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Measuring the Complete-arch Distortion of an Optical Dental Impression
Published on: May 30, 2019
Effect of Head Posture on the Accuracy of Occlusal Contacts at Maximum Intercuspation Using Intraoral Scanners and
Panagiotis Ntovas1,2,3, Abdul B Barmak4, Wael Att5,6
1Department of Prosthodontics, School of Dental Medicine, Tufts University, Boston, Massachusetts, USA.
Objectives:
To evaluate the influence of head posture on the accuracy of occlusal contacts at maximum intercuspal position (MIP) recorded by an intraoral scanner.
Methods:
Occlusal contacts of 46 individuals were initially located using articulating film (8 μm, Accufilm, FastCheck; Parkell). The located contacts were digitized with an intraoral scanner (IOS, Trios 4; 3Shape) by obtaining maxillary and mandibular scans. Bilateral virtual occlusal records in MIP were acquired by setting the dental chair in two different positions: upright (90° to the horizontal plane) and supine (0° to the horizontal plane). In both positions, occlusal contacts were also recorded using a digital occlusal analysis system (T-Scan Novus, Tekscan). Two calibrated examiners evaluated occlusion attribution, using the digitized contacts from the articulating film as the reference. Statistical analysis was performed using one-way ANOVA followed by pairwise multiple comparisons (α = 0.05).
Results:
Head posture did not significantly affect the proportion of coinciding occlusal contacts at MIP between the reference and those identified by the IOS and the digital occlusal analysis system, both for the full arch and individual sections. The digital occlusal analysis system, however, recorded a higher number of false occlusal contacts in the supine position compared to the upright position.
Conclusions:
The use of IOS to locate the occlusal contacts at MIP was not impacted by the evaluated head postures. In contrast, head posture had a significant effect on the recordings obtained with the digital occlusal analysis system.
Clinical Significance:
Intraoral scanning provides reliable MIP acquisition in both upright and supine positions. However, digital occlusal analysis is sensitive to changes in head posture; therefore, recording in the upright patient position is recommended for greater accuracy.
