Critical tooth number without subjective dysphagia.

Aim: To assess the critical tooth number (CTN) required for prevention of subjective dysphagia caused by oral impairments and to evaluate the relationship between this CTN and mortality.

Methods: The baseline study was performed with residents aged 40-89years (n=5,643; 2224 men and 3419 women) in Miyako Islands, Okinawa, in 1987. Dental examinations were performed by dentists, and subjective dysphagia was asked.

Associations between functional tooth number and physical complaints of community-residing adults in a 15-year cohort study.

Background: Oral function influences various general health and organ diseases. We wondered if physical complaints of unknown origin were related to oral function.

Methods: Five thousand five hundred and eighty-four community residents (2206 men and 3378 women, aged 40-89 years) on the Miyako Islands, Okinawa Prefecture, Japan, were recruited for the baseline study in 1987 and followed up for 15 years.

Mortality rates of community-residing adults with and without dentures.

Aim: To prospectively study how dental status with and without dentures could become a predictor of overall mortality risk.

Methods: Five thousand six hundred eighty-eight community residents over 40 years old in the Miyako Islands, Okinawa Prefecture, Japan, were followed up for 15 years from 1987-2002.

Results: We found that female subjects with less than 10 functional teeth and without dentures showed a significantly higher mortality rate than those with dentures.

Acceleration of orthodontic tooth movement by alveolar corticotomy in the dog.

Introduction: Tooth movement and alveolar bone reaction after corticotomies have not been thoroughly examined. In this study, the effects of corticotomies on orthodontic tooth movement and alveolar bone reaction were investigated in dogs.

Methods: Corticotomies were performed on the cortical bone of the mandibular left third premolar region in 12 male adult beagles.

Fatigue and damage to the masseter muscle by prolonged low-frequency stimulation in the rat.

This study aimed to examine peripheral fatigue and the resultant damage to the masseter muscle due to prolonged low-frequency stimulation. Thirty male rats were divided into S1, S2, S4, Dantr and Sham groups. The left masseters were used as experimental muscles.

Unilateral advancement of the maxillary minor segment by distraction osteogenesis in patients with repaired unilateral cleft lip and palate: report of two cases.

Collapse of the maxillary minor segment with lateral crossbite is a common feature in patients with repaired unilateral cleft lip/palate because of maxillary alveolar bony defect and palatal scar tissue. Distraction osteogenesis (DOG) is an effective technique of lengthening and augmentation for bone and gingiva. This case report describes the effects of unilateral advancement of the maxillary minor segment by DOG in two patients with the repaired unilateral cleft lip/palate.

Nitric oxide mediates the effects of pulsed electromagnetic field stimulation on the osteoblast proliferation and differentiation.

The purpose of this research was to investigate whether the effects of pulsed electromagnetic field (PEMF) stimulation on the osteoblast proliferation and differentiation are mediated by the increase in the nitric oxide (NO, nitrogen monoxide) synthesis. The osteoblasts (MC3T3-E1 cell line) were cultured in the absence (-NMMA group) or in the presence (+NMMA group) of the NO synthase inhibitor L-NMMA. First, osteoblasts were subjected to PEMF stimulation (15 Hz and 0.

Effects of pulsed electromagnetic field (PEMF) stimulation on bone tissue like formation are dependent on the maturation stages of the osteoblasts.

The effects of pulsed electromagnetic field (PEMF, 15 Hz pulse burst, 7 mT peak) stimulation on bone tissue-like formation on osteoblasts (MC3T3-E1 cell line) in different stages of maturation were assessed to determine whether the PEMF stimulatory effect on bone tissue-like formation was associated with the increase in the number of cells and/or with the enhancement of the cellular differentiation. The cellular proliferation (DNA content), differentiation (alkaline phosphatase activity), and bone tissue-like formation (area of mineralized matrix) were determined at different time points. PEMF treatment of osteoblasts in the active proliferation stage accelerated cellular proliferation, enhanced cellular differentiation, and increased bone tissue-like formation.

Emotional stress and brux-like activity of the masseter muscle in rats.

The aim of this study was to further clarify the relationship between emotional stress and bruxism. In experiment 1, 60 male 9-week-old Wistar rats were divided into four groups: the emotionally stressed (ES), the emotionally non-stressed (NS), the electrically foot-shocked (FSd), and the non-foot-shocked (NSd). ES rats were confined in a communication box for one hour a day to observe the emotional responses of neighbouring FSd rats.