ABSTRACT
The process of speech production, i.e., the compression of air in the lungs, the vibration activity of the larynx, and the movement of the articulators, is of great interest in phonetics, phonology, and psychology. One technique by which speech production is analysed is electropalatography, in which an artificial palate, moulded to the speaker's hard palate, is introduced in the mouth. The palate contains a grid of electrodes, which monitor the spatial and temporal pattern of contact between the tongue and the palate during speech production. The output is a time sequence of images, known as palatograms, which show the 2D distribution of electrode activation. This paper describes a series of tools for the visualisation and analysis of palatograms and their associated sound signals. The tools are developed as Matlab® routines and released as an open-source toolbox. The particular focus is the analysis of the amount and direction of left-right asymmetry in tongue-palate contact during the production of different speech sounds. Asymmetry in the articulation of speech, as measured by electropalatography, may be related to the language under consideration, the speaker's anatomy, irregularities in the palate manufacture, or speaker handedness (i.e., left or right). In addition, a pipeline for the segmentation and analysis of a three-dimensional computed tomography data set of an artificial palate is described and demonstrated. The segmentation procedure provides quantitative information about asymmetry that is due to a combination of speaker anatomy (the shape of the hard palate) and the positioning of the electrodes during manufacture of the artificial palate. The tools provided here should be useful in future studies of electropalatography.
ABSTRACT
OBJECTIVES: The objective of the study was to show the importance of intraoperative computed tomography as an aid for ensuring inferior alveolar nerve safety during bilateral sagittal split osteotomy. MATERIALS AND METHODS: This study included ten patients who underwent bilateral sagittal split osteotomy procedure. All patients were treated for orthognathic reasons. The unerupted lower third molars, if present, were removed at least 6 months prior to Sagittal Split Osteotomy. The Sagittal Split Osteotomy surgical technique was previously described in detail. Each patient underwent computed tomography with an Artis Zeego multi-axis system (Siemens AG, Healthcare Sector, Henkestrasse 127 D-91052 Erlangen, Germany) at the beginning of the operation and immediately after placement of the osteosynthesis plates and screws. The neurosensory tests consisted of a light touch test using the 5.07/10-g Semmes Weinstein monofilament (Stoelting Co, Wood Dale, IL), and patient self-reporting. RESULTS: Eight (80 %) patients presented with hypoesthesia of lower lip at 6 weeks follow up. At 6 month follow up only two patients (20 %) presented with diminished sensation in the lower lip. Labial sensibility was normal in all patients at the last follow-up visit. CONCLUSION: Intraoperative computed tomography enables immediate assessment of treatment and the option to modify the treatment if necessary. Our results indicate that intra-operative computed tomography would be a helpful procedure during orthognathic surgery to improve the postoperative health of the inferior alveolar nerve.
ABSTRACT
The aim of this study is to evaluate feasibility and accuracy of dental implant placement utilizing a dedicated bone-supported surgical template. Thirty-eight implants (sixteen in maxilla, twenty-two in mandible) were placed in seven fully edentulous jaws (three maxillae, four mandibles) guided by the designed bone-supported surgical template. A voxel-based registration technique was applied to match pre- and post-operative CBCT scans. The mean angular deviation and mean linear deviation at the implant hex and apex were 6.4 ± 3.7° (0.7°-14.8°), 1.47 ± 0.64 mm (0.5-2.56 mm) and 1.70 ± 1.01 mm (0.71-4.39 mm), respectively. The presented bone-supported surgical template showed acceptable accuracy for clinical use. In return for reduced accuracy, clinicians gain accessibility when using this type of surgical template for both the maxilla and the mandible. This is particularly important in patients with reduced mouth opening.
