Ideal Insertion Research Articles

Neonatal Endotracheal Intubation: Comparison of Existing Formulae for Accuracy

Background There are several formulae proposed to calculate the ideal depth of insertion of the endotracheal tube (ETT) in neonates, none of which are universally accurate. Our objective is to identify the most accurate of these formulae and to determine the most suitable formula for babies weighing less than 1 kg. Methods This is a retro-prospective observational study conducted in a tertiary neonatal intensive care unit. All intubated babies, irrespective of their gestational age, were included in this study. Those with congenital airway anomalies or syndromes with involvement of the upper airway and those who required short-term ventilation restricted to the theatre complex were excluded. The ideal insertion depth was determined via a chest X-ray (CXR) with the ETT projecting between thoracic vertebrae 2 and 3. Predictions from eight formulae investigated in the Indian population were analysed using paired Wilcoxon tests and Bland–Altman plots. Results The sample size was 83, of which 16 weighed less than 1 kg. Neither weight-based nor naso-tragal length (NTL)-based formulae were universally accurate in the prediction of the ideal depth of insertion, and using either of the formulae resulted in a high rate of malpositioning. Amongst the NTL-based formulae, Tatwavedi and Singh’s adjustments worked better than the original. Conclusion The currently available formulae remain inaccurate in the prediction of the ideal length of insertion of ETT, more so in babies less than 1 kg in our study population.

The Effect of Force Application on the Stability of Mini-Screw in Different Insertion Angles (An in-vitro Study).

Background and Objective: The stability of the mini-screw is an important factor for the success of orthodontic treatment using an absolute anchorage system. This study aims to evaluate the ideal insertion angle of a mini-implant in relation to force direction and to evaluate the maximum amount of force application at a specific angular configuration. Method: In this experimental study 72 mini-screws were used, 36 of them were used for each shear and tensile force tests, eighteen samples were taken for the bone density D2 (nine for 60 degree angle, and nine for 90 degree angle), and 18 others were taken for the bone density D3 (nine for 60 degree angle, and nine for 90 degree angle). Guiding stents were fabricated for proper insertion angle, torque and speed were controlled by contra -angled handpiece. Shear and tensile force tests are done with the aid of a Universal Testing Machine. Results: Mini-implants inserted at 90 degree angle over D2 density bone had higher stability when performing the tensile force test, while in the shear force test mini-implants placed at 60 degree angle were more stable when inserted on bony blocks with D3 density, however it was noted that the results were statistically not significant when compared with 60 degree insertion on blocks with D2 density. Conclusion: To maintain a stable mini-implant during the orthodontic process, the ideal insertion angle is 90 degree when the force direction is vertical, tensile force, and its more appropriate to place the mini-implant at 60 degree angle when the direction of force is in a horizontal direction, shear force. Keywords: Mini-screw, Stability, Insertion Angle, Shear force, Tensile force

Ideal insertion point and projection of the infra-acetabular screw in acetabular fracture surgery

BackgroundIn acetabular fracture surgery, an infra-acetabular screw (IAS) is inserted from the anterior to the posterior column through the infra-acetabular corridor to stabilize both columns. Although the IAS is useful for increasing fixation strength, proper placement requires proficiency and often results in extraosseous screw penetration. The complex anatomy of the infra-acetabular corridor and difficult intraoperative detection of the ideal insertion point and angle make proper placement of the IAS challenging. This study aimed to detect the ideal insertion point and angle of the IAS based on anatomical landmarks that can be directly identified intraoperatively. MethodsWe retrospectively reviewed the pelvic CT of 50 adults who underwent serial slice CT imaging. The pelvic inlet plane (PIP), which contains the anterior border of both the sacroiliac joint and posterior superior edge of the pubic symphysis, was used as the reference plane for the pelvic coordinate system to simulate the ideal insertion of IAS. The distance from the posterior superior edge of the pubic symphysis to the ideal insertion point of the IAS (IAS distance) and the angle and length of the IAS that could be inserted from the ideal insertion point were measured. ResultsThe mean IAS distance was 61.0 ± 5.7 mm (57.6 ± 4.3 mm in men and 64.4 ± 4.9 mm in women). The mean angle between ideal IAS and yz-plane on the outlet view (α-angle) was 8.4 ± 6.6 ° (6.4 ± 5.6° in men and 10.5 ± 7.0° in women). The mean angle between ideal IAS and y-axis on the yz-plane (β-angle) was 86.5 ± 10.6 ° (86.0 ± 10.3° in men and 87.0 ± 10.9° in women). The length of IAS was 97.1 ± 4.7 mm in men and 89.2 ± 3.6 mm in women. ConclusionThe IAS ideal insertion point detected as a distance from the pubic symphysis may aid in the proper insertion of the IAS during surgery. The insertion angle was parallel or tilted 10 ° laterally to the longitudinal axis in the pelvic outlet plane and almost perpendicular to the PIP in the sagittal plane when inserted from the ideal insertion point.

