Is the use of the cervical vertebrae maturation method justified to determine skeletal age? A comparison of radiation dose of two strategies for skeletal age estimation

The aim of this study was to assess effective doses of a lateral cephalogram radiograph with and without thyroid shield and compare the differences with the radiation dose of a hand-wrist radiograph. Thermoluminescent dosimeters were placed at 19 different sites in the head and neck of a tissue-equivalent human skull (RANDO phantom). Analogue lateral cephalograms with and without thyroid shield (67kV, 250 mA, 10 mAs) and hand-wrist radiographs (40kV, 250 mA, 10 mAs) were obtained. The effective doses were calculated using the 2007 International Commission on Radiological Protection recommendations. The effective dose for conventional lateral cephalogram without a thyroid shield was 5.03 microsieverts (µSv). By applying a thyroid shield to the RANDO phantom, a remarkable dose reduction of 1.73 µSv could be achieved. The effective dose of a conventional hand-wrist radiograph was calculated to be 0.16 µSv. Adding the effective dose of the hand-wrist radiograph to the effective dose of the lateral cephalogram with thyroid shield resulted in a cumulative effective dose of 3.46 µSv. Without thyroid shield, the effective dose of a lateral cephalogram was approximately 1.5-fold increased than the cumulative effective dose of a hand-wrist radiograph and a lateral cephalogram with thyroid shield. Thyroid is an organ that is very sensitive to radiation exposure. Its shielding will significantly reduce the effective dose. An additional hand-wrist radiograph, involving no vulnerable tissues, however, causes very little radiation risk. In accordance with the ALARA (As Low As Reasonably Achievable) principle, if an evaluation of skeletal age is indicated, an additional hand-wrist radiograph seems much more justifiable than removing the thyroid shiel

Pharyngeal airway dimensions: a cephalometric, growth-study-based analysis of physiological variations in children aged 6-17

SummaryOBJECTIVE: The aim was to assess pharyngeal airway dimensions and physiological changes based on lateral cephalometric radiographs from healthy untreated children aged 6-17 years. MATERIALS/METHODS: The sample consisted of 880 lateral cephalograms (412 females and 468 males) of the Zurich Craniofacial Growth Study. Statistical analyses on cephalometric measurements of airway dimensions (distances ‘p': shortest distance between soft palate and posterior pharyngeal wall and ‘t': shortest distance between tongue and posterior pharyngeal wall) and craniofacial parameters were performed. To disclose differences between different age groups, a Kruskal-Wallis test was applied. The influence of gender on ‘p' and ‘t' was analysed by a Mann-Whitney U-test for each age group separately. The Spearman correlation was computed in order to investigate associations between craniofacial parameters. Variables associated with ‘p' and ‘t' were chosen for multiple regression model investigation. RESULTS: The results demonstrated high interindividual variations. A slight influence of age on ‘p' (P = 0.034) could be attested (+1.03mm) but not on ‘t' (P = 0.208). With the exception of the 9-year age group, no significant differences between the genders were found. Correlation analysis revealed several statistically significant correlations between ‘t' or ‘p' and antero-posterior cephalometric variables. All correlation coefficients were, however, very low and the adjusted coefficient of determination also revealed the regression model to be very weak. CONCLUSIONS: The high interindividual variations of ‘p' and ‘t' render the use of reference values problematic. Contrary to other craniofacial structures, neither age-related changes nor sexual dimorphism were found for ‘p' and ‘t'. Any associations to antero-posterior cephalometric characteristics seem lo

The inclination of mandibular incisors revisited

Objective: To reassess the inclination of lower incisors and evaluate possible associations with gender, age, symphyseal parameters, and skeletal pattern. Materials and Methods: Twelve hundred and seventy-two (605 females, 667 males) cephalograms of untreated subjects of a craniofacial growth study (age: 8-16 years) were evaluated. Correlations between the angulation of the lower incisors and age, symphyseal distances (height, width, and depth), symphyseal ratios (height-width, height-depth), and skeletal angles (divergence of the jaws and gonial angle) were investigated for all ages separately and for both sexes independently. Results: The inclination of lower incisors increased over age (8 years: girls  =  93.9° [95% CI, 92.3°-95.7°], boys  =  93.3° [95% CI, 91.8°-94.9°]; 16 years: girls  =  96.1° [95% CI, 94.1°-98.2°], boys  =  97.1° [95% CI, 95.6°-98.6°]). Inclination of lower incisors correlated with the divergence of the jaws for all ages significantly or highly significantly, except for boys and girls 9 years of age and girls 11 and 12 years of age, for which only a tendency was observed. Similarly, a strong correlation to gonial angle could be observed. No correlation could be found between the inclination of lower incisors and any symphyseal parameters (absolute measurements and ratios), except for symphyseal depth. Conclusion: Lower incisor inclination is linked to the subject's sex, age, and skeletal pattern. It is not associated with symphyseal dimensions, except symphyseal depth. Factors related to natural inclination of lower incisors should be respected when establishing a treatment plan

TRACKING OF THE HAND “PRESSURE POINT” ON THE GRIP OF A RECURVE BOW: A WEARABLE SOLUTION

The purpose of this study was to design and prototype a non-invasive wearable solution suitable for measuring speeds, accelerations and orientation of the hand-grip as well as the pressures between the hand and the grip of a recurve bow. Therefore, a device has been created that properly blends two technologies: an Inertial Measurement Unit (IMU) and a Force-Sensitive-Resistor (FSR) membrane. A preliminary evaluation of the device performance was conducted in collaboration with the Olympic athlete Mauro Nespoli. The obtained results demonstrate the potential of the proposed system, as well as highlight a number of interesting information from a biomechanical point of view, closely related to the shooting technique

