scholarly journals Age-related osteogenesis on lateral force application to rat incisor – Part II: Bony recession and cortical remodeling

2021 ◽  
Vol 11 ◽  
pp. 174-182
Author(s):  
Jin-Wook Kim ◽  
Hyoung-Seon Baik ◽  
Sung-Seo Mo ◽  
Hai-Van Giap ◽  
Kee-Joon Lee
Keyword(s):  
Cortical Bone ◽  
Tooth Movement ◽  
Lateral Displacement ◽  
Young Group ◽  
Bone Volume ◽  
Limiting Factor ◽  
Adult Rats ◽  
Skeletal Malocclusion ◽  
Age Related ◽  
Significant Difference

Objective: The aim of this study is to analyze the age-related changes in the bony recession and cortical bone remodeling induced by lateral orthodontic tooth movement, using a three-dimensional micro-computed tomography (CT) analysis. Material and Methods: A total of 40 male Sprague-Dawley rats were divided into two distinct age groups (young, 10 weeks and adult, 52 weeks). Double-helical springs exerting 40 g of force were applied to central incisors to analysis of changes in lateral cortical bone and tooth movement with age and time. The young and adult rats were divided into four subgroups, T0 (0 week), T1 (1 week), T2 (2 weeks), and T3 (3 weeks), depending on the period of wearing the appliance. Micro-CT image was taken on each dissected pre-maxilla specimen. In each subgroup, distance between the center of teeth, suture width, tooth displacement, bony recession, and bone volume was evaluated. Results: The changes in the distance between the center of teeth and the suture width were significantly greater in the young group. However, the change in the tooth displacement showed no significant difference between groups. In the young group, bony recession of outer cortical layer was observed at T1 (P < 0.05), but the amount of recession gradually decreased at T2 and T3. In contrast, in the adult group, bony recession increased gradually over observation period (P < 0.05). The bone volume decreased at T1 (P < 0.05), but recovered at T2 and T3 in both groups. Conclusion: The compensatory bone formation occurs in the pressure side of cortical bone more significantly in the young group than in the adult according to the lateral displacement of incisor in rats. The reduced bone reaction in the adult is considered a limiting factor of the excessive tooth movement in the compromised treatment of skeletal malocclusion.

scholarly journals Characteristic Movement of the Ribs, Thoracic Vertebrae while Elevating the Upper Limbs - Influences of Age and Gender on Movements

2019 ◽  
Vol 13 (1) ◽  
pp. 170-176
Author(s):  
Hisayoshi Tachihara ◽  
Junichiro Hamada
Keyword(s):  
Young Group ◽  
Thoracic Vertebrae ◽  
Middle Aged ◽  
Age And Gender ◽  
Aged Group ◽  
Age Related ◽  
Significant Difference ◽  
Shoulder Disorders ◽  
Arm Elevation ◽  
And Gender

Background: The rib cage, such as the thoracic spine and ribs, influences glenohumeral mobility and the development of shoulder disorders. Objective: To evaluate movements of the ribs, thoracic vertebrae during bilateral arm elevation and to clarify the characteristic influences of age and gender. Methods: Subjects comprised 33 healthy individuals divided into a young group (10 males, 7 females; mean age, 25 years) and a middle-aged group (8 males, 8 females; mean age, 52 years). Chest CT was performed with two arm positions: arms hanging downwards; and arms elevated at 160°. Images were three-dimensionally reconstructed to evaluate rib movement, extension angle of thoracic vertebrae. Results: Maximal movement was observed at the fifth rib, and rib movement decreased with increasing distance from the fifth rib in both the groups. In males, movement of the second to fourth ribs was smaller in the middle-aged group than in the young group (p < 0.05). Movement of the first to ninth ribs was smaller in females than in males (p < 0.05). No significant difference in the extension angle of the thoracic vertebrae was found. Conclusion: Fifth rib movement is the largest among all ribs during bilateral arm elevation. Reduction of upper rib movement initially arises as an age-related degradation in males. Women exhibit less rib movement during bilateral arm elevation.

scholarly journals Cortical Bone Modifications after Radiotherapy: Cortex Porosity and Osteonal Changes Evaluated Over Time

2021 ◽  
Vol 32 (1) ◽  
pp. 9-15
Author(s):  
Juliana Simeão Borges ◽  
Gustavo Davi Rabelo ◽  
Milena Suemi Irie ◽  
João Lucas Carvalho Paz ◽  
Rubens Spin-Neto ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Cortical Thickness ◽  
Bone Microarchitecture ◽  
Total Porosity ◽  
Control Area ◽  
Bone Volume ◽  
Control Group ◽  
Significant Difference ◽  
Area And Perimeter ◽  
Haversian Canals

