Precision evaluation of panoramic morphometric index measurement's performed by experienced clinicians and dental students.

Osteoporosis is a chronic degenerative disease of bones in which the primary type of it affects generally women after postmenopause. According to the literature the panoramic indices are valuable morphometric and visual tools to detect the disorder in a n early and asymptomnatic stage. The goals of study were to evaluate the reproducibility of mandibular cortical and panoramic indices and to assess population-specific index parameters. Panoramic radiographs of 50 osteoporotic (age = 65,1 ? 5,9) and 36 control (age = 66,4 ? 7,1) women were evaluated for the cortical (MCI) and panoramic (PMI) indices by 2 experienced clinicians and 40 dental students with basic clinical experiences. Statistical analysis of data was preformed using SPSS software. the result of MCI and PMI indexes demonstrated high interobserver agreement between the two clinicians but in MCI data, recorded by the clinicians and students, showed statistically significant differences. On the other hand the mean and threshold values of the indices proved to be different from what we had expected from other surveys. Although the panoramic images are taken for specific dental indications that would improve the screening efficiency of osteoporosis when the clinician recognizes the signs of it on the radiographs.

Measurement of periapical pressure created by occlusal loading.

AIM: To develop an in vitro model in which the pressure in the periapical tissues can be measured during loading. METHODOLOGY: Extracted human maxillary central incisors were embedded in resin blocks that had physical characteristics similar to those of bone and periodontal ligament. Each tooth was loaded with 20, 40, 50, 60, 75, 85, 100, 200, 300 and 450 N vertical forces from the incisal edge of the crown on three consecutive occasions. A minute resistor embedded in the periapical space was used to detect apical pressure changes during occlusal loading. The ratio of apical pressure changes (DeltaP) to the loading force changes (DeltaF) was calculated. RESULTS: The periapical pressure detected was in direct proportion to the loading force. The mean value of DeltaP/DeltaF was 5.994 kPa N-1 (SD = 2.04). CONCLUSIONS: Direct proportionality was found between the coronal loading and the apical hydrostatic pressure. The DeltaP/DeltaF ratio determined in this study makes it easier to estimate the apical hydrostatic pressure values during occlusal loading of single-rooted teeth. In this study, the apical pressure generated under occlusal loading was the same magnitude as that estimated with the finite element method.

[Involvement of the temporomandibular joint in rheumatoid arthritis]. / A temporomandibuláris ízület érintettsége rheumatoid arthritis esetén.

The rheumatoid arthritis is a systemic connective tissue disease, that most of the cases involve the temporomandibular joint. The diagnosis of local involvement is usually not difficult because the disease often starts in other peripheral small joints. The radiographic signs can be observed more frequently than clinical and subjective symptoms. The local symptoms are pain, opening difficulty, stiffness in the morning and swelling. The maximal mouth opening is restricted by the reduced translatory movement of the mandibular condyle. The aim of this case presentation is to describe the temporomandibular aspects of the rheumatoid arthritis and to suggest the usefulness of the condylar movement registration in the diagnostic procedure of the disease.

[Reproducibility of the centric relation mandibular position]. / A centrális relációs állkapocshelyzet reprodukálhatóságának vizsgálata.

The centric relation (CR) is an important position either diagnostically or therapeutically. It is supposed to register the proper position of the mandible in a verifiable and reproducible way. This study addresses the reproducibility of the CR. Intra-oral graphic recordings were carried out in 15 dental students and the antero-posterior and medio-lateral positions of the point of the tracings were evaluated. The tracings were reproduced within an area 162 +/- 55 microns on sagittal axis and 141 +/- 32 microns on transversal axis. The other aim of the study was to investigate the effects of the graphic and the leaf gauge registrations on the condyle position of an articulator. It was concluded that there were no significant differences in reproducibility between the two methods on sagittal and transversal axes, but on the vertical axis the graphic registration method proved to be significantly more reproducible than the leaf gauge registration.

[Instrumental analysis of sagittal condylar motion pathway]. / A condylus sagittalis mozgáspálya müszeres vizsgálata.

An analysis of protrusive jaw movement was carried out using Quick-Axis mandibular motion analyser. The condylar path tracings were recorded of 46 individuals (21 women and 25 men). Three recordings were performed on each side and a tangent to the condylar curves was drawn to calculate the condylar angle. Considering all dates the mean value of angulation was 52.2 degrees. There were no statistically significant differences between the two sexes and sides. The authors' findings suggest it is advisable to perform three consecutive registrations on each side and calculate a mean condylar angle to gain a better result.

Technique for fabrication of centric relation-based occlusal splint with central bearing device.

This study presents a technique for constructing an occlusal appliance. The central relation position must be located with Gothic arch registration. A central bearing post is fixed to the upper vacuum-adapted sheet and a registration plate is made for the lower cast. For the eccentric guidance construction, a prefabricated guiding ramp is secured just behind the most anterior point of the Gothic arch. The eccentric guidances, which harmonize with condylar movements, are printed by the mandibular canines on the surface of the self-curing resin as the post slides on the inclined surface of the ramp.

[Testing the reliability of face bow registration]. / Az arcíves regisztrálás megbízhatóságának vizsgálata.

The reliability of the Quick ear face-bow to transfer an arbitrary hinge axis to a Quick articulator was clinically compared with a Dentatus face-bow. 40 measurements were carried out on 8 patients with both instruments and were compared. The statistical analysis of the data indicated no difference between these facebow recordings. Furthermore both showed good reproducibility. This suggests that the same clinical results can be reached by these instruments.