Incisal Edge Research Articles

Evaluation of the effect of attachments on torque control of palatally positioned maxillary lateral teeth with clear aligners: Finite element analysis.

The effect of different attachment positions on torque control during the labialization of maxillary lateral incisors with clear aligners was evaluated using finite element analysis. Anatomical data acquired through cone-beam computed tomography, combined with the design of 0.625-mm-thick aligners and horizontal attachments, were integrated into the software. Six distinct simulations were generated: (1) attachment-free, (2) labial attachment placed gingivally, (3) labial attachment placed mid-crown, (4) labial attachment placed incisally, (5) palatal attachment, and (6) attachment placed labially and palatally. The evaluation was performed using a default aligner activation of 0.25 mm. The crown of the lateral incisor demonstrated labial movement, while the root exhibited palatal movement in all models. Group 6 showed the lowest crown and root displacements on both axes, whereas the attachment-free group exhibited the greatest crown movement. The aligner experienced maximum deformation at the incisal edge, with deformation progressively decreasing towards the gingival region. Group 6 demonstrated the least deformation of all groups. The Von Mises stresses in the periodontal ligament (PDL) were most pronounced at the gingival level, with higher values on the palatal side than on the labial side. The use of attachments, particularly the combination of labial and palatal attachments, enables a more precise labialization process, helping to reduce tipping. Increasing crown movement of the lateral incisor elevates stress within the PDL, with the highest stress observed in the palatal region at the gingival level.

Clinically oriented automatic three-dimensional enamel segmentation via deep learning

BackgroundEstablishing accurate, reliable, and convenient methods for enamel segmentation and analysis is crucial for effectively planning endodontic, orthodontic, and restorative treatments, as well as exploring the evolutionary patterns of mammals. However, no mature, non-destructive method currently exists in clinical dentistry to quickly, accurately, and comprehensively assess the integrity and thickness of enamel chair-side. This study aims to develop a deep learning work, 2.5D Attention U-Net, trained on small sample datasets, for the automatical, efficient, and accurate segmentation of enamel across all teeth in clinical settings.MethodsWe propose a fully automated computer-aided enamel segmentation model based on an instance segmentation network, 2.5D Attention U-Net. After data annotation and augmentation, the model is trained using manually annotated segmented enamel data, and its performance is evaluated using the Dice similarity coefficient metrics. A satisfactory image segmentation model is applied to generate a 3D enamel model for each tooth and to calculate the thickness value of individual enclosed 3D enamel meshes using a normal ray-tracing directional method.ResultsThe model achieves the Dice score on the enamel segmentation task of 96.6%. This study provides an intuitive visualization of irregular enamel morphology and a quantitative analysis of three-dimensional enamel thickness variations. The results indicate that enamel is thickest at the incisal edges of anterior teeth and the cusps of posterior teeth, thinning towards the roots. For posterior teeth, the enamel is thinnest at the central fossae area, with mandibular molars having thicker enamel in the central fossae compared to maxillary molars. The average enamel thickness of maxillary incisors, canines, and premolars is greater than that of mandibular incisors, while the opposite is true for molars. Although there are individual variations in enamel thickness, the average enamel thickness graduallly increases from the incisors to the molars among all teeth within the same quadrant.ConclusionsThis study introduces an automatic, efficient, and accurate 2.5D Attention U-Net system to enhance precise and efficient chair-side diagnosis and treatment of enamel-related diseases in clinical settings, marking a significant advancement in automated diagnostics for enamel-related conditions.

Fracture Resistance of Chairside CAD/CAM Lithium Disilicate Partial and Full Coverage Crowns and Veneers for Maxillary Canines.

