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Biomedical subjects

R J Fonseca

Publications and source records attributed to R J Fonseca.

53 records · Page 3Linked to original sources
PubMed1982

Mandibular interpositional and onlay bone grafting for treatment of mandibular bony deficiency in the edentulous patient.

The development of interpositional and onlay bone grafting techniques for atrophic mandibles is reviewed. A further modification of the visor osteotomy is presented along with follow-up evaluation of the conditions of 16 patients. Results of radiographic measurements show the procedure to be stable, vertical resorption of the augmented mandible in the body regions being 11.2% over a mean follow-up of 8.8 months. Neurosensory evaluation showed altered sensation and dysesthesia as a significant problem in these patients. The results are presented and discussed.

Adult↗
PubMed1982

Postoperative nutritional supplementation for the orthognathic surgery patient.

Twenty-four orthognathic surgery patients were studied to determine the impact of a high-calorie liquid supplement on preventing or minimizing catabolism commonly associated with surgery. The experimental group of 12 subjects, chosen at random, consumed blenderized foods ad libitum and a high-calorie dietary supplement providing a minimum of 50% of energy requirements. The remaining 12 subjects consumed only blenderized foods and served as the control group. The nutritional status of all patients was assessed one day before surgery and on Day 7 of the first, third, and sixth postoperative week. In general, nutrient intake in the experimental group remained similar to that before surgery, whereas intake in the control group decreased significantly, particularly at the one-week postoperative evaluation. It was concluded that the addition of a high-calorie liquid supplement to the dietary regimen of orthognathic surgery patients helped maintain nutrient intake at a level comparable to that before surgery. This resulted in better maintenance of body weight and somatic protein compartments compared with the control group.

Adolescent↗
PubMed1982

Fractures of the mandible: a review of 580 cases.

The anatomic distribution of fractures in this study showed more fractures of the condylar and parasymphysis/symphysis regions, with correspondingly fewer body and angle fractures, than in other reported studies. The site of fracture is related to the type of trauma involved. Altercations, in which most force is directed in a single blow to the lateral aspect of the jaw, tend to result more frequently in angle and body fractures and less often in condylar, symphysis, and alveolar fractures. Automobile accidents, which more frequently involve trauma to the anterior mandible, result in more fractures of the symphysis region, alveolus and condyle. Motorcycle accidents produce many more alveolar fractures, suggesting that the traumatic force in this kind of accident is often directed to the alveolus. As might be expected, those individuals involved in motor vehicle accidents had the highest incidence of other injuries in addition to the mandibular fractures. Injuries to the head and neck were most common, but a wide variety of other injuries occurred. Complications are more common in the patient who has sustained multiple trauma. Most fractures were treated by closed reduction. When open reduction was necessary, the most common sites were the angle, body, and symphysis regions.

Adolescent↗
PubMed1981

Multiosseous osteosarcoma involving the mandible: metastatic or multicentric?

A case of multiosseous osteosarcoma in a 15-year-old girl is presented. Neoplastic foci were initially diagnosed in the right ilium and left mandible. The clinical course was complicated by pregnancy and chemotherapeutic side effects. Postmortem examination revealed multiple tumor emboli in the lungs. The literature concerning metastatic and multicentric origins of multiosseous osteosarcomas is reviewed. The case presented probably represents mandibular metastasis from the ilium.

Adolescent↗
PubMed1981

Early pulp changes after anterior maxillary osteotomy.

For purposes of examining the pulpal reaction to segmental osteotomy, six adult female Macaca fascicularis monkeys received identical anterior maxillary osteotomies involving the incisors only. The mobilized segment was displaced distally a distance of approximately 2 mm, then splinted in place for a week. The healing and revascularization of the bone proceeded well, with no ischemic areas visible on the microangiograms other than in the animal examined immediately after operation. The osteotomy site was bridged with new bone at three months. The majority of the pulps of the mobilized segment and all teeth examined distal to the segment remained vital. No degenerative change other than the temporary disappearance of sensory nerves was observed in the vital pulps of the segments. By the six-month period, the sensory nerve supply to the dental pulp had regenerated completely.

Animals↗
PubMed1980

Cephalometric diagnosis and surgical-orthodontic correction of apertognathia.

Nineteen postadolescent white woman with uncorrected Class I molar and/or canine occlusion were compared cephalometrically to thirteen postadolescent white women with skeletal apertognathia that was later corrected by a combination of surgical procedures, the common denominator being maxillary posterior superior repositioning. The cephalometric tracings were compared statistically by evaluating the study group preoperatively, immediately postoperatively, and at a long-term follow-up appointment. The results indicate that there is a statistical difference in certain important measurements between normal persons and preoperative apertognathic patients with the deformity identified in the dentoalveolar complex of the maxilla. Posterior maxillary superior repositioning tends to correct this skeletal deformity, with postoperative measurements approaching the normal values. The correction proved to be stable over a mean follow-up period of 19 months (range, 7 to 30 months).

