• International Journal of Oral Biology
• /
• v.35 no.4
• /
• pp.169-175
• /
• 2010

Cholinesterase (ChE) is one of the most ubiquitous enzymes and in addition to its well characterized catalytic function, the morphogenetic involvement of ChE has also been demonstrated in neuronal tissues and in non-neuronal tissues such as bone and cartilage. We have previously reported that during mouse tooth development, acetylcholinesterase (AChE) activity is dynamically localized in the dental epithelium and its derivatives whereas butyrylcholinesterase (BuChE) activity is localized in the dental follicles. To test the functional conservation of ChE in tooth morphogenesis among different species, we performed cholinesterase histochemistry following the use of specific inhibitors of developing molar and incisors in the hamster from embryonic day 11 (E11) to postnatal day 1 (P1). In the developing molar in hamster, the localization of ChE activity was found to be very similar to that of the mouse. At the bud stage, no ChE activity was found in the tooth buds, but was first detectable in the dental epithelium and dental follicles at the cap and bell stages. AChE activity was found to be principally localized in the dental epithelium whereas BuChE activity was observed in the dental follicle. In contrast to the ChE activity in the molars, BuChE activity was specifically observed in the secretory ameloblasts of the incisors, whilst no AChE activity was found in the dental epithelium of incisors. The subtype and localization of ChE activity in the dental epithelium of the incisor thus differed from those of the molar in hamster. In addition, these patterns also differed from the ChE activity in the mouse incisor. These results strongly suggest that ChE may play roles in the differentiation of the dental epithelium and dental follicle in hamster, and that morphogenetic subtypes of ChE may be variable among species and tooth types.

• The korean journal of orthodontics
• /
• v.27 no.2
• /
• pp.349-357
• /
• 1997

Epidermal growth factor(EGF), a single chain polypeptide of 53 amino acids with a molecular weight of 6,045 Da, was first isolated from the male mouse submandibular glands. EGF stimulates cellular proliferation and differentiation in several tissues and accelerates the rate of wound healing. EGF is bound to the specific receptor(EGFR) on the cell membrane of its target cell. EGFR is a transmembrane glycoprotein with a molecular weight of 170,000 Da and is detectable on a large variety of cell types and tissues. The authors investigated the expression of EGFR in the normal and inflamed human gingival epithelium to study the role of EGFR in the inflammation of the gingival epithelium, and the expression of EGFR in the dental follicle by using in situ mRNA hybridization and immunohistochenistry. The results weree as follows : 1. The expression of EGFR mRNA in the normal gingival epithelium on in situ mRNA hybridization was mainly localized on the basal cell layer, and the spinous layer was weakly positive The granular and cornified layers were negative 2. The expression of EGFR protein in the normal gingival epithelium on inmunohistochemistry was localized on the cornified and granular layers, and the spinous layer was weakly positive. The basal cell layer was completely negative 3. The expression of EGFR mRNA in the inflamed gingival epithelium on in situ mRNA hybridization was evenly and homogeneously distributed in the whole layers of the gingival epithelium except the cornified layer. The staining intensity appeared to increase progressively from the basal cell layer to the cornified layer. 4. The expression of EGFR protein in the inflamed gingival epithelium on immunohistochemistry was evenly and homogeneously distributed in the whole layers of the gingival epithelium. The staining intensity appeared to increase progressively from the cornified layer to the basal cell layer. 5. Strong positive reaction was seen in the epithelial cell rests of Malassez, whereas only background staining was seen in other cells of the dental follicle. In conclusion, the up-regulation of EGFR in the inflamed gingival epithelium and the high amounts of EGFR in the epthelial cell rests of Malassez in the dental follicle can be regarded as responses to the possible damages to the oral environment to maintain the homeostatic conditions.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.27 no.1
• /
• pp.32-36
• /
• 2001

To investigate epithelial cell proliferation reactivity in the odontogenic cysts, the expression of c-erbB-2 oncoprotein by epithelial lining was studied in odontogenic keratocyst(OKC, n=10), dentigerous cyst(DC, n=12), radicular cyst(RC, n=12) and normal dental follicle(n=7). The c-erbB-2 immunoreactivity was studied using a streptavidine- biotin- peroxidase method with polyclonal rabbit antihuman antibody to c-erbB-2 oncoprotein which is known to react with formalin fixed, paraffin-embedded sections and the intensity of staining was determined by manually. In all of 10(100%) OKCs, showed positive expression for c-erbB-2 oncoprotein compared with 10/12(83.3%) in DCs, 11/12(91.7%) in RCs and 5/7(71.4%) in normal dental follicles. The expression within OKC was higher than that of DC, RC and dental follicle but statistically not significant(p>0.05) and but may reflects underlying genetic defect. These results demonstrate differences in c-erbB-2 expression between the epithelial linings of the three major odontogenic cyst types, indicating differences in proliferation activity and differentiation processes within these lesions. And, in particular, these results are able to explain the peculiar aggressive growth pattern of OKC.

