Gothic Arch Research Articles

Rehabilitation of a patient with atrophic ridges using gothic arch tracing and nonpressure impression: a case report

Rehabilitation of a patient with atrophic ridges using gothic arch tracing and nonpressure impression: a case report

Management of an edentulous patient with temporomandibular disorders by using CAD-CAM prostheses: A clinical report

This clinical report describes the application of computer-aided design and computer-aided manufacturing (CAD-CAM) complete dentures (CDs) in 4 visits and a 2-year follow-up period for a patient with temporomandibular disorders (TMDs), severe occlusal disturbances, and parafunctional habits. The use of a Gothic arch tracing for recording the maxillomandibular relationship and verifying muscular function was particularly helpful in such a symptomatic patient. A trial period was used to determine patient acceptance and adaptation to the new CDs.

3D-printed custom trays with a Gothic arch for centric relation recording and definitive impression making for complete dentures: A dental technique

An appliance was designed and fabricated by using computer-aided design and computer-aided manufacturing (CAD-CAM) and 3-dimensional (3D) printing to combine a custom tray with an intraoral Gothic arch. This helped simplify centric relation recording and combined definitive impression making and centric relation recording into a single step.

Minimum thickness of the gothic arch

The paper investigates how the shape affects the Couplet–Heyman minimum thickness of the masonry pointed arch. The minimum thickness is such a structural thickness, at which a vault made of rigid voussoirs is stable for self-weight. It is expressed as a function of the pointed generator curve’s deviation from the semicircle. The arch is analysed in its undisplaced, geometrically perfect state. In the present study, perfect symmetry is assumed, and any disturbance in the symmetry is not considered. The joints between the voussoirs are placed in the radial direction. Two approaches are applied to derive the minimum thickness of the pointed arch, like Limit State Analysis (henceforth LSA) and Discrete Element Modelling (henceforth DEM). The application of the LSA leads to a nonlinear optimisation problem, which is solved by the so-called active set method. DEM technique is also applied, in which the model consists of discrete blocks each of which can move independently from each other. In DEM, sliding failure can freely develop during the loading process, which is neglected in the LSA. The results of the analyses show great correspondence, if sliding failure does not appear.

A study on the accuracy of horizontal condylar guidance values in edentulous patients using preprosthetic diagnostic radiographs.

Context:Determination of horizontal condylar guidance (HCG) by various clinical and radiographic methods was performed by several investigators. If a correlation between HCG values using lateral radiographic tracing and protrusive interocclusal records can be established, the necessity of performing elaborate recording procedures can be eliminated.Aims:The aim of this study is to evaluate and to compare the correlation between HCG values in edentulous people using the protrusive interocclusal records mounted on a semi-adjustable articulator with the manual tracing of panoramic radiograph and lateral cephalogram.Materials and Methods:A total of 20 completely edentulous individuals of either sex from 45 to 75 years (mean age 63.15 years) fulfilling the inclusion criteria were included in this in vivo study. In all the participants, HCG angles were determined clinically using protrusive interocclusal records and semi-adjustable articulator after intraoral gothic arch tracing. Radiographically, it was obtained by cephalometric tracing of panoramic radiograph and lateral cephalogram.Results:The present study shows mean HCG ± standard deviation (SD) of 28.17° ± 5.99° for interocclusal protrusive record while cephalometric tracing method yielded HCG ± SD of 38.95° ± 4.77° and 35.2° ± 4.94° for lateral cephalogram and orthopantomogram, respectively. A statistically significant positive correlation (P < 0.0001) was found among these three methods.Conclusion:HCG can be successfully determined in edentulous participants by using three aforementioned methods. HCG values from cephalometric tracing of diagnostic radiographs can be used as an adjunct to the clinical method but cannot be used independently for programming a semi-adjustable articulator

Back to the basics ～ゴシックアーチは本当に必要なのか～

Back to the basics ～ゴシックアーチは本当に必要なのか～

A clinico-radiographic study to compare and co-relate sagittal condylar guidance determined by intraoral gothic arch tracing method and panoramic radiograph in completely edentulous patients.

