process. A bone biopsy was performed, which revealed a benign proliferative process composed of histiocytic cells involving and infiltrating trabecular bone in a background of loose fibrous connective tissue devoid of any other significant inflammatory infiltrate. The size of the formation was 2.9 cm by 2.0 cm. Immunohistochemical staining for CD68 was strongly positive and negative for S-100 and CD1a. From routine blood tests, cholesterol, triglycerides, and blood sugar are within normal values, which excludes systemic metabolic disease. Subsequent to the surgical intervention, the patient underwent postoperative assessments at intervals of 14, 30, 60 days, and a year later, revealing the absence of any discernible complications during the aforementioned observation periods.ConclusionThe diagnosis of primary xanthoma of the mandible is rare and can often be confused with other histiocytic lesions. A differential diagnosis should be made with nonossifying fibroma and Langerhans cell histiocytosis, as in our case. In these cases, immunohistochemistry with CD 68, S-100, and CD1a, as well as blood parameters, are crucial for the diagnosis.

Srovnání změn v dolním zubním oblouku u pacientů léčených konvenčními zámky a samoligujícími zámky

Aim: The aim was to assess the changes in the mandible in patients treated with conventional brackets compared to those treated with self-ligating brackets. In particular, we focused on the degree of transversal changes and the length of therapy. Material and method: The sample included 43 patients; 11 men and 32 women. The mean age was 22.2 years. The patients had complete permanent dentition, were treated without extractions, molars in Angle Class I. The subjects were divided into two groups – conventional brackets, self-ligating brackets. Measurements were performed in scans of cast models made prior to therapy (T1), after removal of fixed appliance (T2), the length of treatment was given in months. The changes in intercanine and intermolar distance were compared in teeth and in relevant points on WALA ridge of the mandible. ORTODONCIE | ročník 33 | č. 2/2024 ODBORNÉ PRÁCE / ORGINAL ARTICLES 29 www.ortodonciejournal.cz | e-mail: redakce@ortodonciejournal.cz, office@ortodonciejournal.cz Results: In lower first molars the change in intermolar width was significant in both groups both at T1 and T2. The change was significantly bigger in the group with self-ligating brackets. The change in intercanine width between T2 and T1 was statistically significant only in the group with self-ligating brackets when measured on canine tips. Measurements at FA points (the most prominent point in the middle of longitudinal axis of the clinical crown) did not prove significant change. At WALA the change between T2 and T1 was significant only in the group with self-ligating brackets and only in first lower molars (clinically the change was small). The change in the distance WALA-FA in first lower molars on the left and on the right between T2 and T1 was statistically significant in both groups, however, it was significantly bigger in the group with self-ligating brackets. The difference in the length of therapy was not statistically significant. Conclusion: In patients with self-ligating brackets there is a greater expansion in first molars and canines. We can also observe more prominent vestibular inclination of canines and first molars. In patien