Anterior Position Research Articles

Hyoid Bone Position and Upper Airway Morphology of Children With Obstructive Sleep Apnea: A Systematic Review and Meta-analysis.

The objective of this systematic review was to summarise the existing evidence regarding hyoid bone position and upper airway morphology of children with obstructive sleep apnea (OSA). Electronic searches were carried out in PubMed, Embase, Web of Science, CINAHL and WorldCat databases without any restrictions on language from inception to March 2024. The studies which compared the hyoid bone position and upper airway morphology using lateral cephalograms between children with and without OSA will be included. The methodological quality of the included studies was assessed using Newcastle-Ottawa Scale, and the meta-analysis was conducted utilising random-effects model. Twelve cross-sectional studies and one case-control study were included. One study was rated as low quality, three as medium quality, five as high quality, and four as very high quality. Meta-analysis showed that compared to healthy children, children with OSA tended to have increased distance between hyoid bone and mandibular plane (Hy-MP, MD: 3.33, 95% CI: 1.90 to 4.77, p < 0.00001, I2 = 72%), increased distance between hyoid bone and cervical vertebra (Hy-C3, MD: 1.54, 95% CI: 0.62 to 2.46, p = 0.001, I2 = 68%), and a smaller airway space behind the soft palate (U-MPW, MD: -3.07, 95% CI: -4.76 to -1.38, p = 0.0004, I2 = 68%). Whereas there was no significant difference in inferior posterior airway space between children with OSA and healthy controls (IPAS, MD: -1.51, 95% CI: -3.37 to 0.35, p = 0.11, I2 = 71%). In children with OSA, the hyoid bone may exhibit a more anterior and inferior position and the airway posterior to the soft palate demonstrated a narrower dimension. Registration: PROSPERO (CRD42024528171).

Tactile mechanisms and afferents underlying the rat pup transport response.

Juvenile rodents and other altricial mammals react with calming, immobility, and postural modifications to parental pickup, a set of behaviors referred to as the transport response.1,2,3,4,5 Here, we investigate sensory mechanisms underlying the rat transport response. Grasping rat pups in anterior neck positions evokes strong immobility and folding up of feet, whereas more posterior grasping has lesser effects on immobility and foot position. Transport responses are enhanced by slow (1Hz), and even more so by fast (4Hz), gentle shaking and translation, features consistent with parental transport. With lateral grasping, the forepaw below the grasping position points downward and the forepaw lateral to the grasping position points upward and medially. Such forepaw adjustments put the pup's center of gravity below the grasping point, optimizing pup transportability. Tactile stimuli on the back, belly, tail, whisker, dorsal forepaws, and dorsal hind-paws do not significantly affect behavior of anterior-neck-held pups. Instead, ground contact, or paw stimulation consistent with ground contact, disrupts transport responses. We identify afferents mediating transport response by examining membrane labeling with FM 1-436 following anterior neck grasping. We observe a dense innervation of the anterior-neck-skin region (∼30 terminals/mm2). We find an age-related decrease of cytochrome oxidase reactivity in the rat somatosensory cortical neck representation, a possible correlate to developmental decrease in pup transport response. We conclude that anterior neck grasping and loss of ground contact trigger calming and postural adjustments for parental transport in rat pups, responses putatively driven from the densely innervated anterior neck skin.

Comparative analysis of biometry and anterior chamber metrics in the eyes of extreme hyperopic and emmetropic children

PurposeTo investigate the clinical and biometric features of pediatric eyes with extreme hyperopia and report baseline biometric values. MethodsIn this prospective case-control study, the biometric parameters of eyes in children with extreme hyperopia were compared to those of an emmetropic cohort of similar age. Comprehensive eye examinations were conducted for new patients. Anterior OCT (CASIA-2, Tomey) and ocular biometry imaging (IOL Master 700, Zeiss) were performed for all participants. ResultsA total of 19 children (mean age, 12.3 ± 2.3 years) with extreme hyperopia (+8.84 ± 0.77) were compared with 17 emmetropic (+0.53 ± 0.43) controls of similar age (mean age, 12.4 ± 2.2 years [P = 0.864]). Extreme hyperopic eyes exhibited significantly shorter axial length, normal spherical equivalent corneal keratometry, higher astigmatism, lower anterior chamber area and volume, and narrower iridotrabecular angle optical coherence tomography (OCT) parameters. Lens thickness and curvature were similar, with a slightly anterior and tilted position. ConclusionsIn our study cohort, extreme hyperopia was associated with shorter axial length, reduction in anterior chamber size, with well-formed, regular-sized lens positioned anteriorly, and a narrower iridotrabecular angle.

