The Y-shaped trabecular bone structure in the odontoid process of the axis: a CT scan study in 54 healthy subjects and biomechanical considerations

2019 ◽  
Vol 30 (5) ◽  
pp. 585-592 ◽  
Author(s):  
Nicola Montemurro ◽  
Paolo Perrini ◽  
Vittoriano Mangini ◽  
Massimo Galli ◽  
Andrea Papini

OBJECTIVEOdontoid process fractures are very common in both young and geriatric patients. The axial trabecular architecture of the dens appears to be crucial for physiological and biomechanical function of the C1–2 joint. The aim of this study is to demonstrate the presence of a Y-shaped trabecular structure of the dens on axial CT and to describe its anatomical and biomechanical implications.METHODSFifty-four C2 odontoid processes in healthy subjects were prospectively examined for the presence of a Y-shaped trabecular structure at the odontocentral synchondrosis level with a dental cone beam CT scan. Length, width, and axial area of the odontoid process were measured in all subjects. In addition, measurements of the one-third right anterior area of the Y-shaped structure were taken.RESULTSThe Y-shaped trabecular structure was found in 79.6% of cases. Length and width of the odontoid process were 13.5 ± 0.6 mm and 11.2 ± 0.9 mm, respectively. The mean area of the odontoid process at the odontocentral synchondrosis was 93.5 ± 4.3 mm2, whereas the mean one-third right anterior area of the odontoid process at the same level was 29.3 ± 2.5 mm2. The mean area of the odontoid process and its length and width were similar in men and women (p > 0.05). No significant difference was found in the mean area of the odontoid process in people older than 65 years (94 ± 4.2 mm2) compared to people younger than 65 years (93.3 ± 4.4 mm2; p > 0.05).CONCLUSIONSThe authors identified a new anatomical entity, named the Y-shaped trabecular structure of the odontoid process, on axial CT scans. This structure appears to be the result of bone transformation induced by the elevated dynamic loading at the C1–2 level. The presence of the Y-shaped structure provides new insights into biomechanical responses of C2 under physiological loading and traumatic conditions.

2011 ◽  
Vol 23 (06) ◽  
pp. 527-532 ◽  
Author(s):  
Shou-Jen Wang ◽  
Fu-Shan Jaw ◽  
Yi-Ho Young

This study compared cervical and ocular vestibular-evoked myogenic potentials (cVEMPs and oVEMPs) between air-conducted sound (ACS) and bone-conducted vibration (BCV) modes to determine whether these two stimulation modes activate the same population of primary vestibular afferents. Fifteen healthy subjects underwent cVEMP and oVEMP tests using ACS stimuli at 127 dB pe SPL and BCV stimuli at 128 dB force level. The characteristic parameters of cVEMPs and oVEMPs were compared between ACS and BCV modes. The mean p13 and n23 latencies of ACS-cVEMPs were significantly longer than those of BCV-cVEMPs. Likewise, the mean nI and pI latencies for ACS-oVEMPs were also significantly longer than those for BCV-oVEMPs. There was no significant difference in the mean amplitude of cVEMPs between the ACS and BCV modes. However, comparing the oVEMP amplitude, a relationship: (Amplitude of BCV-oVEMP) = 2.3 x (Amplitude of ACS-oVEMP) was demonstrated. In conclusion, the population of primary vestibular afferents activated by ACS and BCV stimuli is similar for cVEMPs. In contrast with oVEMPs, BCV mode activates more number of primary vestibular afferents than ACS mode does. In interpreting oVEMP and cVEMP results, stimulation mode should be checked first.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243830
Author(s):  
Yining Dai ◽  
Hao Zhou ◽  
Qinqin Zhang ◽  
Zhongdi Chu ◽  
Lisa C. Olmos de Koo ◽  
...  

Purpose To quantitatively assess choriocapillaris (CC) flow deficits in eyes with diabetic retinopathy (DR) using swept-source optical coherence tomography angiography (SS-OCTA). Methods Diabetic subjects with different stages of DR and age-matched healthy subjects were recruited and imaged with SS-OCTA. The en face CC blood flow images were generated using previously published and validated algorithms. The percentage of CC flow deficits (FD%) and the mean CC flow deficit size were calculated in a 5-mm-diameter circle centered on the fovea from the 6×6-mm scans. Results Forty-five diabetic subjects and 27 control subjects were included in the study. The CC FD% in diabetic eyes was on average 1.4-fold greater than in control eyes (12.34±4.14% vs 8.82±2.61%, P < 0.001). The mean CC FD size in diabetic eyes was on average 1.4-fold larger than in control eyes (2151.3± 650.8μm2 vs 1574.4±255.0 μm2, P < 0.001). No significant difference in CC FD% or mean CC FD size was observed between eyes with nonproliferative DR and eyes with proliferative DR (P = 1.000 and P = 1.000, respectively). Conclusions CC perfusion in DR can be objectively and quantitatively assessed with FD% and FD size. In the macular region, both CC FD% and CC FD size are increased in eyes with DR. SS-OCTA provides new insights for the investigations of CC perfusion status in diabetes in vivo.


