Tooth Root Research Articles

Low-intensity pulsed ultrasound reduces alveolar bone resorption during orthodontic treatment via Lamin A/C-Yes-associated protein axis in stem cells.

The bone remodeling during orthodontic treatment for malocclusion often requires a long duration of around two to three years, which also may lead to some complications such as alveolar bone resorption or tooth root resorption. Low-intensity pulsed ultrasound (LIPUS), a noninvasive physical therapy, has been shown to promote bone fracture healing. It is also reported that LIPUS could reduce the duration of orthodontic treatment; however, how LIPUS regulates the bone metabolism during the orthodontic treatment process is still unclear. To investigate the effects of LIPUS on bone remodeling in an orthodontic tooth movement (OTM) model and explore the underlying mechanisms. A rat model of OTM was established, and alveolar bone remodeling and tooth movement rate were evaluated via micro-computed tomography and staining of tissue sections. In vitro, human bone marrow mesenchymal stem cells (hBMSCs) were isolated to detect their osteogenic differentiation potential under compression and LIPUS stimulation by quantitative reverse transcription-polymerase chain reaction, Western blot, alkaline phosphatase (ALP) staining, and Alizarin red staining. The expression of Yes-associated protein (YAP1), the actin cytoskeleton, and the Lamin A/C nucleoskeleton were detected with or without YAP1 small interfering RNA (siRNA) application via immunofluorescence. The force treatment inhibited the osteogenic differentiation potential of hBMSCs; moreover, the expression of osteogenesis markers, such as type 1 collagen (COL1), runt-related transcription factor 2, ALP, and osteocalcin (OCN), decreased. LIPUS could rescue the osteogenic differentiation of hBMSCs with increased expression of osteogenic marker inhibited by force. Mechanically, the expression of LaminA/C, F-actin, and YAP1 was downregulated after force treatment, which could be rescued by LIPUS. Moreover, the osteogenic differentiation of hBMSCs increased by LIPUS could be attenuated by YAP siRNA treatment. Consistently, LIPUS increased alveolar bone density and decreased vertical bone absorption in vivo. The decreased expression of COL1, OCN, and YAP1 on the compression side of the alveolar bone was partially rescued by LIPUS. LIPUS can accelerate tooth movement and reduce alveolar bone resorption by modulating the cytoskeleton-Lamin A/C-YAP axis, which may be a promising strategy to reduce the orthodontic treatment process.

Optimization of splash lubrication in the gearbox considering heat transfer performance

Despite recognizing the importance of cooling within gear systems, there is a lack of clear design guidelines to minimize churning losses while enhancing heat dissipation performance. This study proposes a reliable approach to modeling using a steady-state approximation methodology based on heat-flow coupling for multiphysics around shrouded gears. Computational analyses reveal a distinctive multiphase flow induced by pressure gradients. The efficacy of the proposed methodology is empirically verified through its ability to characterize lubricant distribution and churning losses in splash lubrication systems. Furthermore, an innovative shroud optimization framework is introduced to regulate friction and collision between fluid particles and gear surfaces, enhancing splash lubrication performance. A genetic algorithm is employed within this framework to obtain shroud configurations for gears with a higher wall heat transfer coefficient (WHTC) and lower resistance torque. Implementing the optimal shroud design achieves a trade-off in terms of a notable 13.7% reduction in resistance torque alongside 11.6% and 4% increments in WHTC for the tooth root face and tooth face, respectively. This signifies enhanced reliability in multiphysics governing gearbox functionality, thereby providing valuable guidance for the design of shrouded gear systems.

Nanohydroxyapatite/Peptide Composite Coatings on Pure Titanium Surfaces with Nanonetwork Structures Using Oyster Shells.

Titanium and its alloys are extensively applied in artificial tooth roots because of their excellent corrosion resistance, high specific strength, and low elastic modulus. However, because of their biological inertness, their surface needs to be modified to improve the osteointegration of titanium implants. The preparation of biologically active calcium-phosphorus coatings on the surface of an implant is one effective method for enhancing the likelihood of bone integration. In this study, osteoinductive peptides were extracted from oyster shells by using acetic acid. Two peptide-containing hydroxyapatite (HA) composite coatings were then prepared: one coating was prepared by hydrothermally synthesizing an HA coating in the presence of peptides (HA/P/M), and the other coating was prepared by hydrothermally synthesizing HA and then immersing the hydrothermally synthesized HA in a peptide solution (HA/P/S). Characterization results indicated that the composite HA coatings containing oyster shell-based peptides were successfully prepared on the alkali-treated pure titanium surfaces. The HA/P/M and HA/P/S composite coatings were found to exhibit excellent hydrophilicity. Protein adsorption tests confirmed that the HA/P/M and HA/P/S coatings had an approximately 2.3 times higher concentration of adsorbed proteins than the pure HA coating.

