Hyperbaric oxygen treatment did not significantly affect radiation injury in the mandibular area of rats.

OBJECTIVE: Hyperbaric oxygen therapy (HBOT) has been used to enhance microcirculation and thereby oxygen tension in tissues. The present study aimed to investigate the effect of HBOT on radiation injury in the mandibular area of rats. STUDY DESIGN: The left mandibles of rats were irradiated by external radiotherapy (15 Gy every other week for a total of 75 Gy). Four HBOT strategies were used: 2 prophylactic groups receiving HBOT either between each radiation treatment or immediately following terminated radiation treatment, and 2 therapeutic groups receiving HBOT after the latent period of 6 weeks after irradiation either every day (standard HBOT protocol) or 3 days a week for 6 weeks. Tissue samples of the irradiated area were taken from skin, the salivary gland, and the mandible. All tissues were stained with hematoxylin and eosin for morphologic examination. Furthermore, skin samples were stained with CD31 for blood vessel analysis. RESULTS: There was no change in blood vessel density or morphology between controls and HBOT tissues after radiation. The dentin of 2 of the 5 rats that received HBOT either normalized or was not affected by irradiation. CONCLUSIONS: HBOT did not affect radiation injury of the mandibular area in rats within 12 weeks after irradiation.

Morphological and morphometric study of the mental foramen on the M-CP-18 Jiachenjiang point / Estudio morfológico y morfométrico del foramen mental en el punto M-CP-18 Jiachenjiang

The purpose of this work was to study the morphology and morphometry of the mental foramen (MF), as well as to evaluate its morphological configuration; in addition to taking measures of its localization using as a parameter the distances of the foramen to the inferior border of the mandible and at the alveolar ridge. 80 dry mandibles were analyzed using the test of Qui-square and T test, with 5 percent of significance. Its average distance, on the right side, at the inferior edge of the mandible (IEM) was of 12.96( +/-1 .57) mm and of the alveolar ridge (AR) was of 12.82(+/-3.4) mm. On the left side it was found distant of IEM 12.96(+/-1.32) mm and of the AR 12.82(+/- 3.22)mm. The largest horizontal diameter found was of 3.32 (+/- 0.91) mm to the right and 3.25 (+/- 0.86) mm to the left side while the largest vertical diameter was of 2.38 (+/- 0.63) mm on the right and of 2.39 (+/- 0.58) mm on the left side. It was predominantly found in the oval form, on the right side, of which 98.3 percent presented as a larger diameter the horizontal (type I). On the left side, all the oval foramens were classified as of type I. 76 (95 percent) appeared single on both sides. As to the localization related to the mandibular dentition, it was localized in similar statistic proportions between the 1st and 2nd premolars and above the 2nd premolar, in 45.17 percent of the mandibles, on the right side. On the left side it was predominantly found between the 1st and 2nd premolars 48.48 percent of the mandibles. The study of the MF is of vital importance to the acupuncture practice, as well as to modern surgical procedures, like anesthesia, requiring a detailed and precise study of the morphology and morphometry of the area.

El objetivo de este trabajo fue estudiar la morfología y morfometría del foramen mentoniano (FM), así como evaluar su configuración morfológica; tomar las medidas de su localization usando como parámetro la distancia del foramen hacia el borde inferior de la mandíbula y el reborde alveolar. 80 mandíbulas secas se analizaron mediante la prueba de Chi-cuadrado y prueba t, con un 5 por ciento de significancia. Su distancia media, en el lado derecho, hasta el borde inferior de la mandíbula (BIM) fue de 12,96 (+/- 1,57) mm y del reborde alveolar (RA) fue de 12,82 (+/- 3,4) mm. En el lado izquierdo se encuentro una distancia del BIM de 12,96 (+/- 1,32) mm y del RA de 12,82 (+/- 3,22) mm. El mayor diámetro horizontal encontrado fue de 3,32 (+/- 0,91) mm a la derecha y 3,25 (+/- 0,86) mm a la izquierda, mientras que el mayor diámetro vertical fue de 2,38 (+/- 0,63) mm a la derecha y de 2,39 (+/- 0,58) mm en el lado izquierdo. Se encuentra principalmente en forma oval en el lado derecho, de los cuales 98,3 por ciento presenta un diámetro mayor horizontal (tipo I). En el lado izquierdo, todos los forámenes ovales fueron clasificados como de tipo I. 76 (95 por ciento) aparecieron solamente en ambos lados. En cuanto a la localization en relación con la dentición mandibular, fue localizado en la misma proporción estadística entre el 1er y 2d° premolar y por encima del 2ª premolar en el 45,17 por ciento de las mandíbulas en el lado derecho. En el lado izquierdo se encuentran principalmente entre los l ros y 2ros premolares en el 48,48 por ciento de las mandíbulas. El estudio del FM, es de vital importancia para la práctica de la acupuntura, así como para los modernos procedimientos quirúrgicos, como la anestesia, que requieren un estudio detallado y preciso de la morfología y morfometría de la zona.

