Articulator Settings Research Articles

A novel algorithmic approach for automatic virtual articulation to avoid dynamic interferences in dental restoration designs.

There is an ongoing debate about the benefits of the facebow and individual articulator settings in prosthodontics when compared with simpler methods. The present study aims to determine whether the implementation of novel algorithmic articulator concepts may be an alternative to avoid dynamic interference contacts during the design process of fixed posterior restorations, and to what extent the occlusal morphology of the restoration is affected. From a chairside CAD database, a total of 50 clinical patient cases documenting 61 planned fixed restorations in the posterior tooth region were selected. A common CAD software program was used for the automated knowledge-based design process. When designing the restorations, functional concepts were applied, including the pure static occlusion, the average articulation, three different articulator settings as a control, and a combination of a broad range of articulation parameters (the full range dynamic articulation). The resulting dynamic contact points were compared both visually and metrically with a monitoring software program. There is a highly significant difference in avoiding dynamic interference contacts when applying the full range dynamic articulation compared with the pure static occlusion (P < 0.001) and the average articulation (P < 0.001). Furthermore, the superimposition revealed that the surface of the restorations showed nearly no visual morphologic changes after virtually grinding-in the interpenetrating contact points. The full range dynamic articulation can be used for the design of small fixed posterior restorations to avoid most dynamic interference contacts without the need for determining individual parameters for each patient.

Sagittal Condylar Inclination and Transversal Condylar Inclination in Different Skeletal Classes.

Background: During prosthodontic treatment, the averaged values of the transversal condylar inclination (TCI) and the sagittal condylar inclination (SCI) are used for articulator settings. This study evaluated different parameters of measurable mandibular movements according to skeletal classes. Methods: Seventy-five patients (mean age 30.8 ± 5.49) had a condylography using the Cadiax Compact device (Gamma Dental, Klosterneuburg, Austria) and cephalometric analysis performed. Statistical analysis was performed using R statistical software. Results: There was no statistical evidence to state that the value of SCI angle is different in I compared to II Skeletal Class. There were no statistically significant differences when comparing the I vs. III and II vs. III Skeletal Class. The lowest mean SCI angle values were found in subjects with Skeletal Class III. There were statistically significant differences in left-sided TCI between Class I and II. There was a statistically significant linear relationship between ANB angle value and SCI value. Conclusions: Due to the wide individual variation in SCI and TCI values, it is advisable to use individual measurable parameters of mandibular movements during prosthetic reconstructions. The statistically significant relationship between SCI and ANB angle can be used to individualize the articulating parameters, especially in significant skeletal disproportions.

The patient-specific anatomical articulator

Currently available dental articulators have limitations for reproducing human mandibular movements. The present article describes an innovative device that is a true patient-specific anatomical articulator that accurately simulates patient anatomy and eliminates all technique-sensitive mounting procedures, thus substantially diminishing potential errors in mounting and articulator settings. By using three-dimensional (3D) printing technology, patient cone beam computed tomography (CBCT) data are used to print 3D replicas of the condylar fossae, as well as the actual condyles, at the correct intercondylar distance. The maxilla (maxillary teeth and edentulous ridge) is printed with the correct spatial relationship to the condylar complexes and the Frankfort horizontal plane (FHP). Those printed structures are then premounted onto a modified articulator frame to render it “anatomic.” This new custom anatomical articulator, which accurately mimics patient anatomical movements rather than relying on average values, represents the first truly fully adjustable articulator that is more precise than can be generated by a pantographic tracing. It saves money, time, and effort by eliminating earbow transfers and mounting errors in complex prosthodontic treatment.

Technique to Maintain the Correct Spatial Orientation of the Maxillary Diagnostic Cast to that of the Master Cast in a Full-Mouth Rehabilitation Case.

A common challenge in full-mouth rehabilitation is preserving the correct spatial orientation of the maxillary diagnostic, diagnostic wax-up and master casts within the dental articulator. Any malposition of the maxillary master cast will immediately invalidate the articulator settings that were programmed from the pantographic or axiographic tracing. This will subsequently affect the occlusal morphology of the restorations. The technique presented in this article helps to precisely relocate the maxillary master cast to the same spatial orientation as both the initial diagnostic, and diagnostic wax-up casts.