Lead exposure across the life course and age at death

BackgroundLead (Pb) exposure has been associated with an increased risk of all-cause mortality, even at low levels. Little is known about how the timing of Pb exposure throughout life may influence these relationships. Quantifying the amount of Pb present in various tissues of the body provides measurements of exposure from different periods of life. These include bone, tooth enamel, which is the hard outer layer of the crown, and tooth cementum, which is the calcified connective tissue covering the tooth root. The purpose of the study was to examine Pb exposure at multiple periods throughout life, including childhood (enamel), adulthood (cementum), and later life (bone), and to estimate their associations with age at death. Methods208 skeleton donors (born 1910–1960) from an ongoing case-control study were included in this study. Pb was measured in tibia (shin), bone using X-Ray Florescence and in teeth using Laser-Ablation Inductively Coupled Plasma Mass Spectroscopy. After excluding unusually high measurements (>2sd), this resulted in a final sample of 111 with all exposure measures. Correlations across measures were determined using partial Spearman correlations. Associations between Pb exposure and age at death were estimated using Multivariable Linear Regression. ResultsPb measures across exposure periods were all significantly correlated, with the highest correlation between cementum and tibia measures (r = 0.61). Donors were largely female (63.0 %), White (97.3 %), and attended some college (49.5 %). Single exposure models found that higher tooth cementum Pb (−1.27; 95 % CI: −2.48, −0.06) and tibia bone Pb (−0.91; 95 % CI: −1.67, −0.15) were significantly associated with an earlier age at death. When considered simultaneously, only cementum Pb remained significant (−1.51; 95 % CI: −2.92, −0.11). Secondary analyses suggest that the outer cementum Pb may be especially associated with an earlier age at death. ConclusionResults suggest that higher Pb exposure is associated with an earlier age at death, with adulthood as the life period of most relevance. Additional studies using Pb exposure measures from different life stages should be conducted.

Fused Azulenyl Squaraine Derivatives Improve Phototheranostics in the Second Near‐Infrared Window by Concentrating Excited State Energy on Non‐Radiative Decay Pathways

AbstractThe second near‐infrared (NIR‐II) theranostics offer new opportunities for precise disease phototheranostic due to the enhanced tissue penetration and higher maximum permissible exposure of NIR‐II light. However, traditional regimens lacking effective NIR‐II absorption and uncontrollable excited‐state energy decay pathways often result in insufficient theranostic outcomes. Herein a phototheranostic nano‐agent (PS‐1 NPs) based on azulenyl squaraine derivatives with a strong NIR‐II absorption band centered at 1092 nm is reported, allowing almost all absorbed excitation energy to dissipate through non‐radiative decay pathways, leading to high photothermal conversion efficiency (90.98 %) and strong photoacoustic response. Both in vitro and in vivo photoacoustic/photothermal therapy results demonstrate enhanced deep tissue cancer theranostic performance of PS‐1 NPs. Even in the 5 mm deep‐seated tumor model, PS‐1 NPs demonstrated a satisfactory anti‐tumor effect in photoacoustic imaging‐guided photothermal therapy. Moreover, for the human extracted tooth root canal infection model, the synergistic outcomes of the photothermal effect of PS‐1 NPs and 0.5 % NaClO solution resulted in therapeutic efficacy comparable to the clinical gold standard irrigation agent 5.25 % NaClO, opening up possibilities for the expansion of NIR‐II theranostic agents in oral medicine.

Fused Azulenyl Squaraine Derivatives Improve Phototheranostics in the Second Near-Infrared Window by Concentrating Excited State Energy on Non-Radiative Decay Pathways.