This study aimed to assess the fracture resistance of chairside computer assisted design and computer assisted manufacturing (CAD-CAM) lithium disilicate partial and full-coverage crowns and veneers for maxillary canines. Forty-eight restorations for maxillary right canines (12 per group) were designed as follows: (1) partial crown with finish line in the upper middle third; (2) partial crown with finish line in the lower middle third; (3) traditional labial veneer; and (4) traditional full-coverage crown. Restorations were fabricated out of lithium disilicate (Amber Mill, Hassbio) using a chairside CAD-CAM system (Cerec Dentsply Sirona). Partial and full crowns and veneers were treated with a primer system (Monobond Plus, Ivoclar Vivadent) and cemented using dual-cure resin cement (Variolink Esthetic, Ivoclar Vivadent) and cemented to printed resin dies. Subsequently, the restorations were subjected to 10,000 thermocycles between 5°C and 55°C with a dwell time of 30 seconds. The restorations were then loaded axially on the incisal edge in compression to fracture with a flat indenter. Full-coverage crowns displayed the highest fracture resistance (809±28.57 N) followed by partial crowns with finish line in lower third (649±21.74 N) and crowns with finish line in upper third (421±17.46 N). Veneers displayed the lowest fracture resistance values (259±15.69 N). The fracture resistance of partial and full-coverage crowns and veneers was significantly influenced by the design. Full coverage crowns displayed the highest fracture resistance and partial crowns showed higher fracture resistance than traditional veneers.

PROSTHETIC REHABILITATION WITH CERAMIC RESTORATIONS IN THE ANTERIOR REGION FOLLOWING ORTHODONTIC TREATMENT

This study explores the survival rates and complications associated with zirconia restorations veneered with feldspathic ceramic in patients who had been diagnosed by an orthodontist with spacing issues. All patients had previously undergone orthodontic treatment to improve aesthetics after their teeth had been properly aligned. As a result, these cases were addressed through prosthetic solutions. The study included 18 patients, with 11 pairs of restorations for females and 7 for males, all targeting the anterior region to correct diastema. The restorations were followed over a two-year period, with check-ups scheduled every six months. Of the 18 restorations, 10 experienced chipping, primarily at the incisal edges. Additionally, two cases showed a recurrence of diastema due to non-compliance with wearing their Hawley retainers. Interestingly, the failure rate was higher in female patients, indicating a potential link between gender and the durability of the restorations. Despite these challenges, the restorations that suffered chipping could be successfully repaired, which proved to be a significant benefit. These findings highlight the importance of regular follow-up visits to ensure the longevity of the restorations and to inform future treatment planning.

TRATAMENTO DE MORDIDA ABERTA ANTERIOR COM A UTILIZAÇÃO DE MINI-IMPLANTES EM PACIENTES ADULTOS: UMA REVISÃO DE LITERATURA

Anterior open bite is a malocclusion characterized by a negative overlap between the incisal edges of the upper and lower teeth. The etiology is multifactorial, normally associated with common factors such as non-nutritive sucking, tongue interposition, nasopharyngeal obstructions, respiratory and skeletal factors. The treatment of this condition in adulthood in moderate to severe cases is difficult because the jaw bones are already formed, leaving orthognathic surgery as the ideal treatment for this condition. With the advent of skeletal anchorage devices, a new treatment option for this condition has become viable. Mini-implants are a skeletal anchorage tool that can be used in molar intrusion mechanics during orthodontic treatment. The use of mini-implants has several advantages and is an effective alternative to meet the demand of adult patients seeking treatment, mainly to close skeletal anterior open bites. However, recurrence rates in this treatment also exist, as in other treatments. Being greater in the first year after treatment, highlighting the importance of containment mechanisms and interceptive treatment of this condition, when possible, during the individual’s growth. Therefore, this work aims, through a literature review, to evaluate the use of mini-implants as skeletal anchorage in molar intrusion mechanics.

A clinical comparative analysis using an optical tracking device versus conventional tracking device in the production of occlusal appliances.