MRI of the temporo-mandibular joint: which sequence is best suited to assess the cortical bone of the mandibular condyle? A cadaveric study using micro-CT as the standard of reference

Objective: To determine the best suited sagittal MRI sequence out of a standard temporo-mandibular joint (TMJ) imaging protocol for the assessment of the cortical bone of the mandibular condyles of cadaveric specimens using micro-CT as the standard of reference. Methods: Sixteen TMJs in 8 human cadaveric heads (mean age, 81years) were examined by MRI. Upon all sagittal sequences, two observers measured the cortical bone thickness (CBT) of the anterior, superior and posterior portions of the mandibular condyles (i.e. objective analysis), and assessed for the presence of cortical bone thinning, erosions or surface irregularities as well as subcortical bone cysts and anterior osteophytes (i.e. subjective analysis). Micro-CT of the condyles was performed to serve as the standard of reference for statistical analysis. Results: Inter-observer agreements for objective (r = 0.83-0.99, P < 0.01) and subjective (κ = 0.67-0.88) analyses were very good. Mean CBT measurements were most accurate, and cortical bone thinning, erosions, surface irregularities and subcortical bone cysts were best depicted on the 3D fast spoiled gradient echo recalled sequence (3D FSPGR). Conclusion: The most reliable MRI sequence to assess the cortical bone of the mandibular condyles on sagittal imaging planes is the 3D FSPGR sequence. Key Points : • MRI may be used to assess the cortical bone of the TMJ. • Depiction of cortical bone is best on 3D FSPGR sequences. • MRI can assess treatment response in patients with TMJ abnormalitie

Heavy-ion test report of LTC1668 DAC - LiteBIRD-NOTE-84

This document presents the results of a heavy-ion test program carried out on the Linear Technology LT1668 16-bit 50 Msps DAC (LTC1668IG) to identify single-event effects. In particular, it was studied the detection of single-event latch-up (SEL), single-event upsets (SEU), and single-event transients (SET) due to heavy-ions radiation. The tests were performed at the heavy-ion facility Tandem-ALPI at INFN Legnaro National Laboratory (Italy) in February 2021 and June 2022 for a total irradiation time of ~51 hours

Computational identification of microRNAs associated to both epithelial to mesenchymal transition and NGAL/MMP-9 pathways in bladder cancer

Bladder cancer is one of the leading cancer of the urinary tract. It is often diagnosed at advanced stage of the disease. To date, no specific and effective early detection biomarkers are available. Cancer development and progression are associated with the involvement of both epithelial-mesenchymal transition (EMT) and tumor microenvironment of which NGAL/MMP-9 complex represents the main player in bladder cancer. It is known that change in microRNAs (miRNAs) expression may result in gene modulation. Therefore, the identification of specific miRNAs associated with EMT pathway and NGAL/MMP-9 complex may be useful to detect the development of bladder cancer at early stages. On this ground, the expression levels of miRNAs in public available datasets of bladder cancer containing data of non-coding RNA profiling was evaluated. This analysis revealed a group of 16 miRNAs differentially expressed between bladder cancer patients and related healthy controls. By miRNA prediction tool (mirDIP), the relationship between the identified miRNAs and the EMT genes was established. Using the DIANA-mirPath (v.2) software, miRNAs, able to modulate the expression of NGAL and MMP-9 genes, were recognized. The results of this study provide evidence that the downregulated hsa-miR-145-5p and hsa-miR-214-3p may modulate the expression of both EMT and NGAL/MMP-9 pathways. Therefore, further validation analyses may confirm the usefulness of these selected miRNAs for predicting the development of bladder cancer at the early stage of the disease

The impact of force magnitude on the first and second maxillary molars in cervical headgear therapy

Aim: To study the effect of force magnitude on the maxillary first and second molars in cervical headgear (CHG) therapy. Material and methods: In this controlled clinical trial, patients (n = 40) were treated with CHG with a light (L, 300 g, n = 22) or a heavy force (H, 500 g, n = 18) magnitude. The subjects were asked to wear CHG for 10 hours a day for 10 months. The outer bow of the CHG facebow was lifted up for 10-20 degrees and the inner bow was expanded 3-4 mm. Adherence to instructions and force magnitude were monitored using an electronic module (Smartgear, Swissorthodontics, Switzerland). Panoramic and lateral radiographs before (T1) and after treatment (T2) were analysed using a Romexis Cephalometric module (Planmeca, Finland) focussing on the angular, sagittal, and vertical positions of the permanent first and second molars. Results: According to the cephalometric analysis of the maxillary first and second molars, distal tipping occurred during T1-T2 in the H group (P = 0.010 and 0.000, respectively), and the change was greater in the H group compared to the L group (P = 0.045 and 0.019, respectively). Based on the panoramic analysis, tipping occurred in the distal direction during therapy in the H group in the second molars compared to the midline or condylar line (P = 0.001 and 0.001; P = 0.008 and 0.003 on the right and left, respectively). Conclusion: With heavy force magnitude, the maxillary first and second molars can tilt more easily in the distal direction even if the CHG was used less. Distal tipping of the molar can be considered to be a side effect of CHG therapy.acceptedVersionPeer reviewe

Effects of force magnitude on dental arches in cervical headgear therapy

acceptedVersionPeer reviewe