Joints ◽  
2018 ◽  
Vol 06 (04) ◽  
pp. 220-227 ◽  
Author(s):  
Fabrizio Cuzzocrea ◽  
Eugenio Jannelli ◽  
Alessandro Ivone ◽  
Simone Perelli ◽  
Alberto Fioruzzi ◽  
...  

Abstract Purpose The study aims to present the results at a mean 28-months follow-up of arthroscopic-guided balloon tibioplasty and to spot some technical tricks and some practice using tools and materials. Methods The study relates to six patients with tibial plateau fractures type Schatzker III with tibial plateau depression more than 4 mm at preoperative computed tomography scan (CT-scan). The follow-up period ranged from 22 to 33 months, with a mean of 28 months. No patients were lost to follow-up. The patients were evaluated clinically using the Rasmussen score system and Lysholm score systems at 6 to 12 and 24 months, postoperatively. Radiographic evaluations (standard X-rays) were done preoperatively at 1, 3, and 12 months postoperatively while a CT-scan with 3D reconstruction was performed preoperatively, at the first day and 6 months, postoperatively. Results The mean Rasmussen clinical score at 6 months postoperatively was 26.3 while at 1-year postoperatively the mean Rasmussen clinical score was 28.33. At 2-year postoperatively the mean Rasmussen clinical score was 28.83. Statistically significant difference was found in 6-months and 2-years results (p < 0.05). CT-scan achieved the first postoperative day showed the recovery of approximately 70% of the area of the interested tibial plateau, restoring of the joint surface without articular bone free fragments. Conclusion The described surgical procedure, if correctly performed with proper indications (Schatzker III), respect the principles mentioned above and the clinical and radiological results confirm our purpose. Level of Evidence This is a therapeutic case series, level IV study.


2020 ◽  
pp. 20200191
Author(s):  
Eduarda Helena Leandro Nascimento ◽  
Rocharles Cavalcante Fontenele ◽  
Priscila de Azeredo Lopes ◽  
Gustavo Machado Santaella ◽  
Karla Faria Vasconcelos ◽  
...  

Objectives: To present the ballistic gelatin as a new material capable of simulating the soft tissues in cone-beam CT (CBCT) images. Methods: CBCT images of three piglet heads were acquired with their soft tissues intact (standard group). Subsequently, the piglet heads were fixed in a container using metallic pins and moulded with acrylic resin; the soft tissues were then removed and replaced by ballistic gelatin, with the same thickness of the original soft tissues. The images were evaluated by two oral radiologists, to check the adaptation on bone surfaces, thickness and density, penetration into large bone cavities and cancellous bone, and the presence of air bubbles using a 5-score scale. Additionally, an objective analysis was carried out by one oral radiologist. For each CBCT scan, three axial reconstructions were selected to represent the mandibular, occlusal, and maxillary levels. The mean and standard deviation (SD) of the grey values were calculated in four regions of interest determined on soft tissue areas and compared by two-way ANOVA. Results: The ballistic gelatin showed subjective scores ranging from good to excellent for all parameters evaluated. There was no significant difference in the mean and SD values of the grey values between ballistic gelatin and the gold standard groups for all levels (p > 0.05). Higher SD values were observed in the occlusal level for both groups (p < 0.05). Conclusions: Ballistic gelatin has visual and objective similarity with the gold standard. Thus, the ballistic gelatin is a promising material capable of simulating soft tissues in CBCT images.


2017 ◽  
Vol 1 (1) ◽  
pp. oapoc.0000013
Author(s):  
Rocio Blanco-Garavito ◽  
Polina Astroz ◽  
Salomon Yves Cohen ◽  
Eric H. Souied