The second near-infrared (NIR-II) theranostics offer new opportunities for precise disease phototheranostic due to the enhanced tissue penetration and higher maximum permissible exposure of NIR-II light. However, traditional regimens lacking effective NIR-II absorption and uncontrollable excited-state energy decay pathways often result in insufficient theranostic outcomes. Herein a phototheranostic nano-agent (PS-1 NPs) based on azulenyl squaraine derivatives with a strong NIR-II absorption band centered at 1092 nm is reported, allowing almost all absorbed excitation energy to dissipate through non-radiative decay pathways, leading to high photothermal conversion efficiency (90.98 %) and strong photoacoustic response. Both in vitro and in vivo photoacoustic/photothermal therapy results demonstrate enhanced deep tissue cancer theranostic performance of PS-1 NPs. Even in the 5 mm deep-seated tumor model, PS-1 NPs demonstrated a satisfactory anti-tumor effect in photoacoustic imaging-guided photothermal therapy. Moreover, for the human extracted tooth root canal infection model, the synergistic outcomes of the photothermal effect of PS-1 NPs and 0.5 % NaClO solution resulted in therapeutic efficacy comparable to the clinical gold standard irrigation agent 5.25 % NaClO, opening up possibilities for the expansion of NIR-II theranostic agents in oral medicine.

The micro CT evaluation of crown and root pulp volume versus dentin thickness in teeth in postmortem interval (PMI).

Determining the postmortem interval (PMI) is one of the main study subjects of forensic sciences. The main purpose of this prospective in vitro study that was the Micro-CT evaluation of teeth crown and root pulp volume versus dentin thickness in terms of PMI determination. The study involved 60 female Wistar rats, with weights ranging from 270 to 320g. These rats were grouped into six different post-mortem period categories. Following the animals' sacrifice, they were subjected to a natural putrefaction period, with a control group, in the grounds of a sheltered garden. Hemi-mandible samples were then extracted and placed in glass tubes for Micro-CT evaluations, following the progression of putrefaction processes. The pulp volume and dentin thickness were assessed using Micro-CT, and the gathered data underwent statistical analysis. Micro-CT was employed to analyze sixty right mandibular second molar teeth in the hemi-mandible. The crown pulp volume exhibited a reduction in group 6, with a value of 0.239 mm3 after a three-month period of natural putrefaction (p < 0.001). There is statistically differences among groups in case of pairwise comparison (p < 0.05). However, the root pulp volume and dentin thickness variables did not display any statistically significant changes. Despite certain limitations associated with this study, the Micro-CT findings concerning teeth pulp volume can serve as an objective parameter, especially for late postmortem investigations and the estimation of time of death.

MODERN VIEW ON ISSUES OF DIAGNOSING GINGIVAL RECESSION

Background. Given that the exposure of the tooth root is not only an aesthetic concern but also leads to dental hypersensitivity, cervical caries, non-carious lesions, and even tooth loss, understanding the causes and characteristics of gum recession, along with its timely detection, is crucial and relevant. The aim of this study is to analyze and consolidate scientific research dedicated to the investigation of factors influencing the development of gum recession, its diagnosis, and the clinical features. This understanding is essential for addressing the challenge dealing with the treatment of this condition. A comprehensive review of scientific publications addressing the specified topics was conducted using library sources and search systems, including PubMed, Web of Science, OUCI (Open Ukrainian Citation Index), and Index Copernicus. The prevalence of gingival recession varies from 9.7% in adolescents to nearly 100% in adults. Most investigators identified a higher number of recession areas on both the upper and lower jaws around the central and lateral incisors, as well as the right first molar. However, conflicting findings exist, with some researchers suggesting that gum recession occurs most frequently in the premolars and canines area. Nevertheless, there is a unanimous agreement among researchers that this disease is polyetiological. Authors assess the significance of different factors provoking recession in varying ways. Moreover, under specific conditions, several factors may combine, with one of them dominating. Despite numerous classification attempts by specialists, efforts to propose a classification that accurately reflects the characteristic features of this pathology, the severity of manifestations, and the prognosis of its treatment are still remaining pressing issues. Thus, among the factors that provoke the development of apical migration of the gingival margin, the leading role is played by the thin biotype of the gums and the peculiarities of the anatomical and morphological structure of the periodontal tissues, inflammatory diseases in the oral cavity, incorrect implementation of hygienic and preventive measures, orthopedic and orthodontic devices that lead to mechanical injury. Despite the large number of existing classifications of gum recession, none of them can fully satisfy dentists, as they are not able to objectively determine all the clinical manifestations of the disease, establish a connection with its etiology, and predict the course.