Abstract Aiming to evaluate cortical bone microarchitecture and osteonal morphology after irradiation, twelve male New Zealand rabbits were used. The animals were divided: control group (no radiation-NIr); and 3 irradiated groups, sacrificed after: 7 (Ir7d); 14 (Ir14d) and 21 (Ir21d) days. A single radiation dose of 30 Gy was used. Computed microtomography analyzed the cortical microarchitecture: cortical thickness (CtTh), bone volume (BV), total porosity (Ct.Po), intracortical porosity (CtPo-cl), channel/pore number (Po.N), fractal dimension (FD) and degree of anisotropy (Ct.DA). After scan, osteonal morphology was histologically assessed by means: area and perimeter of the osteons (O.Ar; O.p) and of the Haversian canals (C.Ar; C.p). Microtomographic analysis were performed by ANOVA, followed by Tukey and Dunnet tests. Osteon morphology analyses were performed by Kruskal-Wallis, and test Dunn’s. Cortical thickness was significant difference (p<0.010) between the NIr and irradiated groups, with thicker cortex at Ir7d (1.15±0.09). The intracortical porosity revealed significant difference (p<0.001) between irradiated groups and NIr, with lower value for Ir7d (0.29±0.09). Bone volume was lower in Ir14d compared to control. Area and perimeter of the osteons were statistically different (p<0.0001) between NIr and Ir7d. Haversian canals also revealed lower values (p<0.0001) in Ir7d (80.57±9.3; 31.63±6.5) compared to NIr and irradiated groups. Cortical microarchitecture was affected by radiation, and the effects appear to be time-dependent, mostly regarding the osteons morphology at the initial days. Cortex structure in Ir21d revealed similarities to control suggesting that microarchitecture resembles normal condition after a period.

scholarly journals Age-related changes of dental pulp tissue after experimental tooth movement in rats

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1625 ◽  
Author(s):  
Martina Von Böhl ◽  
Yijin Ren ◽  
Anne M. Kuijpers-Jagtman ◽  
Piotr S. Fudalej ◽  
Jaap C. Maltha
Keyword(s):  
Dental Pulp ◽  
Tooth Movement ◽  
Orthodontic Tooth Movement ◽  
Inflammatory Cells ◽  
Contralateral Side ◽  
Pulp Tissue ◽  
Adult Rats ◽  
Force Application ◽  
Age Related ◽  
Age Related Changes

It is generally accepted that the effect of orthodontic tooth movement on the dental pulp in adolescents is reversible and that it has no long-lasting effect on pulpal physiology. However, it is not clear yet if the same conclusion is also valid for adult subjects. Thus, in two groups of rats, aged 6 and 40 weeks respectively, 3 molars at one side of the maxilla were moved together in a mesial direction with a standardized orthodontic appliance delivering a force of 10 cN. The contralateral side served as a control. Parasagittal histological sections were prepared after tooth movement for 1, 2, 4, 8, and 12 weeks. The pulp tissue was characterized for the different groups, with special emphasis on cell density, inflammatory cells, vascularity, and odontoblasts. Dimensions of dentin and the pulpal horns was determined and related with the duration of orthodontic force application and age ware evaluated. We found that neither in young nor in adult rats, force application led to long-lasting or irreversible changes in pulpal tissues. Dimensional variables showed significant age-related changes. In conclusion, orthodontic tooth movement per se has no long-lasting or irreversible effect on pulpal tissues, neither in the young nor in the adult animals.

scholarly journals Aging Effects on the Limits and Stability of Long-Term Synaptic Potentiation and Depression in Rat Hippocampal Area CA1

2007 ◽  
Vol 98 (2) ◽  
pp. 594-601 ◽  
Author(s):  
Ashok Kumar ◽  
Jeffrey S. Thinschmidt ◽  
Thomas C. Foster ◽  
Michael A. King
Keyword(s):  
Synaptic Plasticity ◽  
Young Adult ◽  
Hippocampal Slices ◽  
Long Term Potentiation ◽  
Brown Norway ◽  
Aging Effects ◽  
Adult Rats ◽  
Age Related ◽  
Significant Difference