Comparison of effects of vitamin E and wen-jing-tang (unkei-to), an herbal medicine, on peripheral blood flow in post-menopausal women with chilly sensation in the lower extremities: a randomized prospective study.

We examined the association between blood flow and chilly sensation in the lower extremities, comparing the changes in blood flow induced by the vitamin E and herbal therapy (Wen-jing-tang) in perimenopausal women with chilly sensation. One hundred sixty-one perimenopausal women aged 42-61 years (mean: 50.4 +/- 3.8 years) with chilly sensation in the lower extremities participated in the study. The participants were randomized for treatment with Wen-jing-tang or a vitamin E preparation containing 600 mg tocopherol nictinate per day for 8 weeks. Blood flow measurement was performed by laser Doppler fluxmetry to determine tissue under the jaw, in the middle finger, and in the third toe. Wen-jing-tang significantly increased the peripheral blood flow in the skin surface in the tiptoe (12.8 +/- 8.8, p = 0.0068) from basal levels (6.0 +/- 5.1), although no significant change was observed in the blood flow in fingertip or under the jaw during treatment. The rate of increase of blood flow in the skin surface of in the lower extremities was significantly higher in the Wen-jing-tang treating group (116.4 +/- 46.5%) than in the vitamin E group (39.8 +/- 21.3%) (p < 0.0001). When the effects of herbal treatment and vitamin E treatment were compared in the subjects with baseline upper extremity blood flow above the mean + 1.5 SD, mean blood flow through the upper extremities was found to have been significantly decreased after Wen-jing-tang treatment (from 57.7 +/- 4.8 to 43.1 +/- 4.2, p = 0.0277), whereas it remained unchanged after treatment with vitamin E. Classical monographs described Wen-jing-tang as being particularly useful in curing chilly sensation in lower extremities. The present study using a laser Doppler fluxmeter demonstrated that treatment with this herbal medicine significantly increased blood flow through the periphery of lower extremities in patients with chilly sensation. It also showed that this herbal medicine suppresses excessive blood flow through the upper half of the body and thus stimulates restoration of physiological distribution of blood flow throughout the entire body.

Effects of selenium on the structure of the mandible in experimental diabetics.

In the treatment of diabetes-induced pathologies, beneficial results have been obtained with administration of antioxidants. Selenium is an antioxidant and essential trace element in living organisms. The aim of this study was to investigate the possible effects of selenium on the structural alterations of the mandible due to diabetes. In this study thirty-nine Wistar rats were used and a control, a selenium given control, a diabetic and a selenium given diabetes groups were formed. Experimental diabetes was induced by a single i.p. injection (50 mg/kg) of streptozotocin (STZ). The diabetic + selenium and the control + selenium groups were injected with a daily dose of 5 micro mol/kg/day sodium selenite (i.p.) for 4 weeks while the diabetic and the control groups were injected with distilled water. Mandibles of all the animals were excised and examined at the 5th week. High blood glucose level and low body weight in the diabetic group were not significantly affected by selenium administration. Furthermore, a negligible increase in blood glucose level was observed in the selenium given control group. Densitometric analysis revealed a significant reduction in bone density and presence of resorption in the diabetic and the selenium given control groups as compared to the selenium given diabetes and the control groups. In X-ray diffraction analysis, the reduction in peak intensity of the reflected light in both the diabetic and the selenium given control groups indicated a possible alteration in the crystallinity or a poor crystalline substance. Histological investigation showed that there was progressive resorption, trabecular and cortical irregularity and vascular proliferation in the diabetic and the selenium given control groups, whereas a more healthy appearance was detected in the selenium given diabetes group. The results of this study suggest the positive effects of selenium on diabetes-induced structural alterations in the mandible. However, the unexpected results in the selenium given control group necessitate further studies on the mechanism of selenium effects in organisms.

Arteriovenous malformation of the mandible: review of literature and case history.

