Oral mucosal lesions during orthodontic treatment.

BACKGROUND: Oral mucosal lesions can result from irritation caused by orthodontic appliances or malocclusion, but their frequency is not known. AIM: To examine the frequency of oral mucosal lesions in wearers of orthodontic appliances in comparison to children with malocclusion. DESIGN: This study comprised 111 subjects: 60 wearers of orthodontic appliances and 51 controls (aged between 6 and 18 years). Type and severity of mucosal lesions, their topography, gingival inflammation, and oral hygiene status were determined by using clinical indices. RESULTS: Mucosal lesions were more present in wearers of orthodontic appliances than in children with malocclusion. Gingival inflammation, erosion, ulceration, and contusion were the most common findings in orthodontic patients. The severity of gingival inflammation was in correlation with oral hygiene status; the poorer oral hygiene, the more severe gingival inflammation was. Better oral hygiene status was found in children during orthodontic treatment than in children with malocclusion. CONCLUSIONS: Orthodontic treatment carries a higher risk of mucosal lesions and implies greater awareness of better oral hygiene as shown by the results of this study. Oral hygiene instructions and early treatment of oral lesions are important considerations in better patient's motivation, treatment planning, and successful outcome.

Influence of different etching times on dentin surface morphology.

The aim of this study is to investigate the influence of different etching times on demineralized dentin surface morphology using scanning electron microscopy and qualitative line microanalysis of chemical structure. Two sample groups, consisting of 30 first premolar teeth in each group, were established. Teeth were cut at the half-distance between the enamel-dentin junction and the pulp. The first group of specimens was etched for 10 seconds and the second group for 30 seconds. 37% ortophosphoric acid was used. SEM (scanning electron microscopy) was utilized to observe the following parameters: number and diameter of dentinal tubules, dentinal and intertubular dentinal surface percentage, appearance of the dentin surface porous zone containing smear layer and demineralized residual collagen particles with dentin demineralization products in acid globules, and dissolved peritubular dentin cuff. After calculating measurements of central tendency (X,C, Mo, SD), Kolmogorov-Smirnov and Student t-test were performed to confirm the quantitative results, and the chi2-test was run to produce qualitative data. In contrast to the 10-second etching time, the increased etching time of 30 seconds resulted in the following findings: (1) an increased number of dentinal tubules (p < 0.05), (2) an increase in dentinal tubule diameter (p < 0.05), (3) an increase in dentinal tubule surface percentage (p < 0.001), (4) a decrease in intertubular dentinal surface percentage (p < 0.001), (5) appearance of dentin surface porous zone containing smear layer and demineralized residual collagen particles with dentin demineralization products in acid globules (p < 0.001), and (6) completely dissolved peritubular dentin cuff (p <0.001). Therefore, different etching times using the same phosphoric acid concentration result in different morphological changes in demineralized dentin surface. Moreover, based on a comparison with current studies, prolonged etching time causes morphological changes to dentin surface. Such changes, have, in turn, negative effects on the dentin hybridization process.

Biological bases of dentin hybridization.

The aims of this study were threefold: (1) to characterize and quantify the number, diameter and surface area of exposed dentinal tubules on the cross section of the human coronal dentin; (2) to determine if any such differences in these properties arise in relation to the distance from the dentinoenamel junction; and (3) to evaluate whether such differences can influence dentin hybridization. To accomplish these aims, scanning electron microscopy comparative observation was carried out on 60 prepared human premolars, which were divided into three groups of 20 samples each. The three sample groups were cut as follows: (1) in the central fissure region, one millimeter from the enamel-dentine junction; (2) halfway between the enamel-dentine junction and the pulp; and (3) one millimeter from the roof of the pulp chamber. Using one-way analysis of variance (one-way ANOVA) and a regression linear model, the data enumerated below were obtained. First, the mean number of the tubule openings was 19600/mm2 on the first level, 32400/mm2 on the second and 42300/mm2 on the third. The mean tubule diameter on the first level was 0.67 microm, 1.52 microm on the second and 2.58 microm on the third. Finally, exposed tubules on the first level occupied 2.79% of of total dentinal surface area, 23.90% on the second, and 87.78% on the third level. Therefore, significant statistical differences (p < 0.01) between all three groups of the specimens for all three properties were observed, as well as positive correlation between the dentin depth and each of these properties. This indicates that the dentin structural variety, which ultimately determines adhesion to dentine, involves a complex interaction between biological material (dentin) and the particular adhesion system applied.

Colorectal Adenocarcinoma Metastasizing to the Oral Mucosa of the Upper Jaw.

INTRODUCTION: Metastases to the oral cavity are uncommon, accounting for only 1% of all oral malignant tumors. When they occur they mostly originate from primary tumors of the lungs, kidney, breast and prostate. Oral metastases from the primary colorectal carcinoma are much more infrequent. CASE OUTLINE: We present an unusual case of a 78-year-old man with a soft tissue oral metastasis originating from the primary colorectal carcinoma.The patient was referred to the Department of Otorhinolaryngology, Head and Neck Surgery with an intraoral mass on the right side of the maxilla. The diagnosis was confirmed by histopathologic examination and immunohistochemical analysis. CONCLUSION: Oral metastases occur rarely and often can mimic much more common benign lesions, therefore they should be considered as a possibility in a differential diagnosis.

Gastric adenocarcinoma metastases to the alveolar mucosa of the mandible: a case report and review of the literature.

Malignant tumours rarely metastasize to the oral cavity. When they do, such metastases may arise from various locations including the lung, breast, kidney, prostate and colon. Soft tissue oral metastasis from gastric adenocarcinoma is extremely rare, and limited information exists regarding the presentation and work-up of metastatic gastric carcinoma into the oral soft tissue. We present an unusual case of a 70-year-old man and review the records of 17 cases of soft tissue oral metastasis from gastric carcinoma in the English and Japanese literature. Metastatic lesions from all sources are typically diagnosed in patients in their fifth to seventh decade, with the most common sites of soft tissue metastasis being the gingiva and alveolar mucosa of the mandible. In almost one quarter of patients a metastatic lesion in the oral cavity is the first manifestation of an undiscovered primary malignancy. They grow rapidly and tend to bleed and ulcerate. Because of their rarity and clinical characteristics, gastric metastatic tumours in the oral cavity are challenging to diagnose. Inflammatory and reactive lesions are common in the oral cavity and they should be considered in the differential diagnosis. Careful examination with a high degree of clinical suspicion, as well as a multidisciplinary approach is suggested.