scholarly journals Effects of a Mandibular Lateral Shift on the Condyle and Mandibular Bone in Growing Rats

2007 ◽  
Vol 77 (5) ◽  
pp. 787-793 ◽  
Author(s):  
Chang Liu ◽  
Sawa Kaneko ◽  
Kunimichi Soma
Keyword(s):  
Periodic Acid ◽  
Growth Direction ◽  
Contralateral Side ◽  
Lateral Shift ◽  
Mechanical Stimuli ◽  
Ipsilateral Side ◽  
Mandibular Bone ◽  
Growing Rats ◽  
Mandibular Asymmetry ◽  
Condylar Head

Abstract Objective: To examine the effects of mandibular lateral shift on the growth and morphology of the condyle and mandibular bone in growing rats. Materials and Methods: A maxillary resin plate was designed to displace 4-week-old rat mandibles 2 mm to the left during closure. The plate was cemented, and the rats were killed after 2, 4, 8, or 12 weeks. Gross dimensions of the condylar head were measured. Radiographic films of the mandibles were exposed, and selected measurements were made. The newly formed bone in the condyle was evaluated with periodic acid and Schiff's reagent (PAS) staining. Results: The length of the condylar head was greater on the ipsilateral side compared with the contralateral side. The experimental rats developed an asymmetric mandible, shorter in horizontal dimension but longer in the vertical dimension on the ipsilateral side. The mandibular growth direction was also affected, with the mandible on the ipsilateral side growing in a more anterior and superior direction. The amount of newly formed bone was greater in the superior subchondral region but lower in the posterior subchondral region on the ipsilateral side compared with the contralateral side. Conclusions: Mechanical stimuli delivered by a functional shift produce a series of morphological and histological responses in the condyle and lead to condylar and mandibular asymmetry in rats.

scholarly journals Glenoid Fossa Responses to Mandibular Lateral Shift in Growing Rats

2007 ◽  
Vol 77 (4) ◽  
pp. 660-667 ◽  
Author(s):  
Chang Liu ◽  
Sawa Kaneko ◽  
Kunimichi Soma
Keyword(s):  
Bone Formation ◽  
Contralateral Side ◽  
Lateral Shift ◽  
Posterior Region ◽  
Control Group ◽  
Glenoid Fossa ◽  
New Bone Formation ◽  
Ipsilateral Side ◽  
Growing Rats ◽  
And Control

Abstract Objective: To evaluate the morphological and histological responses of the glenoid fossa to mandibular lateral shift in growing rats. Materials and Methods: A resin plate was placed on the upper incisors of 4-week-old rats in the experimental groups to displace the mandible to the left during closure. The rats were killed after 2, 4, 8, and 12 weeks. The morphometric measurements were performed on dry skulls, and tissue blocks were processed for periodic acid and Schiff's reagent (PAS) staining to examine the new bone formation. Results: Gross measurements showed asymmetry in both the position and size of the fossae between the two sides after 4 weeks of lateral shift. The glenoid fossa on the ipsilateral side was repositioned relatively backward, outward and upward compared with the contralateral side and control group, whereas the fossa on the contralateral side was relocated relatively forward and downward compared with the control group. The length of the fossa was smaller on the ipsilateral side than on contralateral side and control group. At 2 weeks, the amount of newly formed bone in the posterior region of the fossa was higher in the experimental group than the control group. Conclusion: It is suggested that the mandibular lateral shift causes asymmetry in the position and size of the glenoid fossa and that this phenomenon can be related to different bilateral directional new bone formation in the posterior region.