Effectiveness of palatal anchorage device (PAD) for maxillary anterior retraction with clear aligners using finite element study.

The palatal anchorage device (PAD) is commonly used in fixed appliance for anchorage, but the biomechanics of PAD in patients treated with clear aligners(CAs)remains poorly understood, especially in its elastic mode and force magnitude. This study aimed to assess the biomechanical effects of using PAD for retraction during clear aligner treatment (CAT) with the extraction of two maxillary first premolars. Four finite element models were created: (1) Incisors retraction (IR) with active contraction of the clear aligner only; (2) IR with PAD using different forces (50,75,100g) or not; (3) PAD without IR (forces of 50,75,100g), and (4) Different elastic directions (D1, D2, D3) from aligner to PAD without IR. IR caused lingual tipping and extrusion of the central incisors, as well as mesial and buccal tipping of the first molar. PAD during IR provided strong anchorage for the first molar, with elastics slightly increasing the lingual tipping and extrusion of the central incisors. Elastics applied to the U-shaped arch led to central incisor intrusion and reduced lingual retraction. The highest stress was observed on the mesial attachment of the canine. PAD effectively reinforced posterior anchorage in CAT, while anterior positioning facilitated anterior teeth intrusion. The biomechanical importance of the canine's mesial attachments in maxillary teeth treatment planning was highlighted.

Impact of left ventricular lead position on echocardiographic response after upgrading from right to biventricular pacing - Insights from the BUDAPEST CRT Upgrade Trial

Abstract Introduction Left ventricular (LV) lead position is strongly associated with the long-term outcome of patients undergoing de novo cardiac resynchronization therapy (CRT) implantation. However, data is scarce about patients who undergo upgrade CRT from right ventricular (RV) pacing. Aims To investigate the impact of the LV lead location on the primary outcome of heart failure (HF) hospitalization, all-cause mortality, or echocardiographic reverse remodelling in the BUDAPEST CRT Upgrade trial cohort. Methods Heart failure patients with reduced ejection fraction (HFrEF), with previously implanted pacemaker (PM) or implantable cardioverter defibrillator (ICD) and intermittent or permanent RV pacing, who were randomly assigned to the CRT-D arm (n=215) and those who were cross-overs from the ICD arm (n=27) were investigated. Short-axis position (anterior / posterior / lateral) of the LV lead was assessed. Primary endpoint encompassed HF hospitalization, all-cause mortality, and the end-systolic volume (ESV) decrease less than 15% from baseline to 12 months follow-up. Echocardiographic response was evaluated by percent change of ESV and LVEF. Results LV lead location was available for 223 patients (age 72.8 ± 8 years, 14% female, 38% diabetic, 49% with prior myocardial infarction, 30% with prior ICD) with a median follow-up time of 12.4 months. There was no difference in the occurrence of the primary endpoint by the lead positions (anterior vs. lateral OR 0.33; 95%CI 0.09-1.22, p=0.10, anterior vs. posterior OR 0.58; 95%CI 0.14-2.50, p=0.47). However, LVEF change was more pronounced in those with lateral LV lead location compared with anterior position (adjusted LVEF difference 7.43%, 95%CI 1.25 – 13.62; p=0.02), while those with posterior leads did not differ from the anterior ones (adjusted LVEF difference 3.00%, 95%CI -3.92 – 9.93; p=0.39). Decrease in ESV was also more remarkable with a lateral position as compared to the other locations (lateral vs. anterior adjusted ESV difference -0.17 mL, 95%CI -0.32 – (-0.01); p=0.03, posterior vs. anterior adjusted ESV difference -0.09 mL, 95%CI -0.26– 0.08; p=0.31). Conclusion Upgrade CRT results in better outcomes as compared to ICD alone; however, lateral LV lead position is associated with the most beneficial mid-term echocardiographic response as compared to other short-axis locations. This finding may translate into better clinical outcomes in the long term.

Effective prism diopter for strabismus measurement: Conversion from anterior Prentice position to posterior parallel position and from glass prism to acrylic prism.