Vascular malformations of the jaws can lead to disastrous complications, but there seems to be no consensus as to their treatment. The literature presents the pathophysiology and clinical aspects of these lesions, as well as the divergent views of the authors. Treatment by catheterization and embolization, with direct transosseous injection of cyanoacrylate, appears to be the least harmful and most permanent treatment in certain conditions, as evidenced by the case of this 9-year-old patient having a high-flow mandibular vascular malformation

Osteoradionecrosis of the mandible: a microradiographic study of cortical bone.

We undertook a microradiographic study in osteoradionecrotic mandibular bone to estimate the number of vascular channels in the compact bone, number of resorption areas, and number of regeneration areas. Normal mandibles had a similar number of vascular channels/vision field compared with compact bone in other parts of the body. Irradiation itself did not significantly alter this number. After osteoradionecrosis had developed in the mandible, the number of vascular channels increased (p = 0.02). Treatment with hyperbaric oxygen further increased the number of vascular channels/vision field (p < 0.003). The normal mandible had no resorptive or regenerative areas, either before or after radiotherapy. The osteoradionecrotic mandible, however, had an increased number of resorptive as well as regenerative areas/vision field. Fluorescence as an indication of incorporation of tetracycline was seen in the regenerative areas of all osteoradionecrotic specimens treated with doxycycline. The process started from the vascular channels, periosteum, and endosteum. We conclude that the compact bone of mandibular osteoradionecrosis has high metabolic activity with active resorption and regeneration of bone and the limitation of the blood supply through cortical vascular channels, seems to be only one of many important factors.

Arteriovenous malformations of the dental arcades. The place of endovascular therapy: results in 12 cases are presented.

Twelve arteriovenous malformations of the dental arcades (AVMDAs) (seven mandibular and five maxillary) were seen in our institution between 1977 and 1997. All these lesions consisted of true arteriovenous shunts (of either nidus or fistulous type) involving the bone, with or without soft tissue extension. Haemorrhage was present in eight patients (67%); either torrential, necessitating emergency embolization, or recurrent and progressive. Teeth instability was detected in all patients and was the origin of the bleeding. All lesions were embolized. Lesions in nine patients were embolized with Polyvinyl Alcohol Particles (PVA): this helped to stabilize the situation but could not avoid recurrences in all patients, necessitating complementary embolizations and or surgery. The use of acrylic glue (N-Butyl-Cyano-Acrylate [NBCA] Histoacryl) as the embolic agent has changed the results obtained tremendously. Eight patients have been treated with NBCA (five as complementary therapy to PVA during later sessions and three at the first attempt); injection either via the transarterial route or direct transcutaneous puncture (four patients) achieved a cure in four of these lesions (34%) with stability at long-term follow-up of all the other AVMs. Embolization with glue represents the therapy of choice in these sometimes life-threatening lesions, achieving a cure if directed towards the osseous venous lakes. Surgery, often leading to facial mutilation and necessitating massive reconstruction should be avoided nowadays, at least as the initial therapy.

Titanium osseointegrated implants combined with hyperbaric oxygen therapy in previously irradiated mandibles.

STATEMENT OF PROBLEM: Treatment for head and neck malignancies commonly involves radiation therapy. As a result of this therapy the vascular supply to irradiated structures is altered and results in decreased tissue perfusion. In addition to vascular changes, bony structures undergo a reduction in osteoblastic and osteoclastic activity. These tissue alterations, especially in the mandible, enhance the risk of osteoradionecrosis. To avoid this occurrence, many patients who have undergone radiation therapy do not receive elective preprosthetic surgeries, including implant therapy. PURPOSE OF STUDY AND METHODS: This report presents the preliminary results of placing 18 titanium screw implants into previously irradiated mandibles in conjunction with hyperbaric oxygen therapy. RESULTS: Of the 18 implants placed, 17 (94%) were judged to be osseointegrated at the abutment connection. One implant did not receive an abutment and was "put to sleep." The remaining 16 (88%) were used for prosthetic rehabilitation. CONCLUSION: The use of implants in irradiated tissues may provide a means of enhancing prosthetic rehabilitation while reducing the risk of tissue trauma that may develop into osteoradionecrosis.

Assessment of bone formation during osteoneogenesis: a canine model.