Accuracy of Dynamic Virtual Articulation: Trueness and Precision.

To study the effects of altering condylar settings and pin openings on the trueness and precision of virtual articulators vs. mechanical articulators. Maxillary and mandibular typodonts with fiducial markers were mounted on a mechanical Artex-CR articulator, and the mandibular teeth were prepared to allow guidance solely by the posterior determinants of the articulator and the incisal table. The relationship of the mounted typodonts was preserved digitally by scanning using manufacturer transfer plate adaptors. On the mechanical articulator, pattern resin was allowed to set between the maxillary and mandibular occlusal surfaces (area #25-30) at the endpoints of dynamic movements at 3 condylar inclinations (SCI): 10°, 30°, and 45°, n = 12/inclination, or at 3 incisal pin openings (2, 5, and 10 mm, n = 12/opening). All other articulator settings were kept constant. Resin specimens attached to the typodonts were scanned within 5 minutes of setting, then removed, and the articulated typodonts rescanned. Fixed dental prostheses (FDPs) #25-30 were designed on the virtual articulator using identical parameters to the mechanical articulator. Dynamic virtual movements were used to sculpt the design, and a file of the design was saved. The files of both types of samples were aligned and overlaid. Interocclusal separation was measured in triplicate at the indentation created by the mesiolabioincisal point angle on the incisal edge of #8 and the mesiobucco-occlusal point angle of #3. Trueness and precision of both types of articulators were calculated and compared using one-way ANOVA, followed by the Tukey HSD test (α = 0.05). There was no statistically significant difference at altered pin openings in either trueness (F = 0.202, p = 0.37) or precision (F = 3.134, p = 0.09) for the majority of measurements. The only significant difference was in the precision between the 2 types of articulators at 5 mm incisal opening, and only at the anterior measurement point (F = 15.134, p = 0.0008); however, these differences were less than 100 μm. When the SCI was altered, there was no statistically significant difference (F = 3.624, p > 0.05) between the virtual and mechanical articulators in trueness for 5 of the 6 measurements obtained (F = 3.624, p = 0.07) or for all of the precision measurements (F = 3.529, p = 0.07). The one trueness measurement that was significantly different (F = 9.237, p = 0.006) occured at SCI of 10°, and it was less than 100 µm. Dynamic movements on the virtual articulator were shown to be as true and precise as to the mechanical articulator. When there were deviations, these deviations were less than 100 µm and thus, these deviations may not be clinically relevant.

Revising Average Condylar Inclinations Using Electronic Pantograph Assessment: A Cross-Sectional Study

Introduction: Condylar inclinations produce a frame for the occlusal morphology of dental restorations. Applying arbitrary average values for the articulator settings has brought about more practicality to the prosthesis fabrication procedures. The present study aimed at determining the average sagittal condylar inclination (SCI) and Bennett angle (BA) using electronic pantograph and comparing the inclination quantities obtained from different methods to proposed average measurements. Materials and Methods: Using Cadiax Compact II, condylar inclinations were recorded in 50 participants, generally healthy without any signs of joint problems. The recorded average values were compared with proposed mean values using one sample t-test. The level of significance was set at P < 0.05. The available articles were also searched using electronic databases. Results: A statistically significant difference was observed in the mean SCI (41.66°) and the proposed average value (33°) (P < 0.05). The difference between BA mean value (10.10) and arbitrary proposed value (15) was even more pronounced (P < 0.05). Pantographic records show different values compared to average propositions for condylar inclinations. Conclusion: Ongoing controversies concerning the average values for articulator settings proposed a revision in traditionally used arbitrary settings as well as Hanau formulation on the sagittal and lateral inclination interrelationships.