Altered hippocampal synaptic plasticity may underlie age-related memory impairment. In acute hippocampal slices from aged (22–24 mo) and young adult (1–12 mo) male Brown Norway rats, extracellular excitatory postsynaptic field potentials were recorded in CA1 stratum radiatum evoked by Schaffer collateral stimulation. We used enhanced Ca2+ to Mg2+ ratio and paired-pulse stimulation protocol to induce maximum changes in the synaptic plasticity. Six episodes of theta-burst stimulation (TBS) or nine episodes of paired low-frequency stimulation (pLFS) were used to generate asymptotic long-term potentiation (LTP) and long-term depression (LTD), respectively. In addition, long-term depotentiation (LTdeP) or de-depression (LTdeD) from maximal LTP and LTD were examined using two episodes of pLFS or TBS. Multiple episodes of TBS or pLFS produced significant LTP or LTD in aged and young adult rats; this was not different between age groups. Moreover, there was no significant difference in the amount of LTdeP or LTdeD between aged and young adult rats. Our results show no age differences in the asymptotic magnitude of LTP or LTD, rate of synaptic modifications, development rates, reversal, or decay after postconditioning. Thus impairment of the basic synaptic mechanisms responsible for expression of these forms of plasticity is not likely to account for decline in memory function within this age range.

scholarly journals Evaluation of the Effects of Chronic Injection of D-Galactose on Auditory Brainstem Responses as a Model for Studying Age-Related Hearing Loss

2019 ◽  
Author(s):  
Elham Tavanai ◽  
Ghassem Mohammadkhani
Keyword(s):  
Hearing Loss ◽  
Wistar Rats ◽  
Natural Aging ◽  
Tone Burst ◽  
Auditory Brainstem ◽  
Young Group ◽  
Auditory Brainstem Responses ◽  
Age Related ◽  
Significant Difference ◽  
Age Related Hearing Loss

The D-galactose induced mimetic aging rat model has been widely used in studies of age-associated diseases recently. Evidence indicates that D-GAL could also play a key role in age-related hearing loss. However, there is conflicting data about the relationship between the D-GAL injection and tone-burst auditory brainstem responses (ABRs). The present study aimed to compare ABRs in D-GAL injected rats compared with young and naturally aged rats. Tone-burst ABR was recorded and analyzed at the frequencies of 4,6,8,12 and 16 kHz in male young (3-month-old, n=10), naturally aging (18-month-old, n=10) and D-GAL injected (3-month-old, 500 mg/kg D-GAL injection for 8 weeks, n=10) Wistar rats. When the ABRs thresholds obtained in the D-GAL group and the natural aging group were compared with the thresholds in the young group, we observed a significant increase in thresholds, which affected all of the frequencies (P<0.05). A statistically significant decrease in amplitude of wave PI at 4 and 8 kHz, PII at 4,8 kHz, PIV at 4,6,8,12 and 16 kHz was also observed in naturally aging group compared with young group. However, in D-GAL group, a significant difference was exclusively detected in amplitude of PIII at 4 kHz. Latency did not reveal any significant difference between the groups (P>0.05). The present study confirmed that experimental injection of 500 mg/kg/day D-GAL for 8 weeks to Wistar rats could lead to ABRs threshold shifts but not latency. Because there are several types of presbycusis, further studies are needed to determine what type of presbycusis is induced by D-GAL and where is the first region affected by it to provide the best treatment and prevention methods. © 2019 Tehran University of Medical Sciences. All rights reserved. Acta Med Iran 2019;57(5):281-288.

scholarly journals The use of high-resolution computed tomography to explore age-related trabecular change in human ribs

2021 ◽  
Author(s):  
Sophia Mavroudas ◽  
Victoria M Dominguez
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Trabecular Bone ◽  
Cortical Bone ◽  
Volume Fraction ◽  
Bone Volume ◽  
3D Analysis ◽  
High Resolution Computed Tomography ◽  
Trabecular Thickness ◽  
Age Related

High-resolution computed tomography was used to explore age-related trabecular change in male human ribs ranging in age from 20–95 years (Mean=55 years, SD=21.634 years) from the Texas State Donated Skeletal Collection (TXSTDSC). Two regions of interest (ROIs), midshaft (50%) and anterior (75%) were extracted from each scan to analyze age-related trabecular change. Dragonfly V4.1 was used to isolate cortical bone volumes of interest (VOIs) and three trabecular VOIs for each ROI; one each along the cutaneous cortex, the center of the medullary cavity, and the pleural cortex. Each trabecular VOI was analyzed for bone volume fraction (BV/TV), trabecular thickness (TbTh), trabecular spacing (TbSp), connectivity density (Conn.D), and degree of anisotropy (DA), within and between the 50 and 75% ROIs. Overall, the cutaneous VOIs at both the 50% and 75% ROIs exhibited greater BV/TV, TbTh, and Conn.D when compared to the center and pleural VOIs. All results are consistent with expected biomechanical strain on human ribs. Both trabecular variables and cortical bone volume are only weakly associated with age. These results show that 3D analysis of trabecular bone volume does not improve visualization or understanding of trabecular bone changes with age over traditional 2D methods. Future research should incorporate female samples to explore sex-related trabecular change variation.