Optical tracking devices (OTDs) hold promise for enhancing patient-centered prostheses, but their efficacy remains underexplored. This clinical study aimed to comprehensively evaluate differences in static and dynamic occlusions among occlusal appliances fabricated using optical tracking, conventional tracking, and average articulator values (AAVs), providing insights into their efficacy in clinical and research-based practices. Twelve dentate participants aged over 25 years, with Angle Class I and II occlusal relationships, were enrolled. Occlusal appliances were fabricated by different condylar guidance values obtained by the three systems. The condylar guidance values were measured by an OTD via MODJAW, a conventional tracking device (CTD) via Cadiax compact 2, and the AAV with Bennett angle 10°, immediate mandibular lateral translation 0.5mm, and sagittal condylar inclination (SCI) 35°. Occlusal appliances were designed using computer-aided design (CAD) software with the measured condylar guidance values from three systems. Subsequently, standard tessellation language (STL) files were transferred to computer-aided manufacturing (CAM) software for 3D printing with photopolymer resin. Each participant received three occlusal appliances fabricated using the three different systems. The accuracy of the systems was evaluated by accessing the clinical outcomes of the occlusal appliances. After placement, the number of contact points in maximal intercuspation position (MIP) and dynamic occlusion interferences were recorded, along with any discrepancies between designed and recorded contact points. Any anterior open bites at MIP with the appliance in place were measured from the maxillary incisal edge to the mandibular incisal edge. Statistical analysis included Kruskal-Wallis one-way analysis of variance (ANOVA) and Mann-Whitney tests with Bonferroni correction for pairwise comparisons (α=0.05). In assessing static occlusion, significant differences were found in contact point discrepancies at MIP. OTD exhibited the lowest mean discrepancy of contact points compared with the original design (1.833±0.312), followed by CTD (4.083±0.758) and AAV (4.833±1.389), with a statistical significance (p=0.047). At the final protrusive position, OTD (0.400±0.204) and CTD (1.400±0.438) methods showed significantly lower discrepancies compared with AAV (3.583±0.352) (p<0.001). Additionally, the OTD method demonstrated a statistically significant reduction in anterior open bite at MIP (0.115±0.044mm) compared with AAV (0.617±0.246mm) (p=0.049). In dynamic occlusion, OTD showed no interferences in all subjects during protrusive movement, significantly outperforming both CTD (0.917±0.474) and AAV (0.417±0.202) (p=0.033). No significant differences were observed among the methods for working and nonworking side laterotrusive movements. The OTD offers superior accuracy over traditional methods, with reduced discrepancies and interferences in occlusal appliance fabrication, signifying a substantial advancement in mandibular movement assessment and improving treatment efficiency and outcomes in clinical practice.

Impact of labially inclined implant axes on immediate implant placement and provisionalization in anterior maxilla: A prospective cohort study.

To investigate whether a labially inclined implant axis compromises the clinical outcomes of immediate implant placement and provisionalization (IIPP) in the anterior maxilla. Patients with unsalvageable central or lateral maxillary incisors were enrolled. IIPP with simultaneous connective tissue graft (CTG) was performed in all participants. In the control group, the alveolar ridge had a long axis aligned with the tooth, which ensured that the immediate implant was aimed at the incisor edge or the cingulum of future restoration. The test group had a large angle between the axes of the ridge and tooth. To avoid bone fenestration, the implants were placed labially inclined and emerged from the labial side of future restoration. Intra-oral scanning and cone-beam computed tomography were performed to record soft and hard tissue profiles at baseline and 1 year later. Soft tissue stability, bone remodeling, and pink esthetic score (PES) were evaluated and compared between two groups. Thirty-nine participants (19 tests and 20 controls) completed the study. At 1-year post-surgery, the mid-facial gingival margin migrations were 0.85 ± 0.37 mm (test) and 0.81 ± 0.33 mm (control), without significant differences. No differences were identified in buccal profile alteration, linear ridge reduction, buccal bone thickness, or PES scores. The test group demonstrated thinner buccal soft tissue at the crestal level than the control group. When large tooth-ridge angulation presented, labially inclined implant, avoiding buccal ridge fenestration in IIPP with CTG, did not compromise the clinical outcome in short term.

