The aim of this study was to evaluate the effect of hyperbaric oxygen therapy (HBOT) on microvascular tissue and cell proliferation in the oral mucosa. Twenty patients, aged 51-78 years, were allocated randomly to a treatment or a control group. All had a history of radiotherapy (50-70 Gy) to the orofacial region 2-6 years previously. Tissue samples were taken from the irradiated buccal oral mucosa before HBOT and at 6 months after treatment. In the control group, tissue samples were taken on two occasions, 6 months apart. The samples were subjected to immunohistochemistry staining: double staining with CD31 and D2-40 for microvessels, or Ki-67 for the analysis of cell proliferation. Blood vessel density and area were significantly increased after HBOT (P = 0.002-0.041). D2-40-positive lymphatic vessels were significantly increased in number and area in the sub-epithelial area (P = 0.002 and P = 0.019, respectively). No significant differences were observed in the control group. There were no significant differences in Ki-67-expressing epithelial cells between the two groups. It is concluded that the density and area of blood and lymphatic vessels in the irradiated mucosa are increased by HBOT 6 months after therapy. Epithelial cell proliferation is not affected by HBOT.

The aim of this study was to evaluate the effect of hyperbaric oxygen therapy (HBOT) on vascular function and tissue oxygenation in irradiated facial skin and gingival mucosa. Twenty-two patients, aged 51-90 years, were randomly allocated to a treatment or control group. All had a history of radiotherapy (50 70 Gy) to the orofacial region 2-20 years previously. Skin and mucosal perfusion were recorded with laser Doppler flowmetry (LDF). Tissue oxygenation was recorded by transcutaneous oximetry (TcPO2). Measurements were taken before HBOT and 3 and 6 months after a mean of 28 HBOT sessions (partial pressure of oxygen of 240 kPa for 90 min). For control subjects, measurements were taken on two occasions 6 months apart. After HBOT, blood flow in mucosa and skin after heat provocation increased significantly (P < 0.05). TcPO2 increased significantly in the irradiated cheek (P < 0.05), but not at reference points outside the field of radiation. There were no differences between the 3- and 6-month follow-ups. In the control group, no significant changes in LDF or TcPO2 were observed. It is concluded that oxygenation and vascular capacity in irradiated facial skin and gingival mucosa are increased by HBOT. The effects persist for at least 6 months.

Hyperbaric oxygen (HBO) therapy is used to treat or prevent tissue necrosis in patients undergoing irradiation. Many such patients require reconstructive surgery, but little is known of the effects of HBO on bone vascularization and regeneration. In this study, copolymer poly(l-lactide-co-1,5-dioxepan-2-one) (poly(LLA-co-DXO)) scaffolds were implanted into critical-sized calvarial defects in Wistar rats. The animals were randomly allotted to hyperbaric or normobaric oxygen groups. The treatment group received five sessions weekly for 90min at increased atmospheric pressure, for up to 4 weeks. Samples were retrieved at weeks 2 and 8, i.e. after a total of 10 and 20 sessions, respectively. The samples were analyzed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) and histology at week 2, and radiographically and histologically at week 8. At week 2, defects treated with HBO exhibited greater numbers of cells positive for the endothelial marker CD31, up-regulated gene expression of osteogenic markers, and down-regulated expression of pro-inflammatory cytokines. At week 8, radiographic examination revealed that calvarial defects subjected to HBO exhibited a higher percentage of radiopacities than normobaric controls, and histological examination disclosed enhanced bone healing. These results confirmed that HBO treatment was effective in stimulating vascularization and bone formation in rat calvarial defects.

