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Biomedical subjects

A Yaffe

Publications and source records attributed to A Yaffe.

At least 37 records · Page 2Linked to original sources
PubMed1994

Regional accelerated phenomenon in the mandible following mucoperiosteal flap surgery.

Striking remodeling activity occurs adjacent to the site of injury in orthopedic surgery. This reaction has been described as regional accelerated phenomenon (RAP), as it speeds up the healing stage. The phenomenon is a transient burst of localized remodeling process following surgical wounding of cortical bone. We explored whether RAP occurs following mucoperiosteal flap surgery in the jaw bone. Mucoperiosteal flaps were performed on 60 Wistar rats, either only on the buccal aspect or both on buccal and lingual aspects of the mandible. The surgical procedure lasted an average of 30 seconds and the flap was readapted without sutures. The rats were sacrificed at 3, 7, 10, 14, 21, and 120 days. High resolution x-ray microradiography of 1 to 1.5 mm thick ground sections between premolar and molar regions of the mandible were analyzed and revealed large areas of radiolucency which correlated to massive resorption of the alveolar bone, as well as areas in the bone proper. The RAP was observed as early as 10 days in the treated side group. Striking resorption of the cortical bone, both on the surface and the bone proper, occurred on the periodontal aspect of the crestal bone leading to widening of the periodontal ligament space, where a mucoperiosteal flap was performed on the buccal aspect. The resorption was more prominent when a mucoperiosteal flap was performed both on the lingual and buccal aspect. The alveolar bone recovered almost to control levels 120 days after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Bone Loss↗
PubMed1993

Functional and morphological-occlusal aspects in children treated for unilateral posterior cross-bite.

Morphological and functional aspects were investigated in children with unilateral posterior cross-bite (UPXB) before and after treatment. Sixty-five patients with Class I malocclusion with UPXB in the mixed dentition stage (mean age 8.8 +/- 1.6 years) served as the experimental group and 10 children of comparable age, with normocclusion or very mild Class I malocclusion (without UPXB) served as controls. The morphological aspects were examined on a longitudinal basis while the functional recordings, by means of a sirognathograph, were performed in a cross-sectional fashion. Complete elimination of cross-bite was maintained in 61 per cent and was accompanied by a dramatic reduction in the prevalence of functional mandibular displacement. However, the prevalence of mandibular midline deviation related to the maxillary midline as recorded in the intercuspal position was not affected. In addition, the high prevalence of Class II subdivision relationships which accompanied the UPXB in the intercuspal position was resolved in 50 per cent of the cases only. The sirognathographic recordings of the masticatory pattern showed a very high prevalence of a 'reverse sequencing' type pattern before treatment which was significantly lower following the elimination of UPXB, but still notably higher when compared with the controls. Reasons for these results are suggested and possible inter-relationships between the morphological and functional aspects are discussed.

Child↗
PubMed1992

Splinting: a retrospective 17-year follow-up study.

A retrospective 17-year, longitudinal study monitoring 66 patients with fixed partial denture and removable partial denture restorations revealed that perceptive splinting was beneficial and enhanced the longevity of the restoration. The study discussed the advantages and disadvantages of splinting, the survival rate of splints and splinted teeth, and the importance of oral hygiene and a periodic maintenance program.

Acrylic Resins↗
PubMed1992

Contribution of oral habits to dental disorders.

Oral habits or parafunction may contribute to dental, periodontal, or neuromuscular damage. Such habits, of which the patient is often unaware, may cause considerable damage. Habits may be occlusal or non-occlusal, and may affect the dentition and/or the oral soft tissues. Drawing a patient's attention to the damage caused by some habits of which he or she is unaware often leads to cessation, whereas with certain conscious habits, such as nail or finger biting, success is much more limited.

Adult↗
PubMed1992

The masticatory pattern as an adjunct for diagnosis and treatment.

The sagitally-viewed masticatory pattern was investigated in 125 dentate patients. In 25 patients, the phenomenon of an incisal guided phase during mastication was observed. Clinical examination of these cases revealed slight to severe incisal attrition or various degrees of flaring. The hypothesis that the incisal guided phase contributes to this phenomenon and should therefore be taken into consideration during treatment is put forward.

Adult↗
PubMed1991

Effect of occlusal bite-raising splint on electromyogram, motor unit histochemistry and myoneuronal dimensions in rats.

Composite resin bite-raising splints were fabricated on both sides of the upper jaw in rats. EMG activity of the deep masseter muscle was monitored continuously for 24 h before and up to 4 weeks after treatment. Together with the EMG activity, measurements of the neuromuscular junction area and muscle fibre histochemistry were made. EMG activity showed great variability immediately after splint fabrication. Some of the animals showed increased EMG activity, while others exhibited less activity 48 h after splint application. Overall, the fluctuation lasted for about 4 days, and after approximately 7 days all the animals exhibited decreased EMG activity, followed by a gradual increase in activity towards baseline levels. The neuromuscular junction territory increased significantly 5-10 days after splint application. Histochemical characterization of the deep masseter muscle revealed that it contained the three main types of muscle fibre: slow oxidative (SO), fast-oxidative-glycolytic (FOG) and fast glycolytic (FG). The frequency distribution of fibre types did not change after bite-raising splint treatment. These findings indicated that splint treatment in rats is effective in reducing EMG activity, while the muscle type characteristics remain stable. The effect of lower activity on the motor end-plates suggested that the neuromuscular junctions are quite sensitive to functional changes.

