Post expansion evaluation of the midpalatal suture in children submitted to rapid palatal expansion: A CT study

The aim of this prospective study was to evalute the midpalatal suture in children submitted to rapid palatal expansion, at the end of the retention stage, with CT scans. The sample was comprised of 17 children aged between 5 years 2 months and 10 years 5 months. The tomographic images showed that the midpalatal suture was completely ossified from the anterior nasal spine area to the posterior nasal spine area at the end of the retention phase, that is, 8 to 9 months post-expansion.

Avaliação radiográfica, densitométrica e histológica do uso de perfurações ósseas para o estímulo de consolidação de fraturas do terço distal do rádio de cães

To stimulate the bone callus development process from distal third of radius, 24 adult mongrel dogs used were from both sexes. These dogs were separated in two experimental groups of 12 animals each, named control and treated, divided in 4 moments (M1=15 days; M2=30 days; M3=45 days; M4=60 days), who underwent were performed surgical fractures. In treated group, it was performed bone perforations on proximal and distal edges, craniolateral and mediolateral to the fracture site. At the end of each moment, control and treated animals were evaluated by radiography, histology, and bone mineral densitometry (BMD) was determined on fracture site. According to the radiographic data of treated dogs, it was verified on days 15 and 30 more intense bone regeneration than control group. During M3 and M4, it wasn't detected any difference in bone reparation process betweencontrol and treated groups. In densitometric study, BMD values were greater in treated animals than in control dogs. Histological studies revealed at 15 and 30 days chondrocyte hyperplasia and initial endochondral ossification on drilled limbs; control group showed sustainment connective tissue and initial chondrocyte hiperplasia. At M3 and M4 of the treated group, were verified development and remodeling of periosteal callus in more advanced phases when comparing with limbs from control group. It can be concluded that using perforations enhances blood flow supply and activation of osteogenic cells on fracture site, stimulating the beginning of fracture consolidation process.

Estudo retrospectivo de osteossarcoma primário dos ossos da pelve em cães em um período de 14 meses

The osteosarcoma (OSA) is one of the most common malignant tumors of dogs. Large and giant-breed dogs are affected and the mean age of these dogs is about 7 years. The tumor usually involves the metaphyses of long bones and the treatment is radical amputation and chemotherapy with cisplatin. The therapy of neoplasia located in pelvis is difficult and usually don't accept by owners. This report describes the incidence of primary osteosarcoma in pelvis of dogs, during a period of fourteen months. Of the eight animals taken care with this neoplasia, a bigger frequency in the dogs of the race Rottweiler and German Pastor was observed. Amongst the bones that compose animal's pelvis was observed greater osteosarcoma incidence in ileum (6 cases). Lameness, functional impotence of pelvic member and pain had been the main observed clinical signals. In seven cases was found advanced involvement osseous, mainly, for lyses of the cortical. All the animals had been submitted to the euthanasia for not presenting possibility of surgical treatment with safety margin. Also one was taken in consideration for this decision to the clinical condition of the patients, the possibilities to confer improvement in the quality of life of the dogs and the option of the owners' front to the prognostic.

Comparison between polyurethanes containing castor oil (Soft Segment) and cancellous bone autograft in the treatment of segmental bone defect induced in rabbits

The aim of this study is to compare polyurethanes containing castor oil (soft segment) in granular form compared to cancellous bone autograft applied to a segmental bone defect. Norfolk adult female rabbits - approximately 13 months of age with a mean body weight of 4.5 kg - are used. In both radial diaphyses, 1 cm osteoperiosteal segmental defects are created. The defect in the left radius is filled with the castor-oil-based polyurethane, and the right one, filled with cancellous bone autograft, collected from the left proximal humerus. The rabbits are euthanazed at 15, 30, 60, and 120 days postsurgery (5 animals/ period), for histological analyses. By radiographic analyses, at these time points, the bone regeneration is more evident and accelerated in the bone defects treated with the cancellous bone autograft. At 120 days postsurgery, the segmental bone defects treated with the cancellous bone autograft are totally reconstituted and remodeled, while the bone defects treated with polyurethane polymer have bone formation of 79%. Histological study shows that the polyurethane acts as a space filler, minimizing the local production of fibrous tissue. No granule degradation, resorption or any inflammatory reaction is detected. Thus, it is possible to conclude that the castor-oil-plant-based polyurethane - in the granule presentation - is biocompatible and osteointegrated, but does not show the same bone regeneration capacity as the cancellous bone autograft. © 2007 SAGE Publications.