Laser Doppler flowmetry (LDF) and transcutaneous oximetry (TcPO2) are non-invasive techniques, widely used in the clinical setting, for assessing microvascular blood flow and tissue oxygen tension, e.g. recording vascular changes after radiotherapy and hyperbaric oxygen therapy. With standardized procedures and improved reproducibility, these methods might also be applicable in longitudinal studies. The aim of this study was to evaluate the reproducibility of facial skin and gingival LDF and facial skin TcPO2. The subjects comprised ten healthy volunteers, 5 men, aged 31-68 years. Gingival perfusion was recorded with the LDF probe fixed to a custom made, tooth-supported acrylic splint. Skin perfusion was recorded on the cheek. TcPO2 was recorded on the forehead and cheek and in the second intercostal space. The reproducibility of LDF measurements taken after vasodilation by heat provocation was greater than for basal flow in both facial skin and mandibular gingiva. Pronounced intraday variations were observed. Interweek reproducibility assessed by intraclass correlation coefficient ranged from 0.74 to 0.96 for LDF and from 0.44 to 0.75 for TcPO2. The results confirm acceptable reproducibility of LDF and TcPO2 in longitudinal studies in a vascular laboratory where subjects serve as their own controls. The use of thermoprobes is recommended. Repeat measurements should be taken at the same time of day.

Background and Objectives: Appropriate scaffold and stimulation of angiogenesis will enhance success of bone regeneration. This study was aimed to develop novel copolymer scaffold and investigate effects of endothelial cells (ECs) on osteogenic cells cultured into three-dimensional (3D) scaffolds.

A patient presented with an intraoral red, painful, and hard swelling in the lower right jaw. Radiographs showed a 2 × 1 cm area of radiopaque material surrounding the apex of the second premolar. The material, according to the patient's dentist, was calcium hydroxide paste used as a temporary dressing material in the root canal. The patient developed paraesthesia in her lower lip probably due to a neurotoxic effect caused by calcium hydroxide. The foreign material was surgically excavated from the spongious bone, directly adjacent to the nerve, and the patient later regained her sensation in the lip. A histopathological analysis revealed necrosis, deposits of foreign bodies, and inflammatory cells and foreign-body giant cells. This report illustrates the toxicity and adjacent clinical symptoms of calcium hydroxide paste when displaced into bone tissue close to the alveolar inferior nerve. It also demonstrates the benefits of removing such displaced material before symptoms progress.

BACKGROUND:In patients in whom the height of the alveolar process is adequate but the crest is too narrow to host an implant, lateral augmentation is required. Such augmentations have mostly been performed using autogenous bone blocks secured to the buccal surface. An alternative to autogenous bone may be bovine hydroxyapatite (Bio-Oss, Geistlich Pharma AG, Wolhusen, Switzerland) or other bone substitutes.PURPOSE:The aim of this study was to evaluate the clinical and radiographic outcome of dental implants inserted after lateral augmentation of too narrow alveolar processes with a combination of bovine hydroxyapatite (Bio-Oss) and autogenous bone.METHODS:Thirty patients (14 males and 16 females) with a mean age of 41.6 years fulfilled the inclusion criteria. Twenty-nine augmentation sites with a total of 74 implants could be followed for 3 years.RESULTS:Three implants were lost; these were lost before loading (at the abutment operation). The survival rate was 95.9%. The mean marginal bone loss during the 3-year observation period was 0.3 +/- 0.2 mm.CONCLUSIONS:A 50/50 combination of Bio-Oss and autogenous bone chips stabilized with Tisseel (Baxter AG/Duo Quick AG, Vienna, Austria) was useful for lateral augmentation of the alveolar crest. Lateral grafts with Bio-Oss, autogenous bone, and Tisseel made it possible to achieve good implant stability and high implant survival results. The bone level changes adjacent to the implants were the same as in nongrafted cases.

