Incidence of retromolar foramen in human mandibles: ethnic and clinical aspects

The retromolar foramen allows the passage of the neurovascular bundles that contribute to nutrition and innervation of the pulp and periodontium of the lower teeth. Knowledge of this anatomical variation may prevent complications in the anesthesia and surgical procedures in this area and serve as an anatomical landmark for ethnic identification. The aim of this study was to evaluate the impact of the retromolar foramen in human mandibles of adult Brazilians and discuss the clinical and ethnic related to the presence of this foramen. Were evaluated 222 human mandibles, dry, adults, Brazilians, independent of gender. The evaluation was performed by two examiners who standardized search from a previous anatomical study. The mandibles were analyzed: the presence of the retromolar foramen (bilateral or unilateral), the presence of the foramen on right and left sides, and the number of foramens present on each side. It was found that 59 had at least one mandible retromolar foramens resulting in an incidence of 26.58%. The retromolar foramen was present unilaterally in 41 mandibles and 18 bilaterally, with incidences of 18.47% and 12.16% respectively. on the right side, the retromolar foramen was present in incidences of 16.22% and 18.92% respectively The analysis of the right side of the mandibles revealed that 47.46%, 21.21% and 3.03% had one, two and three foramens, respectively The left side showed 55.93%, 16.22% and 8.11% of the 222 mandibles with one, two and three retromolar foramens, respectively The incidence of retromolar foramen in the Brazilian population is significant and should be considered in the planning and execution of procedures in several areas of clinical practice dentistry in order to avoid complications. Moreover, it was found that the incidence of retromolar foramen contributes to differentiation of ethnic groups in the area of forensic anthropology.

Celecoxib treatment does not alter recruitment and activation of osteoclasts in the initial phase of experimental tooth movement

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

Microscopic evaluation of induced tooth movement in traumatized teeth: an experimental study in rats

The clinical management of orthodontic patients with dental trauma before or during the treatment is mainly founded on clinical experience, expert opinions, and individual case reports. It is proposed in the literature that teeth sustaining mild trauma with minor damage to the periodontium (e.g. subluxation) should be followed for a period of time before being subjected to orthodontic forces. A minimum period of 3 months has been proposed. In this study, we used an animal model to investigate whether shorter observation periods could be established in case of mild trauma. The periradicular region of rat molars was examined microscopically to determine the biological events of tooth movement started 15 and 30 days after intentional subluxation using an experimental method to induce dentoalveolar trauma. Thirty adult male Wistar rats were assigned to 6 groups (n = 5): Group 1 (control no trauma/orthodontic movement); Group 2: the animals received an orthodontic device and were sacrificed after 7 days; Groups 3 and 4: dentoalveolar trauma (subluxation) was experimentally induced by the application of an axial force of 900 cN on the occlusal surface of the maxillary right first molar, and the animals were sacrificed after 22 and 37 days, respectively; and Groups 5 and 6: 15 and 30 days, respectively, after force application, an orthodontic device was installed and the rats were sacrificed 7 days later. In G5 and G6, the periodontal ligament and pulp tissue were rich in cellular elements and blood vessels, the alveolar bone was preserved, and the root surface presented only very small areas of surface resorption (cementum), maintaining the characteristics of normality. In conclusion, the microscopic alterations in the gingival and periodontal tissues in response to an experimentally induced mild dentoalveolar trauma simulating subluxation were not sufficient to contraindicate starting the orthodontic movement 15 and 30 days after trauma.