Characteristics and evaluation of C1 posterior arch variation for transpedicular screw placement between patients with and without basilar invagination.

C1 transpedicular screw (C1TS) placement provided satisfactory pullout resistance and 3D stability, but its application might be limited in patients with basilar invagination (BI) due to the high incidences of the atlas anomaly and vertebral artery (VA) variation. However, no study has explored the classifications of C1 posterior arch variations and investigated their indications and ideal insertion trajectories for C1TS in BI. To investigate the bony and surrounding arterial characteristics of the atlas, classify posterior arch variations, identify indications for C1TS, evaluate ideal insertion trajectories for C1TS in BI patients without atlas occipitalization (AO), and compare them with those without BI and AO as control. A total of 130 non-AO patients with and without BI (52 patients and 78 patients, respectively) from two medical centers were included at a 1:1.5 ratio. The posterior arch variations were assessed using a modified C1 morphological classification. Comparisons regarding the bony and surrounding arterial characteristics, morphological classification distributions, and ideal insertion trajectories between BI and control groups were performed. The subgroup analyses based on different morphological classifications were also conducted. In addition, the factors possibly affecting the insertion parameters were investigated using multiple linear regression analyses. The BI group was associated with significantly smaller lateral mass height and width, sagittal length of posterior arch, pedicle height, vertical height of posterior arch, and distance between VA and VA groove (VAG) than control group. Four types of posterior arch variations with indications for different screw placement techniques were classified; Classifications I and II were suitable for C1TS. The BI cohort showed a significantly lower rate of Classification I than the control cohort. In the BI group, the subgroup of Classification I had significantly larger distance between the insertion point (IP) and inferior aspect of the posterior arch. In addition, it had the narrowest width along ideal screw trajectory, but a significantly more lateral ideal mediolateral angle than the subgroup of Classification II. Multiple linear regression indicated that the cephalad angle was significantly associated with the diagnosis of BI (B = 3.708, P < 0.001) and sagittal diameter of C1 (B = 3.417, P = 0.027); the ideal mediolateral angle was significantly associated with BMI (B = 0.264, P = 0.031), sagittal diameter of C1 (B = - 4.559, P = 0.002), and pedicle height (B = - 2.317, P < 0.001); the distance between the IP and inferior aspects of posterior arch was significantly associated with age (B = - 0.002, P = 0.035), BMI (B = - 0.007, P = 0.028), sagittal length of posterior arch (B = - 0.187, P = 0.032), pedicle height (B = - 0.392, P < 0.001), and middle and lower parts of posterior arch (B = 0.862, P < 0.001). The incidence of posterior arch variation in BI patients without AO was remarkably higher than that in control patients. The insertion parameters of posterior screws were different between the morphological classification types in BI and control groups. The distance between VA V3 segments and VAG in BI cohort was substantially smaller than that in control cohort. Preoperative individual 3D computed tomography (CT), CT angiography and intraoperative navigation are recommended for BI patients receiving posterior screw placement.

Comparison of accuracy between augmented reality/mixed reality techniques and conventional techniques for epidural anesthesia using a practice phantom model kit

