Page 144 - Impact of implant retained overdenture treatment and speech, oromyofunction, social participation and quality of life.
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Chapter 6
overdenture treatment outcome, is a valuable addition to the existing knowledge about this treatment. It is worth noticing that the strength of this thesis lies in the evaluation of articulation by two independent professional speech-language pathologists and the extensive protocol, including evaluation of oromyofunctional behavior, used to evaluate the patients. This method is reliable but can be improved by adding spectral analysis (of the /s/ sound). Especially because the /s/ sound is our most affected sound, comparing spectral characteristics could add more objectivity to the protocol. Also the inclusion of a matched control group and the use of two completely blinded raters, to prevent observer bias, could add to the quality of the study design. The longitudinal, prospective design of the studies in this thesis is of great value but also caused drop-out due to organizational and logistic issues. It is also possible that patients already had some articulation errors during their lifetime. This is impossible to assess because our participants came to the clinic with an existing denture, already influencing articulation and oromyofunctional behavior. In using spectral characteristics to rate speech sounds, it would be possible to detect certain changes in existing speech problems over time, comparing several stages of the treatment 31. A limitation of the multidisciplinarity of our studies was the absence of a sound-treated room for recording the speech evaluation. Patients attended their appointments at the dental clinic, that doesn’t include a sound-treated room. To be able to objectivize the real impact of the background in this room and to make proper adjustments to the room and recording settings, future researchers should estimate the signal to noise ratio of the sound samples used to evaluate speech. This by measuring the background-noise level and comparing it to the speech sound pressure level (e.g. by using PRAAT software68). At last, we didn’t perform an audiological test to assess possible hearing difficulties. In the individual papers the number of patients that reported hearing difficulties is reported. It is important to know that the average age of our participants in the first three studies was respectively 63.3y, 63.44y and 62.6y. From the age of 65 one can expect age related hearing loss 69, which makes it hard to exclude that group during our kind of research.
































































































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