Bone mineralization in Brazilian adolescents: The years of maximum bone mass incorporation

Puberty is the fundamental period for bone mass (BM) acquisition. In this period mineralization is found to increase with levels of high bone formation. The critical years of intense bone anabolism deserve special attention, as adequate gain could minimize fracture risk in later years. The objective of this work was to study bone mineral content (BMC) and bone mineral density (BMD) in male adolescents with age bracket and maturation level. Sixty-one healthy male 10 to 19 year-olds were evaluated for calcium intake, weight, stature, BMI, puberty stage and BMC and BMD in the lumbar spine and femur. BM was measured by bone densitometry (DXA). Calcium intake was calculated by recording 3 days diet. Puberty stage was defined as per Tanner. Descriptive statistics was used with means and standard deviations, linear correlation, and analysis of variance for comparison between age groups, and the Tukey test (p<0.05). Linear correlation was positive and indicated body weight as the main correlation variable with BMD in both studied locations (p<0.01). BMC and BMD increased with age, differences were significant from 14 to 15 years, and when adolescents reached Tanner stage G4. These results showed a pronounced increase in bone mineralization, with the years after 14 to 15 being critical for BM acquisition in Brazilian adolescents.

Role of annexin 1 gene expression in mouse craniofacial bone development

BACKGROUND: Annexin 1 is a 37-kDa protein that has complex intra- and extracellular effects. To discover whether the absence of this protein alters bone development, we monitored this event in the annexin-A1 null mice in comparison with littermate wild-type controls. METHODS: Radiographic and densitometry methods were used for the assessment of bone in annexin-A1 null mice at a gross level. We used whole-skeleton staining, histological analysis, and Western blotting techniques to monitor changes at the tissue and cellular levels. RESULTS: There were no gross differences in the appendicular skeleton between the genotypes, but an anomalous development of the skull was observed in the annexin-A1 null mice. This was characterized in the newborn annexin-A1 null animals by a delayed intramembranous ossification of the skull, incomplete fusion of the interfrontal suture and palatine bone, and the presence of an abnormal suture structure. The annexin-A1 gene was shown to be active in osteocytes during this phase and COX-2 was abundantly expressed in cartilage and bone taken from annexin-A1 null mice. CONCLUSIONS: Expression of the annexin-A1 gene is important for the normal development of the skull in mice, possibly through the regulation of osteoblast differentiation and a secondary effect on the expression of components of the cPLA2-COX-2 system. © 2007 Wiley-Liss, Inc.

Comparison between inverted and unprocessed digitized radiographic imaging in periodontal bone loss measurements

The advances in digital imaging technology in dentistry have provided an alternative to film-based radiography and have given new options to detect periodontal bone loss. The purpose of this study was to compare inverted and unprocessed digitized radiographic imaging in periodontal bone loss measurements. Thirty-five film-based periapical radiographs of patients suffering from moderate to advanced untreated periodontal bone loss associated to lower premolar and molars was selected from the department files, with 40 bone loss areas. The film-based radiographs were digitized with a flatbed scanner with a transparency and radiograph adapter used for transilluminating the radiograph imaging. Digitization was performed at 600 dpi and in gray scale. The images were digitized using Image Tool software by applying image inversion, that is, transformation of radiopaque structures into radiolucent structures and vice-versa. The digital data were saved as JPEG files. The images were displayed on a 15-inch and 24-bit video monitor under reduced room lighting. One calibrated examiner performed all radiographic measurements, three times, from the cementoenamel junction to the most apical extension of the bone loss, in both types of image (inverted and unprocessed). Brightness and contrast were adjusted according to the examiner's individual demand. Intraclass correlation coefficient was used to compare the measurements from both types of images. The means of radiographic measurements, in mm, for inverted and unprocessed digitized imaging were 6.4485 and 6.3790, respectively. The intraclass correlation coefficient was significant (0.99) The inverted and unprocessed digitized radiographic images were reliable and there was no difference in the diagnostic accuracy between these images regarding periodontal bone loss measurements.