Investigations on skeletal growth zones via bone scans as base of determination of optimal time for surgery in mandibular asymmetry

2000 ◽  
Vol 39 (05) ◽  
pp. 121-126 ◽  
Author(s):  
R. Werz ◽  
P. Reuland
Keyword(s):  
Bone Growth ◽  
Region Of Interest ◽  
Tracer Uptake ◽  
Optimal Time ◽  
Mandibular Bone ◽  
The Third ◽  
Mandibular Asymmetry ◽  
Bone Scans ◽  
Epiphyseal Plates

Summary Aim of the study was to find out wether there is a common stop of growth of mandibular bone, so that no individual determination of the optimal time for surgery in patients with asymmetric mandibular bone growth is needed. As there are no epiphyseal plates in the mandibular bone, stop of growth cannot be determined on X-ray films. Methods: Bone scans of 731 patients [687 patients (324 male, 363 female) under 39 y for exact determination of end of growth and 44 (21 male, 23 female) patients over 40 y for evaluation of nongrowth dependant differences in tracer uptake] were reviewed for the study. All the patients were examined 3 hours after injection of 99mTc-DPD. Tracer uptake was measured by region of interest technique in different points of the mandibular bone and in several epiphyseal plates of extremities. Results: Tracer uptake in different epiphyseal plates of the extremities shows strong variation with age and good correlation with reported data of bone growth and closure of the epiphyseal plates. The relative maximum of bone activity is smaller in mandibular bone than in epiphyseal plates, which show well defined peaks, ending at 15-18 years in females and at 18-21 years in males. In contrast, mandibular bone shows no well defined end of growing but a gradually reduction of bone activity which remains higher than bone activity in epiphyseal plates over several years. Conclusion: No well defined end of growth of mandibular bone exists. The optimal age for surgery of asymmetric mandibular bone growth is not before the middle of the third decade of life, bone scans performed earlier for determination of bone growth can be omitted. Bone scans performed at the middle of the third decade of life help to optimize the time of surgical intervention.

Abstract 182: Thermal Imaging as a Diagnostic Biomarker in Acute Ischemic Stroke

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Linda F Aulmann ◽  
Kira Busch ◽  
Andrea Zegelin ◽  
Thomas Eckey ◽  
Alexander Neumann ◽  
...  
Keyword(s):  
Thermal Imaging ◽  
Arterial Occlusion ◽  
Current Method ◽  
Contralateral Side ◽  
Temperature Pattern ◽  
Ipsilateral Side ◽  
Anterior Circulation ◽  
Vessel Occlusion ◽  
Clear Trend ◽  
Infrared Thermal Imaging

Purpose: With highly portable mobile infrared cameras thermal imaging during acute stroke triage has become possible. The purpose of this pilot study was to evaluate the pattern of superficial facial skin temperature in patients with acute proximal arterial occlusion of the anterior circulation compared to non-ischemic controls. We hypothesize, that temperature dysregulation in stroke with associated thermal pattern may be used to predict presence of proximal vessel occlusion. Methods: In 46 patients suffering from acute occlusion in the anterior circulation (ICA: 17, M1-MCA: 13, M2-MCA: 16) infrared thermal imaging of the face was performed before endovascular treatment. Asymmetric temperature patterns were evaluated visually. Quantitative temperature values were obtained from regions of interest (ROIs) placed symmetrically on the left and right half of on the facial thermal image. Presence and side of vessel occlusion was correlated with temperature measurements. Results: Regional facial asymmetric temperature was readily visible at 0.5°C. Temperature differences ranged from 0.5 to 1.5° C in stroke patients, and <0.5°C in controls. In 16 of 17 patients with ICA occlusion, facial asymmetric temperature was detected (in 13 lower temperatures on ipsilateral side, in 3 on the contralateral side). In 11 of 13 patients with M1-MCA occlusion, facial asymmetric temperature was detected (in 8 lower temperatures on the contralateral side, 3 on the ipsilateral side). In 15 of 16 patients with an occlusion of M2-segment, asymmetric temperature pattern was apparent, however no clear trend with regard. In 16 of 20 controls, no asymmetric temperature pattern >0.5°C was observed. Conclusion: Thermal imaging could serve as a fast point-of-care test to detect asymmetrical pattern in facial temperature as a predictor of proximal vessel occlusion in stroke. However, the current method is prone to imaging artifacts and reliability of detected asymmetry is moderate.

