Bridge Length Research Articles

Editor's Choice – Outcomes of Off the Shelf Outer Branched Versus Inner Branched Endografts in the Treatment of Thoraco-Abdominal Aortic Aneurysm in the B.R.I.O. (BRanched Inner – Outer) Study Group

This study aimed to compare two commercially available off the shelf branched endografts for thoraco-abdominal aortic aneurysm (TAAA) repair, namely the E-nside (Artivion) and Zenith t-Branch (Cook Medical) devices. This multicentre retrospective study (2020 - 2023) included patients treated by branched endovascular aortic repair (BEVAR) for TAAA using the inner branched E-nside or the outer branched t-Branch. Endpoints were 30 day technical success and major adverse events (MAEs) as well as one year freedom from target vessel instability and main endograft instability. The study included 163 patients: 79 (307 target vessels) treated with E-nside and 84 (325 target vessels) with t-branch. Aneurysm extent was I - III in 91 patients (55.8%; 47% of E-nside and 66% of t-Branch) and IV in 72 patients (44.2%; 53% of E-nside and 34% of t-Branch) (p= .011). An adjunctive proximal thoracic endograft was used in 43% of E-nside vs. 69% of t-Branch (p < .001), with less frequent thoracic endografting (14% vs. 76%; p < .001) and shorter length of coverage (p= .024) in extent IV TAAA treated by E-nside. E-nside cases had shorter renal artery bridging lengths (66 ± 17 mm vs. 76 ± 20 mm; p < .010) and less frequent use of a distal bifurcated endograft (53% vs. 80%; p < .001). Comparing 30 day results, the mortality rate was 1% vs. 2% (p= .62), any MAE occurred in 18% vs. 21% (p= .55), the stroke rate was 3% vs. 0% (p= .23), and the elective spinal cord ischaemia rate was 5% vs. 8% (p= .40) for E-nside and t-Branch, respectively. At one year, freedom from target vessel instability was 96 ± 3% for E-nside and 95 ± 3% for t-Branch (p= .58), and freedom from endograft instability was 98 ± 2% vs. 97 ± 3% (p= .46), respectively. Both off the shelf devices provided excellent early and one year results. The E-nside may require shorter thoracic aortic coverage and bridging length for the renal arteries, and less frequent implantation of a concomitant proximal thoracic or distal abdominal bifurcated endograft. However, these aspects did not determine significant differences in clinical outcomes.

Study on jetting droplet formation regime in a low-speed annular shear flow field

This study aims to explore the mechanism of droplet generation and the change rule of liquid bridge in an annular shear flow field. With the help of a two-phase system of continuous phase (deionized water)-dispersed phase (fluorescent oil), the process of droplet generation under the jetting mechanism was captured using a camera. By studying the effect of the dispersed phase flow rate on the length of the liquid bridge, it was found that the volume flow rate of the dispersed phase is positively correlated with the frequency of droplet formation and the droplet size, and that the distance of the liquid bridge is also positively correlated with the droplet size under the jetting mechanism. Besides, a prediction mechanism for the maximum stable droplet under the jetting mechanism is proposed based on the droplet formation process.

Internal mucosal resection and LLC suspension: a new method to establish a stable tip rotation angle and reduce the nasal bridge length.

Herein, we describe a new technique to obtain both the appropriate degree of rotation angle and the ideal nasal bridge length. The aim of this study is to investigate the long-term results of this new technique with regard to these two variables. A total of 76 (27 males, 49 females) patients were operated in accordance with the presented technique. Internal caudal mucosal excision and lower lateral cartilage (LLC) suspension were applied to all the patients included in this prospective study. Preoperative, immediate postoperative, and postoperative 1st-year photographs were taken. NOSE scores were obtained in the postoperative 1st year. The mean nasolabial angle values of the patients preoperatively, at the end of the surgery (immediate postoperative), and at the end of the first year were 94.13° ± 5.1, 113.1° ± 5.3, and 109.6° ± 5.2, respectively. The patients had an average gain of 19° at the nasolabial angle at the end of the surgery and experienced a 3.5° (3.1%) loss at the end of the first year. For the nasal bridge length (n-prn) values; the preoperative, immediate postoperative, and first year mean values were 5.1 ± 0.55 cm, 3.98 ± 0.41 cm, and 4.29 ± 0.39 cm, respectively. The noses of the patients were shortened by 1.11 cm on average at the end of the surgery. Internal caudal mucosal resection with a suspension of the LLC to the caudal edge of the upper lateral cartilages (ULC) offers a reliable method to control the nasal tip rotation and shorten the long noses. This technique's effect is more obvious in long noses compared to the short ones.

