Examination of sinus tympani, subtympanic sinus, and facial sinus with MicroCT.

This study aimed to determine sinus tympani, subtympanic sinus (STS), facial sinus (FS) morphologies, and type distributions. Type distributions were based on their relations with the facial nerve (FN). A total of 20 right and 20 left temporal dry bones without physical deformation were scanned with a MicroCT device. All measurements were made using MicroCT programs from sections in the axial plane. For the FS, the average depth was measured as 3.485 mm without any classification, and 29 of the 40 bones had Type C radiological morphology. The mean depth for all sinus tympanicus was 2.646 mm, and 22 of the 40 bones had Type B morphology. For the STS, 29 out of 40 samples had no contact with the FN; regardless of the classification, the average depth was measured as 2.376 mm. We reveal the depths of the tympanic cavities and their relationship with the FN. The results of this study may benefit clinicians performing retrotympanum surgeries.

Thought, attitudes, and practices of the anatomy departments on receiving and embalming cadavers during the pandemic process / Pensamiento, actitudes y prácticas de los departamentos de anatomía sobre la recepción y embalsamamiento de cadáveres durante el proceso pandémico

SUMMARY: During the Covid-19 pandemic that has marked the last years, while governments tried to control the spread of the virus, many-body donation programs were suspended due to difficulties that could potentially be encountered. Given the low body donation acceptance rates during this period, through this study we aimed to evaluate academics' knowledge, attitudes, and behaviors in cadaver acceptance and embalming practices during the pandemic. The research population of th estudy consisted of the faculty of 112 universities in Turkey who taught in under graduate and graduate programs in the Anatomy Department in 2020. An electronic questionnaire of 24 items, including demographic data, was distributed to the participants' official e-mail addresses. In addition, support was received from the Turkish Anatomy and Clinical Anatomy Society, whose members were also approached through their official group e-mail accounts. Answers were collected from 78 (39 %) out of 200 academics. The findings of the study were under 5 headings (ınformation about cadaver donation and ımported cadavers, attitude towards ımportation of cadavers and acceptance of body donations, precautions against contagion in ımportation of cadavers and acceptance of body donations and thoughts on their adequacy, considerations for adoption of cadavers for post-graduation education, advice on avoiding contagion in cadaver embalming) were collected and analyzed. The study high lights the importance of cadaver acceptance and embalming practices for medical education to minimally continue in the post-pandemic period. It can also serve as a reference for being cautious when faced with similar situations in the future.

RESUMEN: Durante la pandemia de COVID-19, que ha marcado los últimos años, mientras los gobiernos intentaban controlar la propagación del virus, muchos programas de donación de cuerpos fueron suspendidos por las dificultades que se podían encontrar. Dadas las bajas tasas de aceptación de la donación de cuerpos durante este período, a través de este estudio buscamos evaluar el conocimiento, las actitudes y los comportamientos de los académicos en la aceptación de cadáveres y las prácticas de embalsamamiento durante la pandemia. El estudio se realizó el año 2020 en los programas de pregrado y posgrado de los Departamentos de Anatomía de 112 universidades de Turquía. Se distribuyó un cuestionario electrónico de 24 ítems, incluidos datos demográficos, a los participantes por correo electrónico oficial. Además, se recibió el apoyo de la Sociedad Turca de Anatomía y Anatomía Clínica, cuyos miembros también fueron contactados a través de las cuentas de correo electrónico de su grupo oficial. Se recopilaron respuestas de 78 (39 %) de 200 académicos. Los hallazgos del estudio se ubicaron en 5 encabezados (información sobre donación de cadáveres y cadáveres importados, actitud hacia la importación de cadáveres y aceptación de donaciones de cuerpos, precauciones contra el contagio en la importación de cadáveres y aceptación de donaciones de cuerpos y opiniones sobre su idoneidad, consideraciones para la adopción de cadáveres para la educación de posgrado y consejos para evitar el contagio en el embalsamamiento de cadáveres). El estudio destaca la importancia de la aceptación de cadáveres y las prácticas de embalsamamiento para que la educación médica continúe mínimamente en el período posterior a la pandemia. También puede servir como referencia para tenerse presente ante situaciones similares en el futuro.