Distraction osteoneogenesis, callotasis, has been demonstrated to be an effective means of lengthening long bones. A variation of Ilizarov's technique produces a transport disk from one cut surface of bone within a defect and advances the disk to the opposite surface to close the defect. This process, previously described by Costantino et al. (Arch Otolaryngol Head Neck Surg 1990; 116:535-45), demonstrated bone formation within the distraction site. The precise mechanism of bone formation has not yet been described for the mandible. Four conditioned beagles were studied, with one control dog maintained in neutral fixation and three dogs distracted at 0.25 mm every 8 hours. A two-cm defect was closed, and dogs were kept in fixation for 1 week after closure, after which they were killed. Three sites were evaluated: (1) the distraction seam, (2) the interface of the cortical and distracted bone, and (3) the cortexes at the closed defect. Each site was bisected, and one half was decalcified for immunohistochemical and hematoxylin and eosin pathologic evaluation. The vascular basement membrane was labeled for laminin and type IV collagen. Both of these substances demonstrate the differentiation of the vascular matrix component predisposing primary bone formation. Labels were intense at the distraction seam where intense angiogenesis occurred. No hyalin cartilage was observed at the distraction site, which indicates that the fixation was stable and that ossification occurred primarily without intermediate callous formation. This model demonstrated that osteoclasts within the canine model produce bone through primary bone formation within an angiogenic matrix rich in basement membrane laminin and type IV collagen. Likewise, bone is species specific in mineral composition for dog mandible. Understanding the formation and composition of distracted bone is essential for understanding application of this technique within the clinical setting.

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 comparative efficacy of different physiotherapy combinations in treating mandibular fractures]. / Sravnitel'naia éffektivnost' razlichnykh kompleksov fizioterapii v lechenii perelomov nizhnei cheliusti.

The authors compare the efficacy of IR laser, a combination of magnetic laser radiation and UHF electric field followed dy calcium chloride electrophoresis on the course of mandibular fracture healing. With this purpose 114 patients with uni- and bilateral mandibular fractures were examined and administered a course of preventive treatment. Analysis of the clinical data, subjective sensations of the injured subjects, and data of functional diagnostic methods (rheography, polarography, echo-osteometry) brought the authors to a conclusion on a positive effect ot IR laser and, more so, of magnetic laser therapy on the recovery of regional hemodynamics and oxygen homeostasis of tissues at the site of injury, this being conducive to reduction of pyoinflammatory complications and a sooner rehabilitation of the patients. These results recommend IR laser combined with magnetic field exposure for multiple-modality treatment of patients with mandibular fractures, particularly for those with marked dislocation of bone fragments and regional blood flow disturbances.

[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.

[The use of vibrotherapy to prevent suppurative-inflammatory complications in mandibular fractures]. / Primenenie vibroterapii s tsel'iu profilaktiki gnoino-vospalitel'nykh oslozhnenii perelomov nizhnei cheliusti.

Patients with uni- and bilateral traumatic fractures of the mandible at risk for pyoinflammatory complications were subjected to vibration massage at frequencies identical to those of cardiovascular system. Rheographic evaluation of the blood flow showed vibration-related normalization of the regional circulation at the lesion which went faster and reached the values on the healthy side on day 14. In controls similar improvement took place only in 58% of cases. The results suggest that vibration massage at cardiovascular frequencies can effectively prevent pyoinflammatory complications in the mandible fractures.

Effects of dextrans, heparin and hyperbaric oxygen on mandibular tissue damage after osteotomy in an experimental system.

The effect of heparin, dextran 40, dextran 70 and hyperbaric oxygen (HBO) therapy to reduce tissue damage after mandibular osteotomy was tested in an experimental system. Tissue damage was recorded morphologically and blood flow and vascular bed was determined by isotope techniques. Subcutaneously administered heparin reduced morphologically determined tissue damage in the incisor odontoblastoma, pulp and ameloblastoma. Furthermore, central and peripheral bone damage was prevented by heparin. Dextrans had no preventive effect on tissue damage. HBO treatment reduced tissue damage in a similar manner to heparin but also induced reparative events as osteodentin formation in pulps and chondroid reactions in bone. Effects on blood flow and vascular bed provided a basis for a possible role for HBO and heparin treatment in tissue damage after osteotomy.

Microsurgical correction of the injured inferior alveolar nerve.

The pathology of inferior alveolar nerve injuries is discussed and the general and special guidelines for microsurgical reconstructive procedures are presented. Twenty-three cases are summarized: 22 cases showed marked restoration of nerve function after surgery.

Mandibular anesthesia and tooth extraction in the bottlenosed dolphin.

Anatomical dissections were done to show the innervation of the teeth and mandible of the bottlenosed dolphin (Turslops truncatus). Using structural landmarks, a method has been devised for anesthetizing the lower jaw. With this procedure teeth can be extracted and age determined by counting dentine layers in sections of etched teeth. Animals of the most desirable ages can thus be selected and the ages of animals already in captivity can be determined.