Gothic Arch Research Articles

The Management of Aortic Coarctation Associated with Hypoplastic Arches and Particular Arch Anatomies: A Literature Review.

The surgical management of aortic coarctation in newborns needs to ensure postoperative evolution and long-term results as much as possible. Patients with a Gothic arch have a higher rate of postoperative hypertension, while newborns with a bovine arch have higher rates of restenosis and, thus, an additional risk of mortality. Late hypertension, even in anatomically successfully repaired patients, confers a high risk for cardiovascular events. This review of the literature focuses on the management of aortic coarctations associated with hypoplastic arch and particular arch anatomies, focusing on surgical techniques and their outcomes.

Orthopaeddontics in Cleft Treatment

Orthopaeddontics offers a comprehensive treatment paradigm tailored to paediatric patients aged 5 to 11 years with cleft anomalies, focussing on early correction of dento-alveolar and orthognathial deformities alongside structured psychological support. The intensive pre- surgical preparational treatment phase, conducted during this very active growth period, lays the foundation for subsequent surgical interventions, particularly secondary osteofusion, in children with the CLA and CLAP deformities. The primary objective is to achieve optimal gothic arch formation, ideal maxillary-mandibular occlusal relationship and attain balanced facial aesthetics while mitigating orthognathial deformities. Following surgery, orthopeaddontic maintenance continues into the pre-adolescent years, typically until the age of 12 years, ensuring sustained treatment efficacy before transitioning to standard orthodontic care. Central to this approach is a non-extraction treatment philosophy targeting both primary and permanent dentition, aimed at aligning teeth to achieve the most ideal arch or horse-shoe- shaped alveolus arch for all of the two (uCLA/uCLAP) or three arch segments (bCLA/bCLAP) within a balanced maxillary-mandibular occlusal relationship with an ideal facial balance. Various orthopaeddontic techniques are employed to address abnormal dimensional appearances, complimented by a psychologically sensitive approach to support paediatric patients and their families. During the orthopaeddontic treatment the treating expert needs to liaise with the parents to support the cleft child with a gentle, psychologically meaningful approach to warrant essential ultimate outcome with lifelong positive aesthetic appearance and functionality and to secure an easier acceptance of their odyssey as a person with a cleft deformity. A result of the utilization of this growth phase, related to the midfacial development and function, needs to be comparable with the expected development of a non-cleft child at a similar age. Ultimately, successful orthopeaddontic intervention during the critical growth phase should yield marked improvements in speech, facial aesthetic and a functional occlusion, potentially reducing the need for future orthodontic treatments and minimizing treatment duration.

Influence of Aortic Arch Morphology on Renal Perfusion in Patients with Coarctation of the Aorta: An Exploratory Study.

Objectives: The configuration of the aortic arch, particularly a Gothic arch shape, in individuals with corrected coarctation of the aorta (CoA) has been associated with a decreased systolic wave amplitude across the arch, which could potentially impair renal perfusion and elevate the risk of arterial hypertension. This study aims to explore the relationship between the morphological characteristics of the aortic arch and their impact on renal perfusion in patients with CoA. Methods: Seventy-one subjects with corrected CoA underwent continuous 24 h ambulatory blood pressure monitoring, computed tomography to assess the aortic arch, and renal perfusion scanning. Subjects were stratified into three groups based on the height-to-width (H/W) ratio of their aortic arch: Group 1 with a H/W ratio of <0.65, Group 2 with a H/W ratio between 0.65 and 0.85, and Group 3 with a H/W ratio of >0.85. Results: Groups 1 and 2 (53,78% and 62.63%) presented with a higher hypertension prevalence of elevated blood pressure than Group 3 (38.89%). Notable variations were observed among the subjects in the time to peak perfusion (Tmax) in the left kidney across the groups. Group 1 showed a median Tmax at 0.27, Group 2 at 0.13, and Group 3 at -0.38 (p-value = 0.079). The differences in Tmax for the right kidney followed a similar trend but were not statistically significant (Group 1 at 0.61, Group 2 at 0.22, and Group 3 at 0.11; p-value = 0.229). Conclusions: This study suggests that variations in the aortic arch morphology might not significantly influence renal perfusion in CoA patients. This indicates the potential adaptability of the renal blood flow, which appears to compensate for reduced perfusion, thus minimizing adverse effects on the kidney function. This adaptability suggests an inherent physiological resilience, emphasizing the need for further targeted research to understand the specific interactions and impacts on treatment strategies for CoA.

