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 anti-human 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.
Dental Sac ; Epithelial Cells ; Formaldehyde ; Immunohistochemistry ; Odontogenic Cysts* ; Peroxidase

PURPOSE: To describe the features of impacted upper canines and their relationship with adjacent structures through three-dimensional cone-beam computed tomography (CBCT) images. MATERIALS AND METHODS: Using the CBCT scans of 79 upper impacted canines, we evaluated the following parameters: gender, unilateral/bilateral occurrence, location, presence and degree of root resorption of adjacent teeth (mild, moderate, or severe), root dilaceration, dental follicle width, and presence of other associated local conditions. RESULTS: Most of the impacted canines were observed in females (56 cases), unilaterally (51 cases), and at a palatine location (53 cases). Root resorption in adjacent teeth and root dilaceration were observed in 55 and 47 impacted canines, respectively. In most of the cases, the width of the dental follicle of the canine was normal; it was abnormally wide in 20 cases. A statistically significant association was observed for all variables, except for root dilaceration (p=0.115) and the side of impaction (p=0.260). CONCLUSION: Root resorption of adjacent teeth was present in most cases of canine impaction, mostly affecting adjacent lateral incisors to a mild degree. A wide dental follicle of impacted canines was not associated with a higher incidence of external root resorption of adjacent teeth.
Cone-Beam Computed Tomography* ; Cuspid ; Dental Sac ; Female ; Humans ; Incidence ; Incisor ; Root Resorption ; Tooth ; Tooth, Impacted

This report describes a 31-year-old female patient with six impacted teeth. The crowns of the impacted teeth were surrounded with cyst-like lesions with a mixed internal structure and well-defined cortical borders. Microscopic examination of the specimen obtained from the follicle of the left mandibular third molar tooth revealed loose to moderately dense collagenous connective tissue with abundant calcified material and sparse epithelial islands. A diagnosis of multiple calcifying hyperplastic dental follicles was made.
Adult ; Collagen ; Connective Tissue ; Crowns ; Dental Sac* ; Diagnosis ; Female ; Humans ; Islands ; Molar, Third ; Tooth ; Tooth, Impacted

OBJECTIVETooth eruption requires the presence of the dental follicle (DF) around the unerupted tooth. This study is to investigate programmed cell death on human dental follicle cells and changes of programmed cell death under different hydrostatic pressures: 0, 50 and 100 kPa.

METHODSHuman dental follicles from third mandibular molars were surgically removed from adolescents who need for orthodontics treatment after informed content, then trypsinized and cultured. Human dental follicle cells were divided into three groups according to different hydrostatic pressures: 0, 50 and 100 kPa and their programmed cell death were labeled by using TdT-medi-ated-dUTP nick and labeling (TUNEL).

RESULTSDental follicle cells cultured were elongate shape and exhibited fibroblastic characteristics. Compared with 0 kPa, programmed cell death cells on human dental follicle cells were increased 0.23% and 31.65% under 50 kPa and 100 kPa hydrostatic pressures respectively. 100 kPa group increased significantly (P < 0.01).

CONCLUSIONIt suggested that programmed cell death occured in human dental follicle cells cultured in vitro and was influenced by different hydrostatic pressures. Hydrostatic pressure may improve tooth erup-tion through dental follicle.

Adolescent ; Apoptosis ; Dental Sac ; Fibroblasts ; Humans ; Hydrostatic Pressure ; Molar ; Tooth Eruption

OBJECTIVEThis study explores the effects of different fibrin glue combination modes on the survival, proliferation, and apoptosis of dental follicle cells (DFCs), as well as to evaluate the feasibility and effectiveness of fibrin glue as transplantation material.

METHODSThe membranes of surviving DFCs were marked using 3,3'-dioctadecyloxa carbocyanine perchlorate (DIO), and the cell number was counted by using ImageJ2x software. The apoptotic cells were marked with prodium iodide (PI).

RESULTSCompared with that of the 3D-2 and 2D-1 groups, the degradation speed of the 3D-1 group was the slowest. DFCs could survive and grow well in fibrinogen with a concentration of 15 mg · mL⁻¹ supplemented with thrombin with a concentration of 2 U · mL⁻¹. In particular, the 3D-1 combination mode was significantly conducive to cell proliferation and stretching.

CONCLUSIONFibrin glue can be used as an effective cell transplantation material. The different combination modes have certain effects on cell proliferation. The 3D-1 combination mode is more conducive to the survival and proliferation of DFCs than other modes.