Maximum permissible safe length of integral abutment bridges supported by steel H-piles

The absence of a defined allowable pile ductility in integral abutment bridges (IABs) creates a critical gap in determining the maximum safe bridge length. This paper introduces a design aid procedure to assist bridge engineers in establishing the length limits of jointless bridges. Numerical and analytical approaches were used in formulating the design aid procedure. A total of 66 finite difference models were established to obtain pile equivalent cantilever length considering various design parameters (soil stiffness, pile size, pile orientation, axial compressive load, and lateral displacement magnitude). The analytical approach incorporates a strain compatibility and equilibrium model to generate moment-curvature diagrams and load-deflection curves for standard HP sections commonly used in IABs construction. The validity of the developed design aid procedure was examined and tested with available experimental and numerical results. Lateral buckling displacement capacity of HP sections ranged from 50 to 100 mm (2–4 in.). Based on these displacement capacities, length limits for IABs were established and compared with existing studies. The maximum length limits for steel integral bridges fall within the range of 162–320 m (530–1050 ft), while concrete integral bridges have limits ranging from 210 to 390 m (680–1285 ft). These limits depend on factors such as pile size, soil stiffness, and climate conditions.

Electrically driven coalescence of charged conical droplet in non-uniform electric field

The dynamic behaviors of charged droplet coalescence in electric field has drawn much attention over the past decades due to its complex underlying physics and potential industrial application. This work experimentally investigated asymmetric coalescence dynamics of conical droplets in non-uniform electric field. With the effect of electric field, the cone apexes of deformed droplets merged with each other to form a liquid bridge that initially expanded but then retracted back gradually. It was found that the bridge length increased fast at initial conical coalescence and shrank slowly at retraction stage in various conditions. In addition, the effect of electric charge distribution and transportation on liquid bridge evolution behaviors was analyzed. The characteristics of cone angle and contact distance during droplet conical coalescence and recoil processes were quantitatively discussed with consideration of different parameters. Besides, the phase diagram for determining droplet coalescence and recoil was illustrated based on contact distance and electric Bond number, where the critical transition boundary was figured out with a linear increasing trend.

Bridging length scales in organic mixed ionic-electronic conductors through internal strain and mesoscale dynamics.

Understanding the structural and dynamic properties of disordered systems at the mesoscale is crucial. This is particularly important in organic mixed ionic-electronic conductors (OMIECs), which undergo significant and complex structural changes when operated in an electrolyte. In this study, we investigate the mesoscale strain, reversibility and dynamics of a model OMIEC material under external electrochemical potential using operando X-ray photon correlation spectroscopy. Our results reveal that strain and structural hysteresis depend on the sample's cycling history, establishing a comprehensive kinetic sequence bridging the macroscopic and microscopic behaviours of OMIECs. Furthermore, we uncover the equilibrium and non-equilibrium dynamics of charge carriers and material-doping states, highlighting the unexpected coupling between charge carrier dynamics and mesoscale order. These findings advance our understanding of the structure-dynamics-function relationships in OMIECs, opening pathways for designing and engineering materials with improved performance and functionality in non-equilibrium states during device operation.

