Clinical Characterization of Oral and Maxillofacial Tumors and Tumor-Like Lesions in Children and Adolescents.

PURPOSE: To investigate the clinical characteristics of oral and maxillofacial tumors in children and adolescents. METHODS: This is a retrospective study of patients who had oral and maxillofacial tumors under the age of 18 years and were treated at the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from January 1990 to July 2021 (31 y). Their general conditions, pathological diagnosis, gender, age, and anatomical location were counted to analyze their morbidity and composition characteristics. RESULTS: This study contained 5405 cases, including 2903 male patients and 2502 female patients, with a median age of 9 years. Peak incidence was observed in the 14 to 18 years age group. The mandible (22.15%), maxilla (11.75%), and tongue (9.25%) were the most common sites of incidence. Malignant and intermediate type tumors accounted for 13.04%, benign tumors and tumor-like lesions for 55.67%, most often occurs in the maxillofacial bone, of which fibro-osseous lesions constitute an important part. Cysts accounted for 31.29%. Among the tumors occurring in the jaws, the most common malignant type was sarcoma, and ameloblastoma was the most common benign tumor. Malignant jaw tumors were mostly treated by resection, 10.64% by fibular flap reconstruction. While benign jaw tumors and tumor-like lesions were mostly treated by resection or curettage. CONCLUSIONS: The distribution of anatomical location and pathological types of oral and maxillofacial tumors in children has certain characteristics, so that the selection of their treatment options is different from that of adults due to the consideration of the growth and developmental characteristics of children.

Interfacial synthesis and functionality of self-stabilized polydiaminonaphthalene nanoparticles.

A simple and effective template-free synthesis method for nanosized conducting polymers with self-stability and functionality is a main challenge. Herein, a strategy is reported for the facile synthesis of poly(1,5-diaminonaphthalene) nanospherical particles by an interfacial miniemulsion oxidative polymerization of 1,5-diaminonaphthalene at mobile microinterfaces between a stirred biphase without external emulsifiers. The size of the nanospheres was carefully optimized by controlling the polymerization conditions. Formation and self-stabilization mechanisms of the nanoparticles are proposed. The constantly movable and refreshed microinterface is a key to successful synthesis of the nanospheres, for significantly suppressing secondary growth leading to agglomerated particles because vigorous stirring makes as-formed self-stabilized nanospheres instantly leave the microinterfaces. The resulting nanospheres possess several advantages: clean surface, self-stability, redispersibility, semiconductivity, electroactivity, and fluorescence emission. The fluorescence emission can be quenched by specific quenchers, thus enabling low-cost, high-performance chemosensors to be obtained for the sensitive detection of Zn(II) ions in a wide linear concentration range of more than five orders of magnitude with a superior detection limit down to 1 nM.

Analysis of dental caries and the impact factors of caries in children aged 3-5 years old in Changdu, Xizang.

OBJECTIVES: To investigate caries status and its impact factors in preschool children in plateau and to provide reference for caries prevention in highlands. METHODS: Examination of caries was performed on 1 597 children aged 3-5 years old in 11 kindergartens in Changdu, Xizang, in accordance with the 4th National Oral Health Survey standards and methods. Their parents were surveyed with the questionnaire regarding oral hygiene habit and consciousness about oral health and related factors. All the data were collected and analyzed. RESULTS: The prevalence of caries among children aged 3-5 years old in Changdu was 52.85%, with dmft index of 2.44. The caries rate and dmft of children aged 3 years old were lower than those of children aged 4 and 5 years old (P<0.05). No significant difference was observed in the caries rate between males and females (P>0.05). Single-factor analysis showed that the frequency of brushing teeth more than twice a day, low frequency of eating sweets, high frequency of drinking butter tea, and regular oral examination can reduce the rate of caries (P<0.05). Multivariate logistic analysis showed that the frequency of eating sweets, drinking butter tea, and oral examination are related impact factors of caries. CONCLUSIONS: The prevalence of ca-ries in children aged 3-5 years old in Changdu increases with aging. Good oral hygiene and eating habits and regular oral examination can reduce the rate of caries.

[Antibacterial activity of erythritol on periodontal pathogen].