Purpose:The purpose of this study was to compare and correlate sagittal condylar guidance determined by intraoral gothic arch tracing method and panoramic radiograph in edentulous patients.Materials and Methods:Twelve completely edentulous patients were selected by the inclusion and exclusion criteria. Conventional steps in the fabrication of complete denture till jaw relation were carried out. Intraoral gothic arch tracing and protrusive interocclusal records were obtained for each patient. Protrusive interocclusal record was used to program the Hanau Wide-Vue semi-adjustable articulator, thus obtaining the sagittal condylar guidance angle. Using RadiAnt DICOM software, on the orthopantomogram obtained for each patient in the study, two reference lines were drawn. The Frankfort's horizontal plane and the mean curvature line (joining the most superior and the inferior points on the glenoid fossa curvature) were drawn. The mean curvature line was extended to intersect the Frankfort's horizontal plane, thus obtaining the radiographic sagittal condylar guidance angle. The condylar guidance angles obtained by these two methods were compared and subjected to paired t-test.Results:There was no statistically significant difference between the sagittal condylar guidance angles obtained between right and left sides with intraoral gothic arch tracing and radiographic methods (P = 0.107 and 0.07, respectively).Conclusion:Within the limitations of this study, it was concluded that the protrusive condylar guidance angles obtained by panoramic radiograph may be used for programming semi-adjustable articulators.

Comparative Analysis of Sagittal Condylar Guidance Recorded by Intraoral Gothic Arch Tracing and Panoramic Radiograph in Completely Edentulous Patients

To compare the intraoral gothic tracing method with panoramic radiographs in patients requiring complete dentures. The present study was conducted on 20 edentulous subjects of both genders. Hanau Wide-Vue semi-adjustable articulator was used to record sagittal condylar guidance in all patients. Panoramic radiographs were taken in all patients and Frankfurt horizontal plane was traced on both sides of orthopantomogram (OPG) and second plane was marked by joining the most superior and most inferior point on the glenoid fossa curvature. Frankfort's horizontal plane was crossed with this line to record radiographic condylar guidance angle. NNT software was used to record the condylar guidance angle. Mean ± standard deviation (SD) clinical SCG (25.15 ± 3.24) and radiographic seismocardiography (SCG) (27.54± 5.01) was non significant (p > 0.05) on left side. Mean ± standard deviation (SD) clinical SCG (26.84 ± 3.69) and radiographic SCG (29.3 5 ± 4.58) was significant (p < 0.05) on right side. The SCG did not show difference in values recorded by both methods on both sides. The difference in values in both sides by clinical method and radiographic method was non-significant (p > 0.05). There was correlation between sagittal condylar guidance obtained by both intraoral gothic arch method as well as radiographic method done on digital panoramic radiographs. Correct centric jaw relation determines the success of the complete denture. Radiographic and clinical methods provide sufficient minute details necessary for the betterment of management.

Functional Assessment of the Stomatognathic System, after the Treatment of Edentulous Patients, with Different Methods of Establishing the Centric Relation.

The study compares subjective experiences of patients, wearing complete dentures. Two different methods of determining a centric relation were performed: the traditional method using wax occlusal rims and the Gerber method, based on gothic arch tracings. The success rate of establishing a centric relation in both methods was evaluated (rentgenodiagnostics). The influence of the method used to obtain the centric relation on patients' stomatognathic system (condyle centralization, pain) was also evaluated. Better results were achieved in gothic arch tracing method. Before every prosthetic treatment of edentulous patients, a functional analysis of the TMJ is necessary. The lack of centric relation, in a long term adaptation patients, does not lead to TMD symptoms. This trial is registered with NCT03343015.

