Influence of alcohol consumption on alveolar bone level associated with ligature-induced periodontitis in rats

Alcohol consumption is a risk indicator for periodontal disease. The purpose of this study was to morphometrically evaluate the influence of alcohol consumption on alveolar bone level associated with ligature-induced periodontitis in rats. Thirty-six female rats (Wistar, 120 days-old) were randomly divided into three groups that received a daily administration of a water diet (control, n = 12), a 10% alcohol diet (10% ethanol, n = 12) or a 20% alcohol diet (20% ethanol, n = 12). Four weeks after the onset of the experiment, cotton ligatures were placed around the cervix of the upper right second molar in six rats. The other 6 rats in each group remained unligated. The rats were sacrificed four weeks after ligature placement. The maxillary bones were removed and alveolar bone loss was analyzed by measuring the distance between the cementoenamel junction and the alveolar bone crest at 2 buccal and 2 palatal sites on the upper right second molar. Analyses between the ligated and unligated groups showed that the presence of ligature induced alveolar bone loss (p < 0.05). Unligated groups showed no significant differences between each other (p > 0.05). In the ligated groups, rats receiving 20% ethanol showed significantly greater bone loss compared to control rats or rats receiving 10% ethanol. These results demonstrate that alcohol consumption may increase alveolar bone loss in female rats in a dosedependent manner.

Influence of implant positioning in extraction sockets on osseointegration: Histomorphometric analyses in dogs

Aim: To evaluate the influence of implant positioning into extraction sockets on osseointegration. Material and methods: Implants were installed immediately into extraction sockets in the mandibles of six Labrador dogs. In the control sites, the implants were positioned in the center of the alveolus, while in the test sites, the implants were positioned 0.8 mm deeper and more lingually. After 4 months of healing, the resorptive patterns of the alveolar crest were evaluated histomorphometrically. Results: All implants were integrated in mineralized bone, mainly composed of mature lamellar bone. The alveolar crest underwent resorption at the control as well as at the test sites. After 4 months of healing, at the buccal aspects of the control and test sites, the location of the implant rough/smooth limit to the alveolar crest was 2±0.9 mm and 0.6±0.9 mm, respectively (P<0.05). At the lingual aspect, the bony crest was located 0.4 mm apically and 0.2 mm coronally to the implant rough/smooth limit at the control and test sites, respectively (NS). Conclusions: From a clinical point of view, implants installed into extraction sockets should be positioned approximately 1 mm deeper than the level of the buccal alveolar crest and in a lingual position in relation to the center of the alveolus in order to reduce or eliminate the exposure above the alveolar crest of the endosseous (rough) portion of the implant. © 2009 John Wiley & Sons A/S.

Utilization of surgical trepan for the obtainment of calvarial autogenous bone graft in maxillary reconstructions

Maxillomandibular reconstructions are traditionally performed by means of autogenous bone grafts collected from intraoral donor areas and extraoral donor areas such as clavicle, iliac bone, rib, and tibia. The calvarial bone has been studied as an alternative donor area, with a low incidence of complications and minimal postoperative morbidity. Complications such as dural lacerations associated with cerebrospinal fluid leakage and extradural and subdural bleeding were minimized due to the use of surgical trepan, allowing the diploic layer delimitation before the osteotomy, preserving the internal calvarial cortical. The purpose of this article is to suggest a new technique for the obtainment of calvarial bone grafts with surgical trepan.

SED-brachydactyly and distinctive speech: Report of a new familial case

Background: Spondyloepiphyseal dysplasia-brachydactyly and distinctive speech (SED-BDS) is a syndrome characterized by short stature, disproportionately short limbs, peculiar face, thick and abundant hair, high-pitched and coarse voice, small epiphyses, brachymetacarpalia, brachymetatarsalia and brachy-phalangia of fingers and toes, small pelvis and delayed carpal bone age, among other features. Case Report: We report a Brazilian patient with father, brother and sister presenting with the same typical features of the syndrome. Clinically, he showed disproportionately short stature, rhizo-meso-acromelic shortness of the extremities, short hands and feet, a peculiar distinctive high-pitched voice, peculiar facies, and other features already reported as characteristic of this syndrome. Radiographic fndings included shape anomalies of the vertebral bodies such as cuboid-shaped vertebral bodies, mild scoliosis, short and broad tubular bones, brachymetacarpalia, brachymetatarsalia, and brachy-dactyly, lumbar hyperlordosis, generalized osteopenia, and hypoplastic iliac wings. Conclusions: Few cases have been described, as this is a rare skeletal dysplasia. This paper describes a new familial case of SED-BDS. © The American Journal of Case Reports.

