Page 73 - Impact of implant retained overdenture treatment and speech, oromyofunction, social participation and quality of life.
P. 73

 Speech and OHRQoL in OD treatment in the maxilla
The characteristics of speech sounds depend on the vibration of the vocal cords, the position of the articulators, and the airflow passing through the mouth along the alveolar ridge, teeth and the hard palate.24 There are two groups of speech sounds: vowels and consonants. The vowels originate as air, coming from the lungs, that starts vibrating while it passes the vocal cords that are opening and closing. In order to produce the vowels, the airflow in the mouth should be unobstructed by the articulators.24 In contrast to vowels, when producing consonants, there is an obstruction somewhere in the oral cavity. It has been demonstrated that changes in the oral environment affect articulation and speech intelligibility.25 The teeth are involved in the production of fricatives (e.g. /f/, /v/ and /s/) and plosives (e.g. /t/ and /d/) with respectively a partial or full obstruction of the airstream. The plosives /t/ and /d/ are produced with the tongue against the upper alveolar ridge.24 Langlois and co-workers (2019) concluded that a significant correlation exists between site of the missing tooth/teeth and articulation distortions.25 More speech disorders are observed when patients are treated with IODs26 and FID,23,27 compared to subjects with natural teeth,23,26 single implant restorations,23 and CDs.23,27 In literature, problems with fricatives: /s/, /z/, /ʃ/ (show), /ξ/ (garage); plosives: /t/, /d/; and other alveolar sounds: /l/, /n/, and /r/ are reported during and after treatment with dental rehabilitation.18,23,26,28 Sigmatism stridens (production of the /s/ with a whistle sound) and sigmatism simplex (production of the /s/ sound with insufficient frication) were the most common distortions observed in patients treated with mini-dental implant overdentures in the maxilla,18 FID in maxilla or mandible,23,26–29 single (anterior) implants,23,30 and CDs.23
In severely resorbed edentulous maxillae implants are positioned more palatal due to bone resorption and this may cause changes in speech.31,32 In patients treated with maxillary FIDs, who encountered speech problems, a reduction of the palatal volume of (pre)molars resulted in improvement of speech.33 Besides the palatal thickness of the denture, the palatal, and especially labial inclination of the maxillary central incisors influences speech and can result in direct changes of the production of the /s/ sound.34
The aim of the current clinical study was to determine the impact on and changes in speech disorders, satisfaction with speech and OHRQoL in patients treated with maxillary IODs after a follow-up period of 3 years. Based on the
3
   71





























































































   71   72   73   74   75