Apoptosis ; Cell Proliferation ; Cell Survival ; Dental Sac ; cytology ; Fibrin Tissue Adhesive ; pharmacology ; Fibrinogen ; Humans ; Thrombin

Tooth eruption is a series of complicated physiological processes occurring once the crown is formed completely, as well as when the tooth moves toward the occasion plane. As such, the tooth moves through the alveolar bone and the oral mucosa until it finally reaches its functional position. Most studies indicate that the process of tooth eruption involves the alveolar bone, dental follicles, osteoclasts, osteoblasts, and multiple cytokines. Dental follicles regulate both resorption and formation of the alveolar bone, which is required for tooth eruption. Furthermore, root formation with periodontal ligament facilitates continuous tooth eruption. However, the exact mechanism underlying tooth eruption remains unclear. Hence, this review describes the recent research progress on the cellular and molecular mechanisms of tooth eruption.
Dental Sac ; Humans ; Osteoblasts ; Osteoclasts ; Periodontal Ligament ; Tooth ; Tooth Eruption ; physiology ; Tooth Root

Tooth eruption requires remodeling of surrounding tissues. This study was aimed to investigate the effect of indomethacin on the dental follicle and paradental tissues during tooth eruption by observing the distribution and expression of MMP by the immunohistochemical method. Ten mongrel dogs of ten to twelve weeks old were divided into 5 groups; four experimental groups administered indomethacin 2 mg/Kg/day and 8 mg/Kg/day orally 2 times a day for 14 days and 7 days respectively, and the control group was administered a placebo. Permanent teeth before eruption and their surrounding tissues were selected and excised. H and E staining and immunohistochemical stainings of MMP-3 and -9 were performed and examined under the light microscope. Osteoclasts, osteoblasts, periodontal ligament cells, ameloblasts and odontoblasts of the control group all expressed MMP-3 and -9. In the experimental group, osteoclasts, osteoblasts and periodontal ligament cells showed reduced expression of MMP-3 and -9. Magnitude of MMP reduction in the experimental group showed a time and dose of indomethacin administration dependent manner. These results show that indomethacin inhibited MMP-3 and -9 expression in the dental follicle and surrounding tissues and suggest that when indomethacin is administered for long periods, tooth eruption could be delayed.
Ameloblasts ; Animals ; Dental Sac ; Dogs ; Indomethacin* ; Matrix Metalloproteinases* ; Odontoblasts ; Osteoblasts ; Osteoclasts ; Periodontal Ligament ; Tooth Eruption* ; Tooth*

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.
Dental Papilla ; Dental Sac ; Diagnosis, Differential ; Jaw ; Jaw Neoplasms ; Magnetic Resonance Imaging ; Mandible ; Maxilla ; Myxoma* ; Odontogenic Tumors ; Periodontal Ligament ; Tooth

Matrix metalloproteinases (MMPs) have been implicated in tissue development and re-modeling. Dynamic morphological changes of tooth germs reflect involvement of these enzymes during odontogenesis. The present study was performed to investigate expression and localization of MMP-2 and MMP-9, which have been known to have type IV collagenase activities, in rat tooth germs at different developmental stages. MMP-2 expression was increased gradually in the tooth germs from cap to crown staged germs at both transcription and translation levels. The localization of this molecule was detected in secretory ameloblasts and preameloblasts. The strong immunoreactivities were occasionally seen along the basement membrane between ameloblasts (or preameloblasts) and odontoblasts (preodontoblasts). However, weak reactivity was detected in odontoblasts and reduced enamel epithelium. The level of MMP-9 expression in the tooth germs was higher in cap stage than in crown staged germs at both transcription and translation levels. They were strongly expressed in both ameloblasts and odontoblasts. Even though reduced enamel epithelium after enamel formation and inner enamel epithelium at the cap stage exhibited weak reactivity, strong reactivity was detected in dental follicles and perifollicular tissues surrounding cap staged germs. These results suggested that MMP-2 may involve degradation of the basement membrane during hard tissue formation, whereas MMP-9 might be involved in remodeling of follicular tissues.
Ameloblasts ; Animals ; Basement Membrane ; Collagenases ; Crowns ; Dental Enamel ; Dental Sac ; Epithelium ; Matrix Metalloproteinases ; Molar ; Odontoblasts ; Odontogenesis ; Rats ; Tooth Germ

OBJECTIVETo study role of dental follicle in tooth root development.

METHODSSixteen mandibular first molar dental germs from eight five-day postnatal Balb/c mice were divided into two groups randomly. Dental follicle of germs in one group was undetached and that of another group was removed. Subsequently, each of the germs was separately transplanted to back-muscles of adult nude mice. At seventh and fourteenth day after transplanting, the germs were collected, fixed, demineralized, dehydrated, and embedded in wax in sequence. Serial sections of 5 microm thick were made following the routine methods, stained with haematoxylin-eosin dying solution, and observed under a light microscope.

RESULTSAll implantations were located in the back-muscles with abundant capillary vasculature. Under microscope, although all tooth germs could further develop after grafting, tooth germs without dental follicle developed slowly with small size and low calcification compared to those with dental follicle. Although position of Hertwig's epithelial root sheath of all germs seemed no changing, roots of the group with dental follicle could further develop and the roots develop toward the apical direction; this tendency couldn't be seen in the germs of another group. Inflammatory cells could be seen in and out of the pulp cavity of the two groups at 7th day after grafting, while no obvious inflammatory cell was observed at 14th day after grafting.

CONCLUSIONDental follicle play an important role in tooth root development. It probably can lead tooth root to develop in normal direction.

Animals ; Dental Pulp Cavity ; Dental Sac ; Enamel Organ ; Mice ; Mice, Nude ; Molar ; Odontogenesis ; Tooth ; Tooth Germ ; Tooth Root