Micro-computed tomography assessment of triple antibiotic paste removal using different irrigation methods.

Purpose: The study aimed to compare four irrigation methods for triple antibiotic paste (TAP) removal using micro-computed tomography (micro-CT) analysis. Materials and methods: Forty bovine central incisor teeth were selected, and the root canals were prepared up to #6 Peeso reamer drills. Equal portions of metronidazole, ciprofloxacin, and minocycline were used for the TAP preparation. The TAP was prepared by mixing the powder with distilled water (with a powder to liquid ratio of 1 mg/1 mL). The TAP was introduced to the canals with a lentulo spiral; then, the access cavities were temporarily sealed. After 21 days of storage, the teeth were randomly divided into four equal groups according to irrigation techniques: open-ended, side-vented, double side-vented needle irrigations and EndoActivator irrigation device. The TAP was removed using 17% EDTA (20 mL) and distilled water (5 mL) for all of the groups. The volume of the intracanal medicament before and after the irrigation procedure was recorded by scanning the samples with micro-CT, and the TAP percentage was calculated. The percentages obtained from each group were compared using ANOVA. The significance level was set at p<0.05. Results: The results showed that there was no statistically significant difference among the TAP percentage volumes removed by the different irrigation techniques. Conclusion: The irrigation techniques used in this study showed similar TAP removal efficiency, however, they could not completely remove the TAP from the root canal systems.

Can Lateral Offset Be Used as a Predictive Marker for Proximal Femur Disorders?

Purpose: When the lateral offset (LO) changes, the forces acting on the head and neck of the femur change. Increase or decrease in LO can cause instability and possible dislocation of the implant. In addition, when the offset is reduced, more force is needed to balance the pelvis by the abductor muscles, and the force that occurs along the hip joint increases and causes wear and tear. In this study we aimed to investigate whether there is a correlation between LO and proximal femur morphology, and according to the results we aimed to investigate whether the LO can be used as a predictive marker for the risk of femoral neck fractures, osteoarthritis or femoroacetabular impingement. Methods: Femur length, femur neck length, femoral neck-shaft angle (NSA), anteroposterior (a-p) and superoinferior (s-i) diameters of femoral head and neck, and LO were measured on 82 dry adult femora of unknown age and gender from Turkish population. Results: There was no statistically significant correlation between the LO and a-p and s-i diameters of femoral head or neck. However, there was found statistically significant correlation between LO and femoral NSA (p < 0.01), femoral neck length (p < 0.05) and femur length (p < 0.01). Conclusion: High LO values can be used as an indicator for neck fractures, a negative marker for OA, but LO does not appear to be used as an indicator for FAI.

Examination of inner ear structures: a micro-CT study.

BACKGROUND: We investigated the inner ear anatomy accurately in detail by microcomputed tomography (micro-CT) to contribute to the data related to the inner ear anatomy and the potential clinical contribution of these data in the treatment of the inner ear's pathologies. AIMS/OBJECTIVES: This study aimed to define a range for normal measurements of the VA, vestibule, lateral semicircular canal, and cochlea. We scanned temporal dry bone samples at high resolution using micro-CT. MATERIAL AND METHODS: Forty dry temporal bones used in anatomy student education were included in this study with a micro-CT device. All measurements were made on sections in the axial plane with micro-CT programs. RESULTS: The operculum and the vestibular aqueduct middle diameters median values were 0.487 mm and 0.294 mm, respectively. The median value of middle diameters for the nonampullated section of lateral semicircular canal was 1.103 mm. The mean height of the cochlea was 3.417 mm and the width of the cochlea was 5.615 mm. The mean length of the vestibule was 6.085 mm and the width of the vestibule was 3.002 mm. CONCLUSIONS AND SIGNIFICANCE: We present a database that clinicians can consider in their studies by creating normal anatomical values measured with high precision for the bone labyrinth.

The retreatment abilities of ProTaper Next and F6 Skytaper: a micro-computed tomography study.