Purpose To investigate the influence of at least 12 hours of fasting followed by acute water ingestion on macular choroidal thickness in eyes of healthy subjects. Methods Prospective case series study including healthy volunteers from April 1, 2015 to May 31, 2015. Macular choroidal thickness was measured on enhanced depth imaging optical coherence tomography (EDI-OCT) and on swept-source (SS)-OCT after 12 hours of fasting, and 60 minutes after acute water ingestion (750 mL in 5 minutes). Results A total of 52 eyes of 26 healthy volunteers were included in this study. The mean age for participants was 32 years old. After 12 hours of fasting, the mean (±SD) subfoveal choroidal thickness was 335.43 (±104.82) μm on EDI-OCT and 286.16 (±80.32) μm on SS-OCT. The mean (±SD) subfoveal choroidal thickness after acute water intake was 352.32 (±120.36) μm and 290.5 (±85.86) μm, respectively. There was no significant difference between the mean subfoveal thickness at baseline and 60 minutes after acute water ingestion for any of the choroidal imaging techniques (p = 0.1386 for EDI-OCT and p = 0.0659 for SS-OCT). Conclusions These results suggest that choroidal circulation can physiologically quickly adapt to systemic vascular changes in healthy eyes. Choroidal thickness did not depend upon the hydration status for the subjects participating in this study.


2015 ◽  
Vol 2015 ◽  
pp. 1-4
Author(s):  
Emrullah Beyazyıldız ◽  
Özlem Beyazyıldız ◽  
Süleyman Günaydın ◽  
Emrah Kan ◽  
Mert Şimşek ◽  
...  

Purpose. To evaluate optical low coherence reflectometry (OLCR) parameters in patients with exfoliation syndrome (EXS) undergoing cataract surgery.Methods. Forty-seven eyes of 47 patients with EXS (Group 1), and 55 eyes of 55 healthy subjects (Group 2) were included in the study. Anterior chamber depth (ACD), lens thickness (LT), axial length (AL), central corneal thickness (CCT), horizontal corneal length (HCL), and pupil diameter (PD) parameters were measured by OLCR (Lenstar LS 900, Haag-Streit) and compared between groups. Shapiro-Wilk test and Mann WhitneyUtests were used for statistical analyses.Results. The mean ACD, HCL, and PD values were significantly lower in EXS group than in healthy subjects (P= 0.01,P= 0.04, andP<0.001, resp.). The mean LT was significantly higher in EXS group than in healthy subjects (P= 0.007). There was no significant difference between groups in means of AXL and CCT.Conclusions. According to OLCR measures, eyes with EXS have shallower ACD, smaller PD, thicker LT, shorter HCL, and no significantly different CCT levels.


2015 ◽  
Vol 23 (6) ◽  
pp. 701-706 ◽  
Author(s):  
David A. Besachio ◽  
Ziyad Khaleel ◽  
Lubdha M. Shah

OBJECT Posterior odontoid process inclination has been demonstrated as a factor associated with Chiari malformation Type I (CM-I) in the pediatric population; however, no studies to date have examined this measurement in the adult CM-I population. The purpose of this study was to evaluate craniocervical junction (CCJ) measurements in adult CM-I versus a control group. METHODS The odontoid retroflexion, odontoid retroversion, odontoid height, posterior basion to C-2 line measured to the dural margin (pB-C2 line), posterior basion to C-2 line measured to the dorsal odontoid cortical margin (pB-C2* line), and clivus-canal angle measurements were retrospectively analyzed in adult patients with CM-I using MRI. These measurements were compared with normative values established from CT scans of the cervical spine in adults without CM-I. RESULTS A statistically significant difference was found between 55 adults with CM-I and 150 sex-matched controls (125 used for analysis) in the mean clivus-canal angle and the mean pB-C2 line. CONCLUSIONS These data suggest that there are sex-specific differences with respect to measurements at the CCJ between men and women, with women showing a more posteriorly inclined odontoid process. There were also differences between the CM-I and control groups: a more acute clivus-canal angle was associated with CM-I in the adult population. These CCJ findings could have an influence on presurgical planning.


2020 ◽  
Vol 5 (1) ◽  
pp. e13-e13
Author(s):  
Arash Alghasi ◽  
Zohreh Hassanpour ◽  
Mohammad Bahadoram ◽  
Somayeh Ashrafi ◽  
Seyed Mohammad Kazem Nourbakhsh

Introduction: Sickle cell disease (SCD) is a genetic disorder that can be diagnosed by early onset screening tests. In embryos and newborns with sickle cell syndrome, the anatomic development and brain circulation is less than the normal people, and brain circulation plays an important role in brain development. Objectives: The purpose of this study was to evaluate the level of IQ in children with SCD. Patients and Patients and Methods: The study was a descriptive-epidemiologic. The population of the present study was all children aged 7-14 years old with SCD in Ahvaz. The sample of this study was 50 children with SCD. They were selected from among clients referring to the hepatitis clinic of Shafa hospital in Ahvaz. About 50 healthy children were selected from the first or second-degree family members of the patients with SCD as the control group. The data was collected using Raven’s Progressive Matrices (RPM) and demographic information questionnaire. Results: The mean and standard deviation of IQ scores of the patients with SCD was 94.52 ± 14.41, and the mean and standard deviation of IQ scores of healthy subjects was 105.86 ± 11.38. The results showed a significant difference between the two groups in terms of IQ score (P<0.05). Moreover, the results showed that IQ level in patients with SCD was significant regarding their place of residence (P<0.05), however IQ level was not significant in patients with SCD regarding gender and race (P>0.05). Conclusion: The results showed that IQ in children with SCD is lower than that of the healthy subjects. Thus, the present study showed the importance of SCD on children’s IQ.