• The Journal of the Korean dental association
• /
• v.50 no.6
• /
• pp.312-321
• /
• 2012

Permanent canine are very important teeth in point of function as well as esthetic. Therefore impaction of canines is a frequently encountered clinical problems. The incidence of impaction ranges between 1-3%. The cause of canine impaction can be result of ectopic position of tooth germ, defect of dental follicle, early loss or delayed exfoliation primary canine, space problem, supernumarary teeth, cyst, odontoma, Impaction frequently involves further complication such as root resorption of adjacent teeth, cyst formation and migration of the neighboring teeth. Various treatment modalities include extraction of primary canine, surgical opening and orthodontic traction, autotransplantation, surgical extraction of impacted canine.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.25 no.1
• /
• pp.151-157
• /
• 1995

Desmoplastic variant of ameloblastoma is a new and unusual variant of ameloblastoma with extensive stromal desmoplastic proliferation. The authors experienced a case of desmoplastic variant of ameloblastoma with moderate-defined radiolucency on the right maxillary anterior area in 62-year-old female. As a result of careful analysis of clinical, radiological, histopathological examinations, we diagnosed it as desmoplastic variant of ameloblastoma, and the following results were obtained : 1. Main clinical symptoms were nontender bony swelling with normal intact overlying mucosa on the right maxillary anterior area. 2. Radiographically, moderate-defined, multilocular radiolucency on the right maxillary anterior area were shown, and severe cortical bony thinning and expansion to labial and palatal sides were also observed. And this lesion was shown to be extended to the right nasal cavity. 3. Histopathologically, follicle-like epithelial islands with densely abundant collagenous stroma were morphologically compressed.

• The Journal of the Korean dental association
• /
• v.50 no.6
• /
• pp.304-311
• /
• 2012

Eruption of the teeth can be disturbed by crowding, ectopic eruption path, retention for pathologic condition of follicle and periodontal ligament, local disturbances in the innervation, and delayed eruption for overlying obstacles in the eruption path. Eruption disturbance of permanent posterior teeth is taken with diverse therapeutic approaches according to the patient age, cooperation of patient, tooth position and maturity, degree of impaction, clinical features, and repercussion on the neighboring teeth. However, delayed treatment usually results in less favorable outcomes. Therefore, In order to prevent this situation, periodically radiographic examinations during the early mixed dentition period and early diagnosis of eruption disturbances of permanent posterior teeth are recommended.

• Imaging Science in Dentistry
• /
• v.32 no.4
• /
• pp.231-234
• /
• 2002

The odontogenic myxoma is an infiltrative benign tumor of bone that occurs almost exclusively in the jaw bones and comprises 3% to 6% of odontogenic tumors. This neoplasm is thought to arise from the primitive mesenchymal structures of a developing tooth, including the dental follicle, dental papilla, or periodontal ligament. Radiographically the odontogenic myxoma may produce several patterns: unicystic, multilocular, pericoronal, and radiolucent-radiopaque, making the differential diagnosis difficult. In this report, two cases of the odontogenic myxoma in the jaw bones are presented. The first case involved only the mandible, while the second case involved the maxilla. Both cases presented extensive multilocular radiolucencies characteristic of odontogenic myxoma.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.34 no.4
• /
• pp.490-494
• /
• 2008

Pilomatricoma, calcifying epithelioma of Malherbe, is a benign skin neoplasm of hair matrix origin that is typically occurred in the head and neck region. It usually presents as a superficial, firm, solitary, slow-growing, and painless mass of less than 3 cm in diameter and most often occurs in young age under 20 years. The tumor does not express an aggressive behavior and surgical excision is the treatment of choice. The purpose of this article is to present a case of pilomatricoma of the preauricular region and to review the literature regarding pilomatricomas of the head and neck region.

• Imaging Science in Dentistry
• /
• v.30 no.3
• /
• pp.169-181
• /
• 2000

Purpose: To investigate the expression of bone morphogenetic protein (BMP)-2/4 during eary tooth development after irradiation and calcium-deficient diet. Materials and Methods: The pregnant three-week-old Sprague-Dawley rats were used for the study. The control group was non-irradiation/normal diet group (Group 1), and the experimental groups were irradiation/normal diet group (Group 2) and irradiation/calcium-deficient diet group (Group 3). The abdomen of the rats at the 9th day of pregnancy were irradiated with single dose of 350 cGy. The rat pups were sacrificed at embryonic 18 days, 3 days and 14 days after delivery and the maxillae tooth germs were taken. The tissue sections of specimen were stained immunohisto-chemically with anti-BMP-2/4 antibody. Results: At embryo-18 days, immunoreacivity for BMP-2/4 of the Group 1 was modetate in stratum intermedium of dental organ and weak in dental papilla and dental follicle, but that of Group 2 was weak in cell layer of dental organ, and no immunoreacivity was shown in dental papilla and dental follice of Group 2 and in all tissue components of the Group 3. At postnatal-3 days, immunoreacivity for BMP-2/4 of the Group 1 was strong in cell layer of dental organ, odontoblasts and developing alveolar bone, but that of Group of 2 and Group 3 was weak in odontoblasts and developing alveolar bone. At postnatal-14 days, immunoreacivity for BMP-2/4 of the Group 1 was strong in newly formed cementum, alveolar bone and odontoblasts, but that of Group 2 was weaker than that of Group 1. In the Group 3, tooth forming cell layer showed weak immunoreactivity, but other cell layers showed no immunoreactivity. Couclusion : The expression of bone morphogenetic protein (BMP)-2/4 during early tooth development was disturbed after irradiation and calcium-deficient diet.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.35 no.6
• /
• pp.486-489
• /
• 2009

Odontogenic Myxoma of the jaws is a rare benign tumor derived from embryonic mesenchymal elements of dental anlage. It appears to originate from the dental papilla, follicle or periodontal ligament. Odontogenic Myxoma of the maxilla is less frequent but behaves more aggressively than that of the mandible, because it spreads through the maxillary sinus. Radiographically, the tumors present as unilocular or multilocular radiolucent lesions with well-defined borders with fine, bony trabeculae. On gross examination, the tumor appears as a smooth, glistening, gelatinous, lobulated mass. On microscopic examination, these neoplasms exhibit loose arrangement of stellate-shaped cells. The intercellular substance is a mucinous and homogeneous matrix. We report a case of odontogenic myxoma of the maxilla observed in our clinic with good prognosis after partial maxillectomy.