Accuracy of occlusal splints printed in different orientations by liquid crystal display technology: an in vitro study

ObjectivesTo evaluate the accuracy of occlusal splints printed in different orientations by liquid crystal display technology. MethodsAn occlusal splint was digitally designed, and additively manufactured using an LCD printer (Phrozen Sonic 4k, Phrozen) at three orientations relative to the printer building plate: 0, 45, and 70 degrees (n=10). The 3D-printed occlusal splints were digitised using a desktop scanner, resulting in experimental meshes. The meshes were analysed in a metrology software program, comparing the experimental ones with the initially designed occlusal splint (trueness) and each other within the same group (precision). The discrepancies were shown in a colour map and the root mean square indicated the magnitude of the total discrepancy between the meshes. Kruskal-Wallis test was used (α=0.05) followed by post-hoc Dunn's test. ResultsThere was no statistical difference in trueness among the groups (P=0.086); however, splints printed at 70 degrees showed better precision compared to those printed at 0 (P<0.001) and 45 degrees (P<0.001). The splints printed at 0 and 45 degrees exhibited a similar discrepancy pattern, with highest values concentrated in the posterior segment—positive on the buccal surface and negative on the lingual surface of molars. In contrast, splints printed at 70 degrees had highest discrepancy values in both anterior and posterior segments, with an inverted pattern on molars. Conclusion: The accuracy of occlusal splints was affected by the different orientation in terms of precision, with 70 degrees resulted in highest precision compared to 0 and 45 degrees. No difference was found in terms of trueness. Higher discrepancies were found located in molars and incisal edge of anterior teeth. Clinical significance3D-printing using LCD technology stands out for its affordability and good resolution, however the optimal printing angle remains unclear. Vertical positioning allows more objects to fit on the printer building plate, while horizontal positioning reduces print time. According to literature, for DLP printers, a 0-degree angle provides good accuracy for occlusal splints, whereas a 90-degree angle results in lower accuracy. This study found that for LCD printers, 0, 45, and 70 degrees had similar trueness, with 70 degrees offering the highest precision. Thus, vertical positioning at 70 degrees can be a safe choice for the accuracy of occlusal splints printed on LCD technology.

Effect of loading angle and fabrication materials on stress distribution with periodontal splint in compromised periodontal tissues: a finite element study

Objective: To evaluate the effect of polyetheretherketone (PEEK) periodontal splints and splints made from other materials under static loading on stress distributions in periodontal tissues, cement layer, and splints themselves. Methods: A finite element model based on cone-beam CT imaging data of a 25-year-old male patient (treated at the Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University in October 2021 for a cracked maxillary molar) with a healthy and intact mandibular dentition and periodontal health was constructed. The finite element model included anterior mandible dentition, mandibular bone model without bone resorption (WBR group), a periodontally compromised mandible model (control group), and three types of periodontal splints: a PEEK periodontal splint (0.7 mm thick, Young's modulus: 4.1 MPa), a fiber-reinforced resin (FRC) splint (1.0 mm thick, Young's modulus: 37.0 MPa), and a titanium splint (1.2 mm thick, Young's modulus: 110.0 MPa). The bone resorption models fixed with different periodontal splints constituted the experimental groups (PEEK group, FRC group and titanium group). Loading of 100 N was applied on the midpoint of the incisal edge of tooth 41. The direction was set at 0°, which was parallel to the long axis of the tooth and downward. The buccal to lingual and downward angles were 30°and 60°, respectively, perpendicular to the long axis of the tooth and 90° to the lingual side. The finite element analysis software was utilized to analyze the stress distribution characteristics of the periodontal tissues, adhesive layer, and the splint itself in the anterior mandibular teeth among the different group. Results: Under the different loading simulation, in the control group, the maximal von Mises stresses of periodontal ligament and bone were 15.7-50.2 MPa and 38.8-130.3 MPa, respectively, and in the WBR group, the maximal von Mises stresses of periodontal ligament and bone were 3.6-6.4 MPa and 16.5-42.7 MPa, respectively. Under the same loading conditions, the magnitude of maximal von Mises stresses in periodontal tissues in the PEEK group was 4.6-6.2 MPa, and the magnitude of stresses in the periodontal ligament of 41 teeth in the WBR group was similar to that in the PEEK group, but higher than that in the FRC and titanium groups. The maximal von Mises stresses of each group is primarily distributed in the periodontal ligament and alveolar bone at the cervical area of the tooth. The higher the elastic modulus of the splint, the higher its own maximal von Mises stresses, and the smaller the maximal principal stresses transmitted to the adhesive layer. In the PEEK group and titanium group, the stress distribution area in the adhesive layer and the splint was near the splint connection adjacent to tooth 41. Conclusions: Periodontal splints fabricated from three types of materials, are effective in distributing stress within the periodontal tissues of the abutment teeth. Compared to FRC and titanium group, the higher PEEK splint stress value was obtained, and the smaller the stress value was transmitted to its adhesive layer.

