IADR Abstract Archives
Variability of methods to determine postural position of the mandible
Objectives: The aim of this study was to compare the variability of different methods to determine postural position of the mandible (PPM), analyzing interocclusal free space and opening angle.
Methods: Using 3D Electromagnetic Articulography, 7 men and 6 women (19 to 28 years old), healthy, with occlusal stability, without orthodontic or prosthetic treatment, without a history of trauma or maxillofacial surgery were evaluated (Scientific Ethics Committee No. 080_18). Three reference sensors and 3 active sensors were placed to register the position of the mandible. The position of the mandible was recorded during maximum intercuspation position and PPM. PPM carried out using different methods: No Command, Swallowing, ‘Mississippi’ Pronunciation and Phoneme ’m’ Pronunciation. The opening angle (ang) and the Euclidean distance (d) were calculated between the coordinates of the sensors in PMI and PPM using Matlab. The Variability Coefficient (CV) was calculated for d and ang using LibreOffice Spreadsheets. SPSS Statistics was used to apply the Shapiro-Wilk test and one-way ANOVA or Kruskal-Wallis for comparisons between the different methods (a = 0.05).
Results: No significant differences were found between the measures (d and ang) obtained with the different methods. However, there were differences between the variabilities. The least variable method for ang was Mississippi Pronunciation (CV = 46%, ang = 0.9 ± 0.4o) and the most variable was the Phoneme 'm' (CV = 97%, ang = 0.8 ± 0.8o). The least variable method for d was No Command (CV = 39%, d = 1.6 ± 0.6mm) and the most variable was the Phoneme ‘m’ Pronunciation (CV = 86%, d = 2.8 ± 2 , 4mm).
Conclusions: The variability obtained by measuring d is different from the one obtained by measuring ang. The opening angle is a more reliable parameter than the interocclusal space maybe because it does not depend on the size of the jaw.
Methods: Using 3D Electromagnetic Articulography, 7 men and 6 women (19 to 28 years old), healthy, with occlusal stability, without orthodontic or prosthetic treatment, without a history of trauma or maxillofacial surgery were evaluated (Scientific Ethics Committee No. 080_18). Three reference sensors and 3 active sensors were placed to register the position of the mandible. The position of the mandible was recorded during maximum intercuspation position and PPM. PPM carried out using different methods: No Command, Swallowing, ‘Mississippi’ Pronunciation and Phoneme ’m’ Pronunciation. The opening angle (ang) and the Euclidean distance (d) were calculated between the coordinates of the sensors in PMI and PPM using Matlab. The Variability Coefficient (CV) was calculated for d and ang using LibreOffice Spreadsheets. SPSS Statistics was used to apply the Shapiro-Wilk test and one-way ANOVA or Kruskal-Wallis for comparisons between the different methods (a = 0.05).
Results: No significant differences were found between the measures (d and ang) obtained with the different methods. However, there were differences between the variabilities. The least variable method for ang was Mississippi Pronunciation (CV = 46%, ang = 0.9 ± 0.4o) and the most variable was the Phoneme 'm' (CV = 97%, ang = 0.8 ± 0.8o). The least variable method for d was No Command (CV = 39%, d = 1.6 ± 0.6mm) and the most variable was the Phoneme ‘m’ Pronunciation (CV = 86%, d = 2.8 ± 2 , 4mm).
Conclusions: The variability obtained by measuring d is different from the one obtained by measuring ang. The opening angle is a more reliable parameter than the interocclusal space maybe because it does not depend on the size of the jaw.