2021 ◽  
Vol 8 ◽  
Author(s):  
Ziqing Feng ◽  
Gengyuan Wang ◽  
Honghui Xia ◽  
Meng Li ◽  
Guoxia Liang ◽  
...  

Purpose: To characterize the sex- and age-related alterations of the macular vascular geometry in a population of healthy eyes using fundus photography.Methods: A cross-sectional study was conducted with 610 eyes from 305 healthy subjects (136 men, 169 women) who underwent fundus photography examination and was divided into four age groups (G1 with age ≤ 25 years, G2 with age 26–35 years, G3 with age 36–45 years, and G4 with age ≥ 46 years). A self-developed automated retinal vasculature analysis system allowed segmentation and separate multiparametric quantification of the macular vascular network according to the Early Treatment Diabetic Retinopathy Study (ETDRS). Vessel fractal dimension (Df), vessel area rate (VAR), average vessel diameter (Dm), and vessel tortuosity (τn) were acquired and compared between sex and age groups.Results: There was no significant difference between the mean age of male and female subjects (32.706 ± 10.372 and 33.494 ± 10.620, respectively, p &gt; 0.05) and the mean age of both sexes in each age group (p &gt; 0.05). The Df, VAR, and Dm of the inner ring, the Df of the outer ring, and the Df and VAR of the whole macula were significantly greater in men than women (p &lt; 0.001, p &lt; 0.001, p &lt; 0.05, respectively). There was no significant change of τn between males and females (p &gt; 0.05). The Df, VAR, and Dm of the whole macula, the inner and outer rings associated negatively with age (p &lt; 0.001), whereas the τn showed no significant association with age (p &gt; 0.05). Comparison between age groups observed that Df started to decrease from G2 compared with G1 in the inner ring (p &lt; 0.05) and Df, VAR, and Dm all decreased from G3 compared with the younger groups in the whole macula, inner and outer rings (p &lt; 0.05).Conclusion: In the healthy subjects, macular vascular geometric parameters obtained from fundus photography showed that Df, VAR, and Dm are related to sex and age while τn is not. The baseline values of the macular vascular geometry were also acquired for both sexes and all age groups.


2018 ◽  
Vol 8 (1) ◽  
pp. 101 ◽  
Author(s):  
Hamidreza Abdolsamadi ◽  
Mohammad vahedi ◽  
Farnaz Fariba ◽  
Alireza Soltanian ◽  
Meghdad Zakavati Avval ◽  
...  

Introduction: Vitamin D deficiency is a major public health problem. Low vitamin D levels associated with adverse health consequences such as musculoskeletal health, cognitive decline and progression of cancer and death. The lack of vitamin D associated with major risk factors for cardiovascular disease (CVD) includes hypertension is considered. The ability to assess the general health, disease and treatment outcomes through saliva as a non-invasive, inexpensive and simple method of interest is located. The aim of this study was a comparative study of salivary and serum levels of vitamin D3 in patients with a history of developing high blood pressure and a healthy person.Methods: This study was a case - control survey, in which 40 patients with high blood pressure were examined. The control group including 40 healthy subjects. Both groups were matched in terms of age and gender. After collecting samples of serum and saliva, the amount of vitamin D level samples were measured using ELISA method by electrochemiluminescence (ELC), and then analyzed the results using software SPSS 16 and statistical test including Chi Square Test, Independent-Samples, linear regression model, the Mann-Whitney Test and Spearman correlation coefficient.Results: There was no significant difference in the mean serum levels of vitamin D among patients and healthy subjects (p= 0.588). In addition, there was no significant difference in the mean salivary levels of vitamin D between patients and healthy subjects (p= 0.833). There was no significant relationship between salivary and serum level of vitamin D in healthy individuals (p= 0.095). As well as there was no significant correlation between salivary and serum level of vitamin D in patients (p= 0.5).Conclusions: This study showed that vitamin D is a measurable marker in saliva, but its analysis in saliva, may not be a reliable tool for determining the vitamin D levels.


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