scholarly journals Regional resting state perfusion variability and delayed cerebrovascular uniform reactivity in subjects with chronic carotid artery stenosis

2018 ◽  
Vol 65 (1) ◽  
pp. 151-162
Author(s):  
Arkadiusz Szarmach ◽  
Mariusz Kaszubowski ◽  
Agnieszka Sabisz ◽  
Andrzej F Frydrychowski ◽  
Grzegorz Halena ◽  
...  
Keyword(s):  
White Matter ◽  
Carotid Artery ◽  
Temporal Lobe ◽  
Resting State ◽  
Carotid Artery Stenosis ◽  
Parietal Lobe ◽  
Contralateral Side ◽  
Artery Stenosis ◽  
Ipsilateral Side ◽  
Acetazolamide Challenge

The aim of this study was to assess regional perfusion at baseline and regional cerebrovascular resistance (CVR) to delayed acetazolamide challenge in subjects with chronic carotid artery stenosis.Sixteen patients (ten males) aged 70.94±7.71 with carotid artery stenosis ≥90% on the ipsilateral side and ≤50% on the contralateral side were enrolled into the study. In all patients, two computed tomography perfusion examinations were carried out; the first was performed before acetazolamide administration and the second 60 minutes after injection.The differences between mean values were examined by paired two-sample t-test and alternative nonparametric Wilcoxon’s test. Normality assumption was examined using W Shapiro-Wilk test.The lowest resting-state cerebral blood flow (CBF) was observed in white matter (ipsilateral side: 18.4±6.2; contralateral side: 19.3±6.6) and brainstem (ipsilateral side: 27.8±8.5;  contralateral side: 29.1±10.8). Grey matter (cerebral cortex) resting state CBF was below the normal value for subjects of this age: frontal lobe – ipsilateral side: 30.4±7.0, contralateral side: 33.7±7.1; parietal lobe – ipsilateral side: 36.4±11.3, contralateral side: 42.7±9.9; temporal lobe – ipsilateral side: 32.5±8.6, contralateral side: 39.4±10.8; occipital lobe – ipsilateral side: 24.0±6.0, contralateral side: 26.4±6.6). The highest resting state CBF was observed in the insula (ipsilateral side: 49.2±17.4; contralateral side: 55.3±18.4). A relatively high resting state CBF was also recorded in the thalamus (ipsilateral side: 39.7±16.9; contralateral side: 41.7±14.1) and cerebellum (ipsilateral side: 41.4±12.2; contralateral side: 38.1±11.3). The highest CVR was observed in temporal lobe cortex (ipsilateral side: +27.1%; contralateral side: +26.1%) and cerebellum (ipsilateral side: +27.0%; contralateral side: +34.6%). The lowest CVR was recorded in brain stem (ipsilateral side: +20.2%; contralateral side: +22.2%) and white matter (ipsilateral side: +18.1%; contralateral side: +18.3%). All CBF values were provided in milliliters of blood per minute per 100 g of brain tissue [ml/100g/min]. Resting state circulation in subjects with carotid artery stenosis is low in all analysed structures with the exception of insula and cerebellum. Acetazolamide challenge yields relatively uniform response in both hemispheres in the investigated population.Grey matter is more reactive to acetazolamide challenge than white matter or brainstem.

The Physiology of a Lepidopteran Muscle Receptor

1966 ◽  
Vol 45 (2) ◽  
pp. 229-249
Author(s):  
R. DE G. WEEVERS
Keyword(s):  
Negative Feedback ◽  
Sense Organ ◽  
Great Majority ◽  
Motor Units ◽  
Contralateral Side ◽  
Ipsilateral Side ◽  
Major Function ◽  
Muscle Receptor ◽  
Spatial Facilitation ◽  
Adjacent Segments