Different methods of determining centric relation – comparison with a digital mandibular motion analyser

BackgroundFinding and registering the maxillary–mandibular jaw relation is crucial in dental practice. Several comparative studies have been conducted to investigate the reproducibility and accuracy of techniques for determining the centric relation (CR) position of the mandible. The aim of our study was to determine which of seven different CR determination methods had the smallest deviation from the theoretical zero with the help of a digital mandibular motion analyser. The chosen theoretical zero position, the maximal intercuspal position (MIP), is the most reproducible and widely used position.MethodsThirty-four volunteers (24 females and 10 males) with a mean (SD) age of 29.1 (± 7.3) years with a negative history of temporomandibular disorder (TMD) participated in the study. A digital mandibular motion analyser was used to register the condylar position after the use of each technique for the determination of CR. The calibration was performed to the maximal intercuspal position (MIP) for each volunteer. The investigated techniques were (A) the gothic arch tracer, (B) the adduction field method, (C) Dawson’s bimanual manipulation, (D) the patient placing the tongue tip on the palatal rugae, (E) the patient placing the tongue tip to the border of the hard and soft palate, (F) the patient actively pulling the chin backwards, and (G) the examiner pushing the patient’s chin back.ResultsThe position of the mandibular condyle was illustrated in a three-dimensional coordinate system, where the origin represented the MIP. Among the seven methods examined, five showed significant deviations compared to the MIP. Among these, two methods resulted in posterior deviation of the condyles. Methods C and E coincided with the MIP in all directions.ConclusionsWithin the limitations of our study, we found that the smallest deviations from our theoretical zero (MIP) among the investigated centric relation determining methods were obtained with the bimanual mandibular manipulation technique derived from Dawson and the placement of the tongue tip on the border of the hard and soft palate (linguomandibular homotrophy theory).

Deep learning based assessment of hemodynamics in the coarctation of the aorta: comparison of bidirectional recurrent and convolutional neural networks.

The utilization of numerical methods, such as computational fluid dynamics (CFD), has been widely established for modeling patient-specific hemodynamics based on medical imaging data. Hemodynamics assessment plays a crucial role in treatment decisions for the coarctation of the aorta (CoA), a congenital heart disease, with the pressure drop (PD) being a crucial biomarker for CoA treatment decisions. However, implementing CFD methods in the clinical environment remains challenging due to their computational cost and the requirement for expert knowledge. This study proposes a deep learning approach to mitigate the computational need and produce fast results. Building upon a previous proof-of-concept study, we compared the effects of two different artificial neural network (ANN) architectures trained on data with different dimensionalities, both capable of predicting hemodynamic parameters in CoA patients: a one-dimensional bidirectional recurrent neural network (1D BRNN) and a three-dimensional convolutional neural network (3D CNN). The performance was evaluated by median point-wise root mean square error (RMSE) for pressures along the centerline in 18 test cases, which were not included in a training cohort. We found that the 3D CNN (median RMSE of 3.23mmHg) outperforms the 1D BRNN (median RMSE of 4.25mmHg). In contrast, the 1D BRNN is more precise in PD prediction, with a lower standard deviation of the error (±7.03mmHg) compared to the 3D CNN (±8.91mmHg). The differences between both ANNs are not statistically significant, suggesting that compressing the 3D aorta hemodynamics into a 1D centerline representation does not result in the loss of valuable information when training ANN models. Additionally, we evaluated the utility of the synthetic geometries of the aortas with CoA generated by using a statistical shape model (SSM), as well as the impact of aortic arch geometry (gothic arch shape) on the model's training. The results show that incorporating a synthetic cohort obtained through the SSM of the clinical cohort does not significantly increase the model's accuracy, indicating that the synthetic cohort generation might be oversimplified. Furthermore, our study reveals that selecting training cases based on aortic arch shape (gothic versus non-gothic) does not improve ANN performance for test cases sharing the same shape.