Adenosine Triphosphatases↗
PubMed1991

Endodontic therapy as an adjunct for treatment of juvenile periodontitis: case report.

The four first permanent molars in a 16-year-old girl with juvenile periodontitis were treated by selective grinding, tooth eruption, conventional periodontic treatment and endodontic therapy. The endodontic treatment was carried out as an elective procedure under ideal conditions, thereby pre-emptying the emergency treatment which would have been necessary following occlusal reduction. The two-year follow-up examination showed successful resolution of the original condition.

Adolescent↗
PubMed1991

Functional and esthetic rehabilitation of an adolescent cleft lip and palate patient.

Many patients with clefts that also affect the alveolar ridge present with congenital absence of the permanent maxillary lateral incisors. This paper describes the treatment of an adolescent cleft lip and palate patient whose missing and unesthetic maxillary incisors were replaced by a combination of fixed and removable partial dentures.

Adolescent↗
PubMed1989

Various methods in achieving anterior guidance.

The anterior teeth are essential for esthetics, phoentics, and mastication and are equally involved in protecting posterior teeth. A 10-year longitudinal study of treatment modalities was conducted for overbite-overjet occlusal relationships. Comprehensive treatment combining orthodontics, occlusal adjustment, and selective restorations minimized the need for extensive restorative dentistry. The treatment of selected patients with a 10-year postoperative evaluation was discussed.

Adolescent↗
PubMed1989

Severe vertical overlap: a modified method of treatment.

Severe vertical overlap may predispose the patient to abnormal function, improper mastication, excessive stress, and functional problems such as bruxing, clenching, and craniomandibular disorders. This report describes the establishment of a new occlusal relationship by using the potential of posterior tooth eruption with the Hawley bite plane or the canine platform method. It was used in patients with a full complement of teeth or with some missing teeth. Patients treated by either the Hawley bite plane or the canine platform demonstrate a stable and long-lasting new occlusal relationship. The method described is efficient, inexpensive, and convenient to the patient.

Bicuspid↗
PubMed1988

A novel method to study directed cell migration in culture.

Directional migration of gingival fibroblasts was elicited in a cell culture system using reconstituted type I collagen fibers as a source of the putative chemoattractant. The rate of migration was expressed as Migration Index which turned out to be dependent on and directly related to the distance between the cells and the collagen. It is believed that this method enables one to study many different phenomena associated with extracellular matrix and cell interactions.

Animals↗
PubMed1987

Re-attachment of periodontal ligament by collagen in experimentally-induced alveolar bone dehiscence in dogs.

Fifty-four bone dehiscences were made in nine dogs by reflecting mucoperiosteal flaps on the labial aspect of lower and upper incisors and premolars and removing alveolar bone. One half of the dehiscences were treated with native enriched collagen solution (ECS) prepared from acid-soluble dog-skin collagen. Six weeks later, histologic sections were prepared from both the ECS-treated and untreated control sites. Re-attachment was promoted by the ECS preparation; there was arrest of epithelial migration apically and formation of new bone and cementum, as well as proliferation of fibrous connective tissue that became attached to the newly-formed cementum. This effect could be due to an influence of ECS on the chemotaxis of connective-tissue cells and to an anti-migratory (barrier) effect on gingival epithelium.

Alveolar Process↗
PubMed1987

The functional range of tooth contact in lateral gliding movements.

The dynamic contact pattern of teeth in lateral glide movement was recorded in 72 individuals, 19 to 35 years of age, with normal tooth alignment and Angle class I molar and canine relationship. The lateral glide movement was divided into three stages to simulate the total range of events in lateral glide movement naturally demonstrated by the patient. This study has shown that lateral glide movement is a complex movement in which the nature of tooth contact is altering in location, direction, and number of teeth participating. Consequently the restoration of an occlusion in accordance with a given concept does not always apply to all patients.

Adult↗
PubMed1985

Cessation of epithelial cell movement at native type I collagen-epithelial interface in vitro.

Two foci of gingival epithelial cells from the dog were grown in culture in dishes which were coated with gingival epithelial extracellular matrix (GEEM). A streak of native, reconstituted type I collagen fibers had been placed at the midline of the dish between the two foci. The epithelial cells spread and proliferated in all directions, but their motility ceased at the collagen-epithelial interface, where they piled up and formed several layers. It is concluded that type I collagen may serve as a biological barrier to stop undesirable epithelial cell movement in vivo.

Animals↗