Effect of isotretinoin on induced tooth movement in rats.

INTRODUCTION: This study was performed to evaluate the effect of isotretinoin on tooth displacement and tissues related to induced tooth movement (ITM) in rats. METHODS: Wistar rats were randomly divided into 4 groups: vegetable oil (O; n = 40), 7.5 mg/kg isotretinoin (I; n = 40), vegetable oil + ITM (OM; n = 44), and 7.5 mg/kg isotretinoin and ITM (IM; n = 39). After the daily application of the solutions for 30 days, an orthodontic appliance was installed to mesially displace the maxillary first right molar (30 cN) of rats in the OM and IM groups. The animals were killed 2, 7, 14, or 21 days after placement of the devices. The animals in the O and I groups did not undergo ITM but were killed simultaneously. The animals were examined for tooth displacement, the neoformation of mature collagen, bone and root resorption, the presence of hyalinized areas, and trabecular bone modeling by microcomputed tomography. RESULTS: There was no difference in tooth displacement, the number of osteoclasts, the presence of hyalinized areas, or trabecular bone among the O, I, OM, and IM groups across the periods tested (P >0.05). A lower percentage of mature collagen was found in the IM group than in the OM group on day 7 (P <0.05). A lower frequency of root resorption was found in the IM group than in the OM group on days 2 and 21 (P <0.05). CONCLUSIONS: Isotretinoin at 7.5 mg/kg decreased root resorption in rats subjected to ITM.

Evaluation of 2 techniques of epithelial removal in subepithelial connective tissue graft surgery: a comparative histological study.

PURPOSE: Subepithelial connective tissue grafts (SCTGs) are commonly performed for the treatment of gingival recession due to their high predictability. This study evaluated and histologically compared connective tissue grafts in terms of the presence of epithelial remnants and composition of the tissue types that were present (epithelium, lamina propria, and submucosa). METHODS: Ten patients underwent epithelium removal using 2 different techniques: the use of a blade (group B) and through abrasion (group A). Twenty samples were collected and each tissue type was analyzed histologically in terms of its area, thickness, and proportion of the total area of the graft. RESULTS: In 4 samples (40%) from group B (n=10) and 2 samples (20%) from group A (n=10), the presence of an epithelial remnant was observed, but the difference between the groups was not statistically significant (P>0.05). Likewise, no statistically significant differences were observed between the groups regarding the area, mean thickness, or proportion of the total area for any of the tissue types (P>0.05). CONCLUSIONS: Histologically, SCTGs did not show statistically significant differences in terms of their tissue composition depending on whether they were separated from the epithelial tissue by abrasion or by using a blade.

Effect of fluoxetine on induced tooth movement in rats.

INTRODUCTION: Fluoxetine is a widely used antidepressant. Its various effects on bone mineral density are well described. The aim of this study was to evaluate the effect of fluoxetine on induced tooth movement. METHODS: Seventy-two Wistar rats were divided into 3 groups: M (n = 24; 0.9% saline solution and induced tooth movement), FM (n = 24; fluoxetine, 10 mg/kg, and induced tooth movement), and F (n = 24; fluoxetine, 10 mg/kg only). After 30 days of daily saline solution or fluoxetine administration, an orthodontic appliance (30 cN) was used to displace the first molar mesially in groups M and FM. The animals were killed 3, 7, and 14 days after placement of the orthodontic appliances. The animals in group F did not receive induced tooth movement but were killed at the same times. We evaluated tooth movement rates, collagen neoformation rates by polarization microscopy, numbers of osteoclast by tartrate-resistant acid phosphatase, and trabecular bone modeling by microcomputed tomography of the femur. RESULTS: The tooth movement rates were similar in groups M and FM at all studied time points (P >0.05). The rate of newly formed collagen had a reverse pattern in groups M and FM, but the difference was not statistically significant (P >0.05). There were significantly more osteoclasts in group FM than in group F on day 3 (P <0.01). The trabecular spacing was significantly larger in group F compared with group M on day 14 (P <0.05). CONCLUSIONS: Fluoxetine did not interfere with induced tooth movement or trabecular bone in rats.

Gingival Anaplastic Large-Cell Lymphoma Mimicking Hyperplastic Benignancy as the First Clinical Manifestation of AIDS: A Case Report and Review of the Literature.

This paper presents an unusual case of gingival ALCL, which mimicked a benign hyperplastic lesion that occurred in a 57-year-old white man representing the first clinical manifestation of acquired immunodeficiency syndrome (AIDS). The patient was referred to the Dental Clinic of PUCPR complaining of a lobulated nodule on the gingiva of his upper central incisors. The presence of advanced chronic periodontitis and dental plaque raised suspicion for a benignancy. An excisional biopsy was performed, and large pleomorphic cells with an abundant cytoplasm, sometimes containing prominent nucleoli and "Hallmark" cells, were observed through hematoxylin and eosin staining. The tumor cells showed strong CD30 expression, EMA, Ki-67, and LCA, and negative stain for p80(NPM/ALK), CKAE1/AE3, CD20, CD3, CD56, and CD15. The final diagnosis was ALCL (ALK-negative). Further laboratory tests revealed positivity for human immunodeficiency virus (HIV). The patient was submitted to chemotherapy, but four months after diagnosis, the patient died due to pneumonia and respiratory failure. Oral anaplastic large-cell lymphoma (ALCL) is a rare disorder. Only 5 cases involving the gingiva have been reported, and to our knowledge, this is the first case reported of the ALCL, which mimicked a hyperplastic benignancy as the first clinical manifestation of AIDS.

Metallothionein immunoexpression in oral leukoplakia

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Objectives: to report the immunoexpression of metallothionein in oral leukoplakia and to correlate with histological grade and clinical localization. Leukoplakia is the most common potentially malignant lesion of the oral cavity. As the histological study of oral leukoplakia can not predict precisely the malignant transformation of this lesion, and metallothionein is a protein that has been associated with carcinogenesis, this study could be auxiliary in this histological assessment of this lesion.Study design: samples of oral leukoplakia (35 cases) and of normal oral mucosa (10 cases) were evaluated. Oralleukoplakia was graded in: hyperkeratosis without dysplasic change (9 cases), mild dysplasia (8 cases), moderated dysplasia (10 cases), and severe dysplasia (8 cases). Immunohistochemistry for the metallothionein was performed and the Mann-Whitney test was used in statistical analysis.Results: metallothionein was identified in squamous cells of the all samples. The metallothionein stain in all cases exhibit a mosaic pattern and was predominantly in compartments cytoplasmatic and nuclear simultaneously. The total stain was significantly higher in moderate dysplasia when compared with normal oral mucosa, hyperkeratosis, and mild dysplasia.Conclusion: it was suggested that the metallothionein may be a marker to moderate dysplasia and may play a rolein oral carcinogenesis