Clinical study on the posterior occlusal plane and morphology of temporomandibular joint / Estudio clínico sobre el plano oclusal posterior y la morfología de la articulación temporomandibular

The objective of the study was to investigate the morphological features of the temporomandibular joint in adult patients with posterior occlusal plane and different inclinations. Fifty five skeletal I occlusion patients with average were included, shooting CBCT in the intercuspal position, divided into 3 groups according to OPP-FH angle, and measurement of the temporomandibular joint morphology was calculated with cone beam computed tomography (CBCT) special software Invivo 5.0, Statistical analysis of three groups of data using SPSS23.0. The condyle usually locates in the middle of the fossa, the maximum axial area of the condyle (A) was statistically significant between the group 1 and the group 3. The internal and external diameter (MD) of the condyle was statistically significant between group 1 and group 3, and group 2 and group 3. The bilateral TMJ morphological features of the three groups were basically symmetrical. The position of the condyle in the fossa is mostly centered, and some of the posterior, the maximum axial area and the internal and external diameter of the condyle are different in three groups.

El objetivo de este estudio fue investigar las características morfológicas de la articulación temporomandibular (ATM) en pacientes adultos con plano oclusal posterior y diferentes inclinaciones. Se incluyeron 55 pacientes con oclusión esquelética tipo I, visualizados por tomografía computarizada de haz cónico (CBCT) en posición intercuspiana, y se dividieron en 3 grupos según el ángulo OPP-FH. La medición morfológica de la articulación temporomandibular se calculó con CBCT y mediante el software especial Invivo 5.0. El análisis estadístico de datos se realizó con el software SPSS 23.0. El cóndilo de la mandíbula generalmente se ubica en el centro de la fosa; el área axial máxima del cóndilo de la mandíbula (A) fue estadísticamente significativa entre los grupos 1 y 3. Los datos de los diámetros medial y lateral (DM) del cóndilo de la mandíbula fueron estadísticamente significativos entre los grupos 1 y 3 y los grupos 2 y 3. Las características morfológicas de la ATM de los tres grupos fueron básicamente simétricas. La posición del cóndilo de la mandíbula en la fosa fue principalmente centrada, y parte del área axial máxima, posterior y los diámetros medial y lateral del cóndilo de la mandíbula fueron diferentes en los tres grupos.

Expression of Ihh signaling pathway in condylar cartilage after bite-raising in adult rats.

Temporomandibular joint osteoarthritis (TMJOA) is a complex inflammatory condition with multiple factors and degenerative processes co-occurring. However, its pathogenesis remains uncertain. The purpose of the study was to observe the expression of Indian hedgehog (Ihh) signal related molecules in TMJOA induced by bite-raising and to study the effect and mechanism of Ihh signaling. Our research indicated that Ihh signaling pathway can be activated in condylar cartilage induced by bite-raising. The histological analysis showed TMJOA-like structural changes of condylar cartilage in experiment groups. Ihh, Smoothened (Smo), and Gli zinc finger transcription factors-1 (Gli-1) were activated in the experimental groups, and the expression levