Comprehensive Analysis of Mandibular First Molar Root and Canal Morphology in Saudi Patients Using Cone Beam Computed Tomography (CBCT).

BACKGROUND The goal of conventional endodontic therapy is to clean the root canal system thoroughly, restore tooth function, and prevent re-infection. Success depends on understanding root canal morphology, resolving apical periodontitis, and using proper techniques. Studies highlight variations in root canal anatomy, with cone-beam computed tomography (CBCT) being crucial for accurate diagnosis despite its high cost and limited availability. MATERIAL AND METHODS This retrospective study reviewed CBCT images of 1820 (907 male, 913 female) patients aged 18 to 78 years. Analysis included 2081 mandibular first molars for variations in root and canal morphology and right- and left-side symmetry. Inter-orifice distance was measured, along with distance from the cementoenamel junction (CEJ) to the level of canal bifurcation. RESULTS In this study, 96.01% of teeth had 2 roots and 3.89% had 3 roots. The percentages of canal configuration were 77.70% for 3 canals, 21.58% for 4 canals, 0.67% for 2 canals, and 0.05% for 1 canal. The inter-orifice distance was 2.07 mm for 2 canals in 1 root and 2.86 mm for 2 canals in separate distal roots. Distance from the CEJ to canal bifurcation varied significantly between 2 canals within 1 distal root (3.35 mm), 2 canals in separate distal roots (1.60 mm), as well as between distal (3.35 mm) and mesial roots (1.10 mm). CONCLUSIONS In mandibular first molars, only 3.89% have additional distolingual roots. Sex and ethnicity showed no influence on number of roots and canals. Distal canals showed a deeper bifurcation and greater inter-orifice distance than did mesial canals.

Characterizing the Root Canal Configuration of Mandibular Incisors in a Western Saudi Arabian Sub-population Using Cone Beam Computed Tomography.

Aim This study aimed to explore the morphology and complexity of mandibular anterior teeth in a Western Saudi Arabian sub-population using cone beam computed tomography (CBCT). Methodology CBCT scans from 818 patients were evaluated, and 3193 mandibular anterior teeth were analyzed for the number of roots, canal, canal configurations, separation level, bilateral symmetry, and gender associations. Results The results showed that all examined central and lateral incisors had a single root, and the majority exhibited a single canal. The prevalence of two canals in mandibular central and lateral incisors was 20.1% and 23.2%, respectively, resulting in an overall prevalence of 21.7% for two root canals in mandibular anterior teeth. The separation level of the two canals was predominantly located in the middle third of the root. Type I canal configuration was the most common, followed by type III. A high degree of bilateral symmetry in the number of canals and canal configurations was noted. Conclusion The findings contribute to the understanding of root canal anatomy in the Saudi population and provide valuable information for endodontic treatment planning.

Outcomes of endodontic microsurgery using different calcium silicate-based retrograde filling materials: a cohort retrospective cone-beam computed tomographic analysis.

PURPOSE: To evaluate the outcomes of endodontic microsurgery (EMS) using mineral trioxide aggregate (MTA; Dentsply Sirona, Charlotte, NC, USA), EndoSequence root repair material (RRM putty; Brasseler, Savannah, GA), and injectable Bioceramic (BC) sealer (Brasseler USA) followed by the application of RRM putty (lid technique) as root-end filling materials. METHODS: One hundred and ten patients who underwent EMS between 2016 and 2020 at King Abdulaziz University Dental Hospital were recruited for clinical and radiographic follow-up after a minimum of 1 year. Radiographic assessment was performed using periapical radiographs (PAs) and cone-beam computed tomography (CBCT). Volumetric analysis of periapical radiolucencies (PARLs) was performed using Amira software. RESULTS: Seventy-nine patients (103 teeth: MTA group, n = 28; RRM putty, n = 41; lid technique, n = 34), attended the follow-up visit, with an average follow-up period of 24 months (recall rate = 74.5%). Of the 103 teeth, 40 were anteriors, 24 were premolars, and 39 were molars. All three groups of retrograde filling materials (MTA, RRM putty, and lid technique) showed high success rates on both PA (85.7, 85.4, 94.1%, respectively) and CBCT imaging (67.9, 75.6, 88.2%, respectively), without any significant difference among the success rates of different materials. Overall, a slight agreement was noted between the PA and CBCT outcomes, with a statistically significant difference (P = 0.029). None of the patient-, tooth-, or treatment-related factors significantly influenced the outcomes of EMS. Adequate density of root canal filling material was significantly associated with a high percentage of completely healed cases on CBCT (P = 0.044). PARL volumes were reduced significantly over 1-4 years follow-up after EMS (P < 0.001) CONCLUSIONS: EMS showed high success rates on both PA and CBCT when MTA, RRM putty or lid technique were used as retrograde filling materials. CBCT imaging is more precise than PA in detecting the healing outcomes of EMS.

Prevalence and Pattern of Idiopathic Osteosclerosis and Condensing Osteitis in a Saudi Subpopulation.

Background This study aims to investigate the prevalence and pattern of idiopathic osteosclerosis (IO) and condensing osteitis (CO) in the jaws of a Saudi Arabian subpopulation with regards to gender, age, shape, localization, and tooth relationship. Methodology Digital panoramic and periapical radiographs with clinical data of 1,000 patients at King Abdulaziz University Dental Hospital were analyzed to determine the incidence of IO and CO lesions in relation to age, gender, location in the jaws, and dental status of the associated tooth. Descriptive statistics and chi-square tests were used for data analysis. Results Out of the 752 patients (495 females, 257 males), IO was identified in 66 (8.8%) patients, while 44 (5.9%) patients had CO. IO occurred more in females (68.2%) than males (31.8%). CO had a statistically significant higher rate of occurrence in females (81.8%) than males (18.2%) (P ≤ 0.05). IO and CO lesions were observed to be higher in individuals in their third decade, and 100% were in the mandibular molar area. Almost half of the identified IO (48.5%) had a rounded shape radiopacity, while CO mostly appeared irregular (63.6%). Conclusions The prevalence of IO and CO in the studied Saudi subpopulation was low. Both lesions were more frequent in females in their third decade and were primarily found in the mandibular molar region.

Pulpal and periapical tissue response after direct pulp capping with endosequence root repair material and low-level laser application.

BACKGROUND: The study aims to investigate the pulp and periapical reaction and healing after capping with EndoSequence Root Repair Material (ERRM) combined with low-level laser application. METHODS: In 6 rabbits, pulps were exposed via class V, half of the samples received a low-level diode laser at 980 nm. Thereafter, cavities were capped with regular-set ERRM. The specimens were processed for histomorphological examination after 2 weeks and two months. RESULTS: After 2 weeks, images show mild inflammation and organized odontoblasts in lased group. The non-lased group shows more severe inflammation. The predentin thickness was thicker in the lased group with statistical significance (p < 0.05). After 2 months, inflammatory cells were sparse in both lased and non-lased groups. In the periapical area, group one showed dilated blood vessels and thick fibrous connective tissues. In group two, there were more numerous maturations of PDL fibers with scattered inflammatory cells and congested blood vessel. CONCLUSIONS: Using low-level laser therapy in combination with ERRM for pulp capping shortens the inflammatory phase and enhances healing.

The impact of vestibular schwannoma and its management on employment.

