Consequences of crown fractures with pulpal exposure: histopathological evaluation in dogs

When a crown fracture involving pulpal exposure is produced, the therapeutic treatment to be applied depends to a great extent on the general histopathological condition of the exposed pulp. Hence, the objective of this study was to evaluate histopathological and bacteriological changes occurring in dental tissue and periradicular tissue of crown-fractured teeth with pulpal exposure. Twenty-four anterior teeth (central and lateral incisors) from the maxillary teeth of four young, adult Mongrel dogs were used. At 48 and 72 h after performing the crown fractures, the animals were sacrificed and the results evaluated. Both observation periods revealed the existence of an area of superficial inflammation with the formation of hyperplastic tissue towards the external surface. Intense neutrophilic infiltrate was observed below it. Mean depth of inflammation was greater at 48 h (4633.33 mum) than at 72 h (3933.33 mum), perhaps coinciding with the bigger pulp chamber opening (x1332.14 mum at 48 h vs. x479.52 mum at 72 h). Upon approaching the cervical portion, the inflammation became less. Bacterial contamination was constant in all the cases evaluated, worsening the histopathological findings with exposure time. This study demonstrates that when a crown fracture with pulpal exposure is produced, the success in treating it depends partly on how quickly therapeutic treatment is administered.

Postsurgical stability of oropharyngeal airway changes following counter-clockwise maxillo-mandibular advancement surgery

Purpose: This study evaluated oropharyngeal airway changes and stability following surgical counter-clockwise rotation and advancement of the maxillo-mandibular complex.Methods and Patients: Fifty-six adults (48 females, 8 males), between 15 and 51 years of age, were treated with Le Fort I osteotomies and bilateral mandibular ramus sagittal split osteotomies to advance the maxillo-mandibular complex with a counter-clockwise rotation. The average postsurgical follow-up was 34 months. Each patient's lateral cephalograms were traced, digitized twice, and averaged to estimate Surgical changes (T2-T1) and Postsurgical changes (T3-T2).Results: During surgery, the occlusal plane angle decreased significantly (8.6 +/- 5.8 degrees) and the maxillo-mandibular complex advanced and rotated counter-clock-wise. The maxilla moved forward (2.4 +/- 2.7 mm) at ANS and the mandible was advanced 13.1 +/- 5.1 min at menton, 10 +/- 4.4 mm at point B, and 6.9 +/- 3.7 mm at lower incisor edge. Postsurgical hard tissue changes were not statistically significant. While the upper oropharyngeal airway decreased significantly (4.2 +/- 3.4 min) immediately after surgery, the narrowest retropalatal, lowest retropalatal airway, and the narrowest retroglossal airway measurements increased 2.9 +/- 2.7, 3.7 +/- 3.2, and 4.4 +/- 4.4 mm, respectively. Over the average 34 months Postsurgical period, upper retropalatal airway increased 3.9 +/- 3.7 mm, while narrowest retropalatal, lowest retropalatal airway, and narrowest retroglossal airway remained stable. Head posture showed flexure immediately after Surgery (4.8 +/- 5.9 degrees) and extension postsurgically (1.6 +/- 5.6 degrees).Conclusion: Maxillo-mandibular advancement with counter-clockwise rotation produces immediate increases in middle and lower oropharyngeal airway dimensions, which were constrained by changes in head posture but remain stable over the postsurgical period. The upper oropharyngeal airway space increased only on the longest follow-up. (C) 2006 American Association of Oral and Maxillofacial Surgeons.

ULTRASTRUCTURE OF THE MANDIBULAR GLANDS OF PACHYCONDYLA-STRIATA ANTS (HYMENOPTERA, PONERINAE) .1. WORKERS

The mandibular glands of Pachycondyla striata workers consists of a proximal reservoir and secretory portion. The secretion is transported from the cytoplasm of the secretory cells to reservoir through individual canaliculi which is subdivided into two portions : an intracytoplasmatic and extracellular one. The reservoir consists of an epithelium made up of thin cells has a thick cuticle. The secretory cells showed a large amount of structures forming the citoskeleton always associated with myelin figures.