In clinical ophthalmology, prisms, commonly made of glass, are labeled based on the prism diopter (PD) value measured in the anterior Prentice position. However, they are often used in the posterior parallel position for practicality, causing a discrepancy between labeled and effective PD. This study proposes a conversion tool to address this issue. Geometric optical analysis was employed to calculate the effective PD of glass prisms in the posterior parallel position. A lookup table was created to convert the labeled PD of the anterior Prentice position to the effective PD when the prism is used in the posterior parallel position. Clinical data from 162 patients with horizontal strabismus were collected to validate the method. Glass prism measurements, converted to effective PD, were compared with acrylic prism results. The variations were significant in glass prism PD with rotation in the anterior Prentice position but stability in the posterior parallel position. Clinical deviations were larger with glass prisms, especially exceeding 30 PD, compared with acrylic prisms. Converted PD from glass prisms correlated well with acrylic prisms (R2 = 0.94, P = 0.002). The half-width of the 95% limit of agreement was ±12.32 PD. The proposed conversion table is valid, facilitating consistency between clinical and literature-based prism use in different positions and materials.

Appropriate sagittal positioning of femoral components in total knee arthroplasty to prevent fracture and loosening.

This study aimed to investigate the optimal sagittal positioning of the uncemented femoral component in total knee arthroplasty to minimize the risk of aseptic loosening and periprosthetic fracture. Ten different sagittal placements of the femoral component, ranging from -5 mm (causing anterior notch) to +4 mm (causing anterior gap), were analyzed using finite element analysis. Both gait and squat loading conditions were simulated, and Von Mises stress and interface micromotion were evaluated to assess fracture and loosening risk. During gait, varied sagittal positioning did not lead to excessive Von Mises stress or micromotion. However, under squat conditions, posterior positioning (-4 and -5 mm) resulted in stress exceeding 150 MPa at the femoral notch, indicating potential fracture risk. Conversely, +1 mm and 0 mm sagittal positions demonstrated minimal interface micromotion. Slightly anterior sagittal positioning (+1 mm) or neutral positioning (0 mm) effectively reduced stress concentration at the femoral notch and minimized interface micromotion. Thus, these positions are deemed suitable to decrease the risk of aseptic loosening and periprosthetic femoral fracture.

Measurement and analysis of condylar morphology and thickness of the roof of the glenoid fossa in patients with unilateral second molar scissor bite

Objective The objective of this study was to measure and analyze the joint space, condylar morphology, and thickness of the roof of the glenoid fossa (RGF) in patients with unilateral second molar scissor bite using cone beam CT (CBCT). Methods A total of 80 patients were included in this study. Forty patients with a normal posterior occlusal relationship, who attended the Department of Orthodontics at the First Hospital of Shanxi Medical University from December 2021 to August 2023, were selected as the control group. The experimental group consisted of 40 patients with unilateral second molar scissor bite during the same period. All patients underwent CBCT scanning, and the resulting images were analyzed using the NNT viewer software in multiplanar reconstruction (MPR). Axial, coronal, and sagittal adjustments were made for each patient. Results In the control group, the right and left joint spaces (PS, SS, AS), the height of the upper part of the condyle, and the depth of the glenoid fossa did not show statistically significant differences (P > 0.05). When comparing bilateral condylar morphology and joint space in the experimental group, it was found that the posterior joint space on the scissor bite side was greater than that on the normal occlusion side, while the anterior joint space on the scissor bite side was smaller than that on the normal occlusal side. Additionally, the height of the upper condyle and the depth of the glenoid fossa on the scissor bite side were greater than that on the normal occlusal side, with statistically significant differences (P < 0.05). However, there were no statistically significant differences in SS, internal and external joint diameter, as well as anterior and posterior diameters (P > 0.05). The comparison of the minimum thickness of the roof of the glenoid fossa in both the sagittal and coronal directions between the patients in the experimental group and the control group showed no statistically significant difference (P > 0.05). Furthermore, the asymmetry index of the supracondylar height in the control group was significantly smaller than that in the experimental group, displaying a statistically significant difference (P < 0.05). The differences in the asymmetry indices of the anterior and posterior diameters of the condyle, as well as the inner and outer diameters, were not statistically significant (P > 0.05). When analyzing the position of the condyle in the sagittal direction of the glenoid fossa in the patients of the control group, it was observed that the majority were in the anterior and medial positions, with only 10% and 5% being in the posterior position. However, the analysis of the condyle position in the sagittal direction of the glenoid fossa in the experimental group revealed statistically significant differences (P < 0.05), with the condyle position on the scissor bite side being more anterior. Conclusion Unilateral second molar scissor bite can result in anterior displacement of the condyle, greater height of the condyle superiorly as well as the depth of the glenoid fossa.