Age-related changes in the 3D hierarchical structure of rat tibia cortical bone characterized by high-resolution micro-CT

2013 ◽  
Vol 114 (7) ◽  
pp. 923-933 ◽  
Author(s):  
John Jast ◽  
Iwona Jasiuk
Keyword(s):  
High Resolution ◽  
Cortical Bone ◽  
Hierarchical Structure ◽  
Volume Density ◽  
Bone Volume ◽  
Number Density ◽  
Micro Computed Tomography ◽  
Age Related ◽  
Canal Diameter ◽  
Rat Tibia

Three-dimensional hierarchical structure of female Sprague-Dawley rat tibia cortical bone was characterized as a function of age (3, 12, 32, 42, 60, and 72 wk) using a high-resolution micro-computed tomography. At the whole bone level, 3-wk samples exhibited statistically significant differences in a mean total tissue volume, mean cortical bone volume, mean cortical bone volume density, mean periosteal perimeter, and mean cortical thickness ( P < 0.05) compared with all other ages. At the tissue level, there was a statistically significant increase in a mean canal number density and a decrease in a mean canal volume and diameter between 3-wk and 12-wk samples. While no significant variations were found between mean canal lengths, there was a dependence of mean canal orientation on age. At the cell level, there were no statistically significant differences in a lacuna number density and a lacuna volume density, and all lacunae element-based parameters displayed no dependence on age across age. In addition, at the microstructural level, the cannular indexes were reported separately for anterior, posterior, medial, and lateral anatomic regions. From 3 to 32 wk of age, there existed significantly fewer canals per volume of bone in the medial region of the tibia vs. other cross-sectional quadrants. Although there were changes with age, there were no statistically significant differences in the mean canal volume, mean canal diameter, and mean canal length between the four anatomic regions.

scholarly journals Age-Related Outcome of Mobile-Bearing Total Ankle Replacement

2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0002
Author(s):  
Camilla Maccario ◽  
Ettore Vulcano ◽  
Cristian Indino ◽  
Luigi Manzi ◽  
Federico Giuseppe Usuelli
Keyword(s):  
Mobile Bearing ◽  
The Elderly ◽  
Young Group ◽  
Total Ankle Replacement ◽  
Ankle Arthritis ◽  
Short Term Treatment ◽  
Age Related ◽  
Ankle Replacement ◽  
Significant Difference ◽  
End Stage

Category: Ankle, Ankle Arthritis Introduction/Purpose: Total ankle replacement (TAR) is becoming increasingly popular amongst patients with end-stage ankle arthritis. This is in part related to the advances in design, technology, and technique that have improved TAR longevity. The ideal candidate for a TAR is not fully clear. For a long time patients over age 50 years, body mass index (BMI) under 30 kg/m2, and with low functional demands represented selection criteria for many patients. However, these criteria were based off a very limited number of scientific studies on older TAR designs. The aim of this study is to investigate clinical and radiographic outcome in patients of 50 years or less versus patients over 50 years undergoing a Hintegra® total ankle replacement (Integra, Plainsboro, NJ). Methods: This study includes 70 consecutive patients who underwent primary TAR from May 2011 to April 2014. The cohort was divided into 2 groups: the young group (YG) with age less than or equal to 50 years, and the older group (OG) with age above 50 years. Patients were assessed clinically and radiologically preoperatively and at 6, 12 and 24 months postoperatively. Results: A significant increase in the AOFAS and SF-12 and decrease in VAS scores was seen in both groups between preoperative and final followup (p < 0.001). There was a statistically significant difference between the YG and OG for the AOFAS score at final follow-up. The YG had significantly greater improvement compared to the OG (p = 0.046). In addition radiographic results showed no statistically significant difference in the coronal and sagittal alignment between the 2 groups. The mean postoperative angles in either study group demonstrated significant improvements compared to the preoperative alignment. Conclusion: This study demonstrates that total ankle arthroplasty is an effective short-term treatment for young, active patients with symptomatic end-stage ankle arthritis. Our findings are in disagreement with the widespread theory that ankle replacement is a more reliable treatment in the elderly