1. When a single MRO of a caterpillar is stretched at least 32 motor units show clear reflex changes in activity. 2. The great majority of muscles are excited and the latency of the reflex differs only slightly from one muscle to another. The response has both tonic and phasic components which reflect more or less faithfully the magnitudes of the same components in the sensory discharge. 3. Muscles are affected on the contralateral side of the stimulated segment and on the ipsilateral side of adjacent segments. The reflex fields of neighbouring receptors therefore overlap; spatial facilitation produces a disproportionate increase in the overall response when two receptors are stimulated simultaneously. 4. The reflex pathway for muscles innervated by nerve 2 is shown to involve synaptic connexions in the ganglion of the segment anterior to the stimulated receptor and responding muscles. 5. The muscles most strongly excited are those which lie functionally in parallel with a stretched sense organ. It is concluded that a major function of the caterpillar MRO is to mediate a negative feedback reflex tending to stabilize bodily position independent of load.

The development of the retinotectal projection in Xenopus with one compound eye

Development ◽  
1975 ◽  
Vol 33 (3) ◽  
pp. 775-787
Author(s):  
Joan D. Feldman ◽  
R. M. Gaze
Keyword(s):  
Compound Eye ◽  
Contralateral Side ◽  
Compound Eyes ◽  
Stages Of Development ◽  
Ipsilateral Side ◽  
Retinotectal Projection ◽  
Xenopus Embryos ◽  
Donor Embryo

Double-nasal and double-temporal compound eyes were constructed in Xenopus embryos at stages 32 and 37/38. A particular half was removed from the host eye anlage and replaced with the opposite half-eye from the contralateral side of a donor embryo. Control operations consisted of removing a half-eye and replacing it with a similar half from the ipsilateral side of the donor embryo. Whereas in control animals, each half-eye projected its fibres to the appropriate half-tectum, in operated animals each half of the compound eye spread its optic teiminals across the entire rostrocaudal extent of the dorsal tectal surface. The area of tectal surface covered by ganglion fibre terminals was similar in operated animals mapped at successive stages of development to that previously observed in normal animals at equivalent stages. Therefore the factors responsible for the extended distribution of fibre terminals from each half of a compound eye must exist at least from mid-tadpole life, and thereafter be continuously present throughout development.

Effect of functional lateral shift of the mandible on hyaluronic acid metabolism related to lubrication of temporomandibular joint in growing rats

2020 ◽  
Vol 42 (6) ◽  
pp. 658-663
Author(s):  
Xiyuan Guo ◽  
Ippei Watari ◽  
Yuhei Ikeda ◽  
Wu Yang ◽  
Takashi Ono
Keyword(s):  
Hyaluronic Acid ◽  
Articular Cartilage ◽  
Temporomandibular Joint ◽  
Experimental Period ◽  
Lateral Shift ◽  
Control Group ◽  
Condylar Cartilage ◽  
Growing Rats ◽  
Shift Group ◽  
Recovery Group

Summary Background Hyaluronic acid (HA) is a major molecular component of the articular cartilage of the temporomandibular joint (TMJ) influencing joint lubrication. Functional lateral shift of the mandible (FLSM) can lead to malocclusion. This study investigated the effects of FLSM on HA metabolism and lubrication of the TMJ in growing rats. Methods Thirty 5-week-old male Wistar rats were divided into shift, recovery, and control groups. Rats in the shift and recovery groups were fitted with guiding plates to produce a 2-mm FLSM which were removed from the rats in the recovery group 14 days later. Animals were sacrificed at 14 and 28 days after the appliances were attached. Immunohistochemistry of HA-binding protein (HABP), hyaluronan synthase (HAS), and hyaluronoglucosaminidases (HYALs) was examined. Results The thickness of HABP-positively stained areas in the lateral regions in the bilateral condyle was reduced during the experimental period in the shift group compared with that in the control group. The proportion of HAS2-stained areas was bilaterally decreased in different regions of condylar cartilage during the experimental period in the shift group. The reduction of the HYAL2-stained area proportion in the condylar cartilage was more significant than that of HYAL1 at 14 days after appliance attachment in the shift group. HAS2 staining was not recovered in the recovery group. Limitations This research was based on animal experiments with a limited experimental period. Conclusion FLSM altered lubrication related HA metabolism in the articular cartilage of the TMJ in growing rats.