Influence of Using a Puncturing Method and Cooldown Period Before Pressing the Second-Layered Sheet on the Final Thickness of Double-Layered Sports Mouthguards: An Experimental Study.

The thickness of the mouthguard is a crucial factor in its protective ability for athletes. This study aimed to investigate the final thickness of double-layered sports mouthguards, which were fabricated using different methods before pressing the second layer. Seven upper working models (n = 7 per group) were prepared for mouthguard fabrication. The first 3-mm mouthguard sheet underwent heating, pressing, and vacuuming onto the model, followed by various protocols before the second 3-mm sheet was pressed. Group 1: The second sheet was pressed immediately. Group 2: The first sheet underwent a 1-h cooldown period before pressing the second sheet. Group 3: The interproximal areas of the first sheet were punctured followed by immediate pressing of the second sheet. Group 4: The first sheet was punctured followed by a 1-hcooldown before pressing the second sheet. After 24 h, the mouthguard thickness was measured at various points on the left and right central incisors and first molars using a digital caliper. The thickness analysis was performed using SPSS 29.0 with one-way ANOVA and Tukey post hoc analysis. At the labial surface of the central incisors, Group 4 exhibited the highest thickness, while Group 3 had the lowest (p < 0.001). Groups 1 and 2 did not show significant differences in thickness. At the incisal edges, Group 3 again had the lowest thickness (p < 0.05), with no significant differences observed among the other groups. There were no significant differences in thickness across all areas at the first molars, including cusp tips, pits, and buccal surfaces (p > 0.05). Group 4 demonstrated greater uniformity at the central incisors in thickness compared with the other groups. Using the puncturing method at interproximal areas combined with a cooldown period could enhance mouthguard thickness at the labial surfaces of the central incisors and improve its thickness uniformity.

Reference points to evaluate changes in the upper lip after labial incisor movement between tipping and translation in crowding patients: A retrospective study

ObjectiveThis study aimed to compare the changes of reference points on the labial surface of upper incisors (U1) to upper lip (UL) after U1 labial movement between a translation group (TSL) and tipping group (TIP). Correlations between changes in U1 and UL were determined. MethodsLateral cephalometric radiographs were selected and divided into TSL and TIP groups by pre- and post-treatment superimpositions. Skeletal, dental, and soft tissue of pre- and post-treatment and variables were evaluated. Independent t-test and Mann-Whitney U test were applied for the statistical analysis between TSL and TIP. Spearman's correlation coefficients and multiple linear regression analysis were used to verify the association between lip profile changes and other variables in TSL and TIP group separately. ResultsAfter U1 labial movement, the incisal edge (LaU1e), middle (LaU1m), and cervical (LaU1c) points of TSL moved evenly labially, whereas the TIP group had incisal edge that moved greater labially than the middle and cervical points. UL moved more labially in TSL (0.87–1.05 mm) than the TIP (0.31–0.41 mm). UL changes to the E-line in TSL showed significant positive correlations to all three LaU1(e, m, c)-SnTV changes. In the TIP group, only a positive correlation presented for the LaU1m-SnTV and LaU1c-SnTV changes. Nevertheless, Multiple linear regression analysis indicated the unfeasibility of predicting the upper lip changing. ConclusionLaU1e in TSL and TIP moved almost equally labially but less labially in TIP at the middle and cervical points. The UL moved more labially in TSL than TIP. Rather than using the incisal edge to estimate upper lip changes, it would be better to use the middle and cervical points of U1, which coincide with Labrale superioris (Ls).

