Estudo anatomico da posição do forame mandibular e da língula em mandíbulas secas

Purpose: The authors tried to verify the anatomic location of the mandibular foramen and língula in dry jaws regarding the anterior and posterior border of the mandible and the incisure, alveolar border and mandibular base, in order to correlate the data with the sagittal split ramus osteotomy. Methods: There were evaluated 44 mandibles (88 sides) from the Morphology Department of the Araraquara Dental School of the São Paulo University (UNESP). The distances measured were previously deter - mined according to the figures presented in this article and were done by the use of a sliding caliper (Brow & Sharpe Digit-Cal Plus), with the mandibles positioned over a Erickson table, and the distan - ces were always measured in millimeters. Results: The pre-determined points and distances founded were X=17,67; Y=14,35; W=20,96 and Z=21,89 for the mandibular foramen, and the relationship between this anatomical structure and the língula shows that the mandibular foramen is in average 5,82 mm below the língula. Conclusions: The authors conclude that the mandibular foramen is lightly posterior in comparison with the ramus mandibular center and that the língula is a very important anatomic landmark for the ramus surgeries as well the knowledge of the distance between it and the mandibular foramen entrance.

Comparative analysis of three rotary instruments used for coronal pre-enlargement in radicular dentin thickness and root canal area of mandibular molars

Purpose: The purpose of this study was to evaluate the increase of the cervical area and dentin thickness in mesial and distal walls of the mesial canals from mandibular molars after the use of LA Axxess (LA), CP Drill (CP) and Gates-Glidden (GG) rotary instruments. Material and Methods: Sixty root canals from thirty mandibular first molar were sectioned 3 mm below the cement-enamel junction, divided in 3 groups (n = 20 root canals, each) according to rotary instrument used, and the cervical images were captured before and after pre-enlargement instrumentation. The increase of the instrumented cervical area (mm2) and the dentin removal thickness (mm), at mesial and distal walls were calculated using Image tools software, by comparison of images. Data were analyzed by ANOVA and Tukey tests (p=0.05). Results: All rotary instruments promoted thickness reduction in dentin walls. In mesial wall, all rotary instruments promoted similar thickness reduction of dentinal wall and did not differ from each other (p>0.05). In distal wall, LA Axxess instrument promoted higher dentin thickness reduction than other groups (p<0.05). The three rotary instruments promoted different increase at the instrumented cervical area (p<0.05), LA promoted the highest increase area and GG and CP presented similar results. Conclusion: LA 20/0.06 promoted the highest thickness reduction in distal wall and increase of cervical area of root canal. On the other hand, CP was the safest instrument, with lower dentin removal of distal wall and similar increased area to GG.

Effects of estrogen deficiency combined with chronic alcohol consumption on rat mandibular condyle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação eletromiográfica dos músculos masseter e temporal, força de mordida e qualidade de vida em pacientes desdentados antes, durante e após a instalação e adaptação de novas próteses - total maxilar e overdenture mandibular sobre implante

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Reconstruction of the Alveolar Buccal Bone Plate in Compromised Fresh Socket after Immediate Implant Placement Followed by Immediate Provisionalization

ObjectiveThe aim of this clinical report was to reestablish the buccal bone wall after immediate implant placement. The socket defect was corrected with autogenous bone, and a connective tissue graft was removed from the maxillary tuberosity to increase the thickness, height, and width of the buccal bone and gingival tissue followed by immediate provisionalization of the crown during the same operation.Clinical ConsiderationsA 66-year-old patient presented with a hopeless maxillary left central incisor with loss of the buccal bone wall. Atraumatic, flapless extraction was performed, and an immediate implant was placed in the extraction socket followed by preparation of an immediate provisional restoration. Subsequently, immediate reconstruction of the buccal bone plate was performed, using the tuberosity as the donor site, to obtain block bone and connective tissue grafts, as well as particulate bone. Finally, immediate provisionalization of the crown followed by simple sutures was performed. Cone-beam computed tomography and periapical radiographs were taken before and after surgery. After 4 months, the final prosthetic crown was made. After a 2-year follow-up, a satisfactory aesthetic result was achieved with lower treatment time and morbidity.ConclusionThis case demonstrates the effective use of immediate reconstruction of the buccal bone wall for the treatment of a hopeless tooth in the maxillary aesthetic area. This procedure efficiently promoted harmonious gingival and bone architecture, recovered lost anatomical structures with sufficient width and thickness, and maintained the stability of the alveolar bone crest in a single procedure.Clinical SignificanceIf appropriate clinical conditions exist, immediate dentoalveolar restoration may be the most conservative means of reconstructing the buccal bone wall after immediate implant placement followed by immediate provisionalization with predictable healing and lower treatment time.