Digital Gothic Arch Tracing Device with Open- Source Software for CAD/CAM Denture Fabrication.

Digital or CAD/CAM workflows and protocols are being increasingly utilized because of their improved efficiency and reproducibility. For the fabrication of complete dentures, digital workflows can reduce treatment time and clinical visits while enhancing the reliability and reproducibility of the laboratory phase and materials. However, establishing centric relation (CR) and vertical dimension of occlusion (VDO) in a reproducible way is still a challenging step for complete denture fabrication in both analog and digital workflows. This clinical report describes a digital workflow using an individualized gothic arch tracing device (GATD) with open-source software for the fabrication of complete dentures. With this workflow, clinicians can offer customized solutions according to patient rehabilitation, with good reproducibility using gothic arch tracing to be implemented in the digital workflow.

Digitally printed custom trays assembled with occlusion rims and gothic arch tracing devices attached with tenon-and-mortise joints for biofunctional complete dentures: A dental technique

A novel technique of digitally printed custom trays assembled with occlusion rims and gothic arch tracing devices attached with tenon-and-mortise joints for biofunctional complete dentures that could be delivered in 2 visits is presented. This technique takes advantage of closed-mouth impressions and objective jaw relation records by following the biofunctional prosthetic system concept with high efficiency and reduced labor.

Comparative Evaluation of the Horizontal Condylar Guidance Using Protrusive Interocclusal Records, OPG, and CBCT in Edentulous Patients: An In Vivo Study.

A clinical study to compare the horizontal condylar guidance using protrusive interocclusal records, orthopantomography (OPG), and cone-beam computed tomography (CBCT) in edentulous patients. Thirty-six edentulous subjects were selected as per predetermined criteria. Horizontal condylar guidance was recorded using protrusive interocclusal records (PIR), OPG, and CBCT for each patient. The PIR were obtained using extraoral Gothic arch tracers to program the Hanau articulator. The horizontal condylar guidance angles (HCGAs) were digitally constructed using appropriate software along the posterior slope of articular eminence for all radiographs. The collected data were recorded, tabulated, and statistically analyzed. The condylar guidance angle values were tested for significance to compare the different angles. The correlation of HCGA measurements on both sides between the three groups was analyzed. The PIR and OPG methods (p = 0.001), as well as the OPG and CBCT methods (p = 0.001), show substantial differences on both sides. On the contrary, the PIR and CBCT methods did not differ significantly (p = 0.11). Cone-beam computed tomography is as reliable and accurate as the clinical method. A significant correlation exists between the clinical method and CBCT. It can be used as a dependable adjunct to the clinical method of HCGA measurement. Cone-beam computed tomography can overcome the shortcomings of the conventional clinical methods to determine the accurate horizontal condylar guidance angulation measurement. It is safer with minimum discomfort and wastage of time for the patients.

Fabrication of complete denture using the gothic arch tracing method in patient with severe bone resorption

Fabrication of complete denture using the gothic arch tracing method in patient with severe bone resorption

Using computed tomography angiography and computational fluid dynamics to study aortic coarctation in different arch morphologies.

