Tongue-palatal contact changes in patients with skeletal mandibular prognathism after sagittal split ramus osteotomy: an electropalatography study

Three-Dimensional Touch Device with Two Terminals

A crossbar array is an essential element that determines the operating position and simplifies the structure of devices. However, in the crossbar array, wiring numerous electrodes to address many positions poses significant challenges. In this study, a method is proposed that utilizes only two electrodes to determine multiple positions. The method significantly simplifies the wiring and device fabrication process. Instead of defining the node location of the crossbar, it is experimentally demonstrated that the x-y-z coordinates can be determined from i) the resistance change as a function of distance, ii) the resistance variation influenced by the electrode composition, and iii) capacitance fluctuation resulting from changes in the dielectric thickness. By employing two-terminal transparent electrodes, a fully functional 3D touch device is successfully fabricated, introducing a groundbreaking approach to simplify input device architectures.

The Physiological Function of Deglutition and Swallowing in Patients With Maxillary Protrusion After Mandibular Advancement

The objective of this study was to determine the tongue-palatal contact changes in patients with skeletal maxillary protrusion after sagittal split ramus osteotomy (SSRO) during swallowing. In this study, 15 patients with maxillary protrusion and 10 normal subjects participated. Before and 3 months after surgery, tongue-palatal contact patterns during swallowing of patients with maxillary protrusion as well as controls were evaluated by electropalatography. The electrode contact number in the alveolar, palatal, and velar parts was examined. The swallowing duration of each phase was also evaluated. In the lateral area of the velar part, incomplete electrode contact was shown at 0.3 seconds in patients with maxillary protrusion. The electrode contact number in the velar part at 0.3 seconds before tongue-palatal complete contact was significantly less in the preoperative patients compared with the controls ( P < 0.05). A small increase in the electrode contact number of the velar part was shown in the postoperative patients at 0.3 and 0.2 seconds before tongue-palatal complete contact ( P < 0.05). The pharyngeal phase duration was significantly larger in the patients with maxillary protrusion before SSRO compared with the controls ( P < 0.05). After SSRO, the pharyngeal phase duration was significantly shortened. It was shown that the tongue-palatal contact pattern during swallowing in patients with maxillary protrusion improved after orthognathic surgery, and the pharyngeal phase duration was also shortened. It is suggested that the changes in the mesiodistal mandibular position by orthognathic surgery can improve tongue posture and movement during swallowing.

Electropalatography (EPG) activities in Japan and the impact of the COVID-19 pandemic on EPG research and therapy: A report of presentations at the 7th EPG Symposium

BACKGROUND

At the 7th Electropalatography Symposium in Japan, held online on the 24 January 2021, a few speakers were invited to talk about how the COVID-19 pandemic had impacted their research and/or speech therapy that involved the use of electropalatography (EPG) as well as the procedures adopted in order to continue their work in a safe manner. The information on protective measures when using instrumental techniques in speech research and therapy may be useful for colleagues in research and the clinic.

AIMS

The primary aims are: (1) to find out whether there are any published recommendations regarding protective measures for using EPG in research and clinic settings; (2) to discuss the impact of the pandemic and the corresponding restrictions and general protective measures directed (or advised) by local government and professional bodies at each stage of EPG work; and (3) to share experiences in using modified procedures for face-to-face EPG therapy sessions and combined EPG teletherapy. In addition, a brief overview of EPG and a summary of EPG research and clinical activities in Japan presented by one of the symposium organizers at the symposium are included.

METHODS & PROCEDURES

A review of the literature regarding protective measures recommended for using EPG for speech assessment and treatment or research, supplemented by a discussion of our own experiences.

MAIN CONTRIBUTION

The literature review showed that there are no guidelines regarding protective measures for using EPG, but there is some advice regarding speech recording using microphones. Most published articles related to speech and language therapy (SLT) service during COVID-19 are about telepractice or general clinical guidelines for face-to-face speech therapy sessions. The protective measures for using EPG developed based on the general guidelines recommended by local government and professional bodies (e.g., using visors, transparent acrylic board) were described. Using EPG in telepractice was discussed as well.

