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Biomedical subjects

B J Gans

Publications and source records attributed to B J Gans.

13 recordsLinked to original sources
PubMed1986

Use of polyglycolic acid mesh to confine particulate hydroxylapatite for augmentation of bone in the rat.

A preliminary report of the use of polyglycolic acid (PGA) mesh to contain particulate nonresorbable hydroxylapatite (HA) used for augmentation of bone in rats is presented. PGA mesh tubes, approximately 2 mm in diameter and 5 mm in length, were fabricated, filled with HA, and placed in surgically created subperiosteal pockets against the medial cortex of the tibia in rats. Specimens were obtained at two, six, 12, and 18 weeks. The results showed that when the HA was contained within the PGA mesh, severe displacement of particles was prevented and greater HA augmentation was possible. Absorption of the mesh took place between six and 12 weeks, after which the histologic features were the same as those seen when HA was implanted alone. Grossly, the implants appeared to hold firmly to bone even two weeks after implantation. A new, more efficacious delivery system is proposed for the augmentation of atrophic alveolar ridges using HA contained within PGA mesh tubes.

Alveolar Ridge Augmentation↗
PubMed1984

Long-term follow-up of a mandibular costochondral graft.

The long-term follow-up of a patient with unilateral mandibular condylar dysplasia and facial asymmetry, treated with a costochondral graft, is presented. The etiology of the deformity and the surgical treatment are discussed. A detailed review of the literature is included to introduce the reader to the biology and rationale for the use of costochondral grafts in growing patients.

Adolescent↗
PubMed1983

A comparison of the cardiovascular and orofacial blood flow changes resulting from hypotension induced by sodium nitroprusside and adenosine triphosphate in the rat.

These experiments compared the cardiovascular effects and the alterations in orofacial blood flow resulting from hypotension induced with sodium nitroprusside and adenosine triphosphate infusions in 30 male rats. The authors found that sodium nitroprusside did not significantly change heart rate or cardiac output, while adenosine triphosphate caused a significant decrease in heart rate associated with a small increase in cardiac output. Both hypotensive agents produced similar profound decreases in total peripheral resistance. Blood flows to orofacial structures were qualitatively similar with both agents. Both adenosine triphosphate and sodium nitroprusside caused decreased flows to the maxilla and mandible. Sodium nitroprusside increased flows to masseter and suprahyoid muscles. Adenosine triphosphate caused increased flows to suprahyoid muscles but masseter muscle flows were not significantly changed. Tongue flows responded similarly to both agents, initially decreasing, then returning to normotensive levels. Finally, sodium nitroprusside-induced hypotension was associated with the development of tachyphylaxis in some animals, whereas no similar problem was observed with use of adenosine triphosphate. The demonstration of reduced blood flows to orofacial bony structures and the absence of resistance or tachyphylaxis during adenosine triphosphate-induced hypotension support its usefulness as a hypotensive agent during orthognathic and other surgery.

Adenosine Triphosphate↗
PubMed1982

Mandibular movement during autorotation as a result of maxillary impaction surgery.

With increasing use of maxillary surgery to reduce vertical dimension, it would be appropriate to evaluate methods of predicting autorotation of the mandible. Experimental data derived from edentulous patients using metallic implants embedded in occlusal wax rims matched geometrically analyzed clinical data accumulated from twenty-three patients treated by maxillary impaction procedures. The center of rotation of mandibular autorotation during maxillary surgical impaction has been represented in the literature as the center of the condyle. Our evidence with lateral head films taken in centric occlusion supports a different instantaneous center of rotation located within the mastoid region. Modification of prediction tracing techniques by orthodontists and oral surgeons engaged in maxillary surgery could be indicated.

Cephalometry↗
PubMed1982

The image intensifier in oral and maxillofacial surgery.

The mobile image intensifier has been found useful in the removal of foreign bodies from both intraoral and extraoral sites. The safety of the machine has been verified, and a technique for its application is described. Additional uses for the machine are stated.

Adult↗
PubMed1982

Blood flow to oral tissues: and experimental study with enflurane, sodium nitroprusside, and nitroglycerin.

Hypotensive anesthesia is currently being used in oral and maxillofacial surgery to reduce blood loss and provide a relatively bloodless surgical field. Radioactively labeled microspheres were used to determine and compare the hemodynamic effects of sodium nitroprusside (SNP), nitroglycerin (NTG), and deep enflurane anesthesia on oral tissues during controlled hypotension when compared with controls. Sodium nitroprusside and NTG produced significant reductions in blood flow to the maxilla, mandible, and tongue, while deep enflurane anesthesia did not. In the masseter and suprahyoid muscles, increases in tissue blood flow were found with SNP and enflurane. Nitroglycerin produced no significant change in blood flow in the masseter and the suprahyoid. These results demonstrate that in spite of a similar cardiac index with all agents tested, local oral blood flow varied significantly with the different agents tested. These differences in tissue blood flow suggest that SNP and NTG may be preferable to deep enflurane anesthesia for maxillary osteotomies to achieve greater flow reduction and diminish blood loss.

Anesthesia, Inhalation↗
PubMed1977

Cranial dislocation of mandibular condyle.

The ninth case of condylar dislocation into the middle cranial fossa is reported. The previously reported cases are reviewed and the clinical findings which they have in common are pointed out. Because difficulty in establishing the diagnosis seems to be the most serious aspect of this clinical entity, it is advised that films of the temporomandibular joint be taken more frequently. Finally, although treatment varied from physical therapy to intracranial condylectomy, our case of closed withdrawal of the condyle from the cranial fossa is the first case on record so treated.

Adolescent↗
PubMedDate not supplied

Regional vascular changes during hypotensive anesthesia.

The regional vascular effects of three different hypotensive drug treatments were compared in enflurane anesthetized rats. Controlled hypotension was induced with sodium nitroprusside (SNP), nitroglycerin (NTG),and deep enflurane anesthesia. Regional blood flow was measured during each hypotensive treatment using radioactive microspheres. All hypotensive treatments were compared with control rats, anesthetized with 2% inspired enflurane anesthesia. Results indicate that when the mean blood pressure was decreased from 124 to 70 torr with all three hypotensive treatments regionally specific blood flow changes occurred. These ranged from approximately 50% decreases seen in skin blood flow with all hypotensive drugs to 50-90% increases in flow in muscle and spleen tissues. When regional vascular resistance changes were compared between hypotensive drug treatments, SNP produced significantly less cerebrovasodilation than either NTG or deep enflurane. Deep enflurane induced hypotension resulted in significantly greater decreases in intestinal vascular resistance than either SNP or NTG. These results indicate that hypotensive anesthesia with SNP, NTG, or deep enflurane shift blood flow away from skin and toward skeletal muscle and spleen tissues. Blood flow in other tissues is relatively well maintained.

Anesthesia↗