ANALYSIS OF THE ROOT CANAL APICAL THIRD OBTURATION QUALITY DEPENDING ON THE TOOTH ROOT INDIVIDUAL ANATOMY

Background: Up-to-date methods of root canal obturation applying gutta-percha do not provide an accurate and predictable result. The different anatomy of the root canal apical third requires the selection of an optimal method that avoids voids and high sealer content. This study compared standard and modified lateral compaction techniques in root canals with different morphologies using computed tomography. Objective: To come up with an optimal method for filling the apical third of the root canal, considering its anatomical structure and to evaluate the quality of obturation using the computed tomography method. Materials and methods: The research was performed on 46 root canals of extracted teeth. All teeth were divided into two groups depending in the obturation technique used. The study included a lateral compaction technique with modification in oval-shaped root canals, followed by control using computed tomography. Results: Basing on the study, it has been revealed that even at the stage of computed tomography it is possible to plan the most appropriate method of root canal obturation, depending on their shape. Conclusion: To increase the endodontic treatment efficiency it is necessary to take into account the individual anatomical and morphological structure of the root canals. Root canals that have an oval shape in the apical third may require an obturation technique different from a standard one.

ANALYSIS OF THE ROOT CANAL APICAL THIRD OBTURATION QUALITY DEPENDING ON THE TOOTH ROOT INDIVIDUAL ANATOMY

Background: Up-to-date methods of root canal obturation applying gutta-percha do not provide an accurate and predictable result. The different anatomy of the root canal apical third requires the selection of an optimal method that avoids voids and high sealer content. This study compared standard and modified lateral compaction techniques in root canals with different morphologies using computed tomography. Objective: To come up with an optimal method for filling the apical third of the root canal, considering its anatomical structure and to evaluate the quality of obturation using the computed tomography method. Materials and methods: The research was performed on 46 root canals of extracted teeth. All teeth were divided into two groups depending in the obturation technique used. The study included a lateral compaction technique with modification in oval-shaped root canals, followed by control using computed tomography. Results: Basing on the study, it has been revealed that even at the stage of computed tomography it is possible to plan the most appropriate method of root canal obturation, depending on their shape. Conclusion: To increase the endodontic treatment efficiency it is necessary to take into account the individual anatomical and morphological structure of the root canals. Root canals that have an oval shape in the apical third may require an obturation technique different from a standard one.

RESTORATION OF CORONAL PART IN CHEWING TEETH WITH SIGNIFICANT LOSS OF HARD TISSUES BY POST AND CORE CROWN

The purpose of this study was to improve the quality of orthopedic treatment of hard dental tissues of chewing teeth destroyed below the level of the gums by a post and core crown using ashless modeling plastics.&#x0D; We examined 30 patients with severe destruction of the hard tissues of the crown portion of the teeth (IROPZ more than 80%) and concurrent periodontal diseases. A retrospective analysis revealed that teeth with deep subgingival defects restored by casts functioned as follows: for up to 1 year in 17 cases (14.2%), from 1 to 3 years in 36 cases (30.0%), from 3 to 5 years in 43 cases (35.8%), and for more than 5 years in 24 cases (20.0%).&#x0D; The results of a comparative evaluation of the effectiveness of tooth restoration with subgingival defects using ashless acrylic plastic "Modeplast" as a modeling material demonstrated the highest quality of such inserts, with most observed cases showing no signs of secondary caries. Complications, such as the dislodgement of metal inserts, were noted in 6.7% of cases, violation of marginal fit in 4.5%, and partial decementation of the structure in 8.3%. Incorrect positioning and suboptimal pin dimensions of the post and core crown occurred with approximately equal frequency: 3.5% and 3.2%, respectively. Destruction of the hard tissues of the tooth and caries relapse during restoration with metal inserts were noted in 13.3% and 29.1% of cases, respectively. Typical complications leading to tooth extraction included tooth root fractures (13.3%).&#x0D; The developed method of manufacturing post and core crowns using ashless acrylic plastic "Modeplast" at the modeling stage enables to gently remove tooth tissues and atraumatic fit of the post to the gums, prevents the accumulation of dental plaque and does not have a destructive effect on periodontal tissues.