The value of quantitative flow ratio in the hemodynamic evaluation of myocardial bridge

Objective: To explore the application value of quantitative flow ratio (QFR) in the hemodynamic evaluation of myocardial bridge and to preliminarily evaluate the correlation and related influencing factors between deformation quantitative flow ratio (D-QFR) and QFR. Methods: This is a cross-sectional study. Patients with CAG-confirmed simple myocardial bridge of the middle anterior descending coronary artery from June 2012 to June 2022 at the Air Force Medical Center were retrospectively included in this study. Systolic stenosis of mural coronary arteries (MCA) and myocardial bridge length were measured using quantitative coronary angiography. The patients were divided into mild stenosis group (<50% systolic stenosis) and moderate-to-severe stenosis group (≥50% systolic stenosis) according to the Nobel grading criteria. At different time periods (systolic and diastolic), the QFR values were measured at 3 locations (1 to 2 cm before the MCA entrance, the middle segment of the MCA, and 1 to 2 cm after the MCA exit), denoted as QFRa, QFRb, and QFRc, respectively, and the D-QFR values, incorporating vessel deformation information, were recorded. The MCA distal QFR≤0.8 in either stage was defined as an abnormal QFR value. QFR values were compared between the two groups at different locations and within each group. Factors associated with abnormal QFR values were analysed using multifactorial logistic regression. Spearman rank correlation analysis was used to examine the correlation between D-QFR values and systolic and diastolic QFR values.Multiple linear regression was used to analyse the factors associated with D-QFR. Results: A total of 83 patients were enrolled, including 58 males, aged (57.1±13.1) years. There were 48 cases in the mild stenosis group and 35 cases in the moderate-to-severe stenosis group, and the differences in systolic and diastolic QFRb and QFRc values between the two groups were statistically significant (all P<0.05). Within-group comparisons showed the values of QFRb and QFRc in the systolic phase were lower than those in the diastolic phase; QFRb and QFRc were both lower than QFRa during the same period (all P<0.05). Multifactorial logistic regression analysis showed that MCA systolic stenosis (OR=1.225, 95%CI 1.093-1.372, P<0.001) was an influential factor for abnormal QFR. D-QFR values were positively correlated with both systolic and diastolic QFR values (correlation coefficients were 0.849 and 0.675, respectively, both P<0.01). Multiple linear regression analysis showed that D-QFR values were negatively correlated with age (β=-0.208, P=0.029), systolic stenosis (β=-0.500, P<0.001), and myocardial bridge length (β=-0.211, P=0.036). Conclusions: The QFR values in middle and distal of myocardial bridge decrease. The systolic stenosis rate of myocardial bridge is an important factor affecting QFR value. D-QFR is positively correlated with both systolic and diastolic QFR values. Age, myocardial bridge systolic stenosis rate and length are factors influencing the D-QFR values.

State-Based Technical Condition Assessment and Prediction of Concrete Box Girder Bridges

The technical condition of bridges has become a crucial issue for organizing the maintenance and repairs in bridge management systems. It is of great practical engineering significance to construct an effective model for predicting the technical condition degradation of the bridge through the use of the historical inspection data. Based on the semi-Markov random process, this paper proposes a useful deterioration prediction model for bridges in the highway network. From the historical inspection data of the prefabricated concrete box girder bridges, the degradation curves of technical condition rating are obtained. The effect of bridge length on degradation rate of the prefabricated concrete box girder bridges is analyzed. According to the Weibull distribution parameters of different condition grades, the technical state degradation models for a bridge group and an individual bridge are proposed to predict the performance of the overall bridge and superstructure of the bridge. The results show that with the increase in bridge length, the degradation rate of bridge technical condition increases. The degradation rate of the technical condition of the superstructure is faster than that of the overall bridge. The proposed semi-Markov stochastic degradation model for the bridge group can not only predict the different condition ratings of the bridges at any time, but also predict the future deterioration trend of an individual bridge under any ratings.

Structural Characterization of 5-Substituted Pyrrolo[3,2-d]pyrimidine Antifolate Inhibitors in Complex with Human Serine Hydroxymethyl Transferase 2.