PURPOSE: The aim of this study was to evaluate the retreatment abilities of the ProTaper Next (PTN) and F6 SkyTaper (F6) systems by using micro-computed tomography (microct), radiographic and microscopic imaging techniques. MATERIALS AND METHODS: The root canals of twenty-six extracted mandibular premolar teeth were prepared and obturated. For the retreatment procedure, the teeth were randomly divided into two equal groups according to endodontic instruments: PTN (X4) and F6 (#40/.06). Pre- and post-operative filling material volumes were measured with micro-ct, and areas were measured with radiographic and microscopic imaging techniques. The percentages of residual material were calculated, and then statistically compared. The significance level was set at p<0.05. RESULTS: There was no statistically significant difference between F6 and PTN for retreatment efficacy in the micro-ct and radiographic imaging techniques (p>0.05). PTN demonstrated better cleaning ability when evaluated by microscopic imaging. (p<0.05). The correlation was moderate between micro-ct and radiographic, and micro-ct and microscopic imaging groups; however, it was strong between radiographic and microscopic imaging methods. CONCLUSION: The PTN and F6 files had similar effects in the removal of filling material with microct evaluation. The radiographic imaging method gave similar results with micro-ct imaging.

Investigation of the effect of ghrelin on bone fracture healing in rats.

Ghrelin is known to have effects on proliferation and differentiation of osteoblasts and improvement of bone mineral density in rats. However, no experimental research on ghrelin's effects on fracture healing has been reported. In this context, the effect of ghrelin on the union of femoral shaft fractures was examined in this study by evaluating whether ghrelin will directly contribute to fracture healing. Forty male Wistar-Albino rats were divided into two groups as control and experimental (ghrelin treated) and standard closed shaft fractures were created in the left femurs of all rats. Daily ghrelin injections were applied to the experimental groups and equal numbers of rats were killed after 14 and 28 days following fracture formation. Tissue samples were examined with radiological, biomechanical, biochemical and histological analyses. Densitometry study showed that bone mineral density was improved after 28 days of ghrelin treatment compared to control. On histological examination, at the end of the 14 and 28 days of recovery, significant union was observed in the ghrelin-treated group. The ghrelin-treated group had higher breaking strength and stiffness at the end of 28 days of recovery. Biochemically, ALP levels were found to be higher in the ghrelin-treated group at the end of 28 days of recovery. Results showed that ghrelin directly contributes to fracture healing and it is promising to consider the effect of ghrelin on fracture healing in human studies with pharmacological applications.

Filling quality of several obturation techniques in the presence of apically separated instruments: A Micro-CT study.

Separated root canal instruments may affect the quality of root canal obturation and hence the survival of endodontically treated teeth. Obturation techniques may influence filling-quality. The aim was to evaluate the obturation quality of teeth filled with different obturation techniques in the presence of apically separated instruments using micro-computed tomography (µ-CT). Notched ProTaper F2 rotary-files were separated in the apical third of 36-human mandibular incisors with single root/canal and mature apex. Samples were filled by an endodontist according to one of the following obturation techniques (n = 12): cold lateral-compaction (CLC), single-cone (SC) and thermoplastic injection (TI). Samples were scanned by the Skyscan 1,274® µ-CT device after 1-week at 37°C in 100% humidity. Images of the sections were evaluated with CTan software in terms of total-volume and volume percentage of the filling materials and voids between coronal end of the separated instrument and gutta-percha/sealer filled void-free sections. Data was analyzed using Kruskal-Wallis and Mann Whitney-U tests with a significance level of 5%. Kruskal-Wallis revealed differences among groups (p < 0.05).Pairwise comparisons revealed that less volume of voids were measured in SC (0.02 ± 0.03 mm3 ) compared to CLC (0.15 ± 0.16 mm3 ) and TI (0.18 ± 0.24 mm3 ) (p < 0.05); while TI was statistically similar with CLC (p > 0.05). Percentages of volumes of voids and filling materials were as follows for SC, CLC and TI, respectively: 8.88 ± 18.52% and 24.45 ± 38.40%, 46.92 ± 33.53% and 53.07 ± 33.53%, 40.54 ± 33.85% and 42.79 ± 34.45%. The obturation technique may have a significant impact on the volume of voids in the presence of a separated file. No obturation technique produced a void-free root canal filling.