BackgroundThis study used an epidural anesthesia practice kit (model) to evaluate the accuracy of epidural anesthesia using standard techniques (blind) and augmented/mixed reality technology and whether visualization using augmented/mixed reality technology would facilitate epidural anesthesia.MethodsThis study was conducted at the Yamagata University Hospital (Yamagata, Japan) between February and June 2022. Thirty medical students with no experience in epidural anesthesia were randomly divided into augmented reality (-), augmented reality (+), and semi-augmented reality groups, with 10 students in each group. Epidural anesthesia was performed using the paramedian approach with an epidural anesthesia practice kit. The augmented reality (-) group performed epidural anesthesia without HoloLens2Ⓡ and the augmented reality (+) group with HoloLens2Ⓡ. The semi-augmented reality group performed epidural anesthesia without HoloLens2Ⓡ after 30 s of image construction of the spine using HoloLens2Ⓡ. The epidural space puncture point distance between the ideal insertion needle and participant’s insertion needle was compared.ResultsFour medical students in the augmented reality (-), zero in the augmented reality (+), and one in the semi-augmented reality groups failed to insert the needle into the epidural space. The epidural space puncture point distance for the augmented reality (-), augmented reality (+), and semi-augmented reality groups were 8.7 (5.7–14.3) mm, 3.5 (1.8–8.0) mm (P = 0.017), and 4.9 (3.2–5.9) mm (P = 0.027), respectively; a significant difference was observed between the two groups.ConclusionsAugmented/mixed reality technology has the potential to contribute significantly to the improvement of epidural anesthesia techniques.

Radiographic considerations for the placement of mini-implants

Skeletal anchorage within the field of orthodontics has become indispensable in recent years, as it allows greater opportunities in the mechanics of treatment; however, there are various radiographic considerations that have been published for the positioning of mini-screws in the maxillae, this is due to the different criteria and methods used by researchers, and there are also different radiographic trends that would allow the ideal insertion point for the placement of mini-implants to be established. The literature was selected through a search of the following electronic databases: Pubmed, Google Academic, Springer, Taylor &amp; Francis, Web of Science and Cochrane, restricted to articles including all languages and published with no time limit. A total of 286 articles on the topic were obtained, and after applying the inclusion and exclusion filters, 16 articles were obtained and reviewed for the development of the present review. The available literature revealed that CT scans are the gold standard compared to periapical, occlusal and panoramic radiographs for the evaluation and diagnosis of mini-implant placement. However, if low-dose CT scans are not available, then the ideal would be to place the mini-screw following the bone/dental anatomy and then take a single periapical or panoramic radiographic image after mini-screw placement to observe possible lesions from the manoeuvre performed.

Accuracy of femoral tunnel positioning in medial patellofemoral ligament reconstruction: anatomic insertion leads to better clinical outcome.

The medial patello-femoral ligament (MPFL) is considered the primary restraint against patellar dislocation and its reconstruction is indicated in recurrent patellar instability. An anatomical positioning of MPFL femoral insertion is recommended to achieve satisfactory clinical outcomes and prevent osteoarthritis (OA) due to an altered kinematics. The purpose of the study was first to assess the relationship between correct femoral tunnel position and better clinical outcomes and lower patellofemoral osteoarthritis rate. Second, correlation of outcomes with factors potentially affecting the results, such as the type of graft, patellar height and trochlear dysplasia. Fifty-three patients (58 knees) who underwent MPFL reconstruction between 2009 and 2018 by a senior knee surgeon were retrospectively evaluated. Knee radiographs were performed before surgery, 12months later and at last follow-up to assess trochlear dysplasia, patellar height and patellofemoral OA. The tibial tuberosity-trochlear groove (TT-TG) value was measured on a CT scan. The accuracy of graft positioning was evaluated on sagittal radiographs according to Schöttle et al. Subjective outcomes were collected before surgery, at 12months and at last follow-up using several validated scores. Forty-six patients (51 knees) with a mean age of 24.1 ± 7.4years were included in the study. Mean follow-up was 8.9 ± 2.1years. A significant improvement in all clinical scores was observed at 12months and final follow-up. Anatomic Insertion (AI) of reconstructed MPFL was considered optimal in 33 (64.7%) and sub-optimal in 18 (35.3%) patients. Sub-optimal AI resulted in lower Kujala, IKCD and higher VAS score (p < 0.01); moreover, for every 1mm distance in any direction from the ideal insertion, a decrease of 0.8 [95% CI (-1.4; -0.2)] in Kujala score and 0.8 [95% CI (-1.3; -0.3)] in IKDC was observed. At final follow-up, 8 patients presented patellofemoral OA Iwano grade 3 (15.7%): although that incidence did not correlate to graft positioning, the use the artificial ligament in all these cases appeared to be significant. The present study confirms the importance of an optimal anatomic femoral insertion in MPFL reconstruction, reporting a significant positive correlation between graft positioning and clinical outcome. No significant correlations were found between anatomic insertion and patello-femoral OA development. IV.

