Microtomographic Evaluation of Canal Centralization and Dentine Removal after Canal Preparation with Two Rotary Systems: HyFlex EDM and ProTaper Next

Objective This study compared the ProTaper Next (PTN; Dentsply Sirona, Tulsa, Oklahoma, United States) and HyFlex EDM (HEDM; Coltene/Whaledent AG, Alstätten, Switzerland) systems using micro–computed tomography (CT). Materials and Methods Twenty-one mesial roots classified as Vertucci's type IV from extracted mandibular first molars with curvatures between 20 and 40 degrees were selected. The teeth were scanned using a micro-CT before and after root canal preparation by both systems, applied to the same root, in alternating canals. The following parameters were analyzed: canal centering, apical transportation, root canal diameter/root diameter. Results No statistically significant differences between both systems were observed for any of the assessed morphological parameters (p > 0.05). All canals presented diameter enlargement of more than 40% in relation to root diameter in the cervical and middle segments. No statistically significant difference was noted between the HEDM and PTN groups. The wear percentage for the HEDM group in the cervical and middle thirds were 49.66 ± 8.65 and 46.48 ± 14.29, respectively, and 51.02 ± 11.81 and 45.48 ± 10.79 for the PTN group, respectively. Conclusion Both systems displayed similar mandibular molar mesial canals preparation, with no differences noted for any of the assessed parameters. Both groups showed increased canal diameter in the cervical and middle thirds by more than 40%.

Plasticity of the bony carotid canal and its clinical use for assessing negative remodeling of the internal carotid artery

Background and objective It has long been believed that the bony carotid canal has no plasticity and that a small canal represents a hypoplastic internal carotid artery. We aimed to show whether the carotid canal can narrow according to morphological changes in the internal carotid artery. Materials and methods The carotid canal diameter was longitudinally measured in seven individuals who underwent carotid artery ligation. As moyamoya disease is known to be associated with negative remodeling of the internal carotid artery, the carotid canal diameter was measured in 106 patients with moyamoya disease, and an association with the outer diameter of the internal carotid artery or a correlation with the disease stage was investigated. The carotid canal was measured by computed tomography (106 patients), and the outer diameter of the artery was measured by high-resolution magnetic resonance imaging (63 patients). The carotid canal area was calculated by the product of the maximum axial diameter and its perpendicular diameter. Results All seven patients who underwent carotid artery ligation showed narrowing of the carotid canal, and the carotid canal area decreased by 12.2%–28.9% during a mean follow-up period of 4.2 years. In patients with moyamoya disease, the carotid canal area showed a linear correlation with the outer area of the internal carotid artery (r = 0.657, p < 0.001), and a negative correlation with the disease stage (ρ = −0.283, p < 0.001). Conclusion The bony carotid canal has plasticity, and its area reflects the outer area of the internal carotid artery, therefore, it can be used to assess the remodeling of the carotid artery. A narrow carotid canal may not necessarily indicate hypoplastic internal carotid artery.

Increase in clivo-axial angle is associated with clinical improvement in children undergoing occipitocervical fusion for complex Chiari malformation: patient series

BACKGROUND The authors analyzed the pre- and postoperative morphometric properties of pediatric patients with complex Chiari malformation undergoing occipitocervical fusion (OCF) to assess clinical outcomes and morphometric properties that might influence postoperative outcomes. OBSERVATIONS The authors retrospectively reviewed 35 patients younger than 22 years with Chiari malformation who underwent posterior fossa decompression and OCF with or without endoscopic endonasal odontoidectomy at their institution (13 with and 22 without odontoidectomy). Clivo-axial angle (CXA), pB-C2, atlantodental interval, basion-dens interval, basion-axial interval, and canal diameter at the level of C1 were measured on preoperative and approximately 3-month postoperative computed tomography or magnetic resonance imaging. The authors further stratified the patient cohort into three age groups and compared the three cohorts. The most common presenting symptoms were headache, neck/shoulder pain, and dysphagia; 80% of the cohort had improved clinical outcomes. CXA increased significantly after surgery. When stratified into those who showed postoperative improvement and those who did not, only the former showed a significant increase in CXA. After age stratification, the significant changes in CXA were observed in the 7- to 13-year-old and 14- to 21-year-old cohorts. LESSONS CXA may be the most important morphometric predictor of clinical outcomes after OCF in pediatric patients with complex Chiari malformation.