scholarly journals Three-dimensional characterization of mandibular asymmetry in craniofacial microsomia

2020 ◽  
Vol 24 (12) ◽  
pp. 4363-4372
Author(s):  
Yun-Fang Chen ◽  
Frank Baan ◽  
Robin Bruggink ◽  
Ewald Bronkhorst ◽  
Yu-Fang Liao ◽  
...  
Keyword(s):  
Average Distance ◽  
Three Dimensional ◽  
Contralateral Side ◽  
Individual Variability ◽  
Distance Map ◽  
Mandibular Asymmetry ◽  
Computed Tomography Images ◽  
Craniofacial Microsomia ◽  
Mandibular Body ◽  
Treatment Plans

Abstract Objectives This study aimed to investigate the three-dimensional (3D) mandibular asymmetry in craniofacial microsomia (CFM) and its association with the Pruzansky–Kaban classification system. Materials and methods Cone-beam computed tomography images of 48 adult CFM cases were collected. The asymmetry of the mandibular body and ramus was analyzed with 3D landmarks. The mirrored mandibular model was registered on the original model, yielding a color-coded distance map and an average distance (i.e., asymmetry score) to quantify the overall mandibular asymmetry. Results The lengths of the mandibular body and ramus were significantly shorter on the affected than the contralateral side (p < 0.001). The ANB (p = 0.009), body and ramal lengths (both p < 0.001), and body and ramal length asymmetry (both p < 0.05) were significantly different between mild (types I/IIA) and severe (types IIB/III) cases. The mandibular asymmetry score correlated with mandibular body length asymmetry (r = 0.296, p = 0.046). CFM mandibles showed high variability in shape asymmetry. Conclusions CFM patients showed distinct body and ramal length asymmetries. In severe cases, mandibles were smaller, more retruded, and more asymmetric in length. The mandibular shape asymmetry was highly variable regardless of the Pruzansky–Kaban types, being a determinant in the extent of overall mandibular asymmetry. Clinical relevance The 3D morphologic analysis provides better insights into real mandibular asymmetry. Although the Pruzansky–Kaban classification was applied, high individual variability of the mandibular morphology still existed within the types. Therefore, individualized analyses and treatment plans for CFM patients are highly recommended.

Developmental Differences in Spinal Cyclooxygenase 1 Expression after Surgical Incision

2006 ◽  
Vol 104 (3) ◽  
pp. 426-431 ◽  
Author(s):  
Douglas G. Ririe ◽  
Heather D. Prout ◽  
David Barclay ◽  
Chuanyo Tong ◽  
Marina Lin ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Developmental Stages ◽  
Intrathecal Administration ◽  
Contralateral Side ◽  
Developmental Differences ◽  
Systemic Administration ◽  
Mechanical Stimuli ◽  
Withdrawal Threshold ◽  
Cyclooxygenase 1 ◽  
Cox 1

Background Systemic administration of a cyclooxygenase 1 (COX-1) inhibitor reduces hypersensitivity to mechanical stimuli after incisional paw surgery in 4-week-old, but not 2-week-old, animals. The purpose of the current study was to test whether this developmental difference was reflected by differences in COX-1 expression in the spinal cord after surgery. Methods Rats 2 and 4 weeks of age, paralleling infant and child human neurologic developmental stages, were used. A paw incision was made under general anesthesia and the withdrawal thresholds were measured before and after systemic and intrathecal administration of a COX-1 selective inhibitor (SC560). Immunohistochemistry was used to assess COX-1 protein in the spinal cord, and real-time polymerase chain reaction was used to quantify gene expression of COX-1 mRNA. Results Systemic and intrathecal administration of SC560 produced an increase in withdrawal threshold in the 4-week-old, but not in the 2-week-old, animals. Intrathecal SC560 increased withdrawal thresholds in the 4-week-old animals at a dose 100-fold less than with systemic administration. Cyclooxygenase 1 protein in the spinal cord was increased ipsilateral to surgery in the 4-week-old, but not in the 2-week-old, animals. Cyclooxygenase 1 mRNA was increased in the 4-week-old animals in the spinal cord ipsilateral to surgery relative to the contralateral side of the spinal cord, but not in the 2-week-old animals. Conclusions These results suggest that developmental differences in COX-1 expression in the spinal cord likely explain the lack of efficacy of COX-1 inhibitors in the 2-week-old rats. Whether this reflects a deficit in factors that stimulate COX-1 expression or a difference in response to these factors is not addressed, but should similar deficits occur in humans, COX-1 inhibitors may exhibit reduced efficacy in infants.

