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Updated: Nov 21, 2025
Measuring the Complete-arch Distortion of an Optical Dental Impression
Published on: May 30, 2019
Elastic deformation of the mandibular jaw revisited-a clinical comparison between digital and conventional
Alexander Schmidt1, Leona Klussmann2, Maximiliane A Schlenz2
1Department of Prosthodontics, Dental Clinic, Justus Liebig University, Schlangenzahl 14, 35392, Giessen, Germany. alexander.schmidt@dentist.med.uni-giessen.de.
Objectives:
Due to the partly strongly differing results in the literature, the aim of the present study was to investigate a possible deformation of the mandible during mouth opening using an intraoral scanner (IOS) and a conventional impression for comparison with a reference aid.
Materials And Methods:
Four steel spheres were reversibly luted in the mandibular (n = 50) with a metallic reference aid at maximum mouth opening (MMO). Two digital impressions (Trios3), at MMO and at slightly mouth opening SMO and a conventional impression (Impregum), were taken as the measuring accuracy of the reference structure was already known. Difference between MMO-SMO for digital impressions and deviations between digital and conventional (SMO) were calculated. Furthermore, the angle between the normal vectors of two constructed planes was measured. Statistical analysis was performed with SPSS25.
Results:
Deviations for linear distances ranged from -1 ± 3 μm up to 17 ± 78 μm (digital impressions, MMO-SMO), from 19 ± 16 μm up to 132 ± 90 μm (digital impressions, SMO), and from 28 ± 17 μm up to 60 ± 52 μm (conventional impressions, SMO). There were no significant differences for digital impressions (MMO-SMO), and there were significant differences between the conventional and digital impressions at SMO.
Conclusions:
Based on the results of the present study, no mandibular deformation could be detected during mouth opening with regard to the digital impressions. The results were rather within the measuring tolerance of the intraoral scanner.
Clinical Relevance:
Based on the present study, no deformation of the mandibular during mouth opening could be observed at the level previously assumed. Therewith related, dental techniques related to a possible mandibular deformation therefore should be reconsidered.