We previously discovered first-in-class multitargeted 5-substituted pyrrolo[3,2-d]pyrimidine antifolates that inhibit serine hydroxymethyltransferase 2 (SHMT2), resulting in potent in vitro and in vivo antitumor efficacies. In this report, we present crystallographic structures for SHMT2 in complex with an expanded series of pyrrolo[3,2-d]pyrimidine compounds with variations in bridge length (3-5 carbons) and the side chain aromatic ring (phenyl, thiophene, fluorine-substituted phenyl, and thiophene). We evaluated structural features of the inhibitor-SHMT2 complexes and correlations to inhibitor potencies (i.e., Kis), highlighting conserved polar contacts and identifying 5-carbon bridge lengths as key determinants of inhibitor potency. Based on the analysis of SHMT2 structural data, we investigated the impact of mutation of Tyr105 in SHMT2 kinetic analysis and studies with HCT116 cells with inducible expression of wild-type and Y105F SHMT2. Increased enzyme inhibition potency by the pyrrolo[3,2-d]pyrimidine inhibitors with Phe105 SHMT2 accompanied an increased growth inhibition of Phe105-expressing HCT116 cells compared to wild-type SHMT2. Pyrrolo[3,2-d]pyrimidine inhibitors with polyglutamate modifications were evaluated for potencies against SHMT2. We determined the crystal structures of SHMT2 in complex with our lead antifolate AGF347 lacking L-glutamate, or as a diglutamate and triglutamate, for comparison with parent AGF347. These data provide the first insights into the influence of antifolate polyglutamylation on SHMT2:inhibitor interactions. Collectively, our results provide new insights into the critical structural determinants of SHMT2 binding by pyrrolo[3,2-d]pyrimidine inhibitors as novel antitumor agents, as well as the first structural characterization of human SHMT2 in complex with polyglutamates of an SHMT2-targeted antifolate.

Secondary Bilateral Cleft Rhinoplasty: Achieving an Aesthetic Result.

Secondary rhinoplasty in patients with bilateral cleft lip poses ongoing challenges and requires a reliable method for achieving optimal outcomes. The purpose of this study was to establish a safe and effective method for secondary bilateral cleft rhinoplasty. A consecutive series of 92 skeletally matured patients with bilateral cleft lip and nasal deformity were included. All had undergone secondary open rhinoplasty, performed by a single surgeon with a bilateral reverse-U flap and septal extension graft, between 2013 and 2021. Medical records of these 92 patients were reviewed to assess the clinical course. A 3-dimensional (3D) anthropometric analysis and panel assessment of 32 patients were performed to evaluate the aesthetic improvement, with an age-, sex-, and ethnicity-matched normal control group for comparisons. The methods showed statistically significant improvement in addressing a short columella (columellar height), short nasal bridge (nasal bridge length), de-projected nasal tip (nasal tip projection, nasal dorsum angle), poorly defined nasal tip (nasal tip angle, dome height, and panel assessment), and transversely oriented nostrils (columellar height, alar width, nostril type). Importantly, these improvements were accompanied by a low complication rate of 4%. However, upper lip deficiency over the upper lip angle and labial-columellar angle remained without significant improvement. In this study we described effective secondary rhinoplasty, which was composed of a bilateral reverse-U flap and septal extension graft, with acceptable outcome. The 3D anthropometric analysis and panel assessment clarified that our rhinoplasty procedure could bring the nasal morphology in these patients closer to the normal data.