Sublime Visions: Piranesi and his Carceri Prints

This paper examines the philosophical concept of the sublime and its impact in the work of the artist Giovanni Battista Piranesi. The main focus of the paper is Piranesi’s Carceri series, created during the period of 1740 – 1760 in Rome. Although Dionysius Longinus wrote of the sublime several centuries earlier, this concept became popular in 18th century aesthetic theory, and Piranesi had access to the writings of Longinus and 18th-century followers of his ideas. According to Longinus’ theory, creating a sublime work of art required daring and great thinking. The sublime was a quality of experience meant to move the soul to a higher realm. Piranesi attempted to emulate this quality in his own works by invoking the grandeur of ancient Rome. Piranesi was surrounded by ancient ruins and he was actively involved in archaeological digs. He wrote on the wonder of observing the ruins of Rome, “these speaking ruins have filled my spirit”. At the same time, Piranesi was not only surrounded by classical concepts; the motif of the gothic arch, which conveys the idea of architecture reaching up to heaven, also plays a role in his prints and their evocation of the sublime. His techniques with etching, composition, and depiction of light show his creativity, skill, and ambition, consistent with Longinus’ ideas. The iconography of the Carceri prints, especially Plates XIII, XIV, XVI, expresses Piranesi’s interest in the sublime through imaginative compositions, relating tiny figures to lofty architectural spaces, and through his demonstrated pride in ancient Rome.

EVALUATION OF TWO METHODS USED TO RECORD THE NEUTRAL ZONE UTILIZED LOW FUSING MODELING COMPOUND- ACCURACY OF CENTRIC RELATION REGISTRATION

Introduction: Many techniques have been described in the literature for molding of the Neutral zone. Gothic arch tracer attached to neutral zone record used for accurate registration of centric relation.Material and method: This study was passed on 10 edentulous patients to compare the accuracy of centric relation using intra-oral Gothic arch tracer attached to two different neutral zone records. The first method includes, recording of neutral zone for each arch separately without vertical stopper then orientation of the occlusal plane on the articulator (indirect method), the other method record the neutral zone at predetermined vertical relation, using upstanding flange, then orient the occlusal plane intra- orally (direct method).Result: within this study, the indirect method of neutral zone exhibit a statistically more accuracy in registration of the centric relation using the Gothic arch tracer compared to the direct method.Conclusion: recording the neutral zone of each arch separately give more accurate registration of the centric relation than that using upstanding flange.

Garlock, Gayle. Canadian Binders’ Tickets and Booksellers’ Labels. New Castle, DE: Oak Knoll Press, 2015. 158 pp. $95.00. Cloth, Illus. CD (ISBN 978-1-58456-337-2).

Garlock, Gayle. <i>Canadian Binders’ Tickets and Booksellers’ Labels</i>. New Castle, DE: Oak Knoll Press, 2015. 158 pp. $95.00. Cloth, Illus. CD (ISBN 978-1-58456-337-2).

Evaluation of electromyogram activity and masticatory efficiency in edentulous individuals whose maxillomandibular horizontal relationship records were obtained with three different methods

This study was performed to investigate the electromyographic (EMG) activity of the masseter muscle and the anterior temporalis muscle, as well as the masticatory efficiency after insertion of the dentures in edentulous individuals whose maxillomandibular horizontal relationship records were obtained with three different methods. Ten edentulous individuals were enrolled in this study. Three types of complete dentures for these 10 edentulous patients were made according to their different maxillomandibular horizontal relationship records. The maxillomandibular horizontal relationship of complete dentures was recorded by three methods. In the first method (A), the maxillomandibular horizontal relationship was determined at the gothic arch tracing apex. In the second method (B), the relationship was 1mm anterior to the tracing apex with the gothic arch. In the last method (C), the horizontal jaw relation was recorded by natural chewing. The muscular activities of the three complete dentures were examined by EMG. The masticatory efficiency was evaluated based on the absorbance. The differences among the dentures were statistically analyzed with SPSS 17.0. The muscular activities of dentures B and C were much higher than that of denture A during clenching in the center occlusion and during chewing (P<0.05). The highest asymmetry index was found indenture C, which was significantly higher than those of dentures A and B (P<0.05). A statistically significant increase in the absorbance was observed between dentures B and C (P<0.05); otherwise, no statistically significant differences were observed (P>0.05) between B and C. Given the limitations of this experimental design, in edentulous individuals the maxillomandibular horizontal relationship recorded at 1mm anterior to the tracing apex with the gothic arch can improve the function of masticatory muscles and strengthen masticatory performance.