CIGALA: Challenging the solar maximum in Brazil with PolaRxS

The upcoming solar maximum, which is expected to reach its peak around May 2013, occurs at a time when our reliance on high-precision GNSS has reached unprecedented proportions. The perturbations of the ionosphere caused by increased solar activity pose a major threat to these applications. This is particularly true in equatorial regions where high exposure to solar-induced disturbances is coupled with explosive growth of precise GNSS applications. Along with the various types of solar-induced ionospheric disturbances, strong scintillations are amongst the most challenging, causing phase measurement errors up to full losses of lock for several satellites. Brazil, which heavily relies on high-precision GNSS, is one of the most affected regions due notably to the proximity to the southern crest of the ionospheric equatorial anomaly and to the South Atlantic Magnetic Anomaly. In the framework of the CIGALA project, we developed the PolaRxS™, a GNSS receiver dedicated to the monitoring of ionospheric scintillation indices not only in the GPS L1 band but for all operational and upcoming constellations and frequency bands. A network of these receivers was deployed across the whole Brazilian territory in order to first investigate and secondly to mitigate the impact of scintillation on the different signals, ensuring high precision GNSS availability and integrity in the area. This paper reports on the validation of the PolaRxS™ receiver as an ionospheric scintillation monitor and the first results of the analysis of the data collected with the CIGALA network.

Unusually rapid growth of brown tumour in the mandible after parathyroidectomy associated with the presence of a supernumerary parathyroid gland

The aim of this study is to report the case of a quick growing brown tumour in the jaw after a parathyroidectomy due to the presence of a rare fifth parathyroid gland. The patient had chronic renal disease and the diagnosis was tertiary hyperparathyroidism. Thirty days after the parathyroidectomy, the patient returned with a significant increase in the tumour size. The suspicion of a supernumerary gland was confirmed by parathyroid scintigraphy. The treatment of brown tumour is dependent on the treatment of the hyperparathyroidism. However, curettage should be considered if a large lesion is disturbing mastication. In conclusion, this case should attract the attention of general practitioner dentists, since they may be the first professionals who have contact with the patient with a brown tumour in the jaws. Likewise, this case emphasises the importance of knowing the type of hyperparathyroidism involved to allow for effective treatment planning. © 2011 European Association for Cranio-Maxillo-Facial Surgery.

Two new feather mite species (Acari, pteronyssidae) from the white-barred piculet, picumnus cirratus (Aves, piciformes)

Two new species of the feather mite family Pteronyssidae Oudemans, 1941 are described from the white-barred piculet, Picumnus cirratus Temminck from Brazil: Pterotrogus picumni sp. n. and Ramphastobius scutatus sp. n., representing the first mites described from this host. Pterotrogus picumni sp. n. can be readily distinguished from all previous species of the simplex group by having dorsal crest on femora I and II in both sexes. This is the first representative of the genus Pterotrogus Gaud, 1981 recorded on a host of the genus Picumnus Temminck. Ramphastobius scutatus sp. n. is unique among species of the genus by having in both sexes the prodorsal and scapular shields fused into a single propodonotal shield covering all prodorsum. An updated key to known species of the genus Ramphastobius Gaud, 1981 is presented. © Institute of Parasitology, Biology Centre ASCR.

Healing outcomes at implants installed in sites augmented with particulate autologous bone and xenografts. An experimental study in dogs