Rebozo and advanced maternal postures: A promising set of intrapartum interventions to reduce persistent occiput posterior position of the fetal head.

Spinning Babies® procedures and the Rebozo technique have been recently implemented as additional interventions in laboring women with a fetus in occiput posterior position (OPP) to favor the rotation to an anterior position, which improve birth experience and health outcomes. Our study aimed to compare the probability of occurrence of persistent OPP (POPP) of the fetal head at the second stage of labor between retrospective and prospective cohorts and to assess associated sociodemographic, obstetric and intrapartum factors. We conducted a combined prospective and retrospective cohort study including 1500 women giving birth in 2017 (retrospective cohort) and 779 between 15 May and 15 December 2023 (prospective cohort). Each cohort was divided into two sub-cohorts depending on presence of OPP. Primary outcomes were compared the probability of occurrence of POPP in the two OPP sub-cohorts by a log binomial regression and logistic regression. A p<0.05 was considered statistically significant. Data analysis was performed using Stata/MP18.0. The proportion of OPP at the onset of labor was similar between the two cohorts (34.9% vs 35.1%). The probability of occurrence of POPP was significantly lower in the prospective OPP sub-cohort (27.7%, n=65/235) compared to the retrospective OPP sub-cohort (35.8%, n=154/430) (risk difference, RD= -0.081; 95% CI: -0.15 - -0.008; p=0.031). In the retrospective OPP sub-cohort, maternal age ≥35 years (RD=0.096; 95% CI: 0.001-0.190, p=0.044) and nulliparity (RD= -0.100; 95% CI: -0.190 - -0.001, p=0.036) were significantly associated with the probability of POPP. Our findings suggest a potential benefit of a set of interventions combining Spinning Babies® and the Rebozo technique in decreasing the probability of POPP.

Comparative analysis of modulation transfer function in various intraocular lenses under normal, decentration, and tilt conditions

PurposeThis study aims to compare the modulation transfer function (MTF) of different intraocular lenses (IOLs) under normal, decentration, and tilt conditions to evaluate their optical performance. DesignExperimental setting. MethodsA total of 12 IOL models (+20 D diopter, n = 3 each) were measured for MTF using the OptiSpheric IOL system with a 3 mm aperture diameter at a water temperature of 35 °C. Measurements were made with a spatial frequency of 0 - 200 lp/mm at the normal, decentration of 0.5 mm, and tilt of 5° positions. ResultsThe MTF values were significantly different between normal and decentration conditions for XY1A (monofocal, toric) (P = 0.03), Tecnis ZCB00V (P = 0.0009), and NS-60YG (P = 0.004). Differences were significant between normal and tilt conditions for MP70 (P = 0.009), XY1 (P = 0.0005), and Clareon (P = 0.049), and were significant between decentration and tilt conditions only for LentisComfort (bifocal) (P = 0.01). With normal condition, MTF of Eyhance DIB00V (extended depth of focus) showed significant differences with 11 other IOLs (P < 0.0001), while LentisComfort exhibited differences with 10 other IOLs (P < 0.0001) except for XY1A (P = 0.0002). Similarly, with decentration condition, Eyhance DIB00V differed significantly from 11 other IOLs (P < 0.0001). With tilt condition, Eyhance DIB00V showed significant differences with 10 other IOLs (P < 0.0001) except for LentisComfort, which itself differed significantly from 10 other IOLs (P < 0.0001). ConclusionsIn the experimental settings, while specialized IOLs can address specific visual issues, monofocal IOLs remain superior in terms of overall contrast transfer quality and resolution even in the implanted IOL position is not ideal. These results provide a basis for recommending the use of monofocal IOLs in cases where the anterior chamber depth and lens position are prone to instability, such as in eyes with weakened zonules or following glaucoma filtering surgery.

From Trypomastigotes to Trypomastigotes: Analyzing the One-Way Intracellular Journey of Trypanosoma cruzi by Ultrastructure Expansion Microscopy.

