Comparative study between 2 methods of mounting models in semiadjustable articulator for orthognathic surgery.

PURPOSE: Compare the traditional method of mounting dental casts on a semiadjustable articulator and the new method suggested by Wolford and Galiano, 1 analyzing the inclination of maxillary occlusal plane in relation to FHP. MATERIALS AND METHODS: Two casts of 10 patients were obtained. One of them was used for mounting of models on a traditional articulator, by using a face bow transfer system and the other one was used to mounting models at Occlusal Plane Indicator platform (OPI), using the SAM articulator. After that, na analysis of the accuracy of mounting models was performed. The angle made by de occlusal plane and FHP on the cephalogram should be equal the angle between the occlusal plane and the upper member of the articulator. RESULTS: The measures were tabulated in Microsoft Excell(®) and calculated using a 1-way analysis variance. Statistically, the results did not reveal significant differences among the measures. CONCLUSION: OPI and face bow presents similar results but more studies are needed to verify its accuracy relative to the maxillary cant in OPI or develop new techniques able to solve the disadvantages of each technique.

An analysis of articulators.

There are situations that do not demand absolute precision and duplication of all pathways. One example is complete denture construction. Denture base movement and tissue resiliency cannot registered accurately. Corrections for these conditions must be made directly. Instruments that use mechanical equivalents and/or accept positional registrations are suitable for this procedure. Instruments used for teaching purposes such as waxing exercises need not be capable of duplicating eccentric pathways. These instruments should be capable of demonstrating alterations of Bennett movement (immediate and progressive side shift) and protrusive inclinations. It would be most convenient and practical for dental schools to use the same instruments for complete dentures and occlusion courses. Static positional instruments are ideal for use in crown and bridge and operative departments, and in the treatment of patients in whom centric occlusion is to be preserved. Instruments that are fully adjustable for eccentric registrations are useful for demonstration purposes, postdoctoral teaching, and for patients requiring extensive reconstruction.

Using articulators to enhance clinical practice.

This paper looks at how articulators can be of value in everyday NHS practice. A variation on the conventional classification of articulators is suggested with advice provided for the practitioner who wants to enhance his or her restorative work without immediately investing in high cost equipment. It is argued that rather than prolong chairside time, for specific types of treatment the use of an appropriate articulator and facebow can not only enhance the quality of the completed restoration, but also save on chairside time.

A comparative study to evaluate the discrepancy in condylar guidance values between two commercially available arcon and non-arcon articulators: a clinical study.

AIM: The purpose of this study was comparative evaluation of sagittal condylar values of arcon and non-arcon articulators with cephalometric readings and to determine the amount of discrepancy in sagittal condylar guidance values between arcon and non-arcon articulators using same protrusive record. MATERIALS AND METHODS: Twenty subjects in the age group of 19-35 years, free from temporomandibular joint dysfunction, and occlusal disharmony, with healthy dentition participated in the study. Hanau H2 (non-arcon type) and Hanau Wide-Vue (arcon type) articulators were programmed for sagittal condylar guidance values using the same protrusive record made in polysiloxane bite registration material with edge to edge degree of protrusion. The resultant values for both the articulators on either side were compared with values obtained from tracing of digital lateral cephalogram using Kodak Dental imaging Window software 6.6.3.0-C program. The tabulated data were subjected to statistical analysis, ANOVA (Fishers 'F' test) for group comparison, Tukey's HSD test for inter-comparison, student's unpaired 't' test for intra-group comparison, and level of significance (P) was calculated using the same. RESULTS: The mean sagittal condylar guidance values of the three different groups were found to be very highly significant (P=0.001) and highly significant (P=0.002) on the right and left sides respectively. There was a very highly significant difference (P=0.001) and highly significant difference (P=0.003) between the arcon and non-arcon group on the right and left side respectively. No significant difference was found between the arcon and cephalometric group (P=0.284 right, P=0.853 left) and a statistically significant difference was found between the non-arcon and cephalometric group (P=0.049 right, P=0.015 left). On intragroup comparison there was no statistically significant difference in sagittal condylar values on the right and left sides. CONCLUSION: The mean difference in the sagittal condylar guidance values obtained from non-arcon and arcon articulators shows a low level of reproducibility, and no significant difference found in mean sagittal condylar values obtained from arcon articulator and cephalometric tracings indicates replication of sagittal condylar guidance value from image of articular eminence.

Classification of articulators.

A simple classification in familiar terms with definite, clear characteristics can be adopted. This classification system is based on the number of records used and the adjustments necessary for the articulator to accept these records. The classification divides the articulators into nonadjustable, semiadjustable, and fully adjustable articulators (Table I).

Does one articulator meet the needs of both fixed and removable prosthodontics?

A survey to determine the type of articulators used in teaching fixed and removable prosthodontics in the 59 United States dental schools was conducted. Of 115 questionnaires mailed, 104 responses were received. The following observations resulted from analysis of the questionnaire. Of the 81 articulators used in fixed and removable prosthodontics, 65 (76.5%) were of the arcon design. The most common articulators used were the Whip-Mix (16 schools), the Hanau 158 (14 schools), the Hanau 96 H-2 (13 schools), and the Denar Mark II (11 schools). The most common articulators used in fixed prosthodontic programs were the Whip-Mix (16) and the Denar Mark II (11), while the most common articulators for removable prosthodontics were the Hanau 158 (14) and the Hanau 96 H-2 (13). Twenty-two schools issued two articulators of different design, and three schools issued two articulators of the same design. The outstanding difference in requirements for fixed and removable prosthodontic teaching programs was that those in fixed prosthodontics desired an articulator in which the maxillary and mandibular members could be separated, while those in removable prosthodontics did not.

The use of an anatomic articulator in segmental orthognathic surgery.

We have tried to discuss briefly the pertinent theory, mechanics, and clinical use of an anatomic articulator in segmental orthognathic surgery. Many of the concepts and clinical uses of the articulator may be applicable to the full range of orthognathic surgical procedures. Many of the ideas presented here may seem needlessly detailed or irrelevant to the uninitiated. It is this attention to details and thoroughness that ultimately determine how closely our treatment will achieve the "ideal" functional and esthetic goals. We must measure the effectiveness of an anatomic articulator by the three original goals of maxillary segmental surgery: 1. Improvement of the patient's esthetic and facial harmony. 2. Improvement of the centric and functional occlusal relationships. 3. Maintenance of the long-term health and function of the teeth, periodontium, temporomandibular joints, and associated structures. I believe that these three criteria will be more closely achieved by the use of an anatomic articulator in segmental maxillary surgery. If the orthognathic surgeon is to be more than a technician performing prescription surgery, a thorough knowledge of the functional stomatognathic system is essential.

Avaliação das dimensões programáveis dos articuladores semi-ajustáveis / Assessment of the programmable dimensions of the semi-adjustable articulador

O articulador semi-ajustável tem o propósito de reproduzir as relações maxilomandibulares estáticas e, parcialmente, as dinâmicas. No entanto, parte destas características depende da qualidade da fabricação dos aparelhos. O objetivo foi aferir os componentes responáveis pela determinação do ângulo de Bennett (AB), da eminência articular (EA) e da distância intercondilar (DI) do articulador semi-ajustável (ASA) Dentflex...