Aim: To evaluate the integration of implants installed at the interface of pristine and grafted tissue augmented with particulate autologous bone or deproteinized bovine bone mineral (DBBM), concomitantly with a collagen membrane. Material and methods: In 6 Labrador dogs, the distal root of 3P3 and 4P4 was endodontically treated and hemi-sected, and the mesial roots extracted concomitantly with the extraction of 2P2. The buccal bony walls were removed, and two box-shaped defects, one larger and one smaller, were created. After 3 months, flaps were elevated, and the defects were filled with particulate autologous bone or DBBM in the right and left side of the mandible, respectively. Collagen membranes were used to cover the grafted areas. Three months later, flaps were elevated, and a customized device was used as surgical guide to prepare the recipient sites at the interface between grafts and pristine bone. One implant was installed in each of the four defects. After 3 months, biopsies were harvested and ground sections prepared for histological evaluation. Results: The augmentation technique was effective at all sites and all the foreseen implants were installed. In the histological analysis, all implants were integrated in mature bone, at both the buccal and lingual aspects. The most coronal bone-to-implant contact and the top of the buccal bony crest were located at a similar distance between test and control implants. However, these distances were higher at the larger compared with the smaller defects. Especially in the large defect, residual particles of DBBM were found embedded into connective tissue and located outside the bony crest. Conclusions: Particulate autologous bone as well as DBBM particles used to augment horizontally the alveolar bony process allowed for the osseointegration of implants installed after 3 months of healing. © 2012 John Wiley & Sons A/S.

Comparisons between Bio-Oss® and Straumann® Bone Ceramic in immediate and staged implant placement in dogs mandible bone defects

Objective: To compare immediate and staged approach implant placement in circumferential defects treated with deproteinized bovine bone mineral (DBBM); hidroxyapatite/tricalcium phosphate (HA/TP); autogenous bone (Ab); and coagulum (Cg); upon implant stability, osseointegration and alveolar crest maintenance. Materials and methods: Six dogs underwent extractions of lower premolars, bilaterally. Twelve weeks later four bone defects (6 mm wide/4 mm long) were drilled at one side and randomly filled with DBBM; HA/TP; Ab; and Cg, respectively, and left to heal (staged approach). Eight weeks later one implant (Osseospeed™, AstraTech) was placed in experimental sites. At the same session four defects were drilled on contra-lateral side and implants were inserted immediately after biomaterials grafting (immediate approach). Animals were euthanized 8 weeks later. Implant stability was measured by resonance frequency analysis (RFA) at installation and after sacrifice. Ground sections were prepared for bone contact (BIC); bone area (BA); distance implant shoulder-bone crest (IS-C); distance implant shoulder first bone contact (IS-B); and areas occupied by soft tissue. Results: The BA and BIC were superior in the staged approach. The Cg exhibited higher BIC and BA as compared with other materials at the total implant body (P = 0.004 and 0.012, respectively). The DBBM, HA/TP and Ab groups rendered similar BA and BIC. The immediate approach resulted in less crest resorption compared to staged approach. The biomaterials did not affect the IS-C and IS-B measurements. Particles area tended to be higher in DBBM group than HA/TP (P = 0.15), while soft tissue infiltrate was higher in DBBM group when used in the immediate approach (P = 0.04). The RFA indicated gain in stability in the staged approach (P = 0.002). The correlation test between RFA vs. BIC and BA demonstrated inferior stability for DBBM group in immediate approach (P = 0.01). Conclusions: Implants placed in healed defects resulted in better stability as a consequence of higher BIC and BA. The Cg alone rendered increased BIC compared to other materials in both approaches. Immediate approach should be preferable to staged approach in terms of alveolar crest maintenance. The BIC and BA values did not vary between micro and macro-threads in this experimental model. Implants installed in sites filled with DBBM in immediate approach were less stable. © 2011 John Wiley & Sons A/S.

Influence of apoptosis on the cutaneous and peripheral lymph node inflammatory response in dogs with visceral leishmaniasis