How successful is successful? Aortic arch shape after successful aortic coarctation repair correlates with left ventricular function

ObjectivesEven after successful aortic coarctation repair, there remains a significant incidence of late systemic hypertension and other morbidities. Independently of residual obstruction, aortic arch morphology alone may affect cardiac function and outcome. We sought to uncover the relationship of arch 3-dimensional shape features with functional data obtained from cardiac magnetic resonance scans. MethodsThree-dimensional aortic arch shape models of 53 patients (mean age, 22.3 ± 5.6 years) 12 to 38 years after aortic coarctation repair were reconstructed from cardiac magnetic resonance data. A novel validated statistical shape analysis method computed a 3-dimensional mean anatomic shape of all aortic arches and calculated deformation vectors of the mean shape toward each patient's arch anatomy. From these deformations, 3-dimensional shape features most related to left ventricular ejection fraction, indexed left ventricular end-diastolic volume, indexed left ventricular mass, and resting systolic blood pressure were extracted from the deformation vectors via partial least-squares regression. ResultsDistinct arch shape features correlated significantly with left ventricular ejection fraction (r = 0.42, P = .024), indexed left ventricular end-diastolic volume (r = 0.65, P < .001), and indexed left ventricular mass (r = 0.44, P = .014). Lower left ventricular ejection fraction, larger indexed left ventricular end-diastolic volume, and increased indexed left ventricular mass were identified with an aortic arch shape that has an elongated ascending aorta with a high arch height-to-width ratio, a relatively short proximal transverse arch, and a relatively dilated descending aorta. High blood pressure seemed to be linked to gothic arch shape features, but this did not achieve statistical significance. ConclusionsIndependently of hemodynamically important arch obstruction or residual aortic coarctation, specific aortic arch shape features late after successful aortic coarctation repair seem to be associated with worse left ventricular function. Analyzing 3-dimensional shape information via statistical shape modeling can be an adjunct to long-term risk assessment in patients after aortic coarctation repair.

An Analytical Model of Four-Point Contact Rolling Element Ball Bearings

The purpose of this work is to establish an analytical model and standard way to predict the performance characteristics of a four-point contact, or gothic arch type, rolling element ball bearing. Classical rolling element bearing theory, as developed by Jones, has been extended to include the complex kinematics of the four-point contact bearing; thereby providing complete elementwise attitude and internal load distribution of the bearing under operating conditions. Standard performance parameters, such as element contact stresses, contact angles, inner ring deflections, nonlinear stiffness's, torque, and L10 life, are solved explicitly via standard Newton–Raphson techniques. Race control theory is replaced with a minimum energy state theory to allow both spin and slip to occur at the ball-to-raceway contact. The developed four-point model was programed within the orbis software program. Various test cases are analyzed and key analytical results are compared with the Jones four-point contact ball bearing analysis program, the Wind Turbine Design Guideline, DG03, and traditional two-point (angular contact) analysis codes. Model results for the internal distribution of ball loads and contact angles match the Jones program extremely well for all cases considered. Some differences are found with the DG03 analysis methods, and it is found that modeling a four-point contact bearing by overlaying two opposed angular contact bearings can result in gross errors.