Adolescent↗
PubMed1980

Technetium bone imaging as an adjunct in the management of fibrous dysplasia.

The diagnosis of fibrous dysplasia is one that is often made on the basis of biopsy findings and routine radiographs of involved areas. Until the advent of total body scanning, early cases of polyostotic fibrous dysplasia went undiagnosed until swelling, asymmetry, or deformity was noticed in other body parts. More sensitive radiographic techniques, (this is, bone imaging) are now available which offer a means for early detection of polyostotic involvement and more accurate delineation of lesions of the monostotic variety.

Adolescent↗
PubMed1980

Revascularization and healing of onlay particulate autologous bone grafts in primates.

Two sizes of bone chips were compared to determine the size that revascularizes faster and what effect this has on the resorption of the graft. To accomplish this, autologous chips of iliac corticocancellous bone of either 2 X 2 X 2 mm or 5 X 5 X 2 mm were placed in the mandibular cortex of monkeys bilaterally. In general, the small-particle graft was quicker to revascularize, showed more osteoclastic activity, and therefore resorbed much more quickly and completely than did the large-particle graft. The resultant net gain in alveolar ridge contour was, therefore, less with the small-particle grafts.

Animals↗
PubMed1980

Healing of interpositional autologous bone grafts after total maxillary osteotomy.

Healing of autologous interpositional bone grafts after total osteotomy in the Macaca fascicularis monkey was studied using clinical, histologic, microangiographic, and autoradiographic methods at varying intervals up to six months. Results indicated that the autologous graft was very osteogenic and incorporated by host bone. Graft revascularization became apparent at two weeks postoperatively, and bone healing time was between two to four weeks. A hypervascular response was present to at least the six-month healing stage. The palatal mucosa plus the facial gingiva provided an adequate nutrient pedicle for total maxillary osteotomies with interpositional bone grafting.

Animals↗
PubMed1978

A cephalometric evaluation of American Negro women.

A cephalometric study of forty American Negro women with an average age of 24.6 years and a Class I molar and/or canine relationship was performed. When measurements were compared to a control population of twenty Caucasian women, using several standard analyses, significant differences were demonstrated between the sample populations. 1. The maxilla and mandible were more protrusive in the Negro sample. 2. The upper and lower incisors were more proclined and the interincisal angle was more acute in the Negro sample. 3. Middle facial height was shorter and lower facial height was longer in the Negro sample. 4. The projection of the soft-tissue nasal tip was less in the Negro sample. 5. The projection of the upper and lower lips as related to the facial plane was greater in the Negro sample. 6. Lip thickness was approximately the same in the two groups.

Adult↗
PubMed1978

Single arch stabilization devices for segmental orthognathic surgery.

Single arch stabilization of segmental osteotomies is desirable because it eliminates intermaxillary fixation while it, in turn, improves oral hygiene and communication and patient comfort, function, and acceptability. Orthodontic appliances with stabilizing arch wires are the method of choice if available. Arch bars modified for segmental stabilization function very well as an alternative to orthodontic appliances. Cast splints are also useful for these cases, although cost and the need for expert laboratory support limit their acceptability. Certain other devices, such as palatal and lingual plates and interocclusal wafers, provide additional support for several of the above-mentioned stabilization systems.

Acrylic Resins↗
PubMed1976

Soft tissue changes associated with total maxillary advancement: a preliminary study.

A retrospective investigation was performed with use of cephalometric radiographs from eight patients with anterior maxillary advancement. Soft tissue changes associated with hard tissue changes were measured. Statistical description of soft tissue behavior in the upper lip was performed using correlation coefficients, regression functions, and ratios of change in the relationship of soft tissue to hard tissue. Ratios of change in relationship of soft tissue to hard tissue for three parameters of upper lip movement are proposed for clinical use in treatment planning. Further investigation of soft tissue behavior with orthognathic surgical procedures is indicated.

Cephalometry↗
PubMed1975

Bone healing and revascularization after total maxillary osteotomy.

Adult rhesus monkeys were used as experimental analogues to investigate vascularization, revascularization, and bone healing associated with total maxillary osteotomy. Microangiographic and histologic studies showed minimal transient vascular ischemia, minimal osteonecrosis, and early osseous union. Transection of the greater palatine arteries had no discernible effect on the circulation to the teeth and bone in the maxilla and its enveloping soft tissues. The results of experiments in animals and clinical studies indicate that palatal mucosa and labial-buccal gingiva provide an adequate nutrient pedicle for single-stage total maxillary osteotomies.

Angiography↗