The protozoan parasite Trypanosoma cruzi is the causative agent of Chagas disease, also called American trypanosomiasis. This neglected tropical disease affects millions of individuals across the Americas. To complete its life cycle, T. cruzi parasitizes both vertebrate hosts and its vector, commonly known as the 'kissing bug'. The parasite's survival and proliferation strategies are driven by the diverse environments it encounters. Despite being described by Carlos Chagas in 1909, significant knowledge gaps persist regarding the parasite's various life forms and adaptive capabilities in response to environmental cues. In this study, we employed Ultrastructure Expansion Microscopy to explore the intricate journey of T. cruzi within the host cell. Upon entry into the host cell, trypomastigotes undergo folding, resulting in intermediate forms characterized by a rounded cell body, anterior positioning of basal bodies, and a shortened flagellum. The repositioning of basal bodies and the kinetoplast and the shortening of the flagella mark the culmination of intracellular amastigogenesis. Furthermore, we analyzed intracellular trypomastigogenesis, identifying discrete intermediate forms, including leaf-shaped stages and epimastigote-like forms, which suggests a complex differentiation process. Notably, we did not observe any dividing intracellular epimastigotes, indicating that these may be non-replicative forms within the host cell. Our detailed examination of amastigote cell division revealed semi-closed nuclear mitosis, with mitotic spindle formation independent of basal bodies. This study provides new insights into the morphological and cytoskeletal changes during the intracellular stages of T. cruzi, providing a model for understanding the dynamics of intracellular amastigogenesis and trypomastigogenesis.

Pelvic and Lower Limb Kinematics in Individuals With Chronic Low Back Pain During Sit-to-Stand Function: A Cross-Sectional Study

ObjectivesThe aim of this study was to investigate the 3-dimensional movement kinematics of pelvic and lower limb joints in CLBP subjects, compared to healthy individuals, utilizing a functional data analysis (FDA) approach. MethodsIn this study, a 7-camera Qualisys motion capture system was employed to record the kinematics of the pelvic, hip, knee, and ankle joints in 20 patients with low back pain (LBP) and 20 control subjects on both sides during the sit-to-stand motion. An FDA statistical approach was utilized to compare the data collected over time between the 2 groups. The STS task was divided into two distinct phases: the prelift off phase (pre-Lo) and the postlift off phase (post-Lo). ResultsDuring the “pre-Lo phase” of the STS motion, our statistical analysis revealed that the only significant difference between the two groups was a decreased medial rotation (P = .00) in the hip joint position of LBP patients on their dominant side, in comparison to healthy subjects. As for the “post-Lo phase,” the LBP group exhibited a more anterior pelvic tilt position (P = .00) and increased pelvic counterclockwise rotation (P = .03) in the sagittal and transverse planes when compared to the control group. Regarding hip joints, the LBP group demonstrated a more flexed position (indicative of reduced extension) on both the dominant (P = .00) and nondominant (P = .00) sides, coupled with diminished abduction (P = .04) and internal rotation (P = .03) of the hip on the dominant side. In relation to the knee and ankle joints, the results indicated a more adducted knee position (P = .00) and decreased ankle joint flexion (P = .02) on the dominant side in CLBP subjects when compared to the healthy group during the STS motion. ConclusionOur findings indicate that patients with CLBP exhibited distinct kinematic patterns in the pelvic and lower limb joints during the STS motion. These kinematic alterations primarily manifest in the joints of the dominant limb, with most of the differences observed during the second phase (postlift off phase) of the motion. It appears that these changes in pelvic and lower limb joint kinematics should be taken into account when planning future rehabilitation programs for CLBP patients engaged in this task.

Preoperative tibiofemoral contact point on standing lateral radiograph predicts anteroposterior knee kinematics in total knee arthroplasty

AbstractPurposeThis study investigated the tibiofemoral contact point (CP) on standing lateral radiographs in knee osteoarthritis and assessed the relationship between CP and pre‐ and postoperative knee kinematics in total knee arthroplasty (TKA).MethodsThe intraoperative knee status of 46 knees with varus deformity that underwent bicruciate stabilized TKA using a navigation system was investigated. The intraoperative anteroposterior (AP) position of the femur relative to the tibia at maximum extension, 15°, 30°, 45°, 60° and 90° was evaluated by the navigation system before and after TKA. The CP, defined as the CP between the femur and tibia, was assessed on standing lateral radiographs at the maximum extension of the knee before and 1 year after TKA. CP was expressed as the ratio of tibial plateau distance on a scale of 0–1, with 0 indicating the most anterior position of the femur relative to the tibia.ResultsThe mean CP on standing lateral radiographs was 0.54 ± 0.12 and 0.46 ± 0.08 before and after TKA, respectively. The postoperative CP was significantly more anterior than the preoperative CP (p = 0.0002). The mean AP position of the femur relative to the tibia moved anteriorly during early knee flexion both before and after TKA, representing nonanatomical AP movement. The preoperative posterior CP group (CP &gt; 0.54) showed more nonanatomical AP movement from 15° to 60° before and after TKA compared with the preoperative anterior CP group (CP &lt; 0.54).ConclusionPreoperative posterior deviation of the femur relative to the tibia in the standing position was a predictive factor for nonanatomical AP knee kinematics. Biomechanical analysis of postoperative knees will be necessary; however, surgeons should focus on preoperative tibiofemoral CP on standing lateral radiographs to predict knee kinematics.Level of EvidenceLevel Ⅲ.