A precise modeling method of three‐dimensional discrete fracture network based on rectangular joint model

AbstractAs the weak structure and main seepage channel of rock mass, the discrete fracture network (DFN) has a significant influence on the physical and mechanical properties of rock mass. In this paper, based on the rectangular joint model, two algorithms are proposed to realize the precise modeling of the DFN in any polyhedron. First, the equivalence of DFN modeling with the rectangular joint model and the elliptical joint model is theoretically deduced. On this basis, the chain splicing algorithm suitable for the rectangular joint model is proposed, which can generate the DFN model according to the actual distribution of joint spacing, trace, and bridge length. Aiming at the concave boundary in the model domain, the segmentation‐stitching operation is put forward, and the continuity of the joint when passing through the interface is ensured. Finally, the effectiveness of the above algorithm is verified by several simple cases, and the relationship between the size of the geometrical representative elementary volume (REV) and discontinuity parameters is discussed. The results show that when the mean values of the joint distribution parameters are the same, even if the distribution rules are different, the number of joints generated in the same spatial region is approximately equal. The size of the geometrical REV is independent of the spacing and bridge length and is approximately three to five times the mean of the trace. The relevant algorithms and conclusions in this paper can be used as the basis for subsequent rock mass stability analysis and seepage calculation.

Numerical Investigation for the Effect of Joint Persistence on Rock Slope Stability Using a Lattice Spring-Based Synthetic Rock Mass Model

This study underscores the profound influence of rock joints, both persistent and non-persistent with rock bridges, on the stability and behavior of rock masses—a critical consideration for sustainable engineering and natural structures, especially in rock slope stability. Leveraging the lattice spring-based synthetic rock mass (LS-SRM) modeling approach, this research aims to understand the impact of persistent and non-persistent joint parameters on rock slope stability. The Slope Model, a Synthetic Rock Mass (SRM) approach-based code, is used to investigate the joint parameters such as dip angle, spacing, rock bridge length, and trace overlapping. The results show that the mobilizing zones in slopes with non-persistent joints were smaller and shallower compared to slopes with fully persistent joints. The joint dip angle was found to heavily influence the failure mode in rock slopes with non-coplanar rock bridges. Shallow joint dip angles led to tensile failures, whereas steeper joint dip angles resulted in shear-tensile failures. Slopes with wider joint spacings exhibited deeper failure zones and a higher factor of safety, while longer rock bridge lengths enhanced slope stability and led to lower failure zones. The overlapping of joint traces has no apparent impact on slope stability and failure mechanism. This comprehensive analysis contributes valuable insights into sustainable rock engineering practices and the design of resilient structures in natural environments.

Dynamic mechanical response and damage constitutive model of end-jointed rock bridge with different water content states under impact load

In rock slope engineering, the dynamic mechanical behavior of rocks is significantly influenced by the length of rock bridges and their moisture content. This study explored the dynamic characteristics of defective rocks under impact loads through dynamic impact tests on specimens varying in rock bridge lengths and moisture states, conducted using a Split Hopkinson Pressure Bar (SHPB). The experimental results revealed that both moisture state and rock bridge length markedly affect the dynamic compressive strength and elastic modulus. Additionally, there is a significant correlation between the energy dissipation density and the specimen's moisture state and rock bridge length. The failure process, captured via a high-speed camera, exhibited a transition in fracture mode from predominantly tensile to tensile-shear failure with increasing rock bridge length. Moreover, an enhanced ZWT model was developed and validated for the dynamic damage constitutive model of defective rocks. This model, incorporating four parameters, precisely characterizes the stress–strain relationship of defective rocks under high strain rates and effectively demonstrates the dynamic response of rocks with varying rock bridge lengths and moisture states. The findings of this study are vital for advancing the understanding of rock dynamics in varying conditions and offer significant insights for geological and civil engineering applications, particularly in the design and assessment of rock structure stability in slopes.

Experimental characterization and cyclic cohesive zone modeling of mode I delamination growth in glass/epoxy composite laminates under high cycle fatigue

Large-scale fiber bridging makes a significant impact on fatigue delamination growth (FDG) in fiber-reinforced polymer composites. As bilinear cyclic cohesive zone modeling (CCZM) is not a promising modeling tool in this case, another solution is needed. The present study aims to evaluate a new easily-calibrating trilinear CCZM framework for modeling the FDG in glass/epoxy double cantilever beam (DCB) laminates with large-scale fiber bridging. First, mode I delamination growth, characterized by a significant R-curve effect, is experimentally determined under both quasi-static and high cycle fatigue regimes. Next, trilinear forms of the Turon et al. and the Kawashita-Hallett damage models are developed to predict such fatigue delamination behavior. Results show that the accuracy and efficiency of the proposed trilinear CCZM framework are enhanced by increasing the bridging length of the composite structure. Additionally, the Kawashita-Hallett trilinear model yields the most consistent and precise predictions with the least computational time.