Dental arch shape in twins: A morphometric study of genetic influences

The objective of this study was to assess the relative contribution of genes to shape variation in the permanent dental arches in individuals of Western European descent. The dental casts from 64 monozygotic and 38 dizygotic twins, housed in the Adelaide Dental School's twin record collection, Australia, were assessed. The subjects were of Western European descent, with a mean age of 19.4 ± 5.4 years. Dental casts were scanned using a 3-dimensional scanner (3Shape E4, 3Shape, Copenhagen, Denmark), and landmarks were placed on incisal edges and cusp tips of canines, premolars, and molars. Procrustes superimposition and principal components analysis were applied to examine shape variation. Two-block partial least-squares analysis was used to assess shape covariation between arches. Structural equation modeling was utilized to decompose observed shape variation into genetic and environmental components using the normal assumptions of the twin model. The first 3 principal components (PCs) of the maxillary and mandibular arch were meaningful, accounting for 53% and 50% of the variation in shape space, respectively. The PCs represented shape variability as follows: PC1 - arch depth-width ratio, PC2 - arch taper, canine position (and first premolar rotation for the mandibular arch), and PC3 - incisor displacement and rotation. Genetic modeling indicated that a model incorporating additive genetic and unique environmental factors optimally explained the observed variation for all meaningful PCs. Within shape space, most of the variation in maxillary and mandibular arches exhibited moderate to high heritability (h2= 0.61-0.74). Maxillary and mandibular dental arches had strong and significant shape covariation, with high heritability in their reciprocal influences on shape (h2= 0.72-0.74; rpls coefficient= 0.87; P<0.05). In this cohort, dental arch shape variation was predominantly influenced by genetic factors. High covariation and heritability were observed between the maxillary and mandibular dental arches. This information may help inform decisions around orthodontic intervention.

Use of hyperboloid as an adjunct in functional jaw orthopedics – case report

Anterior open bite can be defined as a malocclusion with a negative vertical discrepancy between the incisal edges of the upper and lower anterior teeth, which do not have occlusal contacts with the antagonists and sometimes extends to the canines and, less frequently, to the premolars is one of the malocclusions with the greatest aesthetic and/or functional impairment. Anterior open bite can have several etiologies: finger sucking and/or pacifier, oral breathing, onychophagia, lip interposition, atypical swallowing, tongue interposition when uttering phonemes and anterior posture of the tongue at rest. Orofacial myofunctional disorders are present in cases of anterior open bite, generally associated with etiologies and adapt to this altered morphological condition. Regarding the anterior opening amplitude, the anterior open bite is classified as: minimum up to 1 mm, moderate between 1 and 5 mm and severe +5 mm [1]. Open bite can be classified into: maxillary, mandibular and hybrid open bite [2]. Myofunctional therapy is considered a treatment method that can increase muscle strength, cause changes in functional patterns and thus prevent deviations in craniofacial development, as it promotes new posture of structures at rest and during the performance of the functions of the stomatognathic system [3]. The hyperboloid is an instrument for increasing muscle tone and when used in chewing, it is efficient in inducing growth and remodeling. The hyperboloid fills a gap in the modern diet, with the consistency of hard, raw and dry foods [4]. Exercises with a size M hyperboloid with wire were prescribed as an initial approach. After 2 months of treatment, there was an improvement in the interincisor distance. The exercise was maintained for another 5 months. He stopped attending appointments for 2 years and 2 months. Upon his return, the results of the functional examination of swallowing, chewing, protrusion and laterality were observed, and we opted for the installation of the SN3. the hyperboloid, in this case, showed its efficiency in balancing the stomatognathic system.

The "Smile Design and Space" Concept for Altering Vertical Dimension of Occlusion and Esthetic Restorative Material Selection.

This article introduces the smile design and space (SDS) concept for managing the vertical dimension of occlusion (VDO) in full-mouth reconstructions and its influence on the selection of esthetic restorative materials. Limitations of traditional VDO adjustment methods are being addressed through a facially driven treatment approach that enhances esthetics improves function and minimizes invasiveness. The SDS concept involves detailed evaluations of the incisal edges of the maxillary central incisors in relation to the upper lip at rest and at full smile. This includes analyzing variations in incisal exposure due to differing lip mobility, which can significantly impact gingival esthetics, particularly in cases with gingival exposure during smiling. The concept employs a strategic formula to determine the necessary alterations in VDO based on specific dental relationships and wear patterns. The SDS concept provides guidelines for full-mouth reconstructions, emphasizing minimal invasiveness and the integration of esthetics with functional dynamics to enhance the predictability of clinical outcomes and reduce complications associated with traditional restoration techniques. The SDS concept enhances the precision of full-mouth reconstructions through individualized adjustment of the VDO, tailored to the esthetic and functional requirements of each patient.

