Examination of the Relationship between Oral Health and Arterial Sclerosis without Genetic Confounding through the Study of Older Japanese Twins

<div><p>Objective</p><p>Although researchers have recently demonstrated a relationship between oral health and arterial sclerosis, the genetic contribution to this relationship has been ignored even though genetic factors are expected to have some effect on various diseases. The aim of this study was to evaluate oral health as a significant risk factor related to arterial sclerosis after eliminating genetic confounding through study of older Japanese twins.</p><p>Subjects and Methods</p><p>Medical and dental surveys were conducted individually for 106 Japanese twin pairs over the age of 50 years. Maximal carotid intima-media thickness (IMT-Cmax) was measured as a surrogate marker of arterial sclerosis. IMT-Cmax > 1.0 mm was diagnosed as arterial sclerosis. All of the twins were examined for the number of remaining teeth, masticatory performance, and periodontal status. We evaluated each measurement related with IMT-Cmax and arterial sclerosis using generalized estimating equations analysis adjusted for potential risk factors. For non-smoking monozygotic twins, a regression analysis using a “between within” model was conducted to evaluate the relationship between IMT-Cmax and the number of teeth as the environmental factor controlling genetic and familial confounding.</p><p>Results</p><p>We examined 91 monozygotic and 15 dizygotic twin pairs (males: 42, females: 64) with a mean (± standard deviation) age of 67.4 ± 10.0 years. Out of all of the oral health-related measurements collected, only the number of teeth was significantly related to arterial sclerosis (odds ratio: 0.72, 95% confidence interval: 0.52-0.99 per five teeth). Regression analysis showed a significant association between the IMT-Cmax and the number of teeth as an environmental factor (<i>p</i> = 0.037).</p><p>Conclusions</p><p>Analysis of monozygotic twins older than 50 years of age showed that having fewer teeth could be a significant environmental factor related to arterial sclerosis, even after controlling for genetic and familial confounding.</p></div

Association between the number of teeth and IMT-Cmax in regression analysis using the “between within” model.

<p>Association between the number of teeth and IMT-Cmax in regression analysis using the “between within” model.</p

The system for measuring tongue pressure.

<p>A) Swallow scan; Nitta, Osaka, Japan, B) Sensor sheet with five measuring points (Chs.1–5) attached to the hard palate.</p

Representative waves of tongue pressure during oral processing and final swallow.

<p>A) Squeezing; B) Mastication.</p

Comparisons of maximal magnitude of tongue pressure among the three hardnesses of jelly, and between oral strategies.

<p>A) Squeezing; B) Mastication. *P<0.05. ¶: Maximal magnitude of tongue pressure for size reduction was smaller in Mastication than in Squeezing (P<0.05), ‡: Maximal magnitude of tongue pressure for swallowing was smaller in Mastication than in Squeezing (P<0.05).</p

Comparisons of duration of tongue pressure among the three hardnesses of jelly, and between oral strategies.

<p>A) Squeezing; B) Mastication. *P<0.05. ¶: Duration of tongue pressure for size reduction was shorter in Mastication than in Squeezing (P<0.05). : Duration of tongue pressure was longer in Mastication than in Squeezing (P<0.05).</p

Instrumental texture properties of gel samples.

<p>The three mechanical parameters (hardness, adhesiveness, and cohesiveness) were determined by two-bite compression of jelly samples (diameter, 40 mm; height, 15 mm) at a table speed of 10 mm/s using a 20-mm-diameter flat aluminum plunger, and values are given as mean ±SD.</p

Le Courrier

18 août 18481848/08/18 (N229)

Development of a System to Monitor Laryngeal Movement during Swallowing Using a Bend Sensor

<div><p>Background</p><p>Swallowing dysfunction (also known as dysphagia), which results in a deterioration of nutritional intake, slows rehabilitation and causes aspiration pneumonia, is very common following neurological impairments. Although videofluorographic (VF) examination is widely used for detecting aspiration, an objective and non-invasive method for assessing swallowing function has yet to be established because of a lack of adequate devices and protocols. In this paper, a bend sensor whose resistance is altered by bending was introduced to monitor swallowing-related laryngeal movement.</p><p>Methods</p><p>Six healthy male volunteers were recruited in the present study. Specific time points on the signal waveform produced by the bend sensor were defined to describe laryngeal movement by differential analysis. Additionally, the physiological significance of the obtained waveform was confirmed by analyzing the sequential correlations between the signal waveform from the bend sensor and hyoid bone kinetics simultaneously recorded by VF.</p><p>Results</p><p>Seven time points were successfully defined on the signal waveform to reference laryngeal movement. Each time point was well correlated with certain VF events, with evidence of no significant time lags, and there were positive correlations between waveform time points and matched VF events. Furthermore, obvious similarities were noticed between the duration of each phase on the signal waveform and the duration of the matched hyoid bone activity.</p><p>Conclusions</p><p>The present monitoring system using a bend sensor might be useful for observing the temporal aspects of laryngeal movement during swallowing, and it was well coordinated with hyoid bone movement.</p></div

Time points (T1–T7) on the signal waveform from the bend sensor and VF events (V1–V6) on the common time series.

<p>T1 to T6 indicate time points 1 to 6. V1 to V6 indicate VF event 1 to VF event 6. The timing of V2 was set to 0 s. * <i>p</i><0.05 vs. V3. Since T7 was recorded last as the offset of the waveform, it was not compared with any VF events.</p