CheckMyFit

Putting on hearing aids (HAs) is a regular and crucial task for every hearing aid wearer. A sub-optimal insertion can impact user adoption and audiological benefit. Ability to visually evaluate the insertion can be helpful to achieve a proper physical fit of hearing aids or similar devices, but this is currently a challenging task. In this work we present CheckMyFit, a smartphone-based, automated solution enabling users to quickly take a photo of their hearing aid placement, and compare it with a reference ideal insertion. To evaluate the tool's usability and potential benefit we conducted two user studies: a) a pilot lab study with 7 participants, and b) a field study with 17 participants. In the two-week field study, older participants with no prior hearing aid experiences were instructed on hearing aid insertion remotely and performed daily insertions independently at home. We found that CheckMyFit is easy and quick to use for almost all participants. Ear-photo-aided insertions tend to have higher quality than insertions without the tool. This correlation was significant and persisted throughout the 2 weeks of the study, and is retained after a short break. This suggests that CheckMyFit tool can provide real-world benefit to new users learning to insert their hearing aids. We also used CheckMyFit to remotely facilitate the field study, demonstrating its potential usefulness in tele-medicine.

Blind vs. video-laryngoscope-guided laryngeal mask insertion: A prospective randomized comparison of oropharyngeal leak pressure and fiberoptic grading.

Laryngeal Mask Airway (LMA) insertion may not always be smooth without complications. Controversial results of several studies evaluating ideal insertion conditions have been published. This study compared the oropharyngeal leak pressure values and fiberoptic grading scores between blind and video-laryngoscope-guided LMA insertion. Patients were randomly assigned into blind insertion (n = 50) and video-laryngoscope guided insertion (n = 50) groups. The oropharyngeal leak pressure, peak airway pressure, fiberoptic grading score, first attempt success rate, hemodynamic parameters, and complications were recorded. All laryngeal mask airways were successfully inserted in both groups at the first attempt. The fiberoptic staging scores were: grade 1 in 8.2% of patients, grade 2 in 24.4% of patients, grade 3 in 44.8% of patients, grade 4 in 22.4% of patients in the control group. On the other hand, grade 1 in 2.2% of patients, grade 2 in 28.6% of patients, grade 3 in 51% of patients, grade 4 in 8.2% of patients in the VL group (p = 0.260). The peak airway pressure and LMA insertion time were similar between groups. However, the oropharyngeal leak pressure before extubation was significantly higher in the video-laryngoscope-guided insertion than blind insertion (36.29 ± 7.09 vs. 33.79 ± 8.84 cmH2O respectively, p = 0.04). The findings of our study suggest that the video-laryngoscope-guided LMA-Classic insertion with a standard blade technique may be a helpful alternative to blind insertion.

Correlation between lag screw route and the ideal insertion point of the intramedullary nail

Understanding the morphology of the superior aspect of the proximal femur is critical for treating femoral fracture. We assessed the correlation among the ideal insertion point of the femoral nail, femur head-neck axis, and native anteversion. One hundred patients with normal femurs were included in this study. Computed tomography (CT) images of the proximal femur superior aspect and amount of native anteversion were acquired. Generalised Procrustes analysis showed the morphological characteristics of the superior proximal femur according to native anteversion amount. Morphological characteristics were represented by 4 parameters; the correlation between parameters and native anteversion was investigated using CT data. The passing point of the line from the proximal femoral canal parallel to the native anteversion at the greater trochanter was located more posteriorly (mean 35.6%); the passing point of native anteversion was posterior in the femoral neck and head, although the line of the head-neck centre passed more anteriorly at the greater trochanter (mean 67.5%). This posterior translation was significantly associated with native anteversion amount. Morphometric geometric analysis showed that the lag screw could not pass head-neck centre from the nail inserted into proximal femoral canal. Anterior insertion of the nail was needed for positioning the lag screw centre.

The largest secure corridor of the infra-acetabular screw\u2014a 3-D axial perspective analysis