A Prospective Study of Long-Term Regenerative Endodontics Outcomes of Necrotic Immature Permanent Teeth: An 8-Year Follow-Up

For the management of necrotic immature teeth, regenerative endodontics offers the advantage of further root lengthening, thickening of dentin wall, and apical closure. This prospective study aimed to evaluate the long-term outcome of regenerative endodontics in immature necrotic permanent teeth. A total of 23 immature roots were medicated by triple antibiotic paste. After 21 days, bleeding was induced by over-instrumentation, and then mineral trioxide aggregate and coronal restoration were applied. Patients were scheduled for clinical and radiographic follow-up for 8 years. The radiographic changes of root dimensions were assessed using the ImageJ Plugin and statistically analyzed by Kruskal–Wallis test at a 95% confidence level. For qualitative evaluation, images were overlapped and analyzed using Photoshop software. All teeth were asymptomatic one month after the treatment. All teeth (n = 18) with preoperative periapical radiolucency showed complete resolution within 6–9 months. Recall rate at two, three, and eight years was 69.6%, 56.5%, and 34.8%, respectively. Continuous root development with a significant increase in root length and thickening of dentin wall accompanied by a significant decrease in apical canal diameter was seen at the end of the observation period (p < 0.001). In conclusion, the long-term outcome of regenerative endodontics revealed successful clinical and radiographic results with appropriate case selection.

Predicting clinical outcomes using morphometric changes in adults with complex Chiari malformation undergoing occipitocervical fusion with or without ventral decompression: patient series

BACKGROUND The authors assessed the connection between clinical outcomes and morphometrics in patients with complex Chiari malformation (CM) who have undergone posterior fossa decompression (PFD) and subsequent occipitocervical fusion (OCF) with or without ventral decompression (VD). OBSERVATIONS The authors retrospectively reviewed 33 patients with CM aged over 21 years who underwent PFD and OCF with or without endoscopic endonasal odontoidectomy at the authors’ institution (21 OCF only and 12 OCF + VD). Clivoaxial angle (CXA), pB-C2 (perpendicular line to the line between the basion and C2), atlantodental interval (ADI), basion-dens interval (BDI), basion-axial interval (BAI), and C1 canal diameter were measured on preoperative and approximately 3-month postoperative computed tomography or magnetic resonance imaging scans. Common symptoms included headache, paresthesia, and bulbar symptoms. Clinical improvement after surgery was observed in 78.8% of patients. CXA, ADI, and BDI all significantly increased after surgery, whereas pB-C2 and BAI significantly decreased. OCF + VD had a significantly more acute CXA and longer pB-C2 preoperatively than OCF only. Patients who clinically improved postoperatively showed the same significant morphometric changes, but those who did not improve showed no significant morphometric changes. LESSONS Patients showing improvement had greater corrections in skull base morphometrics than those who did not. Although there are various mutually nonexclusive reasons why certain patients do not improve after surgery, smaller degrees of morphometric correction could play a role.

Hearing Results After Type I Tympanoplasty With Versus Without Mastoidectomy

Background and Objectives The purpose of the mastoidectomy and tympanoplasty is to improve the hearing by removing the middle ear lesion and reconstructing the hearing mechanism. The purpose of this study is to verify whether several factors, including the presence of mastoidectomy can affect the hearing outcome of tympanoplasty patients.Subjects and Method From 1989 to 2018, 1260 patients with chronic otitis media who had been followed up for more than 6 months after type 1 tympanoplasty were selected. The each patient group was divided into 2 groups based on the last audiometry; Group A (post operative air-bone gap [ABG] ≤10 dB HL) and Group B (post operative ABG >10 dB HL). We analyzed the various factors including patency of E-tube or mastoid aeration for each group to figure out which factors affect the post operative hearing outcome.Results In conclusion, even with mastoidectomy, the final hearing after surgery was worse than that of the group who underwent tympanoplasty only (final ABG; tympanoplasty only vs. tympanoplasty with mastoidectomy; 6.59±9.09 vs. 9.71±8.94). In both with and without mastoidectomy group, the size of the perforation and external ear canal diameter before surgery did not affect the final hearing outcome. On the otherhand, in the group with mastoidectomy, mastoid pneumatization and E-tube patency affected the postoperative prognosis, but not in the case without mastoidectomy.Conclusion In this study, the factors affecting postoperative hearing success were analyzed. The results can be used to predict the postoperative hearing prognosis and to help select surgical treatment.