Maladaptive aortic properties after the Norwood procedure: An angiographic analysis of the Pediatric Heart Network Single Ventricle Reconstruction Trial

ObjectivesAortic arch reconstruction in children with single ventricle lesions may predispose to circulatory inefficiency and maladaptive physiology leading to increased myocardial workload. We sought to describe neoaortic anatomy and physiology, risk factors for abnormalities, and impact on right ventricular function in patients with single right ventricle lesions after arch reconstruction. MethodsPrestage II aortic angiograms from the Pediatric Heart Network Single Ventricle Reconstruction trial were analyzed to define arch geometry (Romanesque [normal], crenel [elongated], or gothic [angular]), indexed neoaortic dimensions, and distensibility. Comparisons were made with 50 single-ventricle controls without prior arch reconstruction. Factors associated with ascending neoaortic dilation, reduced distensibility, and decreased ventricular function on the 14-month echocardiogram were evaluated using univariate and multivariable logistic regression. ResultsInterpretable angiograms were available for 326 of 389 subjects (84%). Compared with controls, study subjects more often demonstrated abnormal arch geometry (67% vs 22%, P < .01) and had increased ascending neoaortic dilation (Z score 3.8 ± 2.2 vs 2.6 ± 2.0, P < .01) and reduced distensibility index (2.2 ± 1.9 vs 8.0 ± 3.8, P < .01). Adjusted odds of neoaortic dilation were increased in subjects with gothic arch geometry (odds ratio [OR], 3.2 vs crenel geometry, P < .01) and a right ventricle-pulmonary artery shunt (OR, 3.4 vs Blalock–Taussig shunt, P < .01) but were decreased in subjects with aortic atresia (OR, 0.7 vs stenosis, P < .01) and those with recoarctation (OR, 0.3 vs no recoarctation, P = .04). No demographic, anatomic, or surgical factors predicted reduced distensibility. Neither dilation nor distensibility predicted reduced right ventricular function. ConclusionsAfter Norwood surgery, the reconstructed neoaorta demonstrates abnormal anatomy and physiology. Further study is needed to evaluate the longer-term impact of these features.

Augmentation of the Lesser Curvature With an Autologous Vascular Patch in Complex Aortic Coarctation and Interruption

Reconstruction of the aortic arch in patients with complex aortic coarctation or interruption continues to be a challenge because of early left mainbronchial compression or recoarctation and late Gothic arch formation. We propose a modified arch reconstruction technique augmenting the lesser curvature with an autologous vascular patch, which can relieve tension on the anastomosis without a prosthetic material. We retrospectively reviewed 33 patients with coarctation and arch hypoplasia (n= 31) or arch interruption (n= 2) who underwent arch reconstruction with an autologous vascular patch from 2007 to 2012. Median age at the operation was 17 days (range, 5 to 200 days). Median body weight was 3.7 kg (range, 2.3 to 7.0 kg). Cardiopulmonary bypass was used for all operations. Median antegrade selective cerebral perfusion time was 35 minutes (range, 23 to 59 minutes). Combined intracardiac anomalies in 29 patients (88%) were corrected simultaneously. The reconstructed arch was supplemented in the lesser curvature with an autologous vascular patch that was harvested from aortic isthmus (n= 25), pulmonary artery (n= 4), left subclavian artery (n=2), aberrant right subclavian artery (n= 1), or distal arch (n= 1). One patient (3%) died of acute respiratory distress syndrome. All survivors were discharged at 15days (range, 7 to 58 days) postoperatively without neurologic complications or bronchial obstructions. Median follow-up was 24.8 months (range, 0.2 to 48.5 months). No recoarctation was observed during follow-up, and no patient needed reoperation. Augmenting the lesser curvature with an autologous vascular patch during arch reconstruction resulted in excellent midterm outcomes. Not only can a more natural shape of arch and less tension on the anastomosis be obtained, but complications, such as left main bronchial obstruction or recoarctation, can also be minimized. Long-term follow-up is needed to evaluate late development of recoarctation, hypertension, or aneurysm formation.