FEATURES OF THE USE OF DENTAL SPLINTS FOR COMPLETE DISLOCATION OF TEETH

Among dental injuries, complete dislocation of a tooth has a prevalence of 1.2 to 14.8% in the permanent dentition, and is defined as a complete displacement of the tooth from the socket with rupture of the fibers of the periodontal ligament. Among the teeth, the upper central incisors are most often affected. Among children aged seven to eleven, boys are more susceptible to this type of injury than girls. This is mostly associated with industrial and auto traumatism and sports activities, protrusion of front teeth, open bite, etc. In such cases, the severity of the damage is higher, the more pronounced the tooth protrusion.&#x0D; The purpose of the study: comparison and analysis of clinical data on the use of rigid and semi-rigid dental splints after tooth replantation under the conditions of its complete dislocation and immobilization time.&#x0D; We conducted a retrospective study of the medical records of 65 outpatient dental patients with complete dislocation of a tooth on the basis of the Poltava Regional Center of Stomatology Dental Clinical Polyclinic.&#x0D; In 26% of cases, a semi-rigid splint was used for 7-10 days, which was fixed with composite resin and a steel wire with a diameter of 0.02 cm. With rigid fixation, a higher degree of bone tissue regeneration in the periodontal space was observed in 57.5% of cases. According to our data, it was established that in relation to dental splints, semi-rigid nylon splints were used in 62% of cases, steel wire in 9%, and restorative material in 18%. According to the received data on the processing and preparation of the tooth for replantation and immobilization, physiological solution is the most suitable medium for storage (62.4%), the ideal extraalveolar time period was 25-27 minutes (58.5%), while the teeth were in a dry place within 10 minutes after storage in physiological solution. Due to the presence of serious inflammatory root resorption, which demonstrates a connection with the periodontal tissue associated with increased tooth mobility, in 27.6% of cases an intervention regarding extraction, use of a temporary prosthesis, followed by prosthetics with adhesive materials is chosen. Autotransplantation is used in 12.9% of cases and is positioned as an alternative for replacing missing incisors. However, this method has limitations, as the root of the donor tooth must be 2/3 formed, in addition to anatomical problems, where approximately 60% of autografted teeth are dissimilar in appearance in terms of asymmetric gingival width or color mismatch.&#x0D; When evaluating pulp and periodontal tissue regeneration for permanent teeth, the best results were observed with the use of platelet-rich plasma, especially for incisors, with separation after more than 8 hours of extraoral storage of the tooth and delayed replantation. The obtained data allow us to state that several factors can influence the success of replantation: the duration of the injury, the extra-alveolar period of permanence, means of preservation, contamination, manipulation and condition of the extracted tooth, the type of splint used and the time of application.&#x0D; Conclusion. Based on a retrospective analysis of medical records and literature data, it can be stated that after replantation, the use of a splint is mandatory to ensure immobilization of the teeth in the initial period, which is necessary for the restoration of the periodontal ligament.

