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Biomedical subjects

R G Jagger

Publications and source records attributed to R G Jagger.

14 recordsLinked to original sources
PubMed1992

The effect of cross-linking chain length on mechanical properties of a dough-molded poly(methylmethacrylate) resin.

Three different cross-linking agents which provide a range of cross-linking chain lengths and flexibilities were added to the monomer component of a dough-molded poly(methylmethacrylate) resin in various concentrations, and their effects on the impact strength, transverse bend strength, and tensile strength of the cured polymer were investigated. Increase in the chain lengths of cross-linking agents led to a decrease in the properties of transverse bend strength and tensile strength and an increase in the property of impact strength.

Acrylic Resins↗
PubMed1992

Signs and symptoms of temporomandibular joint dysfunction in a Saudi Arabian population.

The signs and symptoms of temporomandibular joint dysfunction present in 219 Saudi Arabians attending a dental clinic for routine dental treatment are described. Joint sounds (36%) and muscle tenderness to palpation (34%) were common findings. Of the subjects examined, 31% reported suffering from frequent headaches. The study demonstrated a high incidence of signs and symptoms of temporomandibular joint dysfunction. Findings were similar to those of a previous study of an investigation in a bedouin community in Western Egypt (Abdel-Hakim, 1983).

Adolescent↗
PubMed1991

Effect of the curing cycle on acrylic denture base glass transition temperatures.

Glass transition temperature of a polymer is an important physical property which may have a major effect on the dimensional stability of denture base materials. Thermomechanical analysis has been used to determine the glass transition temperature of specimens of denture base materials which had been produced by various selected curing cycles. It was found that different curing cycles produced variations in glass transition temperature of up to 20 degrees C.

Acrylic Resins↗
PubMed1991

Reflected light microscopy of the human mandibular condyle--a study of a post-mortem material.

The surface characteristics of the articulating surfaces of 11 human mandibular condyles removed post-mortem were determined by the use of reflected light dark-field microscopy. Good agreement was obtained between macroscopical grading of degenerative change and appearance as observed by microscopy. Microscopical appearances believed to correspond to normal surface, fibrillation and degenerative changes are described.

Aged↗
PubMed1991

Mandibular manipulation of anterior disc displacement without reduction.

The history and clinical symptoms of anterior temporomandibular joint disc displacement without reduction are characteristic, and include limitation of mandibular movement and mandibular deviation on opening of the mouth. Twelve consecutive patients attending a clinic with such symptoms were treated by mandibular manipulation. An immediate increase in the range of mandibular movement was obtained for all patients, with a mean increase in interincisal opening of 8 mm. The method of manipulation is described, and the implications of the results for the treatment of TMJ patients are discussed.

Adolescent↗
PubMed1990

Effect of cross-linking on sorption properties of a denture-base material.

Cross-linking of the polymer of the interstitial matrix of a heat-cured resin denture base is said to provide craze resistance for the denture base. The mechanism of crazing can be related to both water sorption and solvent attack. The present study shows that the addition of ethylene glycol dimethacrylate in concentrations of 0-100% of monomer volume has little effect on water sorption properties but is an efficient method of providing solvent resistance.

Cross-Linking Reagents↗
PubMed1978

Pharmacotherapy of masticatory system dysfunction.

The decision to use drugs systemically in the management of mandibular dysfunction must be made with consideration of the information summarized in this report. It has been shown that pharmacotherapy may be effective. It has also been demonstrated that systemic pharmacotherapy frequently produces side effects which are occasionally severe. The clinician must decide on the appropriateness of therapy with the knowledge that many other conservative measures may also have excellent success rates and that pharmacotherapy is likely to be palliative rather than curative.

Anesthesia, Local↗
PubMed1978

Effect of the curing cycle on some properties of a polymethylmethacrylate denture base material.

The properties of a denture base material may be modified by altering both the temperature and the time of heating during the curing cycle. In this study a polymethylmethacrylate denture base containing no crosslinking agent was polymerised using four different curing cycles. The structure of the materials so obtained was investigated by an acid etching technique. The materials were characterized with respect to degree of cure, strength and water sorption. It was concluded that: 1. No correlation was observed between the curing cycles and polymer structure. 2. The curing cycle of 7 h at 70 degrees C plus 1 h at 100 degrees C produced best indentation strength and tensile strength. 3. A correlation was observed between residual monomer, indentation resistance, tensile strength and water sorption. This suggested that residual monomer concentration is the most important parameter in the determination of the properties of the material investigated in this study.

Chemical Phenomena↗
PubMed1978

Multiple myeloma involving the temporomandibular joint: report of case.

A case of multiple myeloma was reported in which the initial symptom was pain and dysfunction of the TMJ that resulted from pathological fracture of the mandibular condyle. An initial radiographic skeletal survey showed no evidence of further lesions, although hematological and biochemical tests indicated a diagnosis of multiple myeloma. Treatment resulted in improvement of symptoms and of an evident regression of the lesion after 18 months. After a year, however, radiographs disclosed generalized skeletal involvement; deterioration of the general condition followed.

Fractures, Spontaneous↗