[A comparative analysis of reproducibility of the jaws centric relation determined with the use of digital technologies]. / Sravnitel'nyi analiz vosproizvodimosti tsentral'nogo sootnosheniia cheliustei s ispol'zovaniem tsifrovykh tekhnologii.

AIM: To compare the precision of centric relation (CR) assessment by various methods using digital technologies. MATERIAL AND METHODS: Determination of the CR was carried out in the clinic of prosthetic dentistry on patients with intact dentition using methods of bilateral manipulation, anterior jig, leaf gauge and device for intraoral recording of the gothic arch angle. Optical jaw impressions were obtained using the intraoral 3D scanner Trios (3Shape) and the CR registers were scanned using the laboratory scanner Prime (DOF). To evaluate the reproducibility of the CR, the computer program of 3D modeling Avantis (Russia) was used, which integrated the obtained optical impressions and digital copies of the CR registers. RESULTS: None of the methods showed 100% accuracy in CR assessment. The most stable reproducibility of the position of the mandible in the CR relative to the first registration was determined by the method using an anterior jig (of our own design) and amounted to 0.119±0.012 mm, which is significantly less than using the methods of bilateral manipulation (0.225±0.028, p≤0.05) and a leaf gauge (0.207±0.02, p≤0.05). We observed a similar mean values of the reproduction accuracy when determining the CR by recording the Gothic arch angle (0,120±0,013, p≤0.05), which also has a significantly lower value (p≤0.05) compared to other methods for CR determining.

[The precision of central jaw relationship estimation in restorative dentistry]. / Analiz pretsizionnosti opredeleniia tsentral'nogo sootnosheniia cheliustei v klinike ortopedicheskoi stomatologii.

The aim of the study was to investigate accuracy of the most frequently used methods of obtaining centric relation in clinical practice. Finding of CR was carried out in clinic of prosthodontic dentistry on a 5 patients with intact dentition using four methods that are most often used, including: bimanual manipulation, leaf gauge, using an anterior deprogrammind device, the technique of determining CR with intraoral devices recording the gothic angle. To assess the accuracy of each technique there were performed 10 registrations of the central relation by one operator (200 CR registrations), with 30 minutes' intervals between the CA determination. Analysis of the contacts in CR were carried out using a photometric method of investigation. The graphic images were downloaded in Adobe Photoshop for calculation, metric data translated into digital values. The studies above showed that the accuracy of finding CR in all methods were not ideal. It can be noted that the smallest deviation of the position of the first contact in the CR was observed with use of the anterior deprogrammind device and with the intoral gothic angle recording device. The deviation along the VO axis was 0.039±0.002 mm and 0.084±0.004 mm respectively, along the MD axis 0.043±0.002 mm and 0.054±0.001 mm, respectively. The greatest error of recording the CR was shown by bimanual manipulation Dawson technique, the deviation along the axis of the VO and MD was 0.634±0.04 mm and 0.388±0.04 mm, respectively.