• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.1
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• pp.1-7
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• 2001

The Dentigerous cyst is reported to be one of the most common lesions of the jaw. It is derived from reduced enamel epithelium that surrounds the crown of an unerupted tooth. Dentigerous cysts usually remains asymptomatic and presents as well-circumscribed radiolucencies surrounding the crown of a tooth. Most dentigerous cysts are treated by surgical enucleation or marsupialization of the cyst to allow eruption of the permanent tooth. The nasopalatine duct cysts derived from the islands of epithelium remaining after closure of the embryonic nasopalatine duct. The cyst presents as a well-circumscribed oval or heart-shaped radiolucency located in the midline of the anterior maxilla between the roots of the central incisors. Treatment is by surgical enucleation, employing a palatal approach. This report present two cases. One case was diagnosed with dentigerous cyst and treated by enucleation. 12 Months later, affected second premolar was erupted normally. The other case was diagnosed with nasopalation duct cyst. Histological examination of the enucleated cyst confirmed a nasopalatine duct cyst. There was no recurrence during follow up period.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.1
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• pp.38-48
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• 2011

Purpose: Dentists suffer back, neck and shoulder pain during their careers due to bad operating posture. If dentists have a good operating posture ergonomically, there would be less pain and discomfort in the shoulder and back. Therefore, dentists should learn the Home position which enables dentists to approach a stable posture ergonomically. This study was to compare tooth preparation in the Home position and the Random position, and evaluate the clinical efficacy of the Home position. Materials and methods: Tooth preparation for fixed partial denture was performed on the maxillary left 2nd premolar and maxillary left 2nd molar at the two different operating positions were compared. The amount of occlusal reduction, marginal width, subgingival margin depth, and convergence angle were measured. A T-test was performed separately to compare the results of the Random position and the Home position. Results: 1. The amounts of average thickness of occlusal reduction on fossa were deficient to the ordered ones in the Random position and the Home position (P > .05). 2. The average subgingival margin depth of prepared margin on maxillary left 2nd premolar, maxillary left 2nd molar were excessive in the Random position than in the Home position. On the maxillary left 2nd premolar, there was no statistical difference in the Random position and the Home position except Distal midline, DL line angle, Lingual midline, ML line angle (P< .05). On the maxillary left 2nd molar, there was no statistical difference in the Random position and the Home position (P < .05). 3. Average convergence angle in the Random position and the Home position were excessive compared to the ordered angle. There was no statistical difference in the Random position and the Home position (P > .05). 4. Analysis of pearson correlation : In the Random position, the amounts of average thickness of occlusal reduction, the average subgingival margin depth of prepared margin, convergence angle were significantly associated with each other (P < .05). But in the Home position, they were not significantly associated with each other (P < .05). 5. The time needed for preparation in the Home position was faster or equal than that of the Random position as time went on. Conclusion: In conclusion, there were no significant differences between Home position and Random position in measures of occlusal reduction, marginal width, marginal depth, convergence angle. However, preparation time and incidence of damaging adjacent teeth were less in Home position than in Random position. Therefore, if trained properly, Home position which is more ergonomically stable can be adopted for clinical use.