BACKGROUND Although most implant systems have been designed for a two-stage surgical technique, a one-stage surgical technique has always been advocated for the ITI Dental Implant System (Straumann AG, Waldenburg, Switzerland). A new generation of ITI implants was presented in 1988 and included a hollow cylinder, a hollow screw, and a solid screw. PURPOSE The goal of this study was to evaluate the one-stage surgical technique in connection with the ITI hollow screw in a longitudinal study over 5 years. MATERIALS AND METHODS Forty-six patients with edentulous lower jaws were supplied with ITI hollow-screw implants. Patients who requested an overdenture (n = 18) had four implants inserted; those who requested a fixed bridge (n = 28) had five to six implants. The patients have been followed annually for 5 years. There was a dropout of three patients (6.5%); one patient did not want to cooperate, one moved from the area, and one was deceased. The clinical examinations included bridge removal for evaluation of the individual implant stability in connection with the 1-, 3-, and 5-year examinations. Radiographic examinations were performed with intraoral radiographs and the long-cone technique. RESULTS The survival rate after 5 years was 95.7%. The success rate (in which implants undergoing treatment of peri-implantitis were not counted as successes) was 91.4%. The mean marginal bone loss between the baseline and the 1-year examination was 0.1 mm and between the 1- and 5-year examinations was 0.1 mm. These changes in marginal bone level were not significant. CONCLUSIONS The success rate of ITI hollow-screw implants in the edentulous mandible was 91.4% after a 5-year observation period. There was no significant change in mean bone level between the loading of the implants and the 5-year examination. Peri-implantitis was diagnosed in three patients with poor oral hygiene, and it affected six implants. Five of these failed in spite of treatment.

Clinical Otolaryngology & Allied SciencesVolume 25, Issue 1 p. 84-85 Outcome of HBO-treatment of osteoradionecrosis in irradiated patients: a prospective study H.C. Sylvester-jensen, H.C. Sylvester-jensen (Departments of Oral and Maxillo-Facial Surgery andSearch for more papers by this authorO.C. Hansen, O.C. Hansen (Departments of Oral and Maxillo-Facial Surgery andSearch for more papers by this authorJ. Olofsson, J. Olofsson (Departments of Oral and Maxillo-Facial Surgery andSearch for more papers by this authorS. Hellem, S. Hellem (Departments of Oral and Maxillo-Facial Surgery andSearch for more papers by this author H.C. Sylvester-jensen, H.C. Sylvester-jensen (Departments of Oral and Maxillo-Facial Surgery andSearch for more papers by this authorO.C. Hansen, O.C. Hansen (Departments of Oral and Maxillo-Facial Surgery andSearch for more papers by this authorJ. Olofsson, J. Olofsson (Departments of Oral and Maxillo-Facial Surgery andSearch for more papers by this authorS. Hellem, S. Hellem (Departments of Oral and Maxillo-Facial Surgery andSearch for more papers by this author First published: 10 August 2009 https://doi.org/10.1046/j.1365-2273.2000.00329-20.xRead the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume25, Issue1February 2000Pages 84-85 RelatedInformation

BACKGROUND:A new generation of ITI implants, including a hollow cylinder, a hollow screw, and a solid screw, was described in 1988. Currently, the solid screw is the main alternative.PURPOSE:The aim of this study was to gain further clinical documentation of ITI solid-screw implants used in the edentulous upper jaw. This is a report 1 year after loading.MATERIALS AND METHODS:Twenty-eight patients with edentulous upper jaws (mean age, 57 yr) were supplied with four to eight ITI solid-screw implants in the upper jaw. In total, 167 implants (3.3 and 4.1 mm in diameter) were inserted. The implants were loaded about 7 months postoperatively. All patients were supplied with fixed screw-retained bridges.RESULTS:Twelve implants failed: 10 prior to loading and 2 after. Overall implant survival rate was 92.8%. Three of the five patients with implant loss were smokers. Signs of peri-implantitis were found in seven patients, affecting 12 implants. Mean marginal bone level at the loading of the implants (7 months after insertion) was situated 4.7 mm from the reference point of the implant. There was no significant change between loading and the 1-year examination. However, at several implants, the bone level at baseline was situated far apical of the reference point, indicating a bone loss before loading.CONCLUSIONS:The ITI screw implants, used in the edentulous upper jaw, had a survival rate of 92.8%. Mean bone loss between loading and the 1-year examination was 0.1 mm. Some implants had a bone level indicating a significant bone loss before loading. Peri-implantitis was found at about 7.2% of the implants inserted and at 25% of the failing implants.