BACKGROUND: Employment is an important factor in quality of life. For vestibular schwannoma (VS) patients, employment is not self-evident, because of the sequelae of the disease or its treatment and their effects on daily life. OBJECTIVES: This study assessed employment status, sick leave (absenteeism) and being less productive at work (presenteeism) in the long-term follow-up of VS patients, and evaluated the impact of treatment strategy (active surveillance, surgery or radiotherapy). METHODS: A cross-sectional survey study was performed in a tertiary university hospital in the Netherlands. Patients completed the iMTA-post productivity questionnaire (iPCQ). Employment status was compared to that of the general Dutch population. Employment, absenteeism and presenteeism were compared between patients under active surveillance, patients after radiotherapy and post-surgical patients. RESULT: In total 239 patients participated, of which 67% were employed at the time of the study. Only 14% had a disability pension, which was comparable to the age-matched general Dutch population. The proportion of patients with absenteeism was 8%, resulting in a 4% reduction of working hours. Presenteeism was reported by 14% of patients, resulting in a 2% reduction of working hours. The median number of working hours per week was 36, and since the diagnosis, these hours had been reduced by 6%. There were no significant differences between treatment modalities. CONCLUSION: On average, long-term employment status and working hours of VS patients are comparable to the age-matched general population. Treatment strategies do not seem to differentially impact on long-term employment of VS patients.

Dietary obesity in mice is associated with lipid deposition and metabolic shifts in the lungs sharing features with the liver.

Obesity is associated with both chronic and acute respiratory illnesses, such as asthma, chronic obstructive pulmonary disease (COPD) or increased susceptibility to infectious diseases. Anatomical but also systemic and local metabolic alterations are proposed contributors to the pathophysiology of lung diseases in the context of obesity. To bring perspective to this discussion, we used NMR to compare the obesity-associated metabolomic profiles of the lung with those of the liver, heart, skeletal muscles, kidneys, brain and serum from male C57Bl/6J mice fed with a high-fat and high-sucrose (HFHSD) diet vs. standard (SD) chow for 14 weeks. Our results showed that the lung was the second most affected organ after the liver, and that the two organs shared reduced one-carbon (1C) metabolism and increased lipid accumulation. Altered 1C metabolism was found in all organs and in the serum, but serine levels were increased only in the lung of HFHSD compared to SD. Lastly, tricarboxylic acid (TCA)-derived metabolites were specifically and oppositely regulated in the serum and kidneys but not in other organs. Collectively, our data highlighted that HFHSD induced specific metabolic changes in all organs, the lung being the second most affected organ, the main alterations affecting metabolite concentrations of the 1C pathway and, to a minor extend, TCA. The absolute metabolite quantification performed in this study reveals some metabolic specificities affecting both the liver and the lung, that may reveal common metabolic determinants to the ongoing pathological process.

Patient-reported factors that influence the vestibular schwannoma treatment decision: a qualitative study.

PURPOSE: In cases of small- to medium-sized vestibular schwannomas, three management strategies can be opted for: active surveillance, surgery or radiotherapy. In these cases, the patient's preference is pivotal in decision-making. The aim of this study was to identify factors that influence a patient's decision for a particular management strategy. METHODS: A qualitative inductive thematic analysis was performed based on semi-structured interviews. Eighteen patients with small- to medium-sized vestibular schwannomas were interviewed. All patients were diagnosed or treated at one of the two participating university medical centers in the Netherlands. RESULTS: Ten themes were identified that influenced the decision, classified as either medical or patient-related. The medical themes that emerged were: tumor characteristics, the physician's recommendation, treatment outcomes and the perceived center's experience. The patient-related themes were: personal characteristics, anxiety, experiences, cognitions, logistics and trust in the physician. CONCLUSION: Knowledge of the factors that influence decision-making helps physicians to tailor their consultations to arrive at a true shared decision on vestibular schwannoma management.

Universal Design for Learning and Differentiated Instruction in Physical Education.

The aim of this case study was to describe the distinct approaches used by physical education (PE) teachers to accommodate students with disabilities in New York elementary school PE classes. The participants included 1 adapted PE specialist, 5 PE teachers, and 5 elementary school students with various impairments. Through thematic analysis, observations and interviews revealed 3 main approaches: (a) normalized instruction-traditional curriculum with no differentiation in the program; (b) differentiated instruction-adaptations tailored specifically to the needs of each student with disability; and (c) universally designed instruction based on the principles of Universal Design for Learning (UDL) and accessibility to all students. Differentiated instruction, entailing modifications in the program and pedagogical accommodations, was the most prevalent approach at the research site, but lessons based on UDL principles were also observed. In association, the 2 approaches (differentiated instruction and UDL) represented significant resources to accommodate students with disabilities in PE.

