Hematic Cortisol and Craniofacial Morphology in Children with OSAS

Study objectives: This study wanted to evaluate the correlations between haematic cortisol levels and the craniofacial morphology in children with Obstructive Sleep Apnoea Syndrome (OSAS) in comparison with healthy children. Measurements and results: Haematic cortisol concentration at 2.00 am was found higher in OSAS patients than in controls (p<0.05). An increase in craniomandibular (p<0.05) and intermaxillar (p<0.01) angles indicated a high angle tendency in OSAS with a posterior rotation of the mandible. A retro-position of the mandible (p<0.05), an increased overjet (p<0.01) and a reduction of overbite (p<0.01) were also found. Conclusions: The altered hypothalamic-pituitary-adrenal activity and the craniofacial modification found are not enough to state if these conditions are causes rather than consequences of OSAS. Moreover cortisol and sleep fragmentation can cause a reduction of growth hormone secretion so it is possible that the alteration of facial morphology may also have a metabolic cause

Skeletal, Dental and Soft Tissue Cephalometric Changes after Orthodontic Treatment of Dental Class II Malocclusion with Maxillary First Molar or First Premolar Extractions.

The aim of the present retrospective study was evaluating skeletal, dental and soft tissue changes of two groups of Class II patients orthodontically treated with extractions of upper first premolars (U4 group) and upper first molars (U6 group). In total, 21 patient records (9M and 12F; mean age 12.5 ± 1.2 years) were selected for the U4 group, and 38 patient records (17M and 21F; mean age 13.2 ± 1.3 years) were recruited for the U6 group. Twenty cephalometric variables were analysed on standardised lateral cephalograms at baseline (T0) and at the end of orthodontic treatment (T1). Means and standard deviations (SDs) were calculated for both groups and increments were calculated. After revealing the normal distribution of data with the Shapiro-Wilk test, Student's t-test was used to compare variables at T0 between groups. A paired t-test was used to analyse changes between time points within each group, and Student's t-test to compare differences between groups at T1. Both groups showed a significant increase in the distance among upper second molars and the vertical pterygoid line (PTV-maxillary second molar centroid U6 group: 6.66 ± 5.00 mm; U4 group: 3.66 ± 2.20 mm). Moreover, the distance of upper incisors to the palatal plane significantly increased (PP-maxillary incisor tip U6 group: 1.09 ± 1.52 mm; U4 group: 0.20 ± 2.00 mm; p = 0.061). Significant changes were found for overjet (U6 group: -4.86 ± 1.62 mm; U4 group: -3.27 ± 1.90 mm; p = 0.001). The distance between upper lip and esthetic plane showed a significantly reduction in both groups (ULip-E Plane U6 group: -2.98 ± 1.65 mm; U4 group: -1.93 ± 1.57 mm). No statistically significant changes were found in sagittal or vertical skeletal values. The significantly larger reduction of upper lip protrusion and overjet in the U6 group compared to the U4 group suggests preferring molar extraction treatment for severe Class II with protrusive soft tissues' profile and increased overjet. Since no differences on vertical values were found, an increased SN^GoGn angle should not be considered a discriminating factor for choosing molar extraction treatment

Occlusal Plane Changes After Molar Distalization With a Pendulum Appliance in Growing Patients with Class II Malocclusion: A Retrospective Cephalometric Study

Objective: This study aimed to evaluate the skeletal and dental changes after distalization with a pendulum appliance in growing patients with Class II malocclusion, focusing on the occlusal plane (OP).Methods: The sample included 24 patients with Class II malocclusion (10 boys, 14 girls); their mean age was 12.1 years. All patients underwent molar distalization and had 2 serial cephalograms traced at baseline (T1) and after distalization (T2). Angular and linear dental changes were calculated by taking the sella-nasion (SN), palatal plane (PP), and pterygoid vertical as reference. OP inclination was compared with SN, PP, and mandibular plane. The collected data were computed for all the tested variables, and one-way paired t-test was used to assess the significance of the differences between the time points. α was set at 0.05. Multiple linear regressions were used to predict the OP changes.Results: The mean total treatment time was 8±2 months to obtain a super Class I molar relationship. In T1-T2 interval, statistically significant incisor buccal tipping of 5°±3.6° (p<0.05), first molar distal tipping of 8.9°±8.3° (p<0.001), and second molar tipping of 8.2°±8.1° (p<0.001) were observed. The maxillary first and second molars moved significantly backward by 2.8±3.2 mm (p<0.05) and 3.7±2.7 mm (p<0.001), respectively. Only the premolars showed a statistically significant anchorage loss of 2.7±3.3 mm (p<0.05); overjet increased significantly at 1.3±1.2 mm (p<0.05). Regarding the OP, none of the tested variables showed any statistically significant changes between T1-T2.Conclusion:The pendulum appliance showed efficacy in distalizing the maxillary first and second molars at the expense of anterior anchorage loss. The OP did not show statistically significant changes after molar distalization

Cone-Beam Computed Tomographic Assessment of the Mandibular Condylar Volume in Different Skeletal Patterns: A Retrospective Study in Adult Patients