Histomorphometric evaluation of periodontal compression and tension sides during orthodontic tooth movement in rats

OBJECTIVE: The purpose of this study was to evaluate the thickness of the periodontal ligament of rat molars during orthodontic tooth movement (OTM). METHODS: Thirty Wistar rats were divided into three groups of 10 animals each: GI, GII and GIII and the mice were euthanized at 7, 14 and 21 days, respectively. Experimental subjects were compared to their respective controls by the Mann-Whitney test. Comparison of values between compression and tension sides were performed during the same and different time periods through Analysis of Variance (ANOVA), Kruskal-Wallis test and, subsequently, Tukey's test. RESULTS: Groups GI and GII showed decreased PDL size in the apical regions of the mesiobuccal root and in the cervical region of the distobuccal root. There was also an increased PDL in the cervical regions of the mesiobuccal root, apical region of the distobuccal root and middle region of both roots. CONCLUSION: The reduction and increase in PDL size were seen in the same root, which characterizes tooth inclination. The apical, middle and cervical regions were compared with one another in each time period and at three times: 7, 14 and 21 days. They were also compared in each region, confirming a tipping movement in GI and GII and a gradual decreased intensity between GI to GII, reaching normal dimension in GIII.

Quantitation of malondialdehyde in gingival crevicular fluid by a high-performance liquid chromatography-based method

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

Incisive Canal Deflation for Correct Implant Placement: Case Report

Aim: This article is a case report of a patient in whom the prosthetic planning indicated the necessity of an incisive canal deflation for the correct installation of all implant that is to be osseointegrated.Case Report. In the reopening phase after the bone graft installation, the incisive canal deflation (biopsy of its content) was done and titanium implants were installed with one of them invading the anatomical space occupied previously by the incisive canal. The biopsy analysis showed fragments of the incisive artery and nerve., which are responsible for the anterior upper-tooth pulp, the periodontium vascularization. and the innervation. Front the anastomosis present along with other structures allied with the absence of teeth in the region, there was no detriment to the patient caused by the deflation.Conclusion: Incisive canal deflation is a viable technique in implantology. It can permit ideal prosthetic planning with no detriment to the patient. (Implant Dent 2009;18:473-479)

Cell death and quantitative reduction of rests of Malassez according to age

Background and Objective: Rests of Malassez are clusters of epithelial cells that remain in the periodontal ligament throughout life. However, it has been reported that the number of these structures decreases with age, and some epithelial cells undergo apoptosis in rests of Malassez of young and adult rats. Therefore, the purpose of the present study was to investigate the incidence of epithelial cell death and the quantitative changes in the rests of Malassez in rat molars of different ages.Material and Methods: Fragments containing the upper molars of rats aged 29, 45 and 120 d were fixed, decalcified and embedded for analysis by light microscopy. In the sections stained by hematoxylin and eosin, the number of rests of Malassez and the number of nuclei of these epithelial structures were obtained. Moreover, the nuclei exhibiting typical features of cell death were also counted in each rest of Malassez. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method for detection of cell death was also carried out.Results: In all groups examined, some rests of Malassez exhibited epithelial cell nuclei with typical features of apoptosis and some of them were also TUNEL positive. From 29 to 120 d of age in rats, the quantitative analysis showed a significant decrease in the total number of rests of Malassez in the cervical, middle and furcation regions of the periodontal ligament. Moreover, a significant decrease of epithelial cell nuclei was concomitant to an increase in the frequency of cell death in the oldest rats.Conclusion: These results suggest that epithelial cell death by apoptosis may be, at least in part, responsible for the reduction in the number of rests of Malassez according to age.

Histological and histomorphometrical evaluation of furcation perforations filled with MTA, CPM and ZOE

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

Influence of chronic alcoholism and oestrogen deficiency on the variation of stoichiometry of hydroxyapatite within alveolar bone crest of rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Periodontal changes in patients undergoing radiotherapy

Background: the purpose of this study was to evaluate changes in the periodontium in patients who received head and neck radiation therapy.Methods: Periodontal clinical parameters (probing depth, clinical attachment level, gingival recession, plaque index, and bleeding on probing) were assessed on 27 patients before and 6 to 8 months following radiation therapy in the head and neck area.Results: the greatest changes occurred in clinical attachment level: overall, 70.3% of the patients showed a loss, with 92% evincing loss in the mandible. Attachment loss was directly related to the field of radiation and was greater when the jaws were actually included in the irradiated area.Conclusion: Periodontal status should be evaluated prior to and following radiation therapy in the oral-maxillary-facial region to help ensure that periodontal health is maintained in oncology patients.

Biomecánica da movimentação ortodôntica--resposta inicial dos tecidos periodontais.