MORPHOLOGICAL CHANGES OF RAT PERIODONTIUM IN SUPRAOCCLUSAL RELATIONS OF INDIVIDUAL TEETH IN THE AGE ASPECT

Although the issue of the occlusal load influence on the occurrence of pathological phenomena in the body has been discussed for decades, it is still a subject of debate. Pathogenic occlusion is defined as excessive occlusal forces (premature contacts and interference) that can cause injuries to the dentition, including teeth and periodontal tissues. Changes in occlusal dimensions, if not properly performed or treated, can lead to dysfunctions of the dentition, such as joint clicking, difficulty in chewing, occlusal discomfort, muscle fatigue, and pain.&#x0D; Aim: to determine the morphological changes of periodontium in rats of different age groups in the supraocclusal relationship of individual teeth in the age aspect.&#x0D; Materials and methods of the study. The study was conducted on 60 white laboratory rats aged 4 to 22 months and weighing 90 to 330 g. The rats were divided into control (30 animals) and experimental (30 animals) groups. Each group was divided into 3 subgroups (10 animals each) depending on the age of the rats: young, mature and senile. Young animals included rats aged 3 4 months with a weight of 90 100 g; mature animals aged 6-8 months with a weight of 150 170 g; senile rats 20 22 months and weighing 200 220 g. In the experimental group, the state of supraocclusion was modeled by increasing the height of the lower right second molars by placing 1 mm high filling. For the placement of the filling, 37% orthophosphorus etching gel for enamel and dentin (Latus, Ukraine), microapplicators (Latus, Ukraine), the fifth generation Prime&amp;Bond NT adhesive system (Dentsply Sirona, Germany), the universal microhybrid light-curing composite material Latelux (Latus, Ukraine) and the photopolymerizer LED.D (WOODPECKER, China) were used according to the manufacturer's instructions. The experimental animals were withdrawn from the experiment on the 15th day by decapitation under general anesthesia with sodium thiopental. The lower jaws were skeletonized, and dental blocks were cut out in the area of the molars. For histological examination, the dental blocks were fixed in a 10% solution of neutral formalin for two days, dehydrated in alcohols of increasing concentration and embedded in paraffin. Then, sections were made from the obtained preparations on a Shandon Finesse 325 rotary microtome with a section thickness of 4-6 μm. The histological sections were fixed on degreased slides and dried. Van Gieson staining was performed. The width of the periodontal gap was determined using the ZEISS ZEN 3.7 program by Carl Zeiss Microscopy.&#x0D; Results of the study. Histometric analysis has showed significant morphological changes in the experimental group of all age categories. In young rats, the fibrinoid edema phenomena of the periodontal ligament collagen fibers were observed. In mature rats, there was a picture of mucoid edema of collagen fibers of the periodontal ligament. In senile rats, fibrinoid necrosis of collagen fibers of the periodontal ligament were discovered, an inflammatory infiltrate, macrophages and neutrophils, with a predominance of neutrophilic inflammatory microenvironment, and initial hyaline tissue changes were found. In all age groups, there was cement resorption on the lateral surfaces of the tooth root, lacunar resorption of alveolar bone tissue and the presence of a large number of osteoclasts. In senile rats, hypercementosis was determined in the apical part of the root. In the control group of all age categories, neither resorption nor disorganization of connective tissue, nor hypercementosis was detected.&#x0D; Conclusions. The study shows that traumatic occlusion leads to resorption of root and alveolar cementum in all age groups. In young rats, traumatic occlusion causes fibrinoid edema of collagen fibers of the periodontal ligament. In mature rats, traumatic occlusion causes mucoid edema of collagen fibers of the periodontal ligament. In senile rats, traumatic occlusion causes fibrinoid necrosis of collagen fibers of the periodontal ligament, initial hyaline tissue changes and hypercementosis.

Pulpotomy for teeth with irreversible pulpitis in immature permanent teeth: a retrospective case series study

To evaluate the success of pulpotomy in treating immature permanent teeth with irreversible pulpitis. This case series included patients with irreversible pulpitis admitted to the Department of Oral Medicine at the author’s Hospital between 2015 and 2020. The pulpotomies were carried out by clinicians with > 5 years of working experience. The follow-up findings and radiographic images were reviewed by two attending dentists. This study included 49 teeth from 48 children (25 boys and 23 girls). The follow-up was 23.3 ± 6.8 months (from 12 to 40 months). The success rate of pulpotomy was 85.7% (42/49). Pulpotomy failed in seven teeth (14.3%). The treatment success rate for traumatic crown fracture was lower than for dental caries and dens evaginatus (P < 0.001). There were no significant differences in the success rate of the pulp-capping agent, tooth root developmental phase, and pulpotomy method (all P > 0.05). Pulpotomy might be successfully used to treat immature permanent teeth with irreversible pulpitis in young patients mainly caused by caries and a fractured tubercle of dens evaginatus.

Assessment of the root and canal morphology in the permanent dentition of Saudi Arabian population using cone beam computed and micro-computed tomography – a systematic review

IntroductionRoot canal treatment procedures require a thorough understanding of root and canal anatomy. The purpose of this systematic review was to examine the morphological differences of teeth root and their canals assessed using cone-beam computed and micro-computed tomography in Saudi Arabian population.MethodologyAn electronic search was conducted in PubMed / Medline, Scopus, Google Scholar, and Web of Science databases until January 2023 to retrieve related studies. “Root canal morphology,” “Saudi Arabia,” “Micro-CT,” and “cone-beam computed tomography” were used as keywords. A modified version of previously published risk of bias assessment tool was used to determine the quality assessment of included studies.ResultsThe literature search revealed 47 studies that matched the criteria for inclusion, out of which 44 studies used cone beam computed tomography (CBCT) and three were micro-computed tomography (micro-CT) studies. According to the modified version of risk of bias assessment tool, the studies were categorized as low, moderate, and high risk of bias. A total of 47,612 samples were included which comprised of either maxillary teeth (5,412), or mandibular teeth (20,572), and mixed teeth (21,327). 265 samples were used in micro-CT studies while 47,347 teeth samples were used in CBCT studies. Among the CBCT studies, except for three, all the studies were retrospective studies. Frequently used imaging machine and software were 3D Accuitomo 170 and Morita’s i-Dixel 3D imaging software respectively. Minimum and maximum voxel sizes were 75 and 300 μm, Vertucci’s classification was mostly used to classify the root canal morphology of the teeth. The included micro-CT studies were in-vitro studies where SkyScan 1172 X-ray scanner was the imaging machine with pixel size ranging between 13.4 and 27.4 μm. Vertucci, Ahmed et al. and Pomeranz et al. classifications were applied to classify the root canal morphology.ConclusionThis systematic review revealed wide variations in root and canal morphology of Saudi population using high resolution imaging techniques. Clinicians should be aware of the common and unusual root and canal anatomy before commencing root canal treatment. Future micro-CT studies are needed to provide additional qualitative and quantitative data presentations.