Microcomputed Assessment of Transportation, Centering Ratio, Canal Area, and Volume Increase after Single-file Rotary and Reciprocating Glide Path Instrumentation in Curved Root Canals: A Laboratory Study.

INTRODUCTION: The aim of this study was to compare the transportation and centering abilities of the ProGlider (PG; Dentsply-Sirona, Ballaigues, Switzerland), WaveOne Gold Glider (WOGG; Dentsply-Sirona), and R-Pilot (RP; VDW, Munich, Germany) file systems and the changes in the structure model index (SMI), surface area, and root canal volume (after creating the glide path in the mandibular first molar teeth's mesial canals with moderate curvature) using the micro-computed tomographic (micro-CT) method. METHODS: In the present study, 24 mandibular first molar teeth with 2 separate mesial canals and moderate (10°-20°) curvature were used. After scanning with micro-CT imaging before the procedure, the teeth were divided into 3 groups, PG, WOGG, and RP (n = 10/each group), followed by the glide path procedure. After the root canal preparation, changes in the root canals regarding the volume, surface area, SMI, transportation made by the files, and the change of their centering ability in the apical, middle, and coronal third were analyzed by micro-CT imaging. The data were statistically evaluated using 1-way analysis of variance and the Kruskal-Wallis test with a significance level set at 5% (P < .05). RESULTS: The WOGG and RP file systems showed better centering abilities at all thirds compared with the PG file system (P < .05). No significant difference was found in the apical third between the groups in terms of canal transportation degree (P > .05). However, in the WOGG and RP groups, less transportation was observed in the middle and coronal thirds compared with the PG group (P < .05). When the SMI changed, after the root canal preparation was compared, no significant differences were found between the groups (P > .05). Nevertheless, the changes in volume and surface area of the root canal in the WOGG and RP groups were significantly lower than in the PG group (P < .05). CONCLUSIONS: The WOGG and RP file systems caused similar levels of change in the root canal systems based on all parameters. Moreover, it was determined that the PG file system caused a significantly higher volume and surface area increase than the WOGG and RP file systems.

Evaluation of XP-endo Shaper, Reciproc Blue, and ProTaper Universal NiTi Systems on Dentinal Microcrack Formation Using Micro-Computed Tomography.

INTRODUCTION: The purpose of the present study was to evaluate the frequency of dentinal microcracks observed after root canal preparation with XP-endo Shaper (XP), Reciproc Blue (RB), and ProTaper Universal (PTU) instruments using micro-computed tomographic (µCT) analysis. METHODS: Thirty extracted mandibular first and second molars with mesial roots having 2 separate canals with an angle between 10°and 20° were randomly assigned to 3 experimental groups (n = 10) according to the different nickel-titanium systems used for root canal preparation: XP, RB, and PTU. The specimens were scanned using µCT imaging before and after root canal preparation. Then, preoperative and postoperative cross-sectional images of the teeth were evaluated to identify the presence of dentinal defects. For each group, the number of microcracks was determined as a percentage rate. The McNemar test was used to determine significant differences before and after instrumentation. The level of significance was set at P ≤ .05. RESULTS: No new dentinal microcracks were observed in the XP and RB groups. The PTU system significantly increased the percentage rate of microcracks compared with preoperative specimens (P < .05). CONCLUSIONS: Root canal preparations with XP and RB systems might not induce the formation of new dentinal microcracks on the mesial roots of mandibular molars. Further assessments are suggested for the examination of the morphology of microcracks after the use of these instruments.

Evaluation of maxillary trabecular microstructure as an indicator of implant stability by using 2 cone beam computed tomography systems and micro-computed tomography.