M-CSF and IL-34 expression as indicators for growth in sporadic vestibular schwannoma.

Macrophage colony stimulating factor and IL-34 are associated with clinical vestibular schwannoma progression. Investigating the biology behind vestibular schwannoma progression helps understanding tumor growth. Inflammation is important in the microenvironment of neoplasms. Macrophages are major players in the intratumoral infiltrate. These tumor-associated macrophages are known to stimulate angiogenesis and cell growth. M-CSF and IL-34 are cytokines that can regulate tumor-infiltrating macrophages. They are expressed by tumors and form potential targets for therapy. The goal of this study was to investigate these cytokines in vestibular schwannomas and to see if their expression is related to angiogenesis, macrophage numbers, cystic degeneration, and volumetric tumor progression. Immunohistochemical expression of M-CSF and IL-34 was analyzed in ten fast-growing vestibular schwannomas and in ten slow-growing vestibular schwannomas. Expression M-CSF and IL-34 were compared between fast- versus slow-growing and cystic versus non-cystic tumors. Data on macrophage numbers and microvessel density, known from earlier research, was also included. All tumors expressed M-CSF and its expression was higher in fast-growing tumors (p = 0.003) and in cystic tumors (p = 0.035). CD163 expression was higher in tumors with strong M-CSF expression (p = 0.003). All tumors expressed IL-34 as well, but no significant differences were found in relation to clinicopathological characteristics. This study demonstrated the expression of M-CSF and IL-34 in vestibular schwannomas. The results suggest that M-CSF is related to macrophage activity and tumor progression, making it a potential target for therapy. If a similar assumption can be made for IL-34 remains unclear.

Perfusion magnetic resonance imaging provides additional information as compared to anatomical imaging for decision-making in vestibular schwannoma.

OBJECTIVE: The added value of perfusion MRI for decision-making in vestibular schwannoma (VS) patients is unknown. MRI offers two perfusion methods: the first employing contrast agent (dynamic susceptibility contrast (DSC)-MRI) that provides information on cerebral blood volume (CBV) and cerebral blood flow (CBF), the second by magnetic labeling of blood (arterial spin labeling (ASL)-MRI), providing CBF-images. The goal of the current study is to investigate whether DSC and ASL perfusion MRI provides complimentary information to current anatomical imaging in treatment selection process of VS. METHODS: Nine patients with growing VS with extrameatal diameter >9 mm were included (>2 mm/year and 20% volume expansion/year) and one patient with 23 mm extrameatal VS without growth. DSC and ASL perfusion MRI were obtained on 3 T MRI. Perfusion in VS was scored as hyperintense, hypointense or isointense compared to the contralateral region. RESULTS: Seven patients showed hyperintense signal on DSC and ASL sequences. Three patients showed iso- or hypointense signal on at least one perfusion map (1 patient hypointense on both DSC-MRI and ASL; 1 patient isointense on DSC-CBF; 1 patient isointense on ASL). All patients showed enhancement on post-contrast T1 anatomical scan. CONCLUSION: Perfusion MR provides additional information compared to anatomical imaging for decision-making in VS.

Measurement of head and neck paragangliomas: is volumetric analysis worth the effort? A method comparison study.