DOES CRUCIATE LIGAMENT SUBSTITUTION AND IMPLANT ASYMMETRY MAKE A DIFFERENCE FOR TOTAL KNEE ARTHROPLASTY KINEMATICS? A MULTI-IMPLANT EVALUATION

The non-implanted knee differs in comparison to total knee arthroplasty (TKA) designs, with regard to asymmetry and functionality of the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL). While surgeons may choose to implant either posterior stabilized (PS) or bi-cruciate stabilized (BCS) TKAs, substituting for one or both cruciate ligaments, the effects of symmetry versus asymmetry in substituting TKA designs have not been widely analyzed to determine possible benefits. Therefore, the objective of this research study was to determine if either TKA asymmetry and/or anterior ligament stabilization can lead to more normal-like kinematics and clinical benefit for patients. In vivo, femoro-tibial kinematics for 64 subjects were evaluated in this retrospective study. Overall, ten subjects had a normal, non-implanted knee, 20 had a BCS TKA, and 34 had one of two different PS TKAs. All three TKAs had varying degrees of symmetry incorporated into the design, and all were implanted by the same surgeon and were analyzed using fluoroscopy during a deep knee bend. At full extension, the BCS TKA subjects demonstrated a statistically more anterior position of both condyles compared to both PS TKAs. The BCS TKA subjects also experienced more posterior femoral rollback and axial rotation in early flexion and from full extension to maximum knee flexion. Additionally, the TKAs in this study having asymmetry experienced greater amounts of posterior femoral rollback and weight-bearing knee flexion. The results from this study indicated that in early flexion, the anterior cam/post mechanism does pull the femoral component more anterior, and all TKAs experienced posterior femoral rollback when the posterior cam engaged the post. The asymmetric designs also achieved greater rollback and axial rotation compared to the symmetric designs.

The influence of lumbar vertebra and cage related factors on cage-endplate contact after lumbar interbody fusion: An in-vitro experimental study

Lumbar interbody fusion (LIF) using interbody cages is an established treatment for lumbar degenerative disc disease, but fusion results are known to be affected by risk factors such as bone mineral density (BMD), endplate geometry and cage position. At present, direct measurement of endplate-cage contact variables that affect LIF have not been fully identified. The aim of this study was to use cadaveric experiments to investigate the dependency between BMD, endplate geometry, cage parameters like type, orientation, position, and contact variables like stress and area. One vertebral body specimen from each of the five lumbar positions was harvested from five male donors. The lower half of each vertebra was potted and placed in a material testing machine (Instron 8874). A spinal cage was clamped to the machine then lowered to bring it into contact against the superior endplate. A lockable ball-joint was used to rotate the cage such that its inferior surface was congruent with the local endplate surface. A pressure sensor (Tekscan) was placed between the cage and endplate to record contact area and the peak and average contact pressures. Axial compression of 400 N was performed for five positions using a straight cage, and in one anterior position using a curved cage. The linear mixed model was utilised to perform data analyses for experimental results with statistical significance set at p < 0.05. The results indicated two trends toward significance for contact area, one for volumetric BMD (vBMD) of the vertebra (p = 0.081), and another for predicted contact area (p = 0.057). Peak contact pressure correlated significantly with vBMD (p = 0.041), and there was a trend between average contact pressure and lateral position of cage (p = 0.051). In addition, predicted contact area correlated significantly with cage orientation (p < 0.001). These results indicated that high vBMD of vertebra and a medially positioned cage led to higher contact pressures. Logically, low vBMD of vertebra and transverse cage orientation increased the contact area between the cage and endplate. In conclusion, the study identified significant influence of vBMD of vertebra, cage position and orientation on cage-endplate contact which may help to inform cage selection and design for LIF.