Evaluation of the Cadiax Compact® II Accuracy in Recording Preadjusted Condylar Inclinations on Fully Adjustable Articulator

Mandibular movement analysis is a critical step in making the functional occlusal morphology and improving the diagnosis and treatment of temporomandibular joint disorders (TMDs). Cadiax Compact® is an electronic condylograph that claims to record the horizontal condylar inclination (HCI), Bennett angle (BA) and relative shape of the articular eminence. This study aims at assessing the accuracy of Cadiax Compact® II in its claimed abilities. The electronic condylograph (Cadiax Compact®II) was fitted on the fully adjustable articulator (gamma dental reference-SL). After setting of HCI and BA on the arbitrary degrees, eccentric movements were produced manually on the articulator. The Cadiax recorded these preadjusted angles and the accuracy of its recordings was assessed by comparison of the results with the preadjusted HCI, BA and color inserts as references. The majority of the comparisons showed statistically significant differences between articulator settings and Cadiax recordings. However, the maximum difference was about 2.50 which seems acceptable for clinical practice. The obtained results showed that Cadiax Compact is an accurate and reliable instrument for diagnostic purposes, yielding reproducible measurements. Despite this, Cadiax is a technically sensitive device that can preclude its routine usage.

Comparison of the Arcon and the Condylar type articulators on the reproduction of lateral movements Part III. Articulator adjustment for the lateral movements

It is supposed that on the reproduction of lateral movements, the articulator settings of the Condylar type articulator is different from the condylar pathways of the human jaw. The Arcon type articulator shows the same values as the human jaw. It is not clear, however, about the differences of the articulator settings between the Arcon and the Condylar type articulator. In the present study, the angular differences on each adjustable mechanism are analyzed by reproducing the same lateral movement on the Arcon type articulator; which has all guiding systems on the upper member, and the Condylar type articulator; which has all guiding systems on the lower member. The lateral movement is reproduced on the Arcon type using the mandibular movement cubic model three-dimensionally. The lateral movement of the Condylar type is reproduced by calculating the intercuspal position of the Arcon type relative to the lateral occulusal position of the Arcon type. The differences of the articulator settings between both articulators are calculated and compared.The results are as follows;The angular differences of the articulator settings between the Condylar and the Arcon type articulator are not the same on each adjustable mechanism. The maximal difference of the non-working side condylar guidance is about 4°on the horizontal projective angle and 1°on the sagittal projective angle, while the maximal difference of the working side condylar guidance is about 2°on the horizontal and frontal projective angle. In addition, the changing of the sagittal projective angle on the non-working side condylar guidance affects the articulator settings of the Condylar type articulator. It is necessary to consider the angular differences from the condylar pathways of the human jaw, when evaluating the lateral movement by the Condylar type articulator.

Comparison of the Arcon and the Condylar type articulators on the reproduction of lateral movements Part II: Applying the same articulator settings

There are two types of adjustable articulators, the Arcon and Condylar. The guiding systems are located on the upper member of the Arcon type articulator and on the lower of the Condylar type articulator. The movement of the articulators are different when the articulator settings on the adjustable mechanisms of both articulators are the same in the reproduction of lateral movements. In addition, when the movements of both articulators are the same, the articulator settings are different.In the present study, we have focused on the effects of the guiding systems on the movement of the articulators. In order to evaluate the difference between type I and type VIII articulators (type I: which has the Arcon type guiding system on the upper member, type VIII: which has the Condylar type guiding system on the lower member), we calculated the lateral movements of both articulators by using a mathematical formulae.The results are as follows:When we apply the same articulator settings of the average lateral movement to both articulators, the largest difference takes place on the horizontal projective angle of the non-working side condylar guidance at 2.8°, whereas the smallest difference is observable on the sagittal projective angle of the non-working side condylar guidance at 0.6°. The three-dimensional discrepancies between both articulators are almost the same on the condylar and tooth pathways at about 0.15mm. This difference is explained by the three-dimensional rotation occurring during the lateral movement. Therefore, the difference between both articulators is affected by the articulator settings of the adjustable mechanisms.