Further Interventions after Root Canal Treatment Are Most Common in Molars and Teeth Restored with Direct Restorations: A 10–11-Year Follow-Up of the Adult Swedish Population

IntroductionThe aims were to investigate 1) the frequency of nonsurgical retreatment, root-end surgery, extraction, and further restorative treatment during a follow-up of 10–11 years after root filling and compare the frequencies according to tooth group and type of coronal restoration and 2) the timing of nonsurgical retreatment, root-end surgery, and extraction. MethodsData were collected from the Swedish Social Insurance Agency's register. A search for treatment codes identified teeth root filled in 2009 and the type of coronal restoration (direct, indirect, and unspecified) registered within 6 months of root filling. The root-filled teeth were followed 10–11 years, and further interventions were recorded. Descriptive statistics and chi-square tests were used for statistical analysis. ResultsIn 2009, root fillings were registered for 215,611 individuals/teeth. Nonsurgical retreatment, root-end surgery, and extraction were undertaken in 3.5%, 1.4%, and 20% teeth, respectively. The frequency of further interventions varied with respect to tooth group and type of coronal restoration, but only slightly for endodontic retreatments. Further interventions, except for root-end surgery, were registered more often for molars and directly restored teeth (P < .001). The majority of endodontic retreatments were undertaken within 4 years, while extractions were evenly distributed over 10–11 years. ConclusionsThe frequency numbers of nonsurgical retreatment and root-end surgery were low, despite 1 in 5 root-filled teeth registered as extracted. Further interventions were most common in molars and directly restored teeth. Endodontic retreatments were performed more often during the first 4 years.

RADIOLOGICAL FEATURES OF THE LOCATION OF CYSTIC FORMATIONS IN THE MAXILLARY SINUS AND THEIR RELATIONSHIP WITH ALVEOLAR BONE PATHOLOGY OF THE UPPER JAW

The aim of the study. To study the features of the location of cystic formations in the maxillary sinus based on CT scans and to determine their relationship with the pathology of the upper jaw teeth.&#x0D; Materials and methods. The study involved the analysis of 552 head computed tomography scans of patients referred for examination by an otolaryngologist or dentist. The total number of individuals examined was 552, comprising 44.7% females and 55.3% males, aged 18-74 years. The investigation was conducted using the NewTom GO device with a measurement range of 155-172 mGy/cm±10%, with an error of ±4.24%. Statistical processing of data was carried out using the STATISTICA v.12.6 software.&#x0D; Results. Out of 552 computed tomography images analyzed, 92 images of individual maxillary sinuses (MS) of 79 patients with single cysts were selected. They were divided into two groups. Group 1 involved patients with cysts on the lower wall of MS (n=76). Group 2 included patients with cysts on other walls (n=16). The assessment of the ratio of 4, 5, 6, 7 tooth roots of the upper jaw to the lower wall of the upper jaw showed that the protrusion frequency in Group 1 was significantly higher (42.1%) compared to Group 2 (18.7%). Meanwhile, the average thickness of the bone over these teeth in Group 2 was significantly greater (3.4 ± 1.09 mm) than in Group 1 (1.9 ± 0.92 mm) (p=0.0003). In both patient groups, the greatest thickness was observed over tooth 4, and the smallest over tooth 7. Additionally, in 33.7% of cases, the cyst was associated with involvement of deep structures of the projecting teeth and the spread of inflammation to the lower wall of MS.&#x0D; Conclusions. Among patients referred by an otolaryngologist or dentist for CT examination to radiologically verify pathological processes in the nasal cavity, paranasal sinuses, and the upper jaw teeth, MS cysts were detected in 19.6% of cases, with 83% of them being localized in its lower parts. In patients with cysts located in the lower parts of MS, the roots protruding into the sinus cavity and a thinner layer of bone over them are more frequently observed compared to those where cysts are located in other areas of MS. In patients with cystic formations in the alveolar recess of MS, radiological signs of pathology of the upper jaw teeth are detected in 34% of cases.

