Page 96 - Impact of implant retained overdenture treatment and speech, oromyofunction, social participation and quality of life.

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Chapter 4
surgery. In the light of this evolution, one piece mini-dental implants (MDI) with diameter less than or equal to 2.5mm should be considered as an alternative treatment solution for improved denture retention.10,34
Treatment with MDI is introduced early 2000 and in general its outcome is promising although the clinical outcome defined by implant survival, bone stability or complications is often underreported especially in the upper jaw. Literature on treatment outcome related to implant survival, load resistance and quality of life is scarce. Also, the effect of this treatment on people’s speech is lacking.10 The latter has been investigated mainly using regular diameter implant supported overdentures in mandible11, 12 and fixed dentures in the mandible11-14 and maxilla, 11, 13, 15, 16 as well as single tooth replacements17. A frequently heard complaint is the occurrence of distortions of the /s/ sound during speech.7,11-18 One of the causes of deviations in the pronunciation of the /s/ sound is the angle of the frontal teeth.19 Changes in thickness of the ridge and the palate of the prosthesis are also found to be an important factor in the occurrence of speech problems in patients treated with fixed rehabilitation.20, 21 Because the production of most consonants involve speech structures in the upper jaw (palate, upper incisors) it is to expect that speech problems are more likely to occur when people are treated with reconstructions in the maxilla compared to reconstructions in the mandible.18 It is also possible that other problems present depending on which jaw is treated. As suggested in the research of Jacobs et al. (2001) there are especially problems with the fricatives (s and z) in fixed rehabilitation of the maxilla and fixed reconstruction in the mandibula seems to cause more problems with the plosives (t and d).11 Figure 1 shows the tongue contact position with the palate forming the speech sounds. This palate is covered differently with conventional dentures compared to an overdenture with horse-shoe design. It is plausible to say that different shapes of dentures (e.g. with and without palatal coverage) can cause other distortions especially in the maxilla.
Van Lierde et al. (2012) examined the difference in articulation problems in different kinds of fixed dental rehabilitation in the maxilla and found a significant difference between articulation in people who have different kinds of dental rehabilitation. Most problems were observed in fixed rehabilitation on implants followed by conventional dentures and the least problems were seen