OBJECTIVES: The aim of this study was to assess the reproducibility of different measurement methods and define the most workable technique for measuring head and neck paragangliomas, to determine the best method for evaluating tumour growth. The evaluation of tumour growth is vital for a 'wait-and-scan' policy, a management strategy that became increasingly important. STUDY DESIGN: Method comparison study. SETTING AND PARTICIPANTS: Thirty tumours, including carotid body, vagal body, jugulotympanic tumours and conglomerates of multiple tumours, were measured in duplicate, using linear dimensions, manual area tracing and an automated segmentation method. MAIN OUTCOME MEASURES: Reproducibility was assessed using the Bland-Altman method. RESULTS: The smallest detectable difference using the linear dimension method was 11% for carotid body and 27% for vagal body tumours, compared with 17% and 20% for the manual area tracing method. Due to the irregular shape of paragangliomas in the temporal bone and conglomerates, the manual area tracing method showed better results in these tumours (26% and 8% versus 54% and 47%). The linear dimension method was significantly faster (median 4.27 versus 18.46 minutes, P < 0.001). The automatic segmentation method yielded smallest detectable differences between 39% and 75%, and although fast (2.19 ± 1.49 minutes), it failed technically. CONCLUSIONS: Due to a relatively good reproducibility, fast and easy application, we found the linear dimension method to be the most pragmatic approach for evaluation of growth of carotid and vagal body paragangliomas. For jugulotympanic tumours, the preferred method is manual area tracing. However, volumetric changes of these tumours may be of less clinical importance than changes in relation to surrounding anatomical structures.

Dynamic properties of force fields.

Molecular-dynamics simulations are increasingly used to study dynamic properties of biological systems. With this development, the ability of force fields to successfully predict relaxation timescales and the associated conformational exchange processes moves into focus. We assess to what extent the dynamic properties of model peptides (Ac-A-NHMe, Ac-V-NHMe, AVAVA, A10) differ when simulated with different force fields (AMBER ff99SB-ILDN, AMBER ff03, OPLS-AA/L, CHARMM27, and GROMOS43a1). The dynamic properties are extracted using Markov state models. For single-residue models (Ac-A-NHMe, Ac-V-NHMe), the slow conformational exchange processes are similar in all force fields, but the associated relaxation timescales differ by up to an order of magnitude. For the peptide systems, not only the relaxation timescales, but also the conformational exchange processes differ considerably across force fields. This finding calls the significance of dynamic interpretations of molecular-dynamics simulations into question.

The humeral origin of the brachioradialis muscle: an unusual site of high radial nerve compression.

Radial nerve compression is seldom encountered in the upper arm, and most commonly described compression syndromes have their anatomical cause in the forearm. The teres major, the triceps muscle, the intermuscular septum region and the space between the brachialis and brachioradialis muscles have all been identified as radial nerve compression sites above the elbow. We describe the case of a 38-year-old male patient who presented with dorso-lateral forearm pain and paraesthesias without neurological deficit. Surgical exploration revealed radial nerve compression at the humeral origin of the brachioradialis muscle. Liberation of the nerve at this site was successful at relieving the symptoms. To our knowledge, this compression site has not been described in the literature.

Release of hand burn contracture: comparing the ALT perforator flap with the gracilis free flap with split skin graft.

BACKGROUND: The use of microsurgery in the management of burn sequelae is not a new idea. According to the properties of various types of free flaps different goals can be achieved or various additional procedures have to be combined. We report the comparison of two different free flaps on a single patient for reconstruction of both upper extremities for burn sequelae. CASE REPORT: A 1-year-old child sustained severe burns on both hands, arms and thorax and was initially only treated conservatively. This resulted in severe contractures. At the age of 4-years a free gracilis flap was selected for reconstruction of his left hand and a free anterolateral thigh flap for the right hand. RESULTS: We noticed a better functional and esthetic result for the gracilis flap associated with a shorter operative time and a minor donor site morbidity. The intraoperative technique and time, postoperative complications, functional and esthetic results and donor site morbidities were studied in the two types of flaps chosen. A review of literature was also performed. CONCLUSION: Our experience reported a better success of the gracilis muscle flap covered with a split skin graft compared to the anterolateral thigh flap in the reconstruction of hand function after severe burn sequelae.

High prevalence of founder mutations of the succinate dehydrogenase genes in the Netherlands.