There occurs a biological response of the tissues of dental support, in answer to the external physiological forces and those realized during clinical treatments with orthodontical purposes. These forces differ from the first ones because they are continuous and time dependent. A great dental mobility is related to the degree of tissue organization of the periodontium system and the orthodontical movement must utilize this exceptional capacity of renewal and adaptation of the periodontium structures adequately. Therefore, through histological means a search was made to evaluate the succession of alterations of the periodontium system after the application of an orthodontical force on the molars of young rats and to interpret the standards of horizontal mobility and their consequences on the periodontium structures, biologically. An orthodontic force was applied on young rats utilizing steel wire placed in a ring form on a contact point between the first and second lower molars. The animals were sacrificed after 30 minutes, 1, 2, 6, 12, 24, 48, 72, 96 and 168 hours after the placement of the metal ring. After technical preparation, the microscopic slides were examined and the results were compared. In all the sections there was evidence of an intense metabolic activity. A gradual evolution of modification on the phenomenons had occurred.

Comportamento dos tecidos periapicais de dentes de cães após a obturação de canal com Sealapex acrescido ou não de iodoformio.

Some endodontists use iodoform in Sealapex in order to rend it more radiopac. This procedure is empiric and for this reason we decided to observe, histologically, if the iodoform introduces some modification in the biological properties of Sealapex. Thirty root canals of dogs' teeth were overinstrumented and filled, by lateral condensation technique, with gutta percha points and Sealapex, with or without iodoform. The iodoform was added in two different proportions: 30 mg or 112 mg for one centimeter of the base and one centimeter of the catalyst of Sealapex. The pieces were removed for histological studies, 6 months after the treatment. The histological results showed that Sealapex encourages apical closure by cementum deposition and that the addition of iodoform does not change that biological property.

Presença de detritos na região apical de dentes de cães apos o preparo biomecánico com ou sem o emprego de substância auxiliar cremosa.

The subject of this work is to observe if the employment of a cream (ENDO-PTC) during the root canal preparation contributes or not to the condensation of debris in the apical region. Twenty root canals of dogs teeth were divided into two experimental groups: in the first one, the biomechanical preparation was carried out up to the n. 50 Kerr file by using irrigation and aspiration with sodium hypochlorite. In the second experimental group the canal negotiation was done in the same way but using a cream (ENDO-PTC) with sodium hypochlorite as a lubrication substance. A final irrigation and aspiration with sodium hypochlorite was also done in this group. The animal was killed and the pieces prepared for histological analysis. The histological results show us that the employment of a cream during the negotiation of the root canal contributes to a higher condensation of debris in the apical area.

Pulpal and periodontal reactions of immature permanent teeth in the dog to intrusive trauma.

Pulpal and periodontal tissues of immature incisors of 10 dogs were radiographically and histopathologically evaluated immediately, 7, 15, 30 and 60 days after experimental intrusion induced by mechanical blows. Forty upper central and mesial lateral incisors showing incomplete root formation on radiographs were submitted to intrusive force. After the observation periods, the dogs were killed, two at a time. The hemi-maxilas were removed and processed for histopathologic examination. The traumatized teeth showed accelerated apical formation with reduced radicular length. Pulpal vitality was maintained and the subjacent tissues did not present irreversible changes. All traumatized teeth re-erupted spontaneously.

Calcium hydroxide and a corticosteroid-antibiotic association as dressings in cases of biopulpectomy. A comparative study in dogs' teeth.

The subject of this paper was to study the behavior of the periapical tissues of dogs' teeth after biopulpectomy and dressing with calcium hydroxide or a corticosteroid-antibiotic association, before root canal filling with zinc oxide eugenol (ZOE) or Sealapex sealers. The teeth were overinstrumented and dressed for 7 days before the root canal filling. The animals were sacrificed 180 days after treatment and the specimens were prepared for morphological analysis. Specimens treated with Sealapex presented a higher number of cases with biological closure than ZOE. When the root canals were filled with ZOE, better results were observed with the use of the Ca(OH)2 dressing.