Efficacy and complications of endoscopic thoracoscopic versus laparoscopic radical esophagectomy in esophageal cancer treatment: A retrospective study.

To evaluate the efficacy and postoperative complications of endoscopic thoracoscopic and laparoscopic radical esophagectomy compared to open surgery in esophageal cancer treatment. This retrospective study included 103 esophageal cancer patients admitted from August 2018 to March 2022, divided into observation (endoscopic surgery) and control (open surgery) groups. We compared intraoperative parameters, postoperative outcomes, immune function, and one-year overall survival (OS). Intraoperative bleeding volume, the retention time of chest tube, postoperative fasting time, and hospital stay in the observation group were smaller than those in the control group (P < .05). The differences were not statistically significant (P > .05) when comparing operative time, the number of intraoperative blood transfusion cases, and the rate of operating room extubation in these 2 groups. The differences were not statistically significant when comparing the amount of resected lymph nodes and the positive rate of incisal edge in these 2 groups (P > .05). There was no statistically significant difference in the complication rates such as pneumonia, pleural effusion, pneumothorax, pulmonary embolism, anastomotic fistula, the leakage of thoracic duct, the injury of RLN and arrhythmia in these 2 groups (P > .05). At 7 days postoperatively, the CD4+ and CD4+/CD8+ in the observation group and the control group were smaller than the preoperative ones in their same groups, and they were larger in the observation group than those in the control group (P < .05); There was no statistically significant difference on the CD8+ in the observation group and the control group at 7 days postoperatively compared with the preoperative ones in their same groups (P > .05). The 1-year postoperative OS rate was 81.63% (40/49) in the observation group and 72.22% (39/54) in the control group, and the difference was not statistically significant when comparing the OS rates of these 2 groups (P = .238, HR = 0.622, 95% CI = 0.279-1.385). Endoscopic thoracoscopic and laparoscopic esophagectomy offers less invasive treatment with significant short-term benefits and better preservation of immune function in esophageal cancer patients, making it a safe and effective surgical option.

EVALUATION OF THE RELATIONSHIP OF CURVE OF SPEE WITH DENTOSKELETAL MORPHOLOGY IN SAGITTAL MALOCCLUSIONS

Curve of Spee is defined as the line on a cylinder which is tangent to incisal edges of lower anteriors, occlusal surface of lower second molar and anterior border of condyle. The aim of the study is to determine whether there is a relationship between curve of Spee and craniofacial morphology in different sagittal malocclusions and to determine the influence of craniofacial morphological features in different sagittal malocclusions on curve of Spee. The research consists in the analysis of lateral cephalograms and study models of 90 patients, age 15-25 years which includes skeletal class I, class II and skeletal class III. Patients are divided into three groups: group A-flat curve of Spee i.e. &lt; 2mm, group B - normal curve of Spee i.e. 2-3 mm, and group C - deep curve of Spee i.e. &gt;3mm. In the literature, there is little data on research that has been done on this topic, on the other hand, in our daily work as orthodontists, we encounter the problem of leveling the deep bite.

Monson’s sphere in Chinese young adult females with individual normal occlusion: a preliminary study using digital models

BackgroundThis study investigated the characteristics of Monson’s sphere in Chinese young adult females with individual normal occlusion to provide a reference for oral rehabilitation in prosthodontic and orthodontic treatments.MethodsPoints at the dental cusps and incisal edges were selected from 51 digital mandibular dental models of Chinese young adult females (aged 18–22 years) with individual normal occlusion. Monson’s spheres were fitted to the selected points based on the least-squares principle and the radii were calculated. The deviation of each selected point from its relative spherical surface was also calculated. The radii and deviations of these points were examined using conventional descriptive statistics and distributions of the most deviated points inside and outside the spheres were analyzed.ResultsThe mean radius of Monson’s sphere in Chinese young adult females was 79.60 ± 14.13 mm. The deviation of each selected point from its relative sphere surface was 0.38 ± 0.30 mm. The maximum deviations inside and outside the sphere were 0.93 ± 0.25 mm and 0.95 ± 0.30 mm, respectively. The most deviated points outside the spheres were mainly distributed at the distolingual cusps of the mandibular second permanent molars (31.37%), while those inside the spheres were mainly distributed at the mesiolingual cusps of the mandibular first permanent molars (45.10%).ConclusionsThe radius of Monson’s sphere in Chinese young adult females was smaller than the classic four-inch value suggested by Monson. Deviation was observed from all selected points to their Monson’s sphere surface, with the most deviated points distributed primarily in the molar region.