To study the differences in computed tomography angiography (CTA) imaging of gothic arches, crenel arches, and romanesque arches in children with Aortic Coarctation (CoA), and to apply computational fluid dynamics (CFD) to study hemodynamic changes in CoA children with gothic arch aorta. The case data and CTA data of children diagnosed with CoA (95 cases) in our hospital were retrospectively collected, and the morphology of the aortic arch in the children was defined as gothic arch (n = 27), crenel arch (n = 25) and romanesque arch (n = 43). The three groups were compared with D1/AOA, D2/AOA, D3/AOA, D4/AOA, D5/AOA, and AAO-DAO angle, TAO-DAO angle, and aortic arch height to width ratio (A/T). Computational fluid dynamics was applied to assess hemodynamic changes in children with gothic arches. There were no significant differences between D1/AOA and D2/AOA among gothic arch, crenel arch, and romanesque arch (P > 0.05). The differences in D3/AOA, D4/AOA, and D5/AOA among the three groups were statistically significant (P < 0.05), D4/AOA, D5/AOA of the gothic arch group were smaller than the crenel arch group, and the D3/AOA and D5/AOA of the gothic arch group were smaller than the romanesque arch group (P < 0.05). The difference in AAO-DAO angle among the three groups was statistically significant (P < 0.05), and the AAO-DAO angle of gothic arch was smaller than that of romanesque arch and crenel arch group (P < 0.05). There was no significant difference in the TAO-DAO angle between the three groups (P > 0.05). The difference in A/T values among the three groups was statistically significant (P < 0.05), and the A/T values: gothic arch > romanesque arch > crenel arch (P < 0.05). The CFD calculation of children with gothic arch showed that the pressure drop between the distal stenosis and the descending aorta was 58 mmHg, and the flow rate at the isthmus and descending aorta was high and turbulent. Gothic aortic arch is common in CoA, it may put adverse effects on the development of the aortic isthmus and descending aorta, and its A/T value and AAO-DAO angle are high. CFD could assess hemodynamic changes in CoA.

Is There "A Best" Centric Relation Record? Centric Relation Records, Condyle Positions, and Their Practical Significance.

To investigate if and how the positions of condyles in centric relation (CR) varied from each other using different CR records. Condylar positions in CR were repeatedly recorded by four licensed clinicians in 81 stomatognathically healthy, fully dentate subjects with six different types of CR records. The maxillary casts were mounted in articulators after individual facebow transfer, and the mandibular casts were mounted with a central bearing point (CBP) registration on the tip of the Gothic arch. Mean values from three registrations of the centric condylar positions with each of the six methods were calculated, and comparative calculations were made. The median spatial distances of the condylar positions between the CBP and all other CR records was 0.73 ± 0.24 mm (0 to 3.19 mm). The median spatial values between the condylar positions of the different CR records ranged from 0.48 to 0.79 mm. Statistically, the positions of almost all types of registration were slightly different from each other. Different CR records reproduce slightly different positions of the mandible, which is especially true for CBP registration, whereas reproducibilities and SDs between registrations are similar. Unrefined wax-wafer registrations using bimanual manipulation have proven particularly successful with regard to precision and time requirements, as has CBP registration with regard to condylar position.

Impact of occlusal reconstruction positions on airway dimensions in patients with edentulism and long centric occlusion

ObjectiveTo study the airway changes of edentulous patients with a magnitude of long centric (MLC) ≥ 1.5 mm during occlusal reconstruction at the centric relation position (CRP) and muscular position (MP).MethodsThe CRP and MP were determined by Gothic arch. The cephalometric analysis was taken at the two occlusal positions. The sagittal distance of each part of the upper airway was measured. The differences between two occlusal positions were compared. The difference values were calculated by subtracting the two. The correlation between the MLC and the difference value was analyzed.ResultsThe sagittal diameters of palatopharynx and glossopharynx airway at MP were statistically larger than those at CRP (P < 0.05). The MLC had a strong correlation with the ANB angle (r = 0.745, P < 0.001).ConclusionCompared with the occlusal position of CRP, occlusion reconstruction at MP can provide better airway condition for edentulous patients with large MLC.

