Impact of fixed implant prosthetics using the 'all-on-four' treatment concept on speech intelligibility, articulation and oromyofunctional behaviour.

The purpose of this case control study is to determine the impact of screw-retained fixed cross-arch prostheses, supported by four osseointegrated implants, on articulation and oromyofunctional behaviour. Objective (acoustic analysis) and subjective assessment techniques were used to determine the overall intelligibility, phonetic characteristics and oromyofunctional behaviour at an average period of 7.3 months after placement of the fixed implant prosthesis in 15 patients and 9 age-matched controls with intact dentition and without prosthetic appliances. Overall satisfaction with the prosthesis was 87%, but 53% of the subjects mentioned an impact on speech. 87% of the subjects presented with one or more distortions of the consonants. The most common distortions were distortions of the sound /s/ (sigmatismus simplex, 40% and sigmatismus stridens, 33%), simplex /z/ (27%), insufficient frication of /f/ (20%), /[symbol in text]/ (20%), addental production of /d/ (20%), /t/ (20%) or /s/ sound (13%) and devoiced /d/ (7%). In the control group, no articulation disorders were noted. Oromyofunctional behaviour in both groups was normal. To what extent motor-oriented speech therapy (with focus on tongue function) immediately after periodontal treatment (after wound healing) would decrease the persistent phonetic distortions is a subject for further research.

Comparison of speech intelligibility, articulation and oromyofunctional behaviour in subjects with single-tooth implants, fixed implant prosthetics or conventional removable prostheses.

The purpose of this controlled study was to determine the impact of a single-tooth implant, fixed implant prosthesis and completely removable dental prosthesis on intelligibility, articulation and oromyofunctional behaviour. Additionally, the self-perceived overall satisfaction of the dental replacements and the effect on speech was questioned. Objective (acoustic analysis) as well as subjective assessment techniques (perceptual evaluation) were used. The satisfaction of single-tooth implant group was very high (100%) followed by a satisfaction of 87% for the fixed implant prosthesis group and 68% for the removable prosthesis group. The results of the phonetic analyses revealed a normal intelligibility and oromyofunctional behaviour in the three groups of dental replacements. Only one type of articulation disorders was observed in the single-tooth implant group, followed by three types of disorders in the removable prosthesis group and six types of disorders in the fixed implant prosthesis group. In this last group, not only 87% of the subjects showed distortions of one or more consonants but also most consonants of the Dutch language were disturbed in comparison with the single-tooth implant and removable prosthesis users. Special attention must be paid to the fricative /s/ because in more than 50% of all groups, this sound is disturbed.

Impact of anterior single-tooth implants on quality of life, articulation and oromyofunctional behaviour: a pilot study.

The main purpose of this study is to determine the impact (one and a half year after implantation) of a single-tooth implant on articulation and oromyofunctional behaviour. This information is important for dentists, orthodontists or stomatologists who treat professional speakers. Objective (acoustic analysis) as well as subjective (questionnaire, phonetic inventory, phonetic analysis, oromyofunctional assessment of lip and tongue function, blowing, sucking and swallowing) assessment techniques were used to determine the quality of life, articulation and oromyofunctional behaviour. Fourteen subjects who received a single-tooth implant and a control group of nine subjects participated in this study. The mean overall satisfaction of single-implant users was 95%. The subjects who received a single-tooth implant were capable of producing all Dutch vowels and consonants. The phonetic analysis revealed a sigmatism in 57% of the cases. Sigmatisms (stridens sigmatism followed by simplex sigmatism) were the most frequently observed phonetic disorders. There was interobserver agreement about normal lip and tongue functions. Moreover, blowing, sucking and swallowing patterns were normal (concordance value 96%). Detailed analyses 1 or 2 years after implantation of an anterior single-tooth implant revealed normal speech intelligibility and oromyofunctional behaviour. Articulation was characterised by the presence of a persistent phonetic disorder. Further research involving more subjects with an anterior single-tooth implant is needed.

Development of membrane extraction with a sorbent interface-micro gas chromatography system for field analysis.

The commercially available portable gas chromatographs have a rather limited scope of applications, typically allowing analysis of gaseous samples only, and having relatively poor sensitivity. Combination of those instruments with modern sampling/sample preparation techniques can remedy these problems. A Chrompack micro-GC system equipped with a thermal conductivity detector has been coupled to membrane extraction with a sorbent interface (MESI). The sorbent trap has replaced the GC injector. The design of the trap was also modified in order to enhance the preconcentration of analytes. The use of a thin flat sheet membrane reduces the response time, and decreases the memory effect of the system. Rapid separation times were achieved, and the sensitivity was significantly improved. MESI enables semi-continuous monitoring of both gaseous and aqueous samples, owing to the selectivity of the membrane material. The system does not use moving parts, therefore being reliable. The sensitivity of the micro-GC system was increased by a factor of more than 100 by the addition of the MESI system, even with a preconcentration time as short as 1 min. Chloroform, having a concentration lower than 1 ppb, was detected in tap water. A cup system was used to allow headspace sampling of volatile organic compounds from aqueous matrices, keeping the membrane away from interfering species that could be present in water, and improving the mass transfer. A linear calibration line was obtained, and the estimated limit of detection was 60 ppt. This represents a great improvement for the sensitivity of the micro-GC system.

Novel preconcentration technique for on-line coupling to high-speed narrow-bore capillary gas chromatography: sample enrichment by equilibrium (ab)sorption. II. Coupling to a portable micro gas chromatograph.

The technique of equilibrium (ab)sorption has been proven to be a powerful method for preconcentration of gaseous samples for high-speed narrow-bore capillary gas chromatography (GC) in general and field-portable GC instruments, often referred as micro GCs, in particular. Using a simple experimental set-up equipped with an open-tubular enrichment column it is possible to produce a homogeneously enriched sample plug, allowing reproducible injections of an enriched sample into the micro GC. Using a non-polar trapping column enrichment factors found for n-alkanes in the range of C7 to C10 ranged from 15 to 150 and agree well with calculated values. Using a highly retentive Thermocap column, the enrichment factor observed for heptane was above 500. As the use of this new preconcentration method requires only minimum modification of the micro GC, the chromatographic performance of the instrument was not compromised by direct coupling to the preconcentration device. Examples of on-line enrichment with portable micro GC analysis of VOCs from air are shown. These examples clearly demonstrate the potentials of the new method in field analysis.

Fully automated sample handling system for liquid chromatography based on pre-column technology and automated cartridge exchange.

The design of an automated cartridge exchange module for on-line sample handling in liquid chromatography is described. When combined with a low-cost purge pump, a solvent selection valve and an auto-sampler, a fully automated sample handling system is obtained. Samples are sorbed on a disposable cartridge packed with 40 micron octyl-bonded silica, purged for clean-up and eluted on-line to the analytical column. Unattended operation of the system is demonstrated for various examples, i.e., the determination of anti-epileptic drugs in serum, an anti-cancer drug in plasma, barbiturates in urine, phenylurea herbicides in river water and caffeine in a soft drink.