In canine visceral leishmaniasis (CVL), the abnormalities most commonly observed in clinical examination on the animals are lymphadenomegaly and skin lesions. Dogs are the main domestic reservoir for the protozoon Leishmania (L.) chagasi and the skin is the main site of contamination by the vector insect. Some protozoa use apoptosis as an immunological escape mechanism. The aim of this study was to correlate the presence of apoptosis with the parasite load and with the inflammatory response in the skin and lymph nodes of dogs naturally infected with Leishmania (L.) chagasi. Thirty-three dogs from the municipality of Araçatuba (São Paulo, Brazil) were used, an endemic area for CVL. Muzzle, ear and abdominal skin and the popliteal, subscapular, iliac and mesenteric lymph nodes of symptomatic (S), oligosymptomatic (O) and asymptomatic (A) dogs were analyzed histologically. The parasite load and percentage apoptosis were evaluated using an immunohistochemical technique. Microscopically, the lymph nodes presented chronic lymphadenitis and the skin presented plasmacytic infiltrate and granulomatous foci in the superficial dermis, especially in the ear and muzzle regions. The inflammation was most severe in group S. The parasite load and apoptotic cell density were also greatest in this group. The cause of the lymphoid atrophy in these dogs was correlated with T lymphocyte apoptosis, thus leaving the dogs more susceptible to CVL. The peripheral lymph nodes presented the greatest inflammatory response. Independent of the clinical picture, the predominant inflammatory response was granulomatous and plasmacytic, both in the skin and in the peripheral lymph nodes. The ear skin presented the greatest intensity of inflammation and parasite load, followed by the muzzle skin, in group S. The ear skin area presented a non-significant difference in cell profile, with predominance of macrophages, and a significant difference from group A to groups O and S. It was seen that in these areas, there were high densities of parasites and cells undergoing apoptosis, in group S. The association between apoptosis and parasite load was not significant in the lymph nodes, but in the muzzle regions and at the ear tips, a positive correlation was seen between the parasite load and the density of cells undergoing apoptosis. The dogs in group S had the highest parasite load and the greatest number of apoptotic cells, thus suggesting that the parasite had an immune evasion mechanism, which could be proven statistically in the skin. © 2012 Elsevier B.V.

Evaluation of effect of cyclosporine A on the bone tissue with induced periodontal disease to ligature in rats

The administration of cyclosporine A (CsA) has been associated with significant bone loss and increased bone remodeling. The present investigation was designed to evaluate the effects of CsA on alveolar bone of rats subjected to experimental periodontitis, using histomorphometric and histological analysis. Twenty-four rats were divided into groups with 6 animals each: 1, control; 2, rats with ligature around the lower first molars; 3, rats with ligature around the lower first molars and that were treated with 10 mg CsA/kg of body weight/d; and 4, rats treated with 10 mg CsA/kg of body weight/d. At the end of 30 days, rats were humanely killed and subjected to a histological processing, with analysis of the distance cemento-enamel junction and alveolar bone crest, bone area, eroded bone area, and cemento surface. All of them were assessed at the mesial region of the alveolar bone. The CsA therapy combined with ligature placement decreased bone area and increased the eroded bone area around the tooth surface. The results at the histological analysis showed the same combination and changes. Therefore, in spite of the lack of a direct effect on the alveolar bone height, the CsA therapy intensified the imbalance of the alveolar bone homeostasia in a rat model of experimental periodontitis. © 2013 Elsevier Inc.

Influence of presence or absence of teeth adjacent to implants installed immediately into extraction sockets on peri-implant hard tissue levels: An experimental study in the dog

Aim: To evaluate the influence of the presence or absence of adjacent teeth on the level of the mesial and distal alveolar bony crest following healing at sites where implants were installed immediately into extraction sockets. Material and methods: Six Labrador dogs were used. In the right side of the mandible, full-thickness flaps were elevated, and the second, third, and fourth premolars and first molars were extracted. In the left side of the mandible, endodontic treatments of the mesial roots of the third and fourth premolars as well as of the first molars were performed. Full-thickness flaps were elevated, the teeth were hemi-sected, and the distal roots were removed. The second premolars were extracted as well. Subsequently, implants were bilaterally installed with the implant shoulder flush with the buccal bony crest. Implants were placed in the center of the alveoli, but at the fourth premolars, they were placed toward the lingual bony plate of the alveoli. After 3 months of healing, the animals were euthanized and histological sections of the sites prepared. Results: Larger bony crest resorption was observed at the test compared with the control sites, both at the bucco-lingual and mesio-distal aspects. The differences between test and controls for the coronal level of osseointegration were smaller than those for resorption. When data from all mesial and distal sites facing an adjacent tooth were collapsed and compared with those opposing an edentulous zone, lower bony crest resorption and deeper residual marginal defects were found at the sites with neighboring teeth. Conclusion: The extraction of teeth adjacent to a socket into which implants were installed immediately after tooth extraction caused more alveolar bone resorption both for the bucco-lingual and at the mesio-distal aspects compared with sites adjacent to a maintained tooth. © 2012 John Wiley & Sons A/S.