Managing the Open Abdomen: Selecting an Appropriate Treatment Strategy.

Significance: The laparotomy is a common surgical procedure with a wide range of indications. Ideally, once the goals of surgery were achieved, the incision edges could then be approximated and the abdomen primarily closed. However, in some circumstances, it may be impossible to achieve primary closure, and instead the abdomen is intentionally left open. This review discusses the indications and objectives for the open abdomen (OA), summarizes the most common techniques for temporary abdominal closure, and illustrates treatment algorithms grounded in the current recommendations from specialty experts. Recent Advances: Still a relatively young technique, multiple strategies, and technologies have emerged to manage the OA. So too have the recommendations evolved, based on updated classifications that take wound characteristics into account. Recent studies have also brought greater clarity on recommendations for managing infection and malnutrition to support improved clinical outcomes. Critical Issues: The status of the OA can change rapidly depending on the patient's condition, the wound quality, and many other factors. Thus, there is a significant need for comprehensive treatment strategies that can be adapted to these developing circumstances. Future Directions: Treatment recommendations should be continuously updated as new technologies are introduced and old techniques fall out of use.

Microsurgical anatomy of the olfactory filaments in the nasal mucosa.

The aim of this study was to examine the distribution of olfactory filaments (OFs) in the nasal mucosa to facilitate preservation of olfactory function in endonasal approaches and preparation of a nasoseptal flap. One formalin-fixed and 9 fresh cadaveric silicone-injected specimens with 20 total sides were studied to measure the distance of the OFs to the anatomical landmarks and compare the OF presence in the nasal septum mucosa (NSM) and ethmoidal mucosa (EM). The mean distance from the first to the last OF was 19.37 ± 2.16 mm in the NSM and 23.44 ± 5.42 mm in the EM. The NSM had a mean of 7.55 ± 1.31 OFs and the EM had 14.3 ± 1.78. Average OF lengths were measured at 6.44 ± 1.48 (range 3.75-12.40) mm in the NSM and 8.05 ± 1.76 (range 4.14-13.20) mm in the EM. The mean values of the EM measurements were compared with those of the NSM; the number of OFs, the distance between the first and last OF, the average OF length, and the number of OFs between anterior and posterior ethmoidal arteries in the NSM were significantly less (p < 0.05) than those in the EM. The distance between the first OF to the nasal bone on the NSM was greater than on the EM. Compared with the EM, the OFs are significantly fewer in number and smaller in size in the NSM. The uppermost edge of the nasoseptal flap incision in the NSM might be safer to start below 12 mm from the cribriform plate for OF protection.

Papillo-incisal Distance: A guide to Maxillary Anterior teeth placement during Complete Denture Fabrication in Population of Jammu Region – An Original Research

Background: The incisive papilla is a prominent landmark for fabrication of complete denture. Many studies have been conducted to know the relationship of incisive papilla and maxillary central incisors which can be helpful for placement of maxillary central incisors in position as close as possible to natural teeth. Material &amp; Methods: A total number of 100 patients were selected randomly. The incisive papilla shape was outlined and the measurements were made from the mesio-incisal edge of central incisor to the mid-point of incisive papilla. Results: The most common shape of incisive papilla was cylindrical. The mean Papillo-incisal distance was 12.09mm where in case of Pear-shaped papilla it was 12.15mm which is slightly different from cylindrical shape. Conclusions: The Papillo-incisal distance can be helpful in determining the actual position of central incisors during complete denture fabrication.