It is challenging to reproduce both anatomical and functional aspects of anterolateral reconstruction: postoperative 3D-CT analysis of the femoral tunnel position

BackgroundThis study aimed to evaluate the femoral tunnel position and fiber length of the anterolateral ligament (ALL) reconstruction compared with the natural anatomy of the ALL. We also evaluated whether the femoral tunnel position would affect residual pivot shift.MethodsThis study was a retrospective review of 55 knees that underwent ALL reconstruction considering the anatomical and functional aspects, during primary anterior cruciate ligament (ACL) reconstruction in the presence of a high-grade pivot shift or revisional ACL reconstruction. We determined the position of the femoral tunnel and the length of graft using a three-dimensional (3D)-computed tomography (CT) model after ALL reconstruction. We also measured graft excursion during surgery and examined pivot shift 2 years after surgery. We conducted a subgroup analysis of femoral tunnel position, fiber length, isometricity, and residual pivot shift depending on whether the tunnel was anterior or posterior to the lateral epicondyle (LE). We also performed a subgroup analysis depending on whether the ACL reconstruction was primary or revisional.ResultsThe mean femoral tunnel position was 2.04 mm posterior and 14.5 mm proximal from the center of the LE. The mean lengths of the anterior and posterior fibers were 66.6 and 63.4 mm, respectively. The femoral tunnel was positioned more proximally than the anatomical position, and both anterior and posterior ALL fibers were longer than the natural anatomy. The anteroposterior femoral tunnel position was significantly correlated with anterior (p = 0.045) and posterior (p = 0.037) fiber excursion. In the subgroup analysis, there was no significant difference in the residual pivot shift between the posterior and anterior tunnel positions. However, there were significant differences for proximal position (p < 0.001) and fiber length (p = 0.006). There was no significant difference between primary and revisional ACL regarding femoral tunnel position and fiber lengths.ConclusionIt is challenging to reproduce both anatomical and functional aspects of ALL reconstruction in both primary and revision ACL reconstruction. Especially for functional reconstruction, the femoral tunnel tended to be positioned more proximally than the anatomical position. However, the femoral tunnel position did not affect functional clinical outcomes at the 2-year follow-up.Level of evidenceLevel IV Case series.

Tongue and jaw movement assessed by 3D motion capture during gum chewing.

The tongue plays an important role in mastication, swallowing, and articulation, but it cannot be directly observed because of its location inside the oral cavity. This study aimed to clarify detailed 3D tongue movements during chewing using electromagnetic articulography (EMA). The participants were 10 healthy, young volunteers (average age 26.8 ± 2.1years; 5 males, 5 females). Tongue and jaw movement during gum chewing was measured and recorded using EMA. Four EMA sensors were attached to the anterior, posterior, left, and right surfaces of the tongue, and one sensor was also attached to the mandibular left incisor. The tongue motion during the chewing cycle was spatially and sequentially analyzed based on the motion trajectories of the tongue and mandible. The tongue moved downward and to the masticatory side in a manner similar to the movement of the jaw. The anterior tongue marker moved downward to a greater extent than the other tongue markers. However, the tongue moved forward as the jaw moved backward. The anterior marker reached the most anterior position during the jaw-opening phase and the posterior markers reached the most anterior position during the jaw-closing phase. Just before maximum jaw-opening, all markers on the tongue reached the bottom lowest position. During the jaw-closing phase, the tongue reached the dominant farthest position in the masticatory side. All the markers reached the most posterior position during the occlusal phase. These findings demonstrate the sequence of tongue motion patterns during gum chewing.

Tactile Mechanisms and Afferents Underlying the Rat Pup Transport Response.