Nasal profile changes after orthodontic tooth extraction in Class II, Division 1 malocclusion patients: A retrospective study

IntroductionThis study aimed to investigate changes in the facial soft-tissue profile, especially the nose, following fixed orthodontic treatment, with or without tooth extraction, in individuals diagnosed with dental Class II malocclusion. Materials and methodsCephalometric images of 81 individuals with dental Class II malocclusion who underwent fixed orthodontic treatment were assessed before and after treatment. The participants were categorized into three groups: non-extraction; upper first premolar extraction; and four first premolar extractions. The parameters measured were: upper lip height, upper lip to E-plane, lower lip to E-plane, lower lip height, nasolabial angle, nasomental angle, facial convexity, lower anterior face height, soft-tissue facial convexity, nasal tip angle, nasal bridge length, N′-nasal bridge point, nasal bone length, nasal bone angle, nasal depth, columella convexity, and nose height. ResultsWithin the upper two extraction group, there were significant increases at the start and end periods in nasolabial angle (P = 0.023), nasal depth Pr to Ac (P = 0.027), and nasal depth Pr to N-Prn (P = 0.040); and decreases in columella convexity (P = 0.010), upper lip to E-plane (P = 0.009), and nasomental angle (P = 0.009). There were significant results in comparisons between measurements based on the extraction status in the mean nasolabial angle (P = 0.011), mean columella convexity (P = 0.028), and mean lower lip to E-plane (P = 0.045). ConclusionOrthodontic treatment involving tooth extraction may potentially affect the nasolabial angle and nasal depth. During treatment planning, it is crucial to consider the potential changes that may occur to the nose and any alterations that may be needed to achieve the desired esthetic outcome.

Depth variations of second and third tarsometatarsal joints during dorsal compression staple fixation using two different bridge lengths: an anatomic study

Fusion of the second and third tarsometatarsal joints is utilized for various arthritic pathologies and traumatic conditions. A cadaveric study using 20 fresh-frozen transtibial specimens were used for a stimulated arthrodesis study. Half of the specimens underwent drilling via drill guide for a respective 15 mm and 20 mm dorsal bridge length staples. Each drill guide was placed equidistant from each joint at 7.5 mm for the 15 mm bridge length and 10 m for the 20 m bridge length, then drilled bicortically in parallel with the joint line. For the 15 mm bridge length on the second metatarsal, the mean depth was 22.5 mm ± 2.2, and was 26.7 mm ± 3.8 proximal on the intermediate cuneiform. For the 20 mm bridge length on the second metatarsal, the mean depth was 22.3 mm ± 2.2 and was 27.2 mm ± 2.0 proximal on the intermediate cuneiform. For the 15 mm bridge length for the third metatarsal mean depth was 21.5 mm ± 3.2, and was 24.2 mm ± 2.9 proximal on the lateral cuneiform. For the 20 mm bridge length on the third metatarsal, the mean depth was 20.3 mm ± 2.4 and was 24.6 mm ± 2.4 proximal on the lateral cuneiform. A student's two tailed homoscedastic t-Test was calculated for the 7.5 mm vs 10 mm distal and proximal distances for both second and third TMT data sets and found there was no significant differences in depth.The current study found that for both 15 mm and 20mm bridge lengths for 2nd TMT fusions a 22 mm leg length can be used appropriate and similarly for 3rd TMT fusions, a 20 m leg length appears to be appropriate fixation. Although variations will exist, advances towards indication specific fixation may allow for varied leg length for optimal boney purchase.