Mutations in four genes encoding subunits or cofactors of succinate dehydrogenase (SDH) cause hereditary paraganglioma and pheochromocytoma syndromes. Mutations in SDHB and SDHD are generally the most common, whereas mutations in SDHC and SDHAF2 are far less frequently observed. A total of 1045 DNA samples from Dutch paraganglioma and pheochromocytoma patients and their relatives were analyzed for mutations of SDHB, SDHC, SDHD or SDHAF2. Mutations in these genes were identified in 690 cases, 239 of which were index cases. The vast majority of mutation carriers had a mutation in SDHD (87.1%). The second most commonly affected gene was SDHAF2 (6.7%). Mutations in SDHB were found in only 5.9% of samples, whereas SDHC mutations were found in 0.3% of samples. Remarkably, 69.1% of all carriers of a mutation in an SDH gene in the Netherlands can be attributed to a single founder mutation in SDHD, c.274G>T and p.Asp92Tyr. Moreover, 88.8% of all SDH mutation carriers carry one of just six Dutch founder mutations in SDHB, SDHD and SDHAF2. The dominance of SDHD mutations is unique to the Netherlands, contrasting with the higher prevalence of SDHB mutations found elsewhere. In addition, we found that most SDH mutation-related paragangliomas-pheochromocytomas in the Netherlands can be explained by only six founder mutations in SDHAF2, SDHB and SDHD. The findings underline the regional differences in the SDH mutation spectrum, differences that should be taken into account in the development of effective screening protocols. The results show the crucial role that demographic factors play in the frequency of gene mutations.

Positive regulation of the Vibrio cholerae porin OmpT by iron and fur.

The transcription factor Fur regulates the expression of a number of genes in Vibrio cholerae in response to changes in the level of available iron. Fur usually acts as a repressor, but here we show that Fur positively regulates the expression of ompT, which encodes a major outer membrane porin. OmpT levels increased when the bacteria were grown in medium containing relatively high levels of iron, and this effect required Fur. The level of ompT mRNA also is increased in the presence of iron and Fur. The effect of iron on OmpT levels was independent of the known ompT regulators ToxR and Crp, and it did not require RyhB, which has been shown to be responsible for positive regulation by iron of some V. cholerae genes. Electrophoretic mobility shift assays showed that Fur binds upstream of the ompT transcription start site in a region overlapping known binding sites for ToxR and Crp. These data suggest that Fur and iron positively regulate ompT expression through the direct binding of Fur to the ompT promoter.

Mutations in SDHD are the major determinants of the clinical characteristics of Dutch head and neck paraganglioma patients.

OBJECTIVE: Head and neck paragangliomas (HNPGL) are associated with mutations in genes encoding subunits of succinate dehydrogenase (SDH). The aim of this study was to evaluate SDH mutations, family history and phenotypes of patients with HNPGL in the Netherlands. DESIGN: We evaluated the clinical data and the mutation status of 236 patients referred between 1950 and 2009 to Leiden University Medical Center. RESULTS: The large majority of the patients carried mutations in SDHD (83%), and the p.Asp92Tyr Dutch founder mutation in SDHD alone accounted for 72% of all patients with HNPGL. A mutation in SDHAF2 was found in 4%, mutations in SDHB in 3% and a mutation in SDHC was identified in a single patient (0·4%). Over 80% of patients presented with positive family history, of whom 99·5% carried a mutation in an SDH gene. SDH mutations were also found in 56% of isolated patients, chiefly in SDHD (46%), but also in SDHB (8%) and SDHC (2%). The clinical parameters of these different subgroups are discussed: including the age at diagnosis, associated pheochromocytomas, tumour multifocality and malignancy rate. CONCLUSION: The majority of Dutch patients with HNPGL present with a positive family history, in contrast to other European countries. The clinical characteristics of patients with HNPGL are chiefly determined by founder mutations in SDHD, the major causative gene in both familial and isolated patients with HNPGL. The high frequency of founder mutations in SDHD suggests a higher absolute prevalence of paraganglioma syndrome in the Netherlands.