The influence of osteopathic correction on the rate of various rhythms of the body

2019 ◽  
pp. 64-71 ◽  
Author(s):  
A. E. Chernikova ◽  
Yu. P. Potekhina
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Age Groups ◽  
Biomechanical Properties ◽  
Dispersion Analysis ◽  
The Body ◽  
Body Tissues ◽  
Age Related ◽  
Significant Difference ◽  
Before And After

Introduction. An osteopathic examination determines the rate, the amplitude and the strength of the main rhythms (cardiac, respiratory and cranial). However, there are relatively few studies in the available literature dedicated to the influence of osteopathic correction (OC) on the characteristics of these rhythms.Goal of research — to study the influence of OC on the rate characteristics of various rhythms of the human body.Materials and methods. 88 adult osteopathic patients aged from 18 to 81 years were examined, among them 30 men and 58 women. All patients received general osteopathic examination. The rate of the cranial rhythm (RCR), respiratory rate (RR) heart rate (HR), the mobility of the nervous processes (MNP) and the connective tissue mobility (CTM) were assessed before and after the OC session.Results. Since age varied greatly in the examined group, a correlation analysis of age-related changes of the assessed rhythms was carried out. Only the CTM correlated with age (r=–0,28; p<0,05) in a statistically significant way. The rank dispersion analysis of Kruskal–Wallis also showed statistically significant difference in this indicator in different age groups (p=0,043). With the increase of years, the CTM decreases gradually. After the OC, the CTM, increased in a statistically significant way (p<0,0001). The RCR varied from 5 to 12 cycles/min in the examined group, which corresponded to the norm. After the OC, the RCR has increased in a statistically significant way (p<0,0001), the MNP has also increased (p<0,0001). The initial heart rate in the subjects varied from 56 to 94 beats/min, and in 15 % it exceeded the norm. After the OC the heart rate corresponded to the norm in all patients. The heart rate and the respiratory rate significantly decreased after the OC (р<0,0001).Conclusion. The described biorhythm changes after the OC session may be indicative of the improvement of the nervous regulation, of the normalization of the autonomic balance, of the improvement of the biomechanical properties of body tissues and of the increase of their mobility. The assessed parameters can be measured quickly without any additional equipment and can be used in order to study the results of the OC.

Association of Rugae Pattern with Skeletal Malocclusion in Orthodontic Patients Visiting Tertiary Care Hospital

2020 ◽  
Author(s):  
Sarwat Memon
Keyword(s):  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Care Hospital ◽  
Class Iii ◽  
Chi Square ◽  
Cross Sectional ◽  
Skeletal Malocclusion ◽  
Palatal Rugae ◽  
Significant Difference ◽  
Orthodontic Patients

Background: The palatal rugae are special constructions that are inalterable in their position and pattern during the lifestyles of an individual. This imparts them an exceptional role in the forensic dentistry and may play potential role in malocclusion identification. This study was aimed to see association of rugae pattern with sagittal skeletal malocclusion in orthodontic patients visiting tertiary care hospital. Methods: This cross-sectional examination was completed on pretreatment records (lateral Cephalometric radiographs and maxillary dental casts) of 384 subjects at the orthodontic department of Ziauddin Dental Hospital, Karachi. The study duration was from January to July 2019. The samples were sub-divided into three sagittal skeletal groups based on ANB angle proposed by Steiner’s on lateral Cephalometric radiographs (Class I with ANB angle between 0° to 4°; Class II: ANB angle greater than 5°; Class III: ANB angle less than 0°). The shapes of three most-anterior primary rugae were then evaluated bilaterally using Kapali et al., Classification. Chi Square test was applied to find association of rugae pattern among sagittal skeletal malocclusions groups. Results: Circular and curved rugae shapes were the most prevalent in all skeletal malocclusions. The primary palatal rugae pattern was seen to be significantly different among three skeletal malocclusion groups (p<0.05). The right and left sided palatal rugae pattern showed significant difference in all three skeletal malocclusion groups (p<0.05). Conclusion: The present study showed no specific palatal rugae pattern associated with sagittal skeletal malocclusion. Further studies on larger sample and use of modern 3D technologies to scan the maxillary casts are required for results that are more precise.

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