A new design for bone implants, the bottle brush, was recently presented in a pilot study on marrow cavities in the femur of rabbits. In this study, the concept is further evaluated on a mini bottle brush. The fixture, 5 x 7 mm, with an implant shaft made of CP-titanium and bristles of nylon coated with sputtered titanium, was inserted into the cancellous bone of the medial femoral condyle in 15 adult rabbits. The titanium fixture was compared with a similar brush without the titanium sputtered surface. The animals were sacrificed after 4 months and the quantity and quality of bone integration were evaluated with pull-out tests and histological examination. In both parameters, the values were significantly higher for the titanium-sputtered brushes, with removal forces similar to titanium cylinders of the same size and with a bone-to-metal contact area of about 50%.

Non-submerged ITI Bonefit implants (ITI Dental Implant System) were inserted in edentulous lower jaws of 46 patients. The patients were provided with either a fixed prosthesis or an overdenture, and has been followed during a 2-year-period. At the 1-year examination, the suprastructures were removed permitting test of the individual implant stability. Radiographic examinations were performed in connection with the loading of the implants and at the 1-year examination. In total 216 implants were inserted. 4 implants were lost before loading and 4 during the 2nd year of function, which gives a survival rate after 1 year 98% and after 2 years of 96%. The mean marginal bone loss during the first year of function was 0.1 mm. However, the marginal bone changes had a high degree of variation and four implants showed a severe bone loss. The intention is to follow this patient group with annual examinations during 5 years.

Laser Doppler Flowmetry was developed and evaluated mainly for measuring blood flow in exposed or superficial tissue layers like skin. Results showed large variation coefficients between juxtaposed skin sites with apparently homogeneous blood perfusion. Spatial differences in blood flow as well as anatomical differences probably explain the obtained results. Vasomotion, hereto only discovered with a microscopic technique, was recorded and evaluated for the first time. Similar results had been obtained in previous bone perfusion studies. The LDF technique has also been used extensively for skin irritancy tests and microvascular effects of vasoactive substances and drugs. An in vivo model in calibrating LDF quantitatively showed a linear relationship between LDF output signal and total blood flow in the range 0-300 ml min-1 100 g-1. This quantitative calibration is however tissue specific. Most tissues of interest are not superficial. The single fibre LDF provides additional power in studying deep tissue physiology and trauma-induced changes in regulation of microvascular perfusion. Furthermore long-term studies require implantable and biocompatible probes and this could be fulfilled using the SFLDF technique in combination with a tissue-integrated titanium probe. Implantation of the titanium probes initially creates some trauma to the vascular bed in the bone marrow but almost none in the opposite cortical bone layer. The healing process enhances the blood perfusion during the first weeks. The increased perfusion can be due to different parameters such as angiogenesis. The histological findings support this hypothesis. This gives preference to the tissue-integrated probe where interference with the tissue should be avoided. The integrated probe technique has only been evaluated in bone tissue. Modification of the probe shape and dimension, however, would make it suitable for other tissues as well.

Tyrosine kinase activity was studied in the crude cytosolic and particulate fraction of normal mucosa and squamous cell carcinomas of the upper aero-digestive tract. In the presence of exogenously added phosphorylation substrate (Glu,Tyr4:1), the cytosolic tyrosine kinase activity was 6-fold higher in tumors compared to normal mucosa (p = 0.001), and in the particulate fraction the increase was 8-fold in tumors compared to normal mucosa. Different proposed tyrosine kinase inhibitors, including genistein, quercetin and the alpha-cyanocinnamide ST 638, were tested for their ability to inhibit phosphorylation of the synthetic tyrosine phosphorylation substrate. Phosphorylation of Glu,Tyr4:1 in tumors (cytosolic fraction) was reduced to 77.8 +/- 8.7% of the control value by 10 microM ST 638 (p less than 0.05), and to 50.7 +/- 10.4% by 100 microM quercetin (p less than 0.01). In normal mucosa (cytosolic fraction) the corresponding values were 41.7 +/- 16.6% in the presence of 10 microM ST 638 (p less than 0.05) and 32.1 +/- 5.8% in the presence of 100 microM quercetin (p less than 0.05). These inhibitors had no effect on the tyrosine kinase activity in the particulate fractions. Phosphorylation of endogenous proteins in the crude cytosolic fraction was evaluated by SDS-polyacrylamide gel electrophoresis after alkali treatment of the gels. Autoradiography of the gels treated in this manner revealed bands corresponding to phosphorylated proteins with apparent molecular weight of 18, 23, 37-38, 42-44 (double band), 53-55 (double band), 61 and 92-94 (double band) kD. Quercetin (100 microM) markedly reduced the phosphorylation of these proteins, while no effect of ST 638 could be seen. Heparin (20 micrograms/ml) stimulated the phosphorylation of three proteins with apparent molecular weight of 39 and about 72 kD, respectively, and inhibited the phosphorylation of 2 proteins with molecular weight of 92 and 53 kD in tumors. These features were observed in both tumors and normal tissue, with the exception that heparin only stimulated the 72 kD band in normal mucosa and that the phosphorylation was markedly higher in tumors. In summary, our results show an increased tyrosine phosphorylation in squamous cell carcinomas of the upper aero-digestive tract compared to normal oral mucosa. These differences and their origin might be of vital importance in the regulation of events leading to malignant transformation.