Ischiocavernosus Muscle Release for Urethral Obstruction Treatment after Pelvic Symphyseal Distraction Osteotomy in a Cat with Pelvic Stenosis

Symphyseal distraction osteotomy (SDO) with a polymethyl methacrylate (PMMA) spacer is an effective surgical treatment for cats with pelvic stenosis. This study reports the successful treatment of urethral obstruction due to ischiocavernosus muscle (IM) tension after SDO with a PMMA spacer. A 2-year-old castrated male Korean domestic shorthair feline had megacolon and pelvic canal stenosis. The ratio of the maximal diameter of the colon to the L5 length and the pelvic canal diameter ratio were 1.6 and 0.45, respectively. Pelvic SDO was performed with a PMMA spacer, leading to pelvic canal enlargement (pelvic canal diameter ratio: 0.73). Two days after surgery, dysuria was identified immediately after removing the preoperatively placed urinary catheter. Complete blood counts and serum biochemical profiles were within the reference intervals, and a positive contrast retrograde urethrogram confirmed urethral obstruction at the level of the membranous–pelvic urethra region. Increased tension of the IM leading to a narrowed urethra was suspected as the cause of urethral obstruction. After IM release at the level of origin on the ischium, the patient had an uneventful recovery with spontaneous urination. Muscle release resulted in excellent functional restoration, with no intraoperative or postoperative complications reported during the 12-month long-term follow-up. Therefore, SDO with IM release could be a feasible therapeutic option for severe pelvic stenosis without complications, such as urethral obstruction, in cats.

ANTHROPOMETRIC ANALYSIS OF THE HIP JOINT IN CENTRAL INDIA POPULATION USING COMPUTED TOMOGRAPHY

Background: The presently available hip prosthesis used in hip arthroplasty are designed based on the anthropometry of Western patients. These prosthesis do not replicate the exact anatomy of Indian patients, leading to postoperative complications and requiring revision surgery for correction. If the manufacturers keep in considering the anthropometric parameters of Indians while designing the prosthesis, this may lead to better clinical and functional outcome and higher patient satisfaction. So the present study was undertaken to understand the anthropometric variables of hip joint of Central Indian population and to compare these variables with the other Indian Ethnic groups and western population using computed tomographic images. Materials And Methods: We had included 200 patients and both the left and right side hip joints were analysed. The anthropometric variables included were Neck-Shaft Angle (NSA), Head Diameter (HD), Neck Width (NW), Acetabular Angle of sharp(AA), Horizontal Offset (HO), Vertical Offset (VO), Medullary Canal Diameter at the level of Lesser Trochanter (MDLT), and Acetabular Version (AV) were measured in all these individuals. Comparison of these parameters was done between the left and right side and among the males and females and compared with various populations and statistically analyzed Result: The mean values were NSA 132.53°, NW 25.11 mm, HD 43.94 mm, AA of sharp 43.11°, HO 43.76 mm, VO 56.37 mm, MDLT 23.00 mm, and AV 19.47°. We found a large variations in these parameters among the Indian ethnic groups and western population. Significant differences were seen between the males and females. Conclusion: This study indicates that there are significant differences in anthropometric parameters of proximal femur among the Central India population compared with Western population. Even within the Indian population, the anthropometric parameters vary from region to region.

Extent and characteristic of relationships in canal dimension and canal body ratio between cervical and lumbar spine

A known prevalence of concurrent cervical and lumbar spinal stenosis was shown to be 5–25%, but there is a lack of evidence regarding direct relationships in canal dimension and canal-body ratio between cervical and lumbar spine. Total 247 patients (mean age: 61 years, male: 135) with cervical and lumbar computed tomography scans were retrospectively reviewed. Midsagittal vertebral body and canal diameters in reconstructed images were measured at all cervical and lumbar vertebrae, and canal-body ratios were calculated. The canal diameter and ratio were also compared according to the gender and age, and correlation analysis was performed for each value. There were significant correlations between cervical (C3–C7) and lumbar (L1–L5) canal dimension (p < 0.001). C5 canal diameter was most significantly correlated with L4 canal diameter (r = 0.435, p < 0.001). Cervical canal-body ratios (C3–C7) were also correlated with those of lumbar spine (L1–L5) (p < 0.001). The canal-body ratio of C3 was most highly correlated with L3 (r = 0.477, p < 0.001). Meanwhile, mean canal-body ratios of C3 and L3 were significantly smaller in male patients than female (p = 0.038 and p < 0.001) and patient’s age was inversely correlated with C5 canal diameter (r = − 0.223, p < 0.001) and C3 canal-body ratio (r = − 0.224, p < 0.001). Spinal canal dimension and canal-body ratio have moderate degrees of correlations between cervical and lumbar spine and the elderly male patients show the tendency of small canal diameter and canal-body ratio. This relationship of cervical and lumbar spine can be an important evidence to explain to the patients.