An in vivo study to compare and correlate sagittal condylar guidance obtained by radiographic and extraoral gothic arch tracing method in edentulous patients

Purpose: To compare the sagittal condylar guidance angle obtained by extra oral gothic arch tracing and orthopantomogram in completely edentulous subjects. Material and Methods: Ten completely edentulous subjects were selected by the inclusion and exclusion criteria. Conventional steps in the fabrication of complete denture with balanced occlusion were carried out. Extra oral gothic arch tracing records were obtained for every patient. Protrusive interocclusal records were used to program the Hanau wide vue semiadjustable articulator, thus obtaining the sagittal condylar guidance angle by clinical method. On the orthopantomogram obtained for every patient in the study, orbitale and porion were located and the Frankfurts horizontal reference line was drawn. The most superior and the inferior points on the glenoid fossa curvature were located and a mean curvature line was obtained. A third reference line passing through the most superior and the inferior points on the glenoid fossa was extended to intersect the Frankfurts horizontal plane, thus obtaining the radiographic sagittal condylar guidance. These values were tabulated and subjected to Wilcoxon Signed Ranks test. Results: There is statistically significant difference between the sagittal condylar guidance values obtained between right and left sides with extra oral gothic arch tracing and orthopantomographic method (p value is 0.014 and 0.007 respectively). Conclusions: The use of orthopantomogram to set the condylar guidance on the semi adjustable articulator for complete denture therapy is questionable.

Aortic Arch Mapping by Computed Tomography for Actual Anatomic Studies in Times of Emerging Endovascular Therapies

The latest advances in treatment of aortic arch pathologies increasingly included endovascular technologies. For those purposes, more detailed knowledge about the specific anatomic features are of particular interest, especially with regard on the need for better suitable stent grafts or even development of "off-the-shelf" stents. The study enrolled patients undergoing computed tomography of the chest for other reasons than screening for aortic disease. Patients with aortic pathologies were excluded. Finally, 118 patients were included. Anatomic features of the aortic arch, the supra-aortic branches, distances and takeoff angles as well as specific diameters were assessed and analyzed with respect to the patients height, weight, age, and sex. A significant variability of all measurements was observed. Nonetheless, 4 recurrent types of aortic arch geometry were identified: (1) Classic arch (39%), (2) Gothic arch (39%), (3) Rectangle arch (11.9%), and (4) Plain arch (8.5%). Furthermore, the aortic diameter continuously decreased from the beginning of the ascending aorta during the after 200 mm by 24.8% (31.8 ± 3.6 mm to 23.9 ± 3.1 mm in mean). Distances from the aortic annulus to the supra-aortic branches takeoff points showed significant gender- and age-related differences with larger distances in the older and male (P < 0.001). Observed takeoff angles were 44.9 ± 15.9° for the brachiocephalic trunk, 25.7 ± 15.5° for the left common carotid artery, and 28.8 ± 14.5° for the left subclavian artery. Observed anatomic features were highly variable. It seemed that a "standard aortic arch" does not exist. Until today, the aortic arch as a dynamic and 3-dimensional entity is not fully understood. The development of "off-the-shelf" stents in the near future will be limited by this complexity and variability.

Análise tomográfica de posições condilares em indivíduos assintomáticos classe I de Angle

ObjectiveEvaluate by linear sagital corrected tomography in patients Angle's Class I, the condylar position in maximum intercuspation and maximum retrusion position, obtained by the technique of Gothic arch of Gysi and the differences between them. MethodsThere were selected 20 volunteers, 6 men and 14 women, asymptomatic, with complete dentition and Angle's Class I. After anamnesis and clinical examination they were submitted to dental impressions and its casts mounted in a semi‐ajustable articulator. Intraoral record devices were made on the casts and were placed in the mouth for obtaining the Gothic arch tracing, using as reference the vertex for the maximum retrusion position. Tomographic scans were made in maximum intercuspation and maximum retrusion position, determined by the vertex of the Gothic arch tracing. After the results of the tomography scans, data was submitted to statistical analysis by means the Frequency Test, Two way ANOVA and T test, with a significance of 5%. ResultsIn maximum retrusion position, the posterior position was found more frequently and in maximal intercuspation the central position. There were diferences between the two studied positions bilaterally (p<0.0001). There were no diferences in the condilar displacement in both sides (p=0.43). The medium displacement for the right side was 0.68mm (±0.33mm) and the left side 0.69mm (±0.32mm). ConclusionThere were no significant differences when the joint spaces were compared bilaterally. The two studied positions determined distinct positions of the condyles in its respectives mandibular joints.