U-shaped Osteotomy Around the Descending Palatine Artery to Prevent Posterior Osseous Interference for Superior/Posterior Repositioning of the Maxilla in Le Fort I Osteotomy.

In maxillary orthognathic surgery, superior repositioning of the maxilla is sometimes difficult, and removal of bony interference, especially around the descending palatine artery (DPA), is very time-consuming in cases of severe maxillary impaction. Posterior repositioning of the maxilla for removal of bony interference between the posterior maxilla and the pterygoid process is also technically difficult. Because the most common site of hemorrhage in Le Fort I osteotomy is the posterior maxilla, this bone removal is a source of frustration for surgeons in DPA injury. When the DPA is injured during bone removal and ligation is performed, aseptic necrosis of the maxilla may occur. Therefore, a simple and safe method for maxillary superior/posterior repositioning is required to remove osseous interference around the DPA. The authors describe here U-shaped osteotomy around the DPA to prevent posterior osseous interference for superior/posterior repositioning of the maxilla in Le Fort I osteotomy.

The acute effects of CMF-based chemotherapy on maxillary periodontal microcirculation.

PURPOSE: A high incidence of oral complications is associated with chemotherapy (CT) treatment in cancer patients; however, while knowledge into molecular mechanisms of their pathobiology continue to evolve, the direct physiological effects of CT on oral tissue perfusion remain unexplored. The aim of this investigation was to assess the acute effects of CT on gingival microcirculation perfusion by measuring gingival capillary density. METHODS: Twenty female specific-pathogen free New Zealand White rabbits were randomly divided into four groups receiving four different intravenous dose levels of cyclophosphamide, methotrexate, and fluorouracil (CMF). Noninvasive measurements of gingival capillary density were performed using sidestream dark-field (SDF) imaging prior to and 30 min after CT treatment. Four rabbits receiving saline solution were used as control animals. RESULTS: Baseline gingival capillary density was 58 +/- 11 cpll/mm(2), no significant differences in baseline capillary densities between the groups were found. From low to high dose CT, capillary density 30 min after CMF treatment increased in each group by 1 +/- 7, 5 +/- 7, 13 +/- 18 and 20 +/- 13 cpll/mm(2), respectively. Capillary density increase was significant in the high-dose group. No change in gingival capillary density was found in the control group. CONCLUSIONS: Periodontal microcirculation perfusion had increased 30 min after CT treatment as indicated by a rise in gingival capillary density. Our results support the idea that CT-induced microcirculatory response not only diligently delivers but also saturates peripheral oral tissues with antineoplastic agents by increasing surface area exposure. This functional response of the microcirculation to CT drugs may play a role in contribution to oral complications and the treatment of oral tumors.

Transarterial embolization of a high-flow maxillary arteriovenous malformation fed by multiple arteries.

A high-flow maxillary arteriovenous malformation fed by multiple arteries, including bilateral internal maxillary arteries and ophthalmic artery, is reported. A combination of polyvinyl alcohol particles and N-butyl-cyanoacrylate mixed with lipiodol was progressively deposited within the distal vascular bed by transarterial superselective embolization of the branches of bilateral internal maxillary arteries, resulting in complete anatomic and clinical cure. The authors feel that this approach is more secure and effective compared with transfemoral venous embolization and direct transosseous puncture. It also avoids mutilating surgery.

[Pharmacological and physiological specificities of local anesthesia in dentistry]. / Farmaco-fiziologicheskie osobennosti mestnogo obezbolivaniia v stomatologii.

Described in the paper are the specificity of local analgesia at the medical dental procedures and the effect produced by local anesthetics and vasoconstrictive agents on the induction of nervous fibers and peripheral blood circulation. The pharmacological-and-physiological mechanisms of local analgesia by a 2% artikain solution (with adrenalin, concentration 1:100,000) and by a 2% mepivakain solution (with adrenalin, concentration 1:100,000) exerted on the pain sensitivity and blood circulation in the tooth pulp are analyzed.

Orofacial neurogenic pain and maxillofacial ischemic osteonecrosis. A review.

Cavitary alveolar osteopathy was described as an oral disorder of infectious origin characterized by the presence of osteopathic alveolar cavity lesions of significant size though radiologically undetectable and secondary to dental extractions for chronic infectious processes of the alveolar bone of the jaws. Such cavitary alveolar osteopathy has been implicated as a common cause in the origin of idiopathic trigeminal neuralgia and atypical facial pain. The concept of cavitary alveolar osteopathy caused by ischemic necrosis of alveolar bone was introduced in 1992. Recent coagulation studies have reported ischemic alterations in alveolar bone marrow as a cause of cavitation; following tooth extraction, maxillary osteonecrosis could result from thrombosis with or without hyperfibrinolysis, which in turn would lead to obstruction of the vascular spaces -- thereby compromising regional blood flow.

The triangle of safety: a modified posterior superior alveolar injection technique based on the anatomy of the PSA artery.

The posterior superior alveolar (PSA) injection technique is commonly used to anesthetize soft and hard tissues of the posterior maxilla. As with all injections, complications arise, including hematoma formation secondary to needle-induced vascular trauma. In an attempt to develop a hemorrhage-free PSA injection technique, 361 infratemporal dissections were completed on human cadaver specimens. Three distribution patterns were identified for the external branch of the PSA artery. Regardless of distribution pattern, an anatomical Triangle of Safety was found superior to the maxillary second molar that was free of neurovascular tissues in more than 99% of individuals. Injection into this area appears to meet anesthetic needs while reducing the risk of hematoma formation. The combination of this anatomical triangle with newer anesthetic agents and computerized delivery systems holds promise for continued improvement of the PSA injection technique.

Clinical application of bone biology to mandibular and maxillary reconstruction.

Bony reconstruction of the mandible and maxilla is accomplished through the application of three general approaches: cancellous marrow grafts, cranial bone grafts, and microvascular transfers. This article discusses each of these techniques in detail.

[The long-term observation of alveolar bone blood flow during tooth movement with the aid of skeletal scintigraphy in an animal model]. / Langzeitbeobachtung der alveolären Knochendurchblutung während der Zahnbewegung mit Hilfe der Skelettszintigraphie im Tiermodell.

We observed in eleven dogs the blood flow in the alveolar bone during the tooth movement with the bone scintigraphy for one year. Additional we used for histological evaluation polychrome sequence marking and for improving of therapy electrostimulation. There is a correlation between tooth movement and blood flow. Four to six weeks after beginning tooth movement and blood circulation are reduced although the applied force was continuous all the time. This is an advice for stress interruption during treatment. Electrostimulation improves the conditions for tissue regeneration because the lifetime of osteoblasts is prolonged.

Transient diplopia from a posterior alveolar injection.

Several anatomical vascular pathways have been proposed to explain oculomotor disturbances observed after injection of local dental anesthetics. The author suggests another possible pathway to account for the unusual clinical observations described in this report.

Reflex vasoconstriction following dental injections.

Three case reports of transient facial blanching or vasoconstriction that followed administration of dental anesthetic are presented. A review of vasomotor cutaneous control is given, along with a proposal to explain this phenomenon.