Aza-bicyclodiene based photoswitches for molecular solar thermal energy storage

The effect of N-substitution on the properties of bicyclodienes with different bridge lengths is analysed for energy storage application. The improvement in the properties with N-substitution is more prominent for bicyclodienes with longer bridge.

Evaluation of Vertical Human‐Structure Interaction on a Pedestrian Bridge Using a Predictive Human Gait Model

Many modern pedestrian bridges exhibit flexibility and susceptibility to vibrations due to the use of lightweight and high‐strength materials, which can cause discomfort for pedestrians and affect their serviceability. Although gait biomechanics have been extensively studied and optimisation techniques for gait prediction on rigid surfaces have been previously employed, there is a paucity of studies investigating the effects of human‐structure interaction on pedestrian crossings over flexible structures. In this study, inverse dynamics and optimisation techniques were employed to predict human gait on a flexible structure in the sagittal plane. Gait was formulated as an optimal motor task subject to multiple constraints, with the performance criterion being the minimization of mechanical energy expenditure throughout a complete gait cycle. Segmental movements, pedestrian‐applied forces, and bridge vibrations were predicted based on parameters describing gait (such as gait speed, gait frequency, and double support duration), as well as physical and dynamic parameters characterizing the pedestrian bridge (including natural frequency, damping coefficient, and bridge length).

Surgical planning for staple fixation of the first tarsometatarsal joint: An anatomic study

First tarsometatarsal (TMT) arthrodesis is a common procedure utilized by foot and ankle surgeons for the management of a variety of first TMT pathology including hallux valgus and arthritis. The present study was undertaken to determine the average staple leg depth that allows for adequate purchase within the medial cuneiform and first metatarsal base at 2 different staple bridge lengths for dorsal compression across the 1st TMT joint. A cadaveric study was performed using 20 fresh-frozen below knee specimens. After TMT dissection was performed, drill holes were then created from dorsal to plantar and parallel to the first TMT joint at the distances utilized for 20 mm and 25 mm staple bridge lengths. The depths of each drill hole were measured and recorded. The mean medial cuneiform depth corresponding to a 20 mm and 25 mm staple bridge was 31.9 mm +/- 2.8 mm and 31.1 mm +/- 2.1 mm respectively (P-value = 0.38). The mean first metatarsal depth corresponding to a 20 mm and 25 mm staple bridge was 27.9 mm +/- 2.2 mm and 25.4 mm +/- 3.4 mm respectively (P-value = 0.04), showing statistical significance. Based on our anatomic data it is suggested that a 20 mm staple leg depth is consistently a safe depth when using 20×20 and 25×20 mm dorsal compression staples. However, further studies must be conducted to compare the amount of compression between the two respective staples.

Regression analysis of nasal shape from juvenile to adult ages for forensic facial reconstruction

The nose is a prominent feature for facial recognition and reconstruction. To investigate the relationship of the nasal shape with the piriform aperture in Korean adults and juveniles, we performed regression analysis. By regression analysis, prediction equations for nasal shape were obtained in relation to the shape of the piriform aperture considering sex and age groups.Three-dimensional skull and face models, rendered from computed tomography images, were assessed (331 males and 334 females). Juveniles (<20 years) were divided into three age groups according to the development of the dentition. Adults were divided into three age groups of two decades each, according to their age. To measure the nasal area, nine landmarks and nine measurements were chosen, while seven landmarks and five measurements were selected to measure the piriform aperture area. Four measurements were defined to explain the direct relationship between the nasal aperture and nasal shape.First, descriptive statistical analyses were performed according to sex and age groups. Subsequently, the correlation of nasal soft tissue measurements with piriform measurements was analyzed. Last, we performed a linear regression analysis of the measurements with higher correlations, considering sex and age groups as variables. Prediction equations were used to estimate the nasal bridge length, height, protrusion, and width. Equations considering sex and age groups showed better explanation ability. Measurements related to the height of the nasal bridge presented improvement. This study may assist in the more accurate approximation of nasal shape in facial reconstruction.