Homogenous demineralized dentin matrix for application in cranioplasty of rabbits with alloxan-induced diabetes: Histomorphometric analysis

Purpose: The aim of this work was to evaluate the bone-repair process after implantation of homogenous demineralized dentin matrix (HDDM) slices in surgical defects created in the parietal bones of rabbits with alloxan-induced diabetes. Materials and Methods: Forty-eight rabbits were selected and divided into 4 groups of 12 rabbits: the control group, diabetic rabbits (D), diabetic rabbits with a PTFE barrier (D-PTFE), and diabetic rabbits with a PTFE barrier and with slices of homogenous demineralized dentin matrix (D-PTFE+HDDM). The diabetic animals received a single dose of alloxan monohydrate (90 mg/kg) intravenously on the marginal ear vein, and their blood glucose was verified daily. The rabbits were sacrificed after 15, 30, 60, and 90 days. The histologic findings show both better bone structure and significantly greater bone density, as determined by histomorphometric analysis, for the D-PTFE + HDDM group than for the other 3 groups (P < .01). It was also observed that the mean bone density increased gradually from 15 to 90 days (except in the D-PTFE group). Conclusion: It was concluded that the HDDM was biocompatible with the bone repair of diabetic rabbits and that HDDM slices stimulated bone tissue formation. Facilitation of bone repair with HDDM could be useful in diabetic patients.

A survey of radiographic measurement estimation in assessment of dental implant length.

The aim of this study is to survey radiographic measurement estimation in the assessment of dental implant length according to dentists' confidence. A 19-point questionnaire with closed-ended questions was used by two graduate students to interview 69 dentists during a dental implant meeting. Included were 12 questions related to over- and underestimation in three radiographic modalities: panoramic (P), conventional tomography (T), and computerized tomography (CT). The database was analyzed by Epi-Info 6.04 software and the values from two radiographic modalities, P and T, were compared using a chi2 test. The results showed that 38.24% of the dentists' confidence was in the overestimation of measurements in P, 30.56% in T, and 0% in CT. On the other hand, considering the underestimated measurements, the percentages were 47.06% in P, 33.33% in T, and 1.92% in CT. The frequency of under- and overestimation were statistically significant (chi2 = 6.32; P = .0425) between P and T. CT was the radiographic modality with higher measurement precision according to dentists' confidence. In conclusion, the interviewed dentists felt that CT was the best radiographic modality when considering the measurement estimation precision in preoperative dental implant assessment.

Conservative treatment of patients with periapical lesions associated with extraoral sinus tracts

This paper describes the clinical courses of three cases with extra-oral sinus tract formation, from diagnosis and treatment to short-term follow-up and evaluation. All teeth involved had periradicular radiolucent areas noted on radiographic examination and extra-oral sinus tracts appearing on the chin with exudation and unpleasant aesthetic appearance. The adopted treatment protocol included treating the sinus tract surface simultaneously with the root canal therapy. After root canal shaping using 5.25% sodium hypochlorite solution, calcium hydroxide-based pastes associated with different vehicles were inserted into the root canal for 4 months, and were changed monthly. All the sinus tracts healed in 7 to 10 days. The apical lesions were completely repaired in a maximum period of 24 months. The treatment adopted provided a complete healing of the periapical lesions in a short follow-up period. Surgical repair of the cutaneous sinus tract was therefore unnecessary. © 2007 The Authors. Journal compilation © 2007 Australian Society of Endodontology.

Microwave-induced fast decalcification of rat bone for electron microscopic analysis: An ultrastructural and cytochemical study

Bone decalcification is a time-consuming process. It takes weeks and preservation of the tissue structure depends on the quality and velocity of the demineralization process. In the present study, a decalcification methodology was adapted using microwaving to accelerate the decalcification of rat bone for electron microscopic analysis. The ultrastructure of the bone decalcified by microwave energy was observed. Wistar rats were perfused with paraformaldehyde and maxillary segments were removed and fixed in glutaraldehyde. Half of specimens were decalcified by conventional treatment with immersion in Warshawsky solution at 4oC during 45 days, and the other half of specimens were placed into the beaker with 20 mL of the Warshawsky solution in ice bath and thereafter submitted to irradiation in a domestic microwave oven (700 maximum power) during 20 s/350 W/±37°C. In the first day, the specimens were irradiated 9 times and stored at 40°C overnight. In the second day, the specimens were irradiated 20 times changing the solution and the ice after each bath. After decalcification, some specimens were postfixed in osmium tetroxide and others in osmium tetroxide and potassium pyroantimonate. The specimens were observed under transmission electron microscopy. The results showed an increase in the decalcification rate in the specimens activated by microwaving and a reduction of total experiment time from 45 days in the conventional method to 48 hours in the microwave-aided method.