Energy and economic analysis for the selection of optimal greenhouse design: A case study of the six Morocco’s climatic zones

Early in the greenhouses' development, energy optimization must be taken into account. Without a doubt, the greenhouse's design and location affect the amount of energy it requires for heating and cooling. As a result, for a particular type of cultivation and under a specific set of environment conditions, the design of the greenhouse should be chosen to preserve its best possible microclimate conditions. The purpose of this study is to assess various greenhouse designs (shape, envelope material and orientation) in order to choose the most appropriate one for each Morocco’s climatic zone. For that, different shape/ envelope material combinations are considered, namely nine shapes (uneven span, single slop, standard even span, modified IARI, mansard roof, quonset, gothic arch, modified quonset, and modified gothic arch) and four materials (low-density polyethylene, bubbled polyethylene, ethylenevinyl acetate and glass). After the selection of the suitable combination, four orientations were investigated, namely 0°, 90°, 45° and −45° (longer axis vs North-South axis). Further improvements have been made to the greenhouse's energy efficiency by utilizing natural controlled ventilation to reduce the requirement for cooling, and nocturnal thermal insulation that operates during the heating season period. Different parameters are considered to determine the potential for energy savings and to choose the more adequate design in each climatic zone: the greenhouse heating and cooling thermal loads, the incident solar radiation on the greenhouse floor, depending on the considered plant needs, and the yearly air-conditioning cost.

Effect of Different Lateral Condylar Guidance Registration Methods and Articulators on Bilateral Balanced Occlusion of Complete Denture

Purpose: This study was conducted to accomplish the most balanced occlusion of the complete denture through comparing between lateral condylar guidance angle records of Hanau Equation, Gothic arch tracing and Computed tomography (CBCT) using arcon and non arcon articulators. Materials and methods: Twelve completely edentulous patients were selected for this study, with age ranging from 50-60 years. Selected patients were free from any temporomandibular disorders or dental diseases. Each patient received a complete denture and then duplicated another one for work. With bilateral balanced occlusion concept. The lateral condylar guidance measured using Hanau equation calculated from protrusive interocclusal records, Gothic arch tracer and Cone beam computed tomography. All records transferred to two types of semi-adjustable articulators Hanau non arcon articulator and Bio-art arcon articulator. Denture adjusted on the both articulator system to measure and achieve the bilateral balanced occlusion. Results: In present study comparison between the three methods of right and left lateral condylar guidance registrations Hanau Equation, Cone Beam CT and Gothic arch tracing on both types of articulators shows insignificant difference between right side (p=0.443) and left side (p=0.094) of lateral condylar guidance and also the balanced occlusion values of right and left side on arcon and non arcon semi-adjustable articulator were statically non-significant. Conclusions: Within the outcomes of this study, it could be concluded that to achieve balanced occlusion of complete denture Hanau equation obtained from inter occlusal records with using of Hanau arcon semi-adjustable articulator will be recommended.

Effect of Different Lateral Condylar Guidance Registration Methods and Articulators on Bilateral Balanced Occlusion of Complete Denture

Purpose: This study was conducted to accomplish the most balanced occlusion of the complete denture through comparing between lateral condylar guidance angle records of Hanau Equation, Gothic arch tracing and Computed tomography (CBCT) using arcon and non arcon articulators. Materials and methods: Twelve completely edentulous patients were selected for this study, with age ranging from 50-60 years. Selected patients were free from any temporomandibular disorders or dental diseases. Each patient received a complete denture and then duplicated another one for work. With bilateral balanced occlusion concept. The lateral condylar guidance measured using Hanau equation calculated from protrusive interocclusal records, Gothic arch tracer and Cone beam computed tomography. All records transferred to two types of semi-adjustable articulators Hanau non arcon articulator and Bio-art arcon articulator. Denture adjusted on the both articulator system to measure and achieve the bilateral balanced occlusion. Results: In present study comparison between the three methods of right and left lateral condylar guidance registrations Hanau Equation, Cone Beam CT and Gothic arch tracing on both types of articulators shows insignificant difference between right side (p=0.443) and left side (p=0.094) of lateral condylar guidance and also the balanced occlusion values of right and left side on arcon and non arcon semi-adjustable articulator were statically non-significant. Conclusions: Within the outcomes of this study, it could be concluded that to achieve balanced occlusion of complete denture Hanau equation obtained from inter occlusal records with using of Hanau arcon semi-adjustable articulator will be recommended.