The dark matter profile of the Milky Way: a non-parametric reconstruction

We present the results of a new, non-parametric method to reconstruct the Galactic dark matter profile directly from observations. Using the latest kinematic data to track the total gravitational potential and the observed distribution of stars and gas to set the baryonic component, we infer the dark matter contribution to the circular velocity across the Galaxy. The radial derivative of this dynamical contribution is then estimated to extract the dark matter profile. The innovative feature of our approach is that it makes no assumption on the functional form or shape of the profile, thus allowing for a clean determination with no theoretical bias. We illustrate the power of the method by constraining the spherical dark matter profile between 2.5 and 25 kpc away from the Galactic center. The results show that the proposed method, free of widely used assumptions, can already be applied to pinpoint the dark matter distribution in the Milky Way with competitive accuracy, and paves the way for future developments.

Performance of the CMS missing transverse momentum reconstruction in pp data at root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Enamel matrix protein derivative plus synthetic bone substitute for the treatment of mandibular Class II furcation defects: a case series

Objectives: The aim of this study is to report on the treatment of mandibular Class II furcation defects with enamel matrix protein derivative (EMD) combined with a beta TCP/HA (beta-tricalcium phosphate/hydroxyapatite) alloplastic material. Method and Materials: Thirteen patients were selected. All patients were nonsmokers, systemically healthy, and diagnosed with chronic periodontitis; had not taken medications known to interfere with periodontal tissue health and healing; presented one Class II mandibular furcation defect with horizontal probing equal to or greater than 4 mm at buccal site. The clinical parameters evaluated were probing depth (PD), relative gingival margin position (RGMP), relative vertical clinical attachment level (RVCAL), and relative horizontal clinical attachment level (RHCAL). A paired Student t test was used to detect differences between the baseline and 6-month measurements, with the level of significance of .05. Results: After 6 months, the treatment produced a statistically significant reduction in PD and a significant gain in RVCAL and RHCAL, but no observable change in RGMP. RVCAL ranged from 13.77 (+/- 1.31) at baseline to 12.15 (+/- 1.29) after 6 months, with a mean change of -1.62 +/- 1.00 mm (P<.05). RHCAL ranged from 5.54 (+/- 0.75) to 2.92 (+/- 0.92), with a mean change of -2.62 +/- 0.63 mm (P<.05). After 6 months, 76.92% of the patients improved their diagnosis to Class I furcation defects while 23.08% remained as Class II. Conclusion: The present study has shown that positive clinical results may be expected from the combined treatment of Class II furcation defects with EMD and beta TCP/HA, especially considering the gain of horizontal attachment level. Despite this result, controlled clinical studies are needed to confirm our outcomes.

Healing at mandibular block-grafted sites: an experimental study in dogs

AimThe aim of this study was to evaluate the healing of autologous bone block grafts or deproteinized bovine bone mineral (DBBM) block grafts applied concomitantly with collagen membranes for horizontal alveolar ridge augmentation.Material and methodsIn six Labrador dogs, molars were extracted bilaterally, the buccal bony wall was removed, and a buccal box-shaped defect created. After 3months, a bony block graft was harvested from the right ascending ramus of the mandible and reduced to a standardized size. A DBBM block was tailored to similar dimensions. The two blocks were secured with screws onto the buccal wall of the defects in the right and left sides of the mandible, respectively. Resorbable membranes were applied at both sides, and the flaps sutured. After 3months, one implant was installed in each side of the mandible, in the interface between grafts and parent bone. After 3months, biopsies were harvested and ground sections prepared to reveal a 6-month healing period of the grafts.Results776.2% and 5.9 +/- 7.5% of vital mineralized bone were found at the autologous bone and DBBM block graft sites, respectively. Moreover, at the DBBM site, 63 +/- 11.7% of connective tissue and 31 +/- 15.5% of DBBM occupied the area analyzed. Only 0.2 +/- 0.4% of DBBM was found in contact with newly formed bone. The horizontal loss was in a mean range of 0.9-1.8mm, and 0.3-0.8mm, at the autologous bone and DBBM block graft sites, respectively.ConclusionsAutologous bone grafts were vital and integrated to the parent bone after 6months of healing. In contrast, DBBM grafts were embedded into connective tissue, and only a limited amount of bone was found inside the scaffold of the biomaterial.

Cutaneous sensibility impairmentafter mandibular sagittal split osteotomy: a prospective clinical study of the spontaneous recovery

Purpose The aim of this prospective study was to objectively evaluate the inferior alveolar nerve (IAN) sensory disturbances in patients who underwent sagittal split ramus osteotomy (SSRO) and its spontaneous recovery and to define the incidence of sensibility loss, time, and area at which the recovery occurs. Patients and Methods Clinical evaluation of the IAN sensory disturbance was undertaken preoperatively and at the first week, fourth week, 2 months, and 6 months postoperatively in 30 patients who underwent SSRO at the Oral and Maxillofacial Surgery Division of the Araraquara Dental School--Unesp and at the Plastic Surgery Division of the Medical Sciences School--Unicamp. The 30 patients were examined at all periods regarding the IAN functionality by Semmes-Weinstein testing. Results The mean age of the patients included in this study was 29.36 years old. All patients showed sensibility loss at the 7-day evaluation time. The comparison between sides, gender, and age did not show any significant difference. In most of the examined zone, the data collected at 6 months were statistically similar to the data collected at the preoperative period. All zones presented significant recovery, starting from 30 days after surgery. Twenty patients had total spontaneous recovery at the final period, in all examined zones. Conclusions The SSRO presents the disadvantage of temporary paresthesia; however, spontaneous nerve function recovery does occur. The Semmes-Weinstein test is a reliable, inexpensive, and easy-to-apply tool, which can be used for clinical evaluation on a daily basis at offices and hospitals.

