P1957Impact of fraility on the super elderly patients with peripheral artery disease

Background

The current consensus is that frail patients have high risks of mortality. However, it remains unclear whether frailty is associated with mortality risks in super-elderly patients with peripheral artery disease (PAD).

Methods

The I-PAD registry was a prospective multicenter observational study involving 12 institutions in Nagano prefecture in Japan. From July 2015 to July 2016, the I-PAD registry enrolled 371 consecutive PAD patients who had undergone endovascular therapy (EVT). Among them, we selected and analysed 109 PAD patients who were >80 years old when they had undergone EVT and divided them into two groups: those with frailty (Clinical Frailty Scale≥5, n=47) and those without frailty (Clinical Frailty Scale≤4, n=62). The primary endpoints were overall survival and major adverse limb events (MALE), defined as a composite of all-cause death, major amputation and revascularization.

Results

The median follow-up period was 1.58±0.3 years. Overall, 109 patients with a mean age of 84.8±4.0 years, of whom 63.3% were men, were included. Overall survival and freedom from MALE were significantly lower among patients with frailty than among those without frailty (60.5% vs. 91.6%, P<0.001; 51.4% vs. 87.5%, P<0.001; respectively).

Conclusion

The prognosis of super-elderly patients with frailty is worse than that of patients without frailty.

Quantitative study of bite force during sleep associated bruxism

Nocturnal bite force during sleep associated bruxism was measured in 10 subjects. Hard acrylic dental appliances were fabricated for the upper and lower dentitions of each subject. Miniature strain-gauge transducers were mounted to the upper dental appliance at the right and left first molar regions. In addition, thin metal plates that contact the strain-gauge transducers were attached to the lower dental appliance. After a 1-week familiarization with the appliances, nocturnal bite force was measured for three nights at the home of each subject. From the 30 recordings, 499 bruxism events that met the definition criteria were selected. The above described system was also used to measure the maximum voluntary bite forces during the daytime. The mean amplitude of detected bruxism events was 22.5 kgf (s.d. 13.0 kgf) and the mean duration was 7.1 s (s.d. 5.3 s). The highest amplitude of nocturnal bite force in individual subjects was 42.3 kgf (15.6-81.2 kgf). Maximum voluntary bite force during the daytime was 79.0 kgf (51.8-99.7 kgf) and the mean ratio of nocturnal/daytime maximum bite force was 53.1% (17.3-111.6%). These data indicate that nocturnal bite force during bruxism can exceed the amplitude of maximum voluntary bite force during the daytime.

Study of jaw movement and masticatory muscle activity during unilateral chewing with and without balancing side molar contacts

This research evaluated the relationship between balancing side molar contacts and chewing patterns measured with a jaw movement analyser and multi-channel electromyography (EMG) of the masticatory muscles. Nine healthy subjects with relatively normal occlusions participated in the experiment and were divided into those with balancing side molar contacts and those without. The block gum chewing task was performed on each side of the mouth for 10 s. The results showed more asymmetrical levels of jaw closing muscle activity during unilateral chewing in the group with balancing side molar contacts when compared with the group without these contacts.

Criteria for the detection of sleep-associated bruxism in humans

Surface electromyography of the masseter and electrocardiogram recordings of heart activity during sleep were performed on nine subjects who suffer from an oral motor dysfunction (bruxism during sleep. Signals were monitored in the subject's home sleeping environment over 4 consecutive nights. A total of 36 nights of data were analyzed to perform the following: (1) describe the nature and magnitude of total masseter muscle electromyographic activity above a minimum threshold of 3% of each subject's individually established maximum voluntary contraction level; and (2) describe electrocardiograph rate changes (using the R-R interval) that occurred in relation to these electromyographic elevations. From these data, criteria for detection of bruxism events were established and combined into a fully automated event detection algorithm. The mean number and duration of the detected bruxism events are reported. The underlying logic for the criteria selected, and what effect other possible criteria would have on the separation of abnormal from normal motor events, is also presented and discussed.

Effect of jaw position and posture on forced inspiratory airflow in normal subjects and patients with obstructive sleep apnea

OBJECTIVE

This study evaluated whether substantial airflow changes occur by changing both body posture and jaw position in normal subjects and patients with obstructive sleep apnea (OSA).

DESIGN

A case-control design was utilized to assess group differences (OSA vs control) and each subject served as his/her own control subject to assess condition differences (jaw position and body posture changes). Subjects included 16 male patients with OSA (aged 33 to 71 years) whose conditions were diagnosed at the UCLA Sleep Disorders Laboratory with a polysomnographic recording, and 9 male non-OSA subjects (aged 22 to 52 years). The experimental intervention in the study involved alterations in body posture and jaw positioning. Airflow changes were determined using a spirometer that assessed the velocity of airflow during a forced inspiration. Subjects in this study all had the middle portion (25 to 75%) of their maximum forced inspiratory flow (FIF25-75) curve measured in three positions; (1) normal jaw position-upright body posture (N-U); (2) normal jaw position-supine body posture (N-S); and (3) protrusive jaw position-supine body posture (P-S).

SETTING

The study was conducted at the UCLA Dental Clinical Research Center.

RESULTS

Both groups had a significant decrease in their FIF25-75 upon reclining, and there were no significant group differences regarding the magnitude of this change. Both groups also had a nearly full recovery of their FIF25-75 airflow when their jaws were positioned forward while reclining.

CONCLUSIONS

These data document that when a patient is in a supine position, a 100% protrusive jaw position allows significantly more inspiratory airflow to occur.

Effect of altered occlusal guidance on lateral border movement of the mandible

The purpose of this study was to evaluate the effects of a change in the lateral anterior guidance pathway on the lateral border movement pathway of mandible. The results showed that altered occlusal guidance reproducibly and reversibly changed (increased) the lateral border movement area in two subjects who had unilaterally restricted lateral border movements.

The relationship between lateral border movements of the mandible and the determinants of occlusion

Border movements of the mandible were measured with a jaw movement analyzer in nine subjects. This instrument records movement with 6 degrees of freedom and has the ability to accurately and linearly record the full range of jaw movement. The result of this study showed a relationship between the presence of balancing-side molar contacts and restricted contralateral jaw border movements. This restriction is probably due to aberrant external pterygoid muscle activity.

[Influence of occlusal contact on jaw movement and masticatory muscle activity]

Jaw movement in six degree-of-freedom and 8 ch EMG of masticatory muscles were studied in 9 subjects to investigate the influence of occlusal contact on jaw function. The results are as follows. 1. The border jaw movement and the chewing movement changed according to the change of occlusal contact. 2. The tooth contact on balancing side is not good for jaw function because of two following reasons. First, tooth contact on balancing side limited the border jaw movement. Second, tooth contact on balancing side decreased jaw closing muscle activities of non-chewing side. 3. Existence of craniomandibular control system that controls jaw function under the influence of central nervous system and peripheral system was suggested.