CONCLUSIONS

It has been challenging to continue EPG research and therapy during the pandemic. In order to deal with this crisis, available knowledge regarding infection control and recommendations from local government and professional bodies were applied to design methods and procedures that allowed EPG research and therapy to continue.

WHAT THIS PAPER ADDS

What is already known on the subject There are general protective measures recommended by local government and professional bodies regarding speech therapy sessions (e.g., using personal protective equipment (PPE), social distancing), but little is known about the measures for using instrumental techniques in speech research and therapy, particularly EPG. The equipment of each instrumental technique is different, so measures that are appropriate for one may not be suitable for others. Hence, specific recommendations are needed for EPG. What this paper adds to existing knowledge This paper provides pointers to information about recommendations regarding protective measures for speech research and therapy, supplemented with suggestions specific to EPG provided by experienced users based on actual experience. What are the potential or actual clinical implications of this work? In evaluating the impact of the COVID-19 pandemic on EPG research and therapy, an analytical approach was taken to break down the steps involved in carrying out those activities, and the challenges we faced and the possible alternatives for completing the tasks were discussed. A similar approach can be applied to evaluate other aspects of speech therapy service.

An Investigation of Tongue-Palatal Contact Changes in Patients With Skeletal Mandibular Lateral Deviation After Sagittal Split Ramus Osteotomy

ABSTRACT

This study aimed to investigate the changes in tongue-palatal contact patterns in patients with mandibular lateral deviation by electropalatography (EPG) before and after sagittal split ramus osteotomy (SSRO). Ten mandibular asymmetry patients who underwent SSRO participated in the study. Tongue-palatal contact patterns for the production of /t/ and /s/ sounds were observed using EPG before surgery and 3 months after surgery, and the changes in EPG pattern were examined. The number of electrode contacts in the 2 vertical columns of the EPG plate was calculated both in the mandibular deviation side and the nondeviation side. The EPG patterns for /t/ and /s/ showed asymmetry before surgery but became normal after surgery. Before surgery, the number of electrode contacts in the 2 vertical columns in the mandibular deviation side was significantly lower than that in the nondeviation side and the normal participants during /t/ and /s/ articulation. However, the number of electrode contacts in the deviation side significantly increased after surgery. This study demonstrated that the tongue-palatal contact patterns for /t/ and /s/ articulation shifted to the direction of mandibular deviation and improved after SSRO.

Changes in tongue-palatal contact during swallowing in patients with skeletal mandibular prognathism after orthognathic surgery

This study aimed to evaluate improvement of tongue-palatal contact patterns during swallowing after orthognathic surgery in mandibular prognathism patients. Thirty patients with mandibular prognathism treated by orthognathic surgery (average age of 27 years, 3 months) and 10 controls (average age 29 years, 6 months) participated in this study. Tongue-palatal contact patterns of patients before and three months after surgery were evaluated by electropalatography (EPG) as well as controls. Whole total of tongue-palatal contact at 0.3, 0.2, and 0.1 sec before complete tongue-palatal contact during swallowing were evaluated. The duration of swallowing phases was also examined. Complete contact of tongue-tip in the alveolar part of individual artificial EPG plate were shown at 0.3, 0.2, and 0.1 sec before complete tongue-palatal contact in the controls, although incomplete contact in the alveolar part were shown at 0.3 sec in mandibular prognathism patients. Whole total of tongue-palatal contact at 0.3 and 0.2 sec before complete tongue-palatal contact was significantly lower in the patients before surgery than in the controls (p<0.05). However, these values increased after surgery. The duration of oral and pharyngeal phase was significantly longer in the patients before surgery than in the controls and the patients after surgery (p<0.01). This study demonstrated that the tongue-palatal contact pattern improved and the duration of oral and pharyngeal phase was shortened in mandibular prognathism patients during swallowing after orthognathic surgery. It is suggested that changes in maxillofacial morphology by orthognathic surgery can induce normal tongue movement during swallowing. (The data underlying this study have been uploaded to figshare and are accessible using the following DOI: https://doi.org/10.6084/m9.figshare.14101616.v1).