Healing of buccal dehiscence defects at implants installed immediately into extraction sockets - an experimental study in dogs

Aim: To evaluate the influence of implant positioning into extraction sockets on bone formation at buccal alveolar dehiscence defects. Material and Methods: In six Labrador dogs the pulp tissue of the mesial roots of 4P4 was removed and the root canals were filled. Flaps were elevated bilaterally, the premolars hemi-sectioned and the distal roots removed. The implants were placed in contact with either the buccal (test site) or with the lingual (control site) bony wall of the extraction sockets. Healing abutments were affixed and triangular buccal bony dehiscence defects, about 2.7 mm deep and 3.5 mm wide, were then prepared. No regenerative procedures were done and a non-submerged healing was allowed. After 4 months of healing, block sections of the implant sites were obtained for histological processing and peri-implant tissue assessment. Results: After 4 months of healing, the bony crest and the coronal border of osseointegration at the test sites were located 1.71 ± 1.20 and 2.50 ± 1.21 mm apically to the implant shoulder, respectively. At the control sites, the corresponding values were 0.68 ± 0.63 and 1.69 ± 0.99 mm, respectively. The differences between test and control reached statistical significance (P < 0.05). Residual marginal bone defects were found both at the test and control sites. A statistically significant difference between test and control sites was only found at the lingual aspects (depth 2.09 ± 1.01 and 1.01 ± 0.48 mm, respectively). Similar heights of the buccal biological width were observed at both sites (about 5.1 mm). Conclusions: The placement of implants in a lingual position of the extraction sockets allowed a higher degree of bone formation at buccal alveolar dehiscence defects compared with a buccal positioning. © 2012 John Wiley & Sons A/S.

Ridge preservation at implants installed immediately after molar extraction. An experimental study in the dog

Aim: To evaluate the influence of deproteinized bovine bone mineral (DBBM), in conjunction with a collagen membrane, on bone resorption at implants installed in a lingual position immediately into extraction sockets with horizontal residual buccal defects >2.0 mm. Material & methods: The pulp tissue of the mesial roots of 1M1 was removed in six Labrador dogs, and the root canals were filled with gutta-percha and cement. Flaps were elevated. The molars were hemi-sectioned and the distal roots removed. Implants were installed in a lingual position and with the shoulder flush with the buccal bony crest. After installation, defects of about 2.5 and 2.7 mm in width resulted at the buccal aspects of the test and control sites, respectively. Only in the left site (test), deproteinized bovine bone mineral (DBBM) particles were placed into the defect concomitantly with the placement of a collagen membrane. On the control sites, no biomaterials were applied. A non-submerged healing was allowed. Results: After 3 months of healing, one control implant was not integrated and was excluded from the analysis, together with the contralateral test implant. All remaining implants were integrated into mature bone. The buccal alveolar bony crest was resorbed more at the test compared with the control sites, 2.2 ± 0.9 mm and 1.5 ± 1.3 mm, respectively. The vertical resorption of the lingual plate was 1.6 ± 1.5 mm and 1.5 ± 1.1 mm at the test and control sites, respectively. Only small residual DBBM particles were found at the test sites (1.4%). Conclusion: The use of DBBM particles to fill buccal defects of ≥2.5 mm at implants installed immediately into alveolar extraction sockets did not preserve the buccal bony wall. © 2012 John Wiley & Sons A/S.

Incomplete mandibular fracture after lateralization of the inferior alveolar nerve for implant placement

PURPOSE: The present case describes an inferior alveolar nerve lateralization for implant placement that caused mandible fracture a few days after surgery. CLINICAL REPORT: In this case, a 56-year-old female patient who had a severely atrophied jaw and showing bone height less than 7 mm from the bone crest and the mandibular canal was submitted to surgery lateralization of the inferior alveolar conducted with piezzo. Even with all postoperative care, the patient suffered an incomplete fracture of the mandible a few days after lateralization of the inferior alveolar nerve for implant placement. The patient was treated with soft diet and medications for pain and antibiotics, besides removing the implant associated with the fracture. CONCLUSION: It is suggested that this procedure may be conducted in 2 operative periods: firstly, the lateralization of the inferior alveolar; and secondly, after a period of 3 months, the implant placement in a situation of more bone stability. Copyright © 2013 by Mutaz B. Habal, MD.