The aim of this study was to assess the condylar volume in adult patients with different skeletal classes and vertical patterns using cone‐beam computed tomography (CBCT). CBCT scans of 146 condyles from 73 patients (mean age 30   12 years old; 49 female, 24 male) were selected from the archive of the Department of Dentistry and Maxillofacial Surgery of Fondazione IRCCS Ca’ Granda, Milan, Italy, and retrospectively analyzed. The following inclusion criteria were used: adult patients; CBCT performed with the same protocol (0.4 mm slice thickness, 16   22 cm field of view, 20 s scan time); no systemic diseases; and no previous orthodontic treatments. Three‐dimensional cephalometric tracings were performed for each patient, the mandibular condyles were segmented and the relevant volumes calculated using Mimics Materialize 20.0  software (Materialise, Leuven, Belgium). Right and left variables were analyzed together using random‐intercept linear regression models. No significant association between condylar volumes and skeletal class was found. On the other hand, in relation to vertical patterns, the mean values of the mandibular condyle volumes in hyperdivergent subjects (688 mm3) with a post‐rotation growth pattern (625 mm3) were smaller than in hypodivergent patients (812 mm3) with a horizontal growth pattern (900 mm3). Patients with an increased divergence angle had smaller condylar volumes than subjects with normal or decreased mandibular plane divergence. This relationship may help the clinician when planning orthodontic treatment

Maxillary premolars extraction or molar distalization with or without TADs: cephalometric evaluation of soft tissue changes in Class II treatment

Introduction: Problem solving in Class II malocclusion treatment performed with premolars extractions or distalizing techniques in relation to the profile modification. Aim: To cephalometrically compare soft tissue changes produced either by maxillary premolar extraction, tooth-borne Pendulum appliance or bone-borne MGBM appliance. Materials and Methods: Both pre- (T1) and post-treatment (T2) lateral cephalograms of 89 skeletal Class II patients (36 M, 53 F), treated during pubertal growth spurt, were retrospectively selected. Three groups were formed based on the therapy performed: 30 patients had been treated with maxillary first premolars extraction (U4), 31 patients with a conventional tooth-borne distalizing with Pendulum appliance (PA), and 28 patients with a skeletally anchored distalizing appliance (MGBM). Soft tissue was analyzed comparing upper (UL) and lower (LL) lip’s points with regard to True Vertical Line (TVL) and Esthetic plane (E-plane). Skeletal and dental values have been recorded in order to cephalometrically compare ΔT2-T1 changes among groups and to correlate dental and skeletal changes to profile modifications. One-way ANOVA was employed to compare groups at T1. Paired sample t-tests were employed to assess significant intra- and intergroup differences between T2 and T1. Significance level was set at 0.05 Results: UL and LL showed a slight but not significant retrusion relative to TVL in all three groups. UL and LL distances to E-plane were not statistically significant among U4, PA, and MGBM groups. Independently of the treatment, UL was tangent to TVL in all groups. No statistically significant differences have been shown in skeletal records. Significant differences were recorded in Overjet among U4 than PA and MGBM groups. Conclusions: Class II malocclusion treatment with maxillary first premolar extraction, conventional or skeletal distalization did not significantly affect the profile producing similar changes in the soft tissue

The SNAP-tag technology revised: an effective chemo-enzymatic approach by using a universal azide-based substrate

SNAP-tag ® is a powerful technology for the labelling of protein/enzymes by using benzyl-guanine (BG) derivatives as substrates. Although commercially available or ad hoc produced, their synthesis and purification are necessary, increasing time and costs. To address this limitation, here we suggest a revision of this methodology, by performing a chemo-enzymatic approach, by using a BG-substrate containing an azide group appropriately distanced by a spacer from the benzyl ring. The SNAP-tag ® and its relative thermostable version (SsOGT-H5 ) proved to be very active on this substrate. The stability of these tags upon enzymatic reaction makes possible the exposition to the solvent of the azide-moiety linked to the catalytic cysteine, compatible for the subsequent conjugation with DBCO-derivatives by azide-alkyne Huisgen cycloaddition. Our studies propose a strengthening and an improvement in terms of biotechnological applications for this self-labelling protein-tag

Accuracy of automated 3D cephalometric landmarks by deep learning algorithms: systematic review and meta-analysis

Objectives The aim of the present systematic review and meta-analysis is to assess the accuracy of automated landmarking using deep learning in comparison with manual tracing for cephalometric analysis of 3D medical images. Methods PubMed/Medline, IEEE Xplore, Scopus and ArXiv electronic databases were searched. Selection criteria were: ex vivo and in vivo volumetric data images suitable for 3D landmarking (Problem), a minimum of five automated landmarking performed by deep learning method (Intervention), manual landmarking (Comparison), and mean accuracy, in mm, between manual and automated landmarking (Outcome). QUADAS-2 was adapted for quality analysis. Meta-analysis was performed on studies that reported as outcome mean values and standard deviation of the difference (error) between manual and automated landmarking. Linear regression plots were used to analyze correlations between mean accuracy and year of publication. Results The initial electronic screening yielded 252 papers published between 2020 and 2022. A total of 15 studies were included for the qualitative synthesis, whereas 11 studies were used for the meta-analysis. Overall random effect model revealed a mean value of 2.44 mm, with a high heterogeneity (I-2 = 98.13%, tau(2) = 1.018, p-value &lt; 0.001); risk of bias was high due to the presence of issues for several domains per study. Meta-regression indicated a significant relation between mean error and year of publication (p value = 0.012). Conclusion Deep learning algorithms showed an excellent accuracy for automated 3D cephalometric landmarking. In the last two years promising algorithms have been developed and improvements in landmarks annotation accuracy have been done