The Effect of the Articulator Settings on the Cusp Inclines as Measured by a Coordinate Measuring Machine

The purpose of the study was to learn the effect of changes in the articulator settings on the cusp angles during working, nonworking, and protrusive movements; the purpose was also to determine the ability of the coordinate measuring machine to measure the movements. The condylar angles and the anterior guide angles on a Hanau 96H2 articulator (Teledyne Hanau Corp, Buffalo, NY) were varied; 432 working, nonworking, and protrusive cusp angles were measured at the first molar by a coordinate measuring machine. The data from the coordinate measuring machine was used to produce formulas. The formulas were used to calculate the working, nonworking, and protrusive cusp angles that will occur as a result of 72 different articulator settings. The coordinate measuring machine is useful for making measurements of articulator movements. Additional research may measure the movements of other articulators or compare articulators (such as the arcon and nonarcon).

Comparison of the intercondylar distance and the interfacial width as used with the electronic pantograph

The electronic pantograph (Pantronic) records mandibular movements and computes the articulator settings. The Pantronic pantograph does not determine the intercondylar distance but approximates it from the interfacial width at the condyles. An average distance of 12.5 mm is subtracted from each side to determine the intercondylar distance. This study recorded 45 patients' articulator intercondylar distances that had been set from a mechanical pantograph and they were compared with the Pantronic's approximation. The difference between the interfacial width and the actual intercondylar distance was 15.1 mm on the right side and 14.9 mm on the left side. A numerical value of 15.0 mm was statistically superior to the Pantronic's 12.5 mm in estimating the average distance between the intercondylar distance and the surface of the skin at the condyle. No statistically significant difference was found between the differences of interfacial width and intercondylar distance values for men and women ( p > 0.05). The mean intercondylar distance was 56.5 mm on the right side and 56.7 mm on the left side. A statistically significant difference was found between the mean intercondylar distances of men and women ( p < 0.05).

Effects of changes in articulator settings on generated occlusal tracings. Part II: Immediate side shift, intercondylar distance, and rear and top wall settings

An occlusal scribing device attached to a fully adjustable articulator was used to generate occlusal tracings. The tracings were analyzed to determine the effect changes in immediate side shift, intercondylar distance, and rear and top wall settings had on molar occlusal morphology. When ranked from greatest to least effect, a 0.2 mm change in the immediate side shift setting had the greatest effect on the occlusion, whereas a 5-degree change in the rear and top wall settings had the least effect.

Effects of changes in articulator settings on generated occlusal tracings. Part I: Condylar inclination and progressive side shift settings

An occlusal scribing device attached to a fully adjustable articulator was used to generate occlusal tracings. The tracings were analyzed to determine the effect changes in progressive side shift and condylar inclination settings had on molar occlusal morphology. The progressive side shift adjustment affected the cusp height and ridge and groove position, primarily in the nonworking excursion. The condylar inclination adjustment affected the cusp heights in the protrusive and nonworking excursion without affecting the working excursion.

Potential errors when using a computerized pantograph

This study determined the effect on articulator settings of using an arbitrary hinge axis as compared with the terminal hinge axis in orienting a computerized pantograph on a patient. The effect of an error in measuring the reference plane angle or clutch angle was also determined. Two subjects were pantographed 30 times by using the terminal hinge axis and 30 times by using the arbitrary hinge axis. Statistically the articulator settings obtained by using the arbitrary hinge axis and the terminal hinge axis were different, but the difference was small. One subject was pantographed on 18 occasions by using different reference plane angle and clutch angle settings. Analysis showed that 1-degree change in the reference plane angle setting produced ~0.9-degree change in the protrusive and orbiting path articulator settings. A 1-degree change in the clutch angle setting produced ~0.9-degree change in the progressive side shift settings. It was concluded that the terminal hinge axis should be used as the posterior reference point and the reference plane angle and clutch angle should be carefully recorded.