Protein phosphorylation was studied in crude and in protein kinase C (Pk-C)-enriched preparations from squamous cell carcinomas and normal mucosa of the human upper aero-digestive tract. In crude soluble preparations from neoplastic mucosa we found a 5-fold higher basal endogenous phosphorylation when compared to normal mucosa. In particulate fractions the increase was 3-fold. SDS-PAGE and autoradiography of phosphorylated proteins in crude soluble tumor extracts showed bands corresponding to proteins with apparent molecular weights of 18, 37, 40-42, 52, 60, 62 and 90 kDa. In normal mucosa the phosphorylation of these proteins was very low or absent, except for the proteins with molecular weights of 40-42 and 52-55 kDa. Addition of Ca2+ or Ca2+/phospholipids to the reaction mixture caused phosphorylation of additional proteins with apparent molecular weight of 45-50 kDa in soluble preparations of tumors. Cyclic AMP or cGMP had no significant effect on the phosphorylation of endogenous proteins. In the partially purified, Pk-C-enriched fractions the phosphorylation in the presence of Ca2+/phospholipids was distinctly higher in tumors when compared to the phosphorylation observed in normal mucosa, and some phosphorylation substrates were detected only in tumor tissue. In order to find out whether the elevated basal phosphorylation was due to an endogenous activation of protein kinases, different inhibitors of serine/threonine protein kinases were tested. These inhibitors included: heat-stable cyclic AMP-dependent protein kinase (Pk-A) inhibitor, Pk-A inhibitor peptide (Wiptide), heparin and the Pk-C inhibitors peptide 19-36 and H-7. None of these inhibitors had any significant effect on the basal phosphorylation. In conclusion, our results show the existence of endogenous phosphorylation substrates in human squamous cell carcinomas from the upper aerodigestive tract, and indicates that there is a significantly higher basal and Pk-C specific phosphorylation of endogenous substrates in tumors compared to normal mucosa. This may be of importance for the transformation and altered growth regulation in epithelial tumors.

Clinical results are presented which have been obtained from mandibular reconstruction with the Titanium-coated Hollow Screw and Reconstruction-Plate system (THORP) in 7 selected patients. In 3 of the patients primary bone grafting was performed with simultaneous implantation of titanium fixtures for dental reconstruction.

The titanium-coated hollow screw and reconstruction plate system (THORP) was used in 7 selected patients; 3 of whom underwent simultaneous bone grafting and implantation of titanium fixtures for dental reconstruction.The advantages of the system with an excellent anchorage and no loosening of the screws, the possibility of lingual application of the plate and reconstruction with a three-dimensionally free adjustable condylar prosthesis, are well demonstrated in our series with an observation period up to 2 1/2 years

16 adults were treated by inferior repositioning of the maxilla. Miniaturized plates were used for stabilizing the jaw in its new position. No interpositional bone grafts were used but the osteotomy spaces were covered by strips of cancellous iliac bone. Healing was uncomplicated. Retrospective cephalometric study of the results of treatment showed a mean frontal vertical relapse of about 20% (range 0-100%). The relapse occurred during the early postoperative period. No linear correlation was found between the amount of vertical repositioning and the anterior vertical relapse. We consider that the mini-plate technique is more advantageous than previous methods.