Changes in Tissue pH and Temperature after Incision Indicate Acidosis May Contribute to Postoperative Pain

2004 ◽  
Vol 101 (2) ◽  
pp. 468-475 ◽  
Author(s):  
Young Cheol Woo ◽  
Soo Seog Park ◽  
Alberto R. Subieta ◽  
Timothy J. Brennan
Keyword(s):  
Postoperative Pain ◽  
Skin Temperature ◽  
Gastrocnemius Muscle ◽  
Contralateral Side ◽  
Mechanical Stimuli ◽  
Ph Change ◽  
Tissue Ph ◽  
Pain Behaviors ◽  
Guarding Behavior ◽  
Plantar Incision

Background Incisional pain is a common form of acute pain. Previously, the authors studied persistent pain behaviors caused by incisions, using animal models for postoperative pain. In this study, the authors measured tissue pH and hind paw temperature before and after incision to understand factors that may activate and sensitize nociceptors in the incision. Methods Rats underwent a plantar incision, a gastrocnemius muscle incision, or a cutaneous paraspinal incision. For the hind paw incision, pain behaviors were measured. Tissue pH was measured using a pH-sensitive needle electrode in halothane-anesthetized rats. The pH in the incision was compared to a corresponding control site on the contralateral side of the rat or to the sham-operated group. Results Plantar tissue pH was 7.16 +/- 0.04 in sham-operated rats. Ten minutes after plantar incision, tissue pH was decreased to 6.91 +/- 0.20 (P &lt; 0.05), and this decrease was sustained through 60 min after incision, when pH was 6.99 +/- 0.06 (P &lt; 0.05). Tissue pH values were 6.95, 6.90, 6.89, and 6.95 (P &lt; 0.05 vs. sham) 4 h and 1, 2, and 4 days after incision, respectively. On postoperative day 7, when plantar pH was same as for the control side (7.13 +/- 0.05), guarding behavior, heat responses, and responses to mechanical stimuli recovered. Outside the incised area in the hind paw, tissue pH was normal. Tissue pH was significantly correlated with all pain behaviors. In the gastrocnemius muscle, tissue pH was 7.14 +/- 0.7 in the sham-operated side. Ten minutes after incision, tissue pH was 6.54 +/- 0.12 (P &lt; 0.05), and muscle pH remained decreased through 60 min after gastrocnemius incision when pH was 6.76 +/- 0.17 (P &lt; 0.05). Tissue pH was also significantly decreased (P &lt; 0.05) on day 1 (6.96 vs. 7.20) and day 4 (7.06 vs. 7.18) after gastrocnemius incision but was not reduced on postoperative day 8 (7.11 vs. 7.15). A paraspinal incision also decreased tissue pH in the hairy skin of the rat compared with the preincision value. Hind paw skin temperature did not change after incision. Conclusion A decrease in pH occurs immediately after incision and is sustained for at least 4 days. During the period of decreased tissue pH, pain behaviors are evident. When the tissue pH returns to normal, pain behaviors are diminished. The decreased pH is localized at the incision site and not to areas surrounding the incision. Decreased pH likely contributes to nociceptor sensitization and pain related behaviors after incision. The magnitude of the pH change varies among tissues. An increase in hind paw skin temperature does not play a role in these pain-related behaviors.

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