BackgroundThe infra-acetabular screw which is placed from the pubis to the ischium can be used as a special positional screw of the posterior column of the acetabulum. This study was performed to simulate the surgical procedure and obtain the ideal insertion point, diameter, length and angle of the screw through the method of axial perspective in Chinese patients.MethodsWe randomly collected the pelvic computed tomography (CT) scans of 200 adults. DICOM-formatted CT-scan images were imported into Mimics software to establish the 3D digital model of the right semi-pelvic was established. A virtual cylinder representing the screw was placed from the pubis to the ischium to fix the posterior column. The largest secure diameter and length of the virtual screw were measured and the position of the insertion point and the directions of the screw were also researched.ResultsThe screw insertion safe zone exhibits an irregular shape of “tear drop” in the reconstructed pelvic model. The mean maximum diameter of screws was 5.01 ± 1.28 mm, and the mean maximum length of screws was 93.99 ± 8.92 mm. The screw insertion corridor with the least diameter 3.5 mm was found in 94 of 100 males (94%) and 86 of 100 females (86%). We found gender-dependent differences for the mean maximum diameter and the maximum length of the screw. There was statistically significant difference between genders in the position of insertion point.ConclusionsIn this study, we suggest an individual preoperative 3D reconstruction simulation to develop better screw placement plans, which provides a valuable guideline for seeking the largest secure corridor of infra-acetabular screw. Further biomechanical studies are needed to verify the function of the screw.

Design method and research of high temperature gas floating ring seal with slightly variable gap

The problem of seal failure caused by rubbing between floating ring and shaft directly affects the actual production efficiency. In this paper, the mathematical model of floating ring seal was established, the expression of seal clearance under the working condition of floating ring was calculated, and the design method of “slightly variable gap” gas floating ring was proposed. The finite element model was established by using Workbench, and the correctness of the mathematical model was verified. The results show that the ideal insert ring material calculated by the “slightly variable gap” design method can keep the working clearance of floating ring seal stable. In practical application, the insert ring with the same material as the axle runway can also be selected to achieve a more stable working clearance. The design method can avoid the rubbing between the runway and the inside of the floating ring under harsh conditions.

Modeling and Shaping of the DC-Side Admittance of a Modular Multilevel Converter Under Closed-Loop Voltage Control

The dc-side admittance of a modular multilevel converter can be used in assessing the stability of the dc system by means of impedance-based stability criteria. An accurate mathematical representation of the small-signal admittance can be given using harmonic linearization. To this end, the effect of the internal dynamics of the converter, e.g., the circulating current, the converter control scheme, and the controller parameters on the admittance of the converter should be analyzed. In this article, a linear analytical model for the dc-side admittance of the converter is derived based on a combination of harmonic linearization and frequency-domain representation, which incorporates different control schemes. Moreover, an admittance model is given for the closed-loop voltage control mode of the converter, where the ideal insertion indices are applied. To this end, the impact of an arm-balancing controller and its parameters on the dc-side admittance of the converter is investigated. Finally, experiments are carried out on a down-scaled prototype to validate the accuracy of the analytical model.

A Tailored Approach to Cortical Bone Track for Spine Fixation Surgery: 3-Dimensional Printed Custom Made Guides for Screws Placement: 2-Dimensional Operative Video.

Cortical bone trajectory (CBT) screw fixation is an attractive technique.1-4 However, the ideal insertion of those screws could be technically demanding.5,6 The use of 3-dimensional (3D) patient-matched guides increase safety for CBT screws implantation.7 In this video, the case of a 46 yr old male is presented. He complained low back pain with left sciatica. magnetic resonance imaging showed an L5/S1 degenerative disc disease with left herniation. The patient was positioned prone; the L5 spinous process was identified under fluoroscopic guidance than skin incision was performed. Preserving the cranial facet joints, spinous processes and laminae of L5 and S1 vertebrae were exposed. Guides were positioned on the corresponding vertebra and the contact areas checked to avoid any discrepancy. With a high-speed drill the cortical bone was violated through the guide tubes. The drill itself has a stop mechanism provided by the guides. With this mechanism the drilling can be safely performed up to the planned depth. Guidewires were than introduced into the pedicle and body of the vertebra; undertapping could be performed with cannulated instrument. Laminectomy and facetectomy were performed. Diskectomy was performed, then a titanium kidney-shaped pivoting cage was implanted. Four Screws were finally placed. Proper positioning of the implants were verified on fluoroscopy and on the postoperative computed tomography scan confirming the accuracy of the trajectory. All procedures performed for this study were in accordance with the ethical standards of our Institute and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Written informed consent was obtained from the patient who is operated in this video.

