Abscess ; etiology ; Adult ; Humans ; Male ; Nasal Septum ; pathology ; Tooth, Impacted ; complications

Child ; Child, Preschool ; Dentition, Mixed ; Humans ; Radiography, Panoramic ; Tooth Extraction ; Tooth Migration ; therapy ; Tooth, Impacted ; therapy ; Tooth, Supernumerary ; diagnostic imaging ; pathology ; surgery

OBJECTIVETo assess the treatment method and outcome of mesially or horizontally impacted mandibular molars.

METHODSEleven patients with mandibular impacted molars, including 9 horizontally impacted molars and 5 mesially impacted molars were treated with fixed appliance in conjunction with molar band soldered with pushing spring. Crowns of impacted molars were moved occlusally and distally.

RESULTSAll mesially or horizontally mandibular impacted molars were uprighted and brought into occlusion. Mean treatment period was 7.4 months (6 to 12 months).

CONCLUSIONSThis orthodontic molar uprighting technique was effective in uprighting and distalizing the impacted molars.

Adolescent ; Adult ; Female ; Humans ; Male ; Molar ; pathology ; physiology ; Orthodontic Appliances ; Orthodontics, Corrective ; methods ; Tooth, Impacted ; therapy ; Young Adult

OBJECTIVETo investigate the frequency, sex differences and location of impacted maxillary canine in orthodontic patients.

METHODSTwo hundred and fifteen patients (77 males and 138 females) with maxillary canine impaction were included in the study. The experimental group was gathered from the Department of Orthodontics, Peking University School and Hospital of Stomatology. CT scan images were evaluated. Chi-square test was used in the analysis.

RESULTSThe prevalence of maxillary canine impaction among Chinese orthodontic patients was 2.05%. The ratio between male and female was 1.8:1 and the ratio between buccal and palatal location was 2.1:1. Surgical exposure and orthodontic alignment had been predominant in such conditions. There was significant deference in the treatment between palatally impacted canine and buccally impacted one. More palatally impacted canines were extracted than buccally impacted ones.

CONCLUSIONSThere was significant difference in the treatment of maxillary canine impaction. More buccally impacted canines were found in Chinese patients, especially in female patients.

Adolescent ; Adult ; Child ; Cuspid ; pathology ; Female ; Humans ; Male ; Maxilla ; Orthodontics, Corrective ; Sex Factors ; Tooth, Impacted ; epidemiology ; therapy ; Young Adult

OBJECTIVETo study the alveolar bone surrounding situation and the length of the root of the maxillary labial inverted impacted incisor in mixed dentition after orthodontic treatment.

METHODSFourteen cases with maxillary labial inverted impacted incisor in mixed dentition were collected. Modified Nance arch and conventional appliance were used. Cone-bean CT (CBCT) was taken after the treatment. Simplant13.0 three-dimensional reconstruction and multi-planer reconstruction (MPR) method were used to observe the labial and lingual alveolar bone crest morphology, besides, the labial and lingual length from the alveolar bone crest to cemento-enamel junction (CEJ) of the impacted incisor and the homonym tooth after treatment, along with their root length and their labial and lingual length ratio of the root surrounded by the alveolar bone to the total root length were measured. The idependent samples t-test were used to analyze the variable differences.

RESULTSThe labial and lingual alveolar bone of fourteen cases crest of the diseased tooth after treatment presented general symmetry U shape from qualitative observation through the three-dimensional reconstruction. The labial and the lingual length of the diseased incisor from alveolar bone crest to CEJ [(2.47 ± 1.35) and (1.47 ± 0.84) mm] was significant increased than those of the homonym incisor [(1.03 ± 0.35) and (0.90 ± 0.37) mm] (P < 0.05); the length of the diseased incisor's post-treatment root [(9.82 ± 2.82) mm] was no statistically significant decreased than that of the homonym incisor root [(10.28 ± 1.38) mm, P = 0.59]; the labial and the lingual length ratio of the impacted tooth's root surrounded by the alveolar bone to the total root length [(72.83 ± 17.16)% and (85.32 ± 5.98)%] was statistically significant decrease than those of homonym teeth[(89.66 ± 3.98)% and (90.84 ± 4.61)%] (P < 0.05).

CONCLUSIONSThe diseased tooth's root had gotten enough length after the treatment. The labial and lingual alveolar bone of the maxillary labial inverted impacted incisor in mixed dentition can't offer sufficient adaptive hyperplasia after treatment, of which labial alveolar bone is more apparent, prompting careful protection when they were used.

