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Biomedical subjects

H Devlin

Publications and source records attributed to H Devlin.

At least 73 records · Page 4Linked to original sources
PubMed1989

A radiographic investigation into bone resorption of mandibular alveolar bone in elderly edentulous adults.

Clinical experience suggests that severe alveolar bone resorption can limit the success of complete denture wearing. The loss of bone mineral with age occurs throughout the skeleton, which contributes to the high incidence of bone fractures later in life. Women are more commonly affected by some of these fractures. The decline in serum oestrogen concentration following the menopause has been implicated in the aetiology of these fractures. We have found that age is important in determining the bone resorption observed in females but not in males.

Aged↗
PubMed1989

Compositional changes in the rat femur following ovariectomy.

Ovariectomy has been shown to produce osteoporosis in the femur of the rat. 11-month-old Sprague-Dawley rats were either ovariectomized or given a sham operation. The loss of calcium in the femur of the rats was compared with two indices of osteoporosis, the ponderal index and the femur score. The calcium content was more closely associated with the femur score (r = 0.5, p = 0.0064) than with the ponderal index (r = -0.367, p = 0.05). An accelerated rate of fat deposition in the ovariectomized rat femur reduced the femur weight loss, which resulted in a barely significant association of calcium content with the ponderal index.

Animals↗
PubMed1987

The accelerative component of EMG in bite force development in man.

Masseter EMG and bite force recordings were made from six subjects. Multiple regression analysis was performed and an equation produced relating EMG and bite force in SI units. Evidence is presented for a component of masseter EMG which can be related to the acceleration of bite force during onset of a clench.

Bite Force↗
PubMed1986

The mechanical advantage of biting with the posterior teeth.

The greater forces generated between posterior teeth compared with between anteriors, may be explained by interpreting the behaviour of the mandible as a lever system, with the condyle as a fulcrum. This study used a semi-conductor strain gauge transducer to measure load, and EMG activity to index muscular effort. A posterior and an anterior load position were compared by using parallel metal platforms which maintained the occlusal vertical dimension for different biting positions. Reductions in muscular effort were observed for the posterior position of a magnitude that was consistent with the greater mechanical advantage predicted by the level model.

Adult↗
PubMed1985

Bite force and masseter muscle electromyographic activity during onset of an isometric clench in man.

The surface electromyogram (EMG) of the masseter muscle and interocclusal force were recorded in six human subjects during fast and slow clenches. The simple linear force/EMG relation that applies for steady bite-force levels was inadequate to explain their relationship under conditions of changing force: a second component of force, its rate of change, was necessary. EMG/force equations for fast and slow clenches were broadly similar. The rate of change factor may account for the apparent EMG/force lag observed in earlier studies.

Adult↗
PubMed1984

Acrylic 'allergy'?

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Acrylic Resins↗