PURPOSE: To explore the effect of erythritol on the growth of Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans(Aa), Actinomices viscosus (Av), and to explore how Porphyromonas gingivalis affected by erythritol influence mRNA expression level of inflammatory in periodontal cells. METHODS: Pg, Aa, Av were anaerobically cultured (80%N2, 10%CO2, 10%H2) at 37℃ in 2, 4, 8, 16, 32, 64, 128 g/L erythritol- BHI mixture groups (experimental groups) and BHI groups (control group). The lowest erythritol concentration without turbidity or precipitation was the minimum inhibitory concentration. Pg was cultured in MIC, 1/2, 1/4, 1/8 MIC erythritol- BHI mixture groups (experimental groups) and BHI groups (control group). Each kind of bacteria in each concentration group was centrifugalled and cleaned before added into DMEM. The mixed suspension was co-cultured with the periodontal ligament cells in four generations for 24 hours, the supernatan was removed , then the total RNA in cracking cells was extracted and reversing transcription. At last, the relative expression of IL-1, IL-6, TNF-a was detected real-time fluorescent quantitative PCR. The data were analyzed with SPSS19.0 software package. RESULTS: The minimum inhibitory by concentrations of erythritol on three bacteria were as followed: Pg: 64 g/L，Aa: 128 g/L，Av: 128 g/L. The ability of stimulating periodontal ligament cells to produce IL-1ß, IL-6 and TNF-α was different when Pg was cultured under different concentrations of erythritol. There was no significant difference between 0 g/L of control group and 8 g/L of experimental group. As the concentration reached 16 g/L, the relative expression of IL-1ß, IL-6, TNF-α was reduced, and the higher concentration was, the less inflammatory factors was. However, the inflammatory factors in all the experimental groups were always significantly higher than that in the blank control group (P<0.05). CONCLUSIONS: Erythritol has an inhibitory effect on the growth of Pg, Aa and Av. In a certain range, higher concentration of erythritol delivers better inhibition effect. Erythritol can also reduce the periodontal pathogenicity of pathogenic bacteria in a way inhibiting the virulence of these bacteria, reducing the production of IL-1ß, IL-6, and TNF-a in periodontal cells.

Primary small cell neuroendocrine carcinoma of the oral cavity: A case report and review of the literature.

Small cell neuroendocrine carcinoma (SNEC) of the oral cavity is a rare and distinctive tumor with aggressive clinical behavior. Thus far, only a small number of cases have been reported and no definitive standard treatment strategy has been determined. The current study reports a case of oral SNEC arising in the lower gingiva in a 73-year-old male. Computed tomography displayed a relatively well-defined mass measuring 2.8×2×1.4 cm in size. The mass was located in the buccal side of the right mandibular posterior gingiva and exhibited no bony involvement. Histopathological examination revealed a proliferation of small cells with ovoid- to spindle-shaped nuclei, fine granular chromatin, inconspicuous nucleoli, scant cytoplasm and high mitotic activity. Immunohistochemically, the tumor cells were positive for cytokeratin AE1/AE3, chromogranin A, synaptophysin and neuron-specific enolase. Surgical resection and radical neck dissection were performed prior to the administration of adjuvant chemotherapy with a combination of cisplatin and etoposide. No evidence of local recurrence or metastasis was observed at 14 months post-surgery.

[Effects of surface potentials of tooth hard tissue on bone remodeling in rabbit tibiae].

OBJECTIVE: To investigate the influence of surface potentials of tooth hard tissue on bone remodeling. METHODS: After insured the surface potentials of human extracted teeth with electrochemical methods, teeth sections and artificial hydroxyapatite were implanted into 25 rabbits' tibiae. The rabbits were sacrificed at 1, 2, 4, 6 and 8 weeks after implantation, respectively. The bone regeneration was compared between opposite two sides (cathode side and anode side) of tooth sections using hematoxylin-eosin (HE) staining, tartrate-resistant acid phosphatase (TRAP) activity detecting and tetracycline tracing method. RESULTS: Resorption lacunae was seen in the tibiae facing to the enamel anode and new bone density in the implant bed near the cathode of tooth samples was much higher than that near the anode, while the number of TRAP positive cells near the cathode was smaller than that near the anode (P < 0.01). The fluorescent area of tetracycline tracing near the cathode was larger than that near the anode (P < 0.05). CONCLUSIONS: The cathode of tooth hard tissue (cementum) could improve or trigger new bone formation, while the other side, anode (enamel), could improve the bone resorption. This study suggests that tooth hard tissue's electrochemical characteristic might affect the remodeling of alveolar bone, and tooth supraeruption and the alveolar bone loss after tooth extraction might result from the redundant or lack of root electrochemical stimulation to bone.