OBJECTIVE: The aim of this study was to assess the trabecular microarchitecture of the maxilla by using cone beam computed tomography (CBCT) and micro-computed tomography (micro-CT) ex vivo. STUDY DESIGN: Seventeen maxillary cadaver specimens were scanned by using micro-CT and CBCT devices. Samples were scanned with 2 CBCT devices at different voxel sizes (0.08, 0.125, and 0.160 mm for 3-D Accuitomo 170; 0.75 and 0.200 mm for Planmeca Promax 3-D Max). Morphometric parameters, such as bone volume/total volume (BV/TV) ratio, trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular number (Tb.N), and degree of anisotropy (DA) were assessed by using CTAnalyzer software. Bland-Altman limits of agreement and intraclass correlation coefficient (ICC) were performed to evaluate agreement between CBCT and micro-CT in consideration of measured morphometric parameters. Statistical significance was set at P < .05. RESULTS: The BV/TV, Tb.Th, Tb.Sp, and DA values were higher for CBCT images compared with micro-CT images, whereas the Tb.N value was lower with CBCT images than with micro-CT images. The BV/TV and DA parameters showed the highest agreement between CBCT and micro-CT devices (ICC = 0.421 for BV/TV and ICC = 0.439 for DA; P < .01). CONCLUSIONS: The BV/TV and DA parameters measured on CBCT obtained at the smallest voxel size were found to be useful for the assessment of maxillary trabecular microstructure.

Evaluation of 3 Different Retreatment Techniques in Maxillary Molar Teeth by Using Micro-computed Tomography.

INTRODUCTION: Nonsurgical retreatment procedure involves the complete removal of the previous filling material to allow thorough instrumentation, disinfection, and refilling of root canal system. We aimed to determine the residuals of the root-filling material by using 3 different retreatment techniques with the aid of micro-computed tomography. METHODS: Thirty extracted human maxillary molar teeth were included. All root canals were also obturated with F2 ProTaper single cones and AH Plus sealer. The following retreatment techniques were performed: group 1, ProTaper retreatment files; group 2, Mtwo retreatment files; and group 3, ProFile files. For the assessment of residual filling material, preoperative and postoperative micro-computed tomography scans were compared with each other, and the working time was recorded. One-way analysis of variance was used to analyze the differences between the groups. The significance level was set at P < .05. RESULTS: None of the retreatment techniques were capable of removing the whole filling material. The percentages of the residual filling materials for groups 1, 2, and 3 were 34.45, 45.43, and 23.63, respectively. There was a statistically significant difference between groups 2 and 3 (P < .05). ProTaper and ProFile instruments required less time for the removal of filling materials when compared with Mtwo instrument. CONCLUSIONS: ProFile files revealed the best results for endodontic retreatment in terms of both removing capacity and time requirement.

Micro-computed Tomographic Evaluation of Dentinal Microcrack Formation after Using New Heat-treated Nickel-titanium Systems.

INTRODUCTION: The aim of the present study was to evaluate the frequency of dentinal microcracks observed after root canal preparation with HyFlex CM (Coltène/Whaledent, Altstätten, Switzerland), HyFlex EDM (Coltène/Whaledent), Vortex Blue (Dentsply Tulsa Dental Specialties, Tulsa, OK), and TRUShape (Dentsply Tulsa Dental Specialties) systems using micro-computed tomographic (micro-CT) analysis. METHODS: Forty human mandibular incisors with 1 and straight root canals were randomly assigned to 4 experimental groups (n = 10) and 1 control group for root canal preparation: group 1, HyFlex CM; group 2, HyFlex EDM; group 3, Vortex Blue; and group 4, TRUShape. The specimens were scanned using high-resolution micro-CT imaging before and after root canal preparation. Afterward, preoperative and postoperative cross-sectional images of the teeth were screened to identify the presence of dentinal defects. The number of microcracks was determined as a percentage for each group. RESULTS: Before and after canal preparation, 36,152 cross-sectional images were examined. Four thousand four hundred fifty-two (12.31%) dentinal defects were observed. No new microcracks were observed after root canal instrumentation with the tested systems. CONCLUSIONS: Root canal preparation with the HyFlex CM, HyFlex EDM, Vortex Blue, and TRUShape systems did not induce the formation of new dentinal microcracks on straight root canals of mandibular incisors.