A case of the right articular process dysplasia treated with application of a gothic arch tracer

A case of the right articular process dysplasia treated with application of a gothic arch tracer

Exact Formulation for the Curvature of Gothic Arch Ball Screw Profiles and New Approximated Solution Based on Simplified Groove Geometry

The correct evaluation of the curvatures of ball screw grooves allows the accurate design of the constructive parameters of this mechanism and enhancing its performance. The formulation commonly used in the literature, however, refers to ball bearing geometry, ignoring the shape of the section’s profile and the helix angle. In this paper, the exact formulae for calculating the principal curvature radii of the screw shaft and the nut grooves are analytically derived and presented. These equations, obtained through a rigorous differential geometry approach, consider the helix angle and a gothic arch profile. An approximated formulation is proposed simplifying the exact solution under the assumption of a circular groove profile. These new simple formulae accurately reproduce the exact curvature radii values with a mean relative error of approximatively 0.51% and 0.40%, respectively, for the screw shaft and nut grooves, against the value of more than 50% obtained by using the literature formulae for common off-the-shelf ball screws, especially those with high helix angles. Furthermore, they allow a computational time saving of 98%, making them suitable for being incorporated in high-fidelity dynamic models of ball. Finally, two MATLAB functions are provided to easily evaluate the complex curvature exact solution.

Sifrim-Hitz-Weiss/CHD4-related syndrome: A new case report.

Sifrim-Hitz-Weiss/CHD4-related syndrome: A new case report.

A digital, custom gothic arch tracing technique for vertical dimension of occlusion and centric relation recording

A method for identifying the vertical dimension of occlusion and centric relation in patients requiring dental rehabilitation is described. The technique relies on designing and fabricating a custom variant of the gothic arch tracer based on intraoral scans and its application following the principles of neuromuscular balance of the stomatognathic system.

Evaluation of accuracy between extraoral Gothic arch tracing and various other methods assessing horizontal condylar guidance angle in completely edentulous patients: A systematic review and meta-analysis.

The aim of this systematic review and meta-analysis was to determine the accuracy of different methods of measuring horizontal condylar guidance (HCG) angle in comparison with extraoral Gothic arch tracing for completely edentulous patients. This was a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two reviewers searched the EBSCOhost, Cochrane Library, and PubMed/MEDLINE databases and the Google Scholar search engine for in vivo studies, randomized controlled trials, cross-sectional studies, and quasi-experimental studies published from January 2005 to December 2022 on various other methods of determining HCG angle in completely edentulous patients compared with extraoral Gothic arch tracing method. Meta-analysis was conducted from the reported quantitative data. A total of 513 articles were obtained from different electronic databases, of which 22 studies were included for qualitative synthesis and 20 studies were included for meta-analysis. For the right side, a statistically significant difference was observed for panoramic radiograph (P < 0.05, pooled mean difference = 5.08 [2.17, 7]) and cephalogram (P < 0.05, pooled mean difference = 10.65 [8.81, 12.49]), whereas no statistically significant difference was observed for cone-beam computed tomography (CBCT) (P = 0.41, pooled mean difference = 4.39 [-6.10, 14.87]) and protrusive interocclusal wax record (P = 0.92, pooled mean difference = -0.45 [-9.62, 8.72]) as compared with extraoral Gothic arch tracing method. For the left side, a statistically significant difference was observed for panoramic radiograph (P < 0.05, pooled mean difference = 5.07 [1.95, 8.18]) and cephalogram (P < 0.05, pooled mean difference = 10.24 [8.65, 11.83]), whereas no statistically significant difference was observed for CBCT (P = 0.31, pooled mean difference = 4.05 [-3.74, 11.84]) and protrusive interocclusal wax record (P = 0.72, pooled mean difference = -1.21 [-7.86, 5.43]) as compared with extraoral Gothic arch tracing method. The cephalogram and panoramic radiograph obtained higher HCG angles in completely edentulous patients than extraoral Gothic arch tracing.