Treatment of radius, ulna and humerus fractures with the aid of a bone morphogenetic protein in a giant anteater (Myrmecophaga tridactyla)

A giant anteater (Myrmecophaga tridactyla) was found with closed comminuted fractures on the fight radius and ulna and left humerus he duration of which was unknown. The animal was unable to use either of he thoracic limbs. The fractures were stabilized with 3.5-mm titanium plates and a commercially available mixture of micro lyophilized bovine cortical osseous and bovine BMP (Gen-tech(R), Baumer, Brazil) was implanted into the fractures sites. Postoperative radiographic evaluations were performed every 30 days and after four months. Bone healing was observed in all of he fractures. The animal was able to be reintroduced into its natural habitat. From his case we conclude that despite he low metabolic fate of the giant anteater, which is an inherent characteristic of this species, he treatment of radius, ulna and humerus fractures by means of plates and screws, associated with BMP on the Myrmecophaga tridactyla, was a success.

Comparing the efficacy of mandibular implant-retained overdentures and conventional dentures among elderly edentulous patients: satisfaction and quality of life

Objectives: the aim of this study was to compare the satisfaction and the quality of life in an elderly population using either mandibular conventional dentures or implant-retained overdentures.Materials and methods: A total of 34 patients were divided into two groups: group I-complete dentures users; group II - users of upper complete dentures opposed by implant-retained overdentures. The subjects were submitted to a questionnaire based on Oral Health impact Profile and oral health related quality of life to evaluate their satisfaction levels and quality of life with their prostheses. Data were evaluated using a non-parametric statistical analysis (Fischer test) with significant difference at alpha = 0.05.Results: There were no significant differences between the groups in relation to comfort, aesthetics, chewing ability, overall satisfaction, pain, functional, phonetic, social, and psychological limitations (p > 0.05). Comparing the stability of mandibular dentures, group II presented the better results (p < 0.05).Conclusion: Although the stability of the mandibular implant-retained overdenture was enhanced compared to a conventional denture, the quality of life and satisfaction levels were similar for both the groups.

Influence of the period after ovariectomy on femoral and mandibular bone density and on induced periodontal disease

Background: This study investigated the influence of the period after ovariectomy on femoral and mandibular bone mineral density (BMD) and on induced periodontal disease.Methods: One hundred and twenty-six female Holtzman rats were divided into nine groups: control, sham surgery (SHAM) with and without induction of periodontal disease for 51 and 150 days, and ovariectomy (OVX) with and without induction of periodontal disease for 51 and 150 days. Periodontal disease was induced by placing ligatures on the first lower molars during the last 30 days of each period. BMD was measured by dual-energy x-ray absorptiometry. Vertical bone loss was determined by measuring the distance from the alveolar bone crest to the cemento-enamel junction on the mesial side of the first lower molar.Results: Statistical analyses (Kruskal-Wallis test) revealed a significant difference between the OVX and SHAM groups' global and femoral proximal epiphysis BMD (P < 0.001) for 150 days and in the global evaluation for 51 days. For mandibular BMD, no difference was found between the groups of each period. Influence of the period on femoral BMD was found only for the SHAM groups, with lower BMD for the 51-day period compared to the 150-day period (P < 0.05). In the global evaluation of the mandible, a lower BMD was found after 51 days. The period was a contributing factor for the vertical bone loss, and it resulted in higher values for the 51-day period (P < 0.05).Conclusion: the period influenced the femoral BMD and the vertical bone loss in induced periodontal disease.

Validity and reliability of the Portuguese version of Mandibular Function Impairment Questionnaire

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

Synthesis Pengo System plates for the treatment of long-bone diaphyseal fractures in dogs

A Brazilian orthopaedic company designed a stainless steel plate called Synthesis Pengo System (S.P.S.), which has one fixed and one changeable extremity. According to the assembly of the changeable extremity, it is possible to obtain dynamization or neutralization of the fracture site. Since the S.P.S. plate was developed for use in human patients, the aim of this study was to evaluate this system in long-bone diaphyseal fractures in dogs. Eight dogs with closed diaphyseal fractures of the femur (n = 1), radius and ulna (n = 5), and tibia (n = 2) were used. Patients were aged seven months to three years and weighed 18 to 31.2 kg. The S.P.S. plate was assembled with one fixed extremity and one changeable extremity in dynamization mode. The trail bar was positioned for synthesis modules with holes for cortical screws. The modules were positioned close to one another in two fractures and for away from the fracture site in the others. The bone healing occurred by external callus. Since motion at the fracture site determines the amount of callus required, the secondary bone healing that was observed in all of the cases indicated less rigid fixation of this system. A potential benefit of this system was a lesser interface contact with the bone since it was only done by trail bar. The major disadvantage was the prominence of the implant. It was possible to conclude that the S.P.S. plate appears to be a suitable method for the treatment of diaphyseal fractures in dogs.