A comparison of articulator settings obtained by using an electronic pantograph and lateral interocclusal recordings

Articulator settings were obtained for two subjects 10 times in a 2-week period by using both a lateral interocclusal record technique and a Pantronic pantograph. The ORB and PSS articulator settings obtained from the two techniques were compared and the following conclusions drawn. 1. Over a 2-week period, the variance in the Pantronic pantograph ORB and PSS articulator settings was less than the variance in the setting obtained by using lateral interocclusal records. For the Pantronic pantograph technique, 95% of any ORB settings were within 2.5 degrees of the Pantronic pantograph mean and 95% of any PSS settings were within 1.9 degrees of the Pantronic pantograph mean. For the interocclusal record technique, 95% of the ORB settings made with interocclusal records were within 11.9 degrees of the mean for one subject and 13.4 degrees of the mean interocclusal records setting for the other subject. For the PSS settings, 95% of the interocclusal record settings were within 10.1 degrees of the mean setting for one subject and 11.6 degrees of the mean interoccusal record setting for the other subject. 2. In adjusting the ORB and PSS articulator settings, the maximum potential occlusal errors that may be produced by using the Pantronic pantograph are smaller than the maximum errors that may be produced in using the lateral interocclusal record technique.

A comparison of articulator settings to age and sex

A comparison of articulator settings to age and sex

Comparison of an electronic and a mechanical pantograph. Part I: Consistency of an electronic computerized pantograph to record articulator settings

Comparison of an electronic and a mechanical pantograph. Part I: Consistency of an electronic computerized pantograph to record articulator settings

Electronic computerized pantographic recording of a PRI TMJ dysfunction

We previously reported (Clayton et al. 1976) on the use of recorded mandibular movements to detect the uncoordinated movement symptoms of TM J dysfunction. Uncoordinated muscles affect a patient’s ability to make mandibular movements. Patients retraced lateral movements on a mechanical (m) pantograph. The quality of the movements was quantitated by a pantographic reproducibility index (PRI) for TM J dysfunction. Last year we reported (Clayton et al. 1983) on the clinical evaluation of a new electronic, computerized pantograph. Mandibular movements were evaluated as they were made, and the computer printed out articulator settings. Previously, the PRI was scored by a human being who had to be trained and calibrated. This was very time consuming. The purpose of this study was to

Processing acrylic resin bases for removable partial dentures on a hydrocolloid cast

P a n t o g r a p h t r a n s f e r o f t e r m i n a l h i n g e a x i s , e f f e c t s o n o c c l u s a l m o r p h o l o g y M. J. Jaarda, ]. A. Clayton, and G. E. Myers University of Michigan, Ann Arbor, Mich. The importance of the terminal hinge axis (THA) in pantography has been viewed as a basic assumption, but the significance and effect is unproven with only limited research. Previous studies have indicated that the transference of the THA does affect articulator settings, however, the effect on occlusai morphology has not been sufficiently shown. Instrumentation was developed whereby ridge and direction and cusp height could be measured in the form of co-ordinates of an x-y-z co-ordinate system. The instrumentation consisted basically of a precision linear variable differential transformer (LVDT) that could be rotated through all three Reprinted from the Journal of Dental Research with permission of the author and editor. planes and mounted within the first molar area on a Denar D5A articulator. Two subjects were investi- gated by means of pantographic surveys performed relative to the THA. This was repeated with the survey relative to the arbitrary hinge axis (AHA). The DSA articulator was correspondingly programmed and the LVDT mounted in the maxillary first molar area. Cusp height and ridge and groove directions were then measured respective to each pantograph survey. The measuring error of the entire procedure was + .05 mm. along any given axis of the coordinate system. Statistical difference (p = .05) was shown for ridge and groove and cusp height. Magnitude of the difference was .2 mm. in protrusive excursion and .1 mm. in lateral excursion at the edge to edge position. 696 JUNE 1978 VOLUME 39 NUMBER 6

Observations on the use of the Denar pantograph and articulator

An investigation was undertaken to determine the reproducibility of articulator settings from graphic records of simulated mandibular movement using the Denar pantograph and the Denar D4-A articulator. The results of the study showed that most of the articulator adjustments were reproducible with a reasonable degree of accuracy, although not quite to the extent one would hope for. The rear-wall and top-wall adjustments are of questionable value in reproducing mandibular movements with this technique, since the results for these adjustments in the present study were unreliable. However, familiarity with the technique gave better results, as shown in the third experiment. It would, therefore, seem that much of the basis for adverse reports depended upon results obtained by operators with insufficient experience in the technique.