A Wnt10a-Notch signaling axis controls Hertwig’s epithelial root sheath cell behaviors during root furcation patterning

Human with bi-allelic WNT10A mutations and epithelial Wnt10a knockout mice present enlarged pulp chamber and apical displacement of the root furcation of multi-rooted teeth, known as taurodontism; thus, indicating the critical role of Wnt10a in tooth root morphogenesis. However, the endogenous mechanism by which epithelial Wnt10a regulates Hertwig’s epithelial root sheath (HERS) cellular behaviors and contributes to root furcation patterning remains unclear. In this study, we found that HERS in the presumptive root furcating region failed to elongate at an appropriate horizontal level in K14-Cre;Wnt10afl/fl mice from post-natal day 0.5 (PN0.5) to PN4.5. EdU assays and immunofluorescent staining of cyclin D1 revealed significantly decreased proliferation activity of inner enamel epithelial (IEE) cells of HERS in K14-Cre;Wnt10afl/fl mice at PN2.5 and PN3.5. Immunofluorescent staining of E-Cadherin and acetyl-α-Tubulin demonstrated that the IEE cells of HERS tended to divide perpendicularly to the horizontal plane, which impaired the horizontal extension of HERS in the presumptive root furcating region of K14-Cre;Wnt10afl/fl mice. RNA-seq and immunofluorescence showed that the expressions of Jag1 and Notch2 were downregulated in IEE cells of HERS in K14-Cre;Wnt10afl/fl mice. Furthermore, after activation of Notch signaling in K14-Cre;Wnt10afl/fl molars by Notch2 adenovirus and kidney capsule grafts, the root furcation defect was partially rescued. Taken together, our study demonstrates that an epithelial Wnt10a-Notch signaling axis is crucial for modulating HERS cell proper proliferation and horizontal-oriented division during tooth root furcation morphogenesis.

Unilateral Impaction of Mandibular Canine in a Down Syndrome Patient: A Case Report

A 12-year-old female patient, with large nasal bridge, mongoloid slants, clinodactyly, saddle gap of toes, slanting palpebral fissures, and a flat facies with ocular hypertelorism was reported. The patient’s medical history showed intellectual impairment, hypothyroidism, and allergy to penicillin and cow milk. Intraoral examination revealed that there was severe crowding, with Angles class I Dewey’s modification type I. A radiographic examination showed that the root of tooth 44 has sharp dilaceration toward the mesial in the apical third. Impacted canines were measured approximately 17.5 mm from the cusp till root apex. Treatment plan included prescription for pain relief. Oral prophylaxis was followed by root canal treatment and full coverage restoration. Induced eruption was planned. This case report provides insight into various oral conditions associated with Down syndrome (DS). The treatment was challenging and it needed a comprehensive approach with a preventive dentistry practice and regular screening. Dental practitioners should be aware of DS and its effect on oral health with the main focus on an effective treatment plan.

Ventricular empyema in a dog diagnosed by magnetic resonance imaging and immediate postmortem cerebrospinal fluid culture

AbstractA 1‐year 5‐month‐old, female, neutered springer spaniel presented collapsed in extensor rigidity. The dog had undergone ovariectomy 6 weeks previously, and a tooth root abscess was documented 2 months before this. Neurological signs were first reported 24 days after surgery, starting with lethargy and tremors, which progressed to generalised tonic‐clonic cluster seizures with inter‐ictal neurological deficits by 33 days after surgery. Magnetic resonance imaging of the brain revealed a conspicuous fluid–fluid level in the lateral ventricles consistent with ventricular empyema. Treatment was declined in favour of euthanasia, but postmortem cerebrospinal fluid sample showed marked pleocytosis with elevated protein and cultured a heavy growth of Staphylococcus pseudintermedius. The magnetic resonance imaging findings and positive cerebrospinal fluid culture were consistent with bacterial meningoencephalitis. Aetiology in this case was unknown, but may have been secondary to haematogenous spread, which is a rare but potential sequel to abdominal surgery, or intracranial extension of an oral infection.