Effects of fibrin sealer and resorbable gelatin on the repair of osseous defects in rat tibia

Gelfoam® - a biologically resorbable gelatin sponge - has the function of restricting hemorrhage, providing platelet rupture, and supporting fibrin threads. Beriplast® - a fibrinogen-thrombin compound - is used to adhere tissues, to consolidate sutures and in hemostasis. The objective of this study was to perform a histological analysis of the effects of haemostatic agents on osseous repair. These materials were inserted into surgical sites in young rat right and left tibiae. After the observation periods of 7, 14, 30 and 45 days, according to the bioethic protocol, the animals were killed, the tibiae were removed and fixed in 10% formalin and decalcified in equal parts of formic acid and sodium citrate solutions. After routine processing, the specimens were embedded in paraffin for microtomy. Analysis of the results demonstrated that the haemostatic agents are effective in controlling hemorrhage; they stimulate osteogenesis, featuring a pattern of osseous tissue formation similar to the control pattern, although the amount of osseous trabeculae was superior, especially in the Gelfoam group in the periods of 7 and 14 days; 30 days after surgery, the delay in tissue healing in the control group in relation to the experimental groups started to decrease, and the control and experimental groups exhibited similar tissue repair after 45 days, when all the groups exhibited secondary osseous tissue.

Dental age in patients with Down syndrome

The aim of this research was to evaluate dental age in 102 patients with Down Syndrome, using panoramic radiographs. A software program developed by the Discipline of Radiology, School of Dentistry of São José dos Campos, São Paulo State University (UNESP), was used. A table of mineralization chronology of permanent teeth among Brazilians conceived by Nicodemo, Moraes and Medici Filho was used within the software. Statistical analysis of the results showed that 70.91% of the males land 61.21% of the females presented advanced dental age. Only 32.09% of the males and 39.79% of the females presented delayed dental age. Regarding the differences between the dental and chronological ages, two thirds of the males and females presented dental age with differences of up to 12 months, which means that they can be considered to be within normal standards, whereas only 18.87% of the males and 10.21% of the females presented dental age outside normal standards, with differences of over 24 months. In conclusion, the majority of the patients with Down Syndrome were considered to be within the normal standards of mineralization chronology.

Hindlimb unloading producing effects on bone biomechanical properties in mature male rats

Aging is associated with decline in muscle mass and strength and reduced bone density. Age-related bone loss is a primary factor in osteoporosis and all individuals are potential candidates for osteoporosis because bone loss with aging occurs in men and women, but less studied in men. To examine the appropriateness of hindlimb elevation, by tail suspension as a model for diminished mechanical loading, and to determine the influence of age on bone responsiveness to skeletal unloading, we use dual X ray absorptiometry (DXA) and digital radiographic images to analyze the response of the femur from mature rats to biomechanical loads. Femurs from male Wistar rats (9-mo-old) were scanned using DXA and DIGORA and measures obtained in ephipyseal and diaphyseal regions of interest. The mechanical testing was divided into compression load to fracture the head and a three-point bending load to fracture the femur middiaphysis. In femoral epiphysis from hindlimb unload (HU), animals presented significant differences between mineral bone content and density assessed by DXA. Detailed regions of femoral epiphysis (head, throcanteric fossa, throcanter and metaphysis) presented significant lower values from radiographic density. Only compressive load necessary to fracture the femoral head neck was also significantly diminished in HU animals. Disuse induced, as in elderly patients, deterioration of the trabecular bone architecture with critical effect on bone fragility. Rats with 21 days of hindlimb unloading can simulate disuse, suggesting that certain sub-regions of their aging bones are more susceptible to fracture, while other, i.e. diaphyses, are not.

Mesh skin graft and digital pad transfer to reconstruct the weight-bearing surface in a dog

A 2-month-old dog was presented with injuries involving both hind paws. Only the 5th digit and its digital pad were present on the right paw. Following a full-thickness skin graft, the 5th digital pad was transferred distal to the metatarsal bones. The transferred pad permitted weight-bearing on the limb.