Alveolar Process ; diagnostic imaging ; pathology ; Child ; Cone-Beam Computed Tomography ; Dentition, Mixed ; Female ; Follow-Up Studies ; Humans ; Incisor ; diagnostic imaging ; pathology ; surgery ; Male ; Maxilla ; diagnostic imaging ; pathology ; surgery ; Orthodontic Extrusion ; Tooth Root ; diagnostic imaging ; pathology ; Tooth, Impacted ; diagnostic imaging ; surgery

Dentigerous cysts are benign odontogenic cysts that are associated with the crowns of permanent teeth. They are developmental epithelial-lined lesions which are formed from fluid accumulation in the space between the reduced enamel epithelium and the surface of crown. This may occure due to the obstructin of venous return caused by tooth impaction. The most prevalent location of dentigerous cysts are the third molar of mandible. While the single dentigerous cysts are the second most common odontogenic cysts following the radicular cysts of jaw, multiple cysts are observed in patients with some conditions such as mucopolysaccharidosis type IV, basal cell nevus syndrome, and cleidocranial dysplasia. They occur in young patients in the second or third decades of life, but it is a rare occurrence for children. A sixteen-year-old girl with painful swelling in the right mandible visited to our department. All routine laboratory test results were within normal limits. However, we were able to diagnose that she had facial asymmetry. Computed tomography showed a well-defined soft tissue mass obliterating right mandible ramus with an impacted tooth. We performed total enucleation of cyst and molar tooth. The pathology revealed a non-keratinized squamous epithelial lined cyst associated with an undamaged tooth.
Basal Cell Nevus Syndrome ; Child ; Cleidocranial Dysplasia ; Crowns ; Dental Enamel ; Dentigerous Cyst* ; Epithelium ; Facial Asymmetry ; Female ; Humans ; Jaw ; Mandible* ; Molar ; Molar, Third ; Mucopolysaccharidoses ; Odontogenic Cysts ; Pathology ; Radicular Cyst ; Tooth ; Tooth, Impacted

It is not known whether the presence of an impacted tooth or the radiographic types in an odontogenic keratocyst (OKC) change the clinical biologic behavior and therapeutic approaches. This study evaluated the comparative proliferative activity and apoptosis in OKC associated with or without an impacted tooth, as well as between the unilocular and multilocular OKC varieties. Immunohistochemical expression of Ki-67 as a proliferation marker and the apoptotic reactions were assessed by the TUNEL method for 32 cases of OKC (OKC with impacted tooth, n=16; OKC without impacted tooth, n=16) and 10 cases of dentigerous cyst (DC). OKC showed a greater proliferative potential and more apoptotic reactions than DC. In particular, OKC contained proliferating and apoptotic cells situated predominantly in the suprabasal and superficial layers, respectively. However, no significant difference was found between OKC associated with or without impacted tooth, or between the unilocular and multilocular OKC varieties, in terms of proliferative activity or apoptosis. In conclusion, OKC is characterized by an increase in both cell proliferation and apoptosis, suggesting a unique proliferative and differentiation process. It is believed that incomplete removal or other contributing factors, rather than intrinsic growth or apoptosis, may be the main reasons for the aggressive biologic behavior or recurrence in multilocular OKC.
Adult ; *Apoptosis ; Cell Division ; Comparative Study ; Female ; Human ; Immunohistochemistry ; In Situ Nick-End Labeling ; Ki-67 Antigen/*analysis ; Male ; Odontogenic Cysts/*pathology ; Proliferating Cell Nuclear Antigen/analysis ; Support, Non-U.S. Gov't ; Tooth, Impacted/*pathology

The periodontal ligament-derived mesenchymal stem cell is regarded as a source of adult stem cells due to its multipotency. However, the proof of chondrogenic potential of the cells is scarce. Therefore, we investigated the chondrogenic differentiation capacity of periodontal ligament derived mesenchymal stem cells induced by transforming growth factor (TGF)-β3 and bone morphogenetic protein (BMP)-6. After isolation of periodontal ligament stem cells (PDLSCs) from human periodontal ligament, the cells were cultured in Dulbecco's modified Eagle's medium (DMEM) with 20% fetal bovine serum (FBS). A mechanical force initiated chondrogenic differentiation of the cells. For chondrogenic differentiation, 10 µg·L⁻¹ TGF-β3 or 100 µg∙L⁻¹ BMP-6 and the combination treating group for synergistic effect of the growth factors. We analyzed the PDLSCs by fluorescence-activated cell sorting and chondrogenesis were evaluated by glycosaminoglycans assay, histology, immunohistochemistry and genetic analysis. PDLSCs showed mesenchymal stem cell properties proved by FACS analysis. Glycosaminoglycans contents were increased 217% by TGF-β3 and 220% by BMP-6. The synergetic effect of TGF-β3 and BMP-6 were shown up to 281% compared to control. The combination treatment increased Sox9, aggrecan and collagen II expression compared with not only controls, but also TGF-β3 or BMP-6 single treatment dramatically. The histological analysis also indicated the chondrogenic differentiation of PDLSCs in our conditions. The results of the present study demonstrate the potential of the dental stem cell as a valuable cell source for chondrogenesis, which may be applicable for regeneration of cartilage and bone fracture in the field of cell therapy.
Adult Stem Cells ; physiology ; Aggrecans ; analysis ; Bone Morphogenetic Protein 6 ; pharmacology ; Cell Culture Techniques ; Cell Differentiation ; drug effects ; Cell Separation ; Chondrogenesis ; drug effects ; physiology ; Collagen Type II ; analysis ; Flow Cytometry ; Glycosaminoglycans ; analysis ; Humans ; Immunohistochemistry ; Mesenchymal Stromal Cells ; drug effects ; physiology ; Molar, Third ; cytology ; Periodontal Ligament ; cytology ; drug effects ; Reverse Transcriptase Polymerase Chain Reaction ; SOX9 Transcription Factor ; analysis ; Stress, Mechanical ; Tooth, Impacted ; pathology ; Transforming Growth Factor beta3 ; pharmacology