The ideal insertion angle after immediate loading in Jeil, Storm, and Thunder miniscrews: A 3D-FEM study

The miniscrew is effectively used to provide additional anchorage for orthodontic purposes. The aim of this study was to identify an optimal insertion angle for Jeil, Storm, and Thunder miniscrews on stress distribution at the bone miniscrew interface. To perform 3-dimensional finite element model analysis, a 3-dimensional model with a bone block was constructed with type D2 of bone quality, and with miniscrews of Storm, Thunder, Jeil, with the diameter of 2, 1.5. 1.6mm and length 15.9, 12.4, 14.4mm respectively. The miniscrews were inserted at 15° 30°, 45°, 60°, 75° and 90° to the bone surface. A simulated horizontal orthodontic force of 200 gram was applied to the centre of the miniscrews head in all models, and stress distribution and its magnitude were evaluated with a 3-dimensional finite element analysis program. In the cancellous bone, minimum stress was found at placement angles of 90° for Jeil and Storm, which was 0.37 and 0.39MPa respectively, and 15° for Thunder, which was 0.85MPa. The maximum von Mises stresses in the cancellous bone for Jeil was at 60°, which was 0.92MPa, and for Thunder at 90°, which was 1.3MPa. Each miniscrew has an ideal insertion angle, optimal insertion positions were found within 90° for Jeil and for Storm but 15° for Thunder. Clinical significance 3-dimensional finite element analysis confirmed that each miniscrew has an ideal insertion angle according to its characteristics.

Weight-Based Estimation of Insertion Length of the Nasogastric Tube in Extremely Low Birth-Weight Infants.

Nasogastric (NG) tubes are used in the neonatal intensive care unit (NICU) for various indications. However, evidence of the best practice for estimating the NG tube insertion length in extremely low birth-weight (ELBW) infants is limited. To determine a weight-based estimation formula of NG tube length in ELBW infants. This prospective study was performed at a single-center level III neonatal intensive care unit. Low birth-weight infants admitted between May 2009 and May 2010 who required radiography for clinical reasons were included. Radiographs of participants whose current body weights (BWs) were less than 2500 g were reviewed, and the appropriate ideal insertion length of the NG tube adjusted based on radiographs and the infant's current BW was assessed. A regression model was used to determine the ideal insertion length of the NG tube with respect to the current BW. Overall, 533 radiographs (152 patients weighing 422-2486 g) were analyzed. Among the patients, 246 had BWs less than 1000 g and 287 had BWs more than 1000 g. Formulas that predicted NG tube length (centimeters) were derived as follows: (5 × weight [kg] + 10 [BW < 1.0 kg]) or (3 × weight [kg] + 12.5 [1.0 < BW <2.5 kg]). The application of the weight-based formula for estimating the NG tube length derived from the present study together with commonly used morphological methods may improve the accuracy of the NG tube insertion procedure in ELBW infants. Further studies in other cohorts are needed.

Analysis of the ideal insertion point of the short femoral nail in trochanteric fracture using three-dimensional templating software

Analysis of the ideal insertion point of the short femoral nail in trochanteric fracture using three-dimensional templating software

In Vivo Dynamics of Reporter Flaviviridae Viruses

Recombinant viruses possessing reporter proteins have been generated for virus research. In the case of the family Flaviviridae, we recently generated recombinant viruses, including the hepatitis C virus of the genus Hepacivirus, Japanese encephalitis virus (JEV) of the genus Flavivirus, and bovine viral diarrhea virus of the genus Pestivirus; all three viruses possess an 11-amino-acid subunit derived from NanoLuc luciferase (HiBiT). Here, we further developed the recombinant viruses and investigated their utility in vivo Recombinant viruses harboring HiBiT in the E, NS1, or NS3 protein constructed based on the predicted secondary structure, solvent-accessible surface area, and root mean square fluctuation of the proteins exhibited comparable replication to that of the wild-type virus in vitro The recombinant JEV carrying HiBiT in the NS1 protein exhibited propagation in mice comparable to that of the parental virus, and propagation of the recombinant was monitored by the luciferase activity. In addition, the recombinants of classical swine fever virus (CSFV) possessing HiBiT in the Erns or E2 protein also showed propagation comparable to that of the wild-type virus. The recombinant CSFV carrying HiBiT in Erns exhibited similar replication to the parental CSFV in pigs, and detection of viral propagation of this recombinant by luciferase activity was higher than that by quantitative PCR (qPCR). Taken together, these results demonstrated that the reporter Flaviviridae viruses generated herein are powerful tools for elucidating the viral life cycle and pathogeneses and provide a robust platform for the development of novel antivirals.IMPORTANCE In vivo applications of reporter viruses are necessary to understand viral pathogenesis and provide a robust platform for antiviral development. In developing such applications, determination of an ideal locus to accommodate foreign genes is important, because insertion of foreign genes into irrelevant loci can disrupt the protein functions required for viral replication. Here, we investigated the criteria to determine ideal insertion sites of foreign genes from the protein structure of viral proteins. The recombinant viruses generated by our criteria exhibited propagation comparable to that of parental viruses in vivo Our proteomic approach based on the flexibility profile of viral proteins may provide a useful tool for constructing reporter viruses, including Flaviviridae viruses.