Visualisation and reconstruction in dentistry

Visualisation in the field of dentistry has nor, thus far, reached the same development as other medical fields. Potential applications of visualisation techniques in this area, however, are many, ranging from educational displays to training for delicate procedures. This paper reports on the investigation of techniques for handling three-dimensional models of teeth, aiming at investigation of dental structures. An algorithm was implemented for this purpose, which reconstructs three-dimensional teeth models from two-dimensional contour slices. Results employing various data sets are presented, including the output of VRML models for exploration.

Changes in cells's secretory organelles and extracellular matrix during endochondral ossification in the mandibular condyle of the growing rat

The mandibular condyle from 20-day-old rats was examined in the electron microscope with particular attention to intracellular secretory granules and extracellular matrix. Moreover, type II collagen was localized by an immunoperoxidase method. The condyle has been divided into five layers: (1) the most superficial, articular layer, (2) polymorphic cell layer, (3) flattened cell layer, (4) upper hypertrophic, and (5) lower hypertrophic cell layers. In the articular layer, the cells seldom divide, but in the polymorphic layer and upper part of the flattened cell layer, mitosis gives rise to new cells. In these layers, cells produce two types of secretory granules, usually in distinct stacks of the Golgi apparatus; type a, cylindrical granules, in which 300-nm-long threads are packed in bundles which appear lucent after formaldehyde fixation; and type b, spherical granules loaded with short, dotted filaments. The matrix is composed of thick banded lucent fibrils in a loose feltwork of short, dotted filaments. The cells arising from mitosis undergo endochondral differentiation, which begins in the lower part of the flattened cell layer and is completed in the upper hypertrophic cell layer; it is followed by gradual cell degeneration in the lower hypertrophic cell layer. The cells produce two main types of secretory granules: type b as above; and type c, ovoid granules containing 300-nm-long threads associated with short, dotted filaments. A possibly different secretory granule, type d, dense and cigar-shaped, is also produced. The matrix is composed of thin banded fibrils in a dense feltwork. In the matrix of the superficial layers, the lucency of the fibrils indicated that they were composed of collagen I, whereas the lucency of the cylindrical secretory granules suggested that they transported collagen I precursors to the matrix. Moreover, the use of ruthenium red indicated that the feltwork was composed of proteoglycan; the dotted filaments packed in spherical granules were similar to, and presumably the source of, the matrix feltwork. The superficial layers did not contain collagen II and were collectively referred to as perichondrium. In the deep layers, the ovoid secretory granules displayed collagen II antigenicity and were likely to transport precursors of this collagen to the matrix, where it appeared in the thin banded fibrils. That these granules also carried proteoglycan to the matrix was suggested by their content of short dotted filaments. Thus the deep layers contained collagen II and proteoglycan as in cartilage; they were collectively referred to as the hyaline cartilage region.

Gastric and small intestinal lesions after partial stomach resection with Billroth II or Roux-en-Y reconstruction in the rat

The evolution and phenotypic expression of mucosal lesions of the gastric stump were investigated in male rats submitted to gastric resection with reconstruction by the Billroth II technique (BII with biliopancreatic reflux, BPR) or by the Roux-en-Y procedure (without BPR). Animals were studied at 24, 36, 54 and 64 weeks after surgery and the phenotypic expression of lesions analysed using routine hematoxylin and eosin staining, immunohistochemical staining for pepsinogen isoenzyme 1 and histochemical procedures for mucins (paradoxical concanavalin A, galactose oxidase Schiff (GOS) and sialidase GOS reactions). BPR was found to be responsible for the formation of adenomatous hyperplasia (AH), increasing in incidence and size with time, since the Roux-en-Y procedure failed to induce the gastric stump lesions observed after BII reconstruction. AHs always occurred in the transition of the gastrojejunal junction, a site offering special conditions for BPR influence, and were classified as gastric (G), intestinal (I) and G+I types according to their phenotypic expression. No pure I type AH was diagnosed at any time point. The G and G+I types developed at approximately equal incidences (i.e., G type 7/17, G+I type 10/17 at the 64th week). It was suggested that both gastric and intestinal mucosal elements were stimulated to proliferate by BPR, with the gastric mucosa tending to demonstrate AH. Intestinal type components of AH were found adjacent to the jejunum and not at the stomach margin, indicating an origin from intestinal mucosa. No metaplasia of the gastric mucosa was observed in any animal after partial gastric resection. In 101 rats submitted to the BII procedure, 5 mucinous adenocarcinomas were eventually diagnosed, mostly located in the subserosa of the gastrojejunal junction. All carcinomas expressed the phenotype of cells of the small intestine. Evidence of malignant transformation within the gastric components of AH was not observed even at the 64th week. In conclusion, all lesions induced by BPR in the rat remnant stomach are benign, and the few true cancers that arise in association are derived from the small intestine.