Juvenile rodents and other altricial mammals react with calming, immobility and folding up of feet to parental pickup, a set of behaviors referred to as transport response. Here we investigate sensory mechanisms underlying the rat transport response. Grasping rat pups in anterior neck positions evokes strong immobility and folding up of feet, whereas more posterior grasping positions have lesser effects on immobility and foot position. Transport responses are enhanced by slow (1Hz) and even more so by fast (4Hz) gentle shaking and translation of the pup, features consistent with parental transport. In response to lateral grasping, the forepaw below the grasping position points downwards and the forepaw lateral to the grasping position points upwards and medially. Such forepaw adjustments put the pup's center of gravity below the grasping point, optimizing pup transportability along with folding up of feet and tail lifting. Tactile stimuli on the back, belly, tail, whisker, dorsal forepaws and dorsal hind-paws do not significantly affect the behaviour of anterior-neck-held pups. Instead, ground contact or paw stimulation consistent with ground contact disrupts transport responses. We identify afferents mediating the transport response by examining membrane labelling with FM1-43 following anterior neck grasping. We observe a dense innervation of the anterior neck skin region (~30 terminals/ mm2). We also observed an age-related decrease of cytochrome oxidase reactivity in the rat somatosensory cortical neck representation, a possible correlate to the developmental decrease in the pup transport response. We conclude anterior neck grasping and loss of ground contact trigger calming and postural adjustments for parental transport in rat pups, responses putatively driven from the densely innervated anterior neck skin.

Anterior cruciate ligament reconstruction: Effect of graft tunnel position on early to mid-term clinical outcomes.

Patient reported outcome measures (PROMs) can be used to assess knee function following anterior cruciate ligament (ACL) reconstruction. Intra-operatively, femoral and tibial tunnels are created to accommodate the new ACL graft. It is postulated that there is an optimum position and orientation of these tunnels and that outcomes from this procedure are affected by their position. To evaluate the influence of graft tunnel position on early to mid-term clinical outcomes following ACL reconstruction. Six PROMs were collected following ACL reconstruction which included the Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee, Lysholm, Tegner, EuroQol-5 Dimension-5 level, and Short Form 12-item Health Survey. A total of 8 radiological parameters were measured from post-operative X-rays relating to graft tunnel positions. This data was analysed to assess for any correlations between graft tunnel position and post-operative PROMs. A total of 87 patients were included in the study with a mean post-operative follow-up of 2.3 years (range 1 to 7 years). Posterior position of tibial tunnel was associated with improved KOOS quality of life (rho = 0.43, P = 0.002) and EQ-5D VAS (rho = 0.36, P = 0.010). Anterior position of EndoButton femoral tunnel was associated with an improved EQ-5D index (rho = -0.38, P = 0.028). There were no other significant correlations between any of the other radiological parameters and PROM scores. Overall, graft tunnel position had very little correlation with clinical outcomes following ACL reconstruction. A few (posterior) tibial tunnel and (anterior) EndoButton femoral tunnel measurements were associated with better PROMs.

Analysis and consideration of radiation dose distribution in cardiac catheterization interventions

objective: To assess the variations in radiation dose at different areas in the cardiac catheterization room during cardiac catheterization interventions. methods:To simulate the conventional operation in cardiac catheterization interventions, perform angiography on standard manikins ,the radiation dose was collected from 22 areas in the cardiac catheterization room under 8 projection angles, and each area was repeated 5 times, and the collected data was analyzed using one-way ANOVA and independent sample t-test. results:Analysis of the radiation dose in 22 areas under 8 projection angles revealed that the lowest radiation dose was found in the area at the end of the operating table in the cardiac catheterization room (p &lt; 0.05), and the highest radiation dose was found in the area on the left and right sides of the X-ray tube (p &lt; 0.05); the radiation dose in the area on the right side of the X-ray tube of the DSA machine was greater than that in the conventional standing area of the first operator (p &lt; 0.05)，and the radiation dose in the conventional standing area of the second operator was greater than that in the conventional standing area of the first operator (p &lt; 0.05); the radiation dose in the standing area of the first operator was highest in the cephalic position (CRA 30°) (p &lt; 0.05), and the radiation dose in the standing area of the second operator was highest in the left anterior oblique position (LAO 45°) (p &lt; 0.05); in the angle of RAO projection, the radiation dose in the right area of the X-ray tube was greater than that in the left area of the X-ray tube (p &lt; 0.05). Under the RAO projection angle, the radiation dose from the right side of the X-ray tube of the DSA machine was greater than that from the left side (p&lt;0.05), and the result was reversed at the projection angle of the LAO. conclusion:The radiation dose during cardiac catheterization interventions is lowest in the area at the end of the operating table, which can be used as a standing area for nurses and as an area for the placement of surgical equipment and supplies. At the same time, it is necessary to pay attention to the radiation dose to the second operator and to further improve the radiation protection measures for the second operator, and additional measures are needed to minimize the radiation dose to the operators in the cephalic position (CRA 30°) and in the left anterior oblique position (LAO 45°).