Is there an ideal insertion angle and position for orthodontic mini-implants in the anterior palate? A CBCT study in humans

Orthodontic mini-implants are frequently used to provide additional anchorage for orthodontic appliances. The anterior palate is frequently used owing to sufficient bone quality and low risk of iatrogenic trauma to adjacent anatomical structures. Even though the success rates in this site are high, failure of an implant will result in anchorage loss. Therefore, implants should be placed in areas with sufficient bone quality. The aim of the present study was to identify an optimal insertion angle and position for orthodontic mini-implants in the anterior palate. Maxillary cone-beam computed tomographic (CBCT) scans from 30 patients (8 male, 22 female, age 18.6±12.0years) were analyzed. To assess the maximum possible length of an implant, a 25-reference-point grid was defined: 5 sagittal slices were extracted along the median plane and bilaterally at 3mm and 6mm distances, respectively. Within each slice, 5 dental reference points were projected to the palatal curvature at the contact point between the cuspid (C) and first bicuspid (PM1), midpoint of PM1, between PM1 and PM2, midpoint of PM2, and between PM2 and the first molar (M1). Measurements were conducted at -30°, -20°, -10°, 0°, 10°, 20°, and 30° to a vector placed perpendicular to the local palatal curvature. Statistical analysis was conducted with the use of R using a random-effects mixed linear model and a Tukey post hoc test with Holm correction. High interindividual variability was detected. Maximum effective bone heights were detected within a T-shaped area at the midpoint of PM1 and contact point PM1-PM2 (P<0.01). Within the anterior region a posterior tipping was advantageous, whereas in the posterior regions an anterior tipping was beneficial (P<0.01). In the middle of the median plane, tipping did not reveal a significant influence. No gender- or age-related differences were observed. Within the limitations of this study, optimal insertion positions were found within a T-shaped area at the height of PM1-PM2 in the anterior palate. In general, a posterior tipping was beneficial at anterior positions, and an anterior tipping appeared beneficial at posterior positions. High interindividual variation was found and should be carefully considered by the clinician.

Three-dimensional quantitative assessment of palatal bone height for insertion of orthodontic implants - a retrospective CBCT study

BackgroundOrthodontic implants have found widespread use as means of maximum skeletal anchorage in fixed orthodontic treatment, their optimal insertion location in the hard palate, however, is still controversial. The aim of this study was therefore to assess mean bone height across the hard palate and possible age- and sex related differences to identify the most favourable location according to maximum bone height, optimizing primary stability and survival of inserted orthodontic implants.MethodsIn this retrospective cross-sectional study, maxillary pretreatment CBCT scans of 180 healthy orthodontic patients (95♀, 85♂, age 8–40 years) were analysed with regard to vertical palatal bone height in the midpalatal area at 88 validated points distanced 2 mm from each other forming a grid of 0–14 mm posterior to the incisive foramen and 10 mm lateral of the midpalatal suture. Differences in bone height regarding sex and topographical location were assessed by three-way ANOVA.ResultsIn general, the midpalatal suture as well as the anterior-lateral palatal region showed distinctly higher mean palatal bone height with its maximum 4 mm posterior of the incisive foramen, whereas bone height was limited at the posterior region of the midpalatal suture. Women generally had significantly decreased palatal bone height compared to men at all measurement points. Higher age was associated with a decrease of bone height in the anterior and posterior lateral palatal region and the median palatal raphe with significant age differences.ConclusionsThe midpalatal suture as well as the anterior lateral palate seem to be most suitable for the insertion of orthodontic implants. Palatal bone height, however, was found to be sex- and age-specific, thus sex- and age-related differences should be taken into account, particularly regarding implant length. The ideal insertion site in the palate with sufficient bone height for orthodontic implants is 0-8 mm (men) or 0-6 mm (women) posterior to the incisive foramen and 10 mm lateral to the midpalatal suture.Trial registraionThis study has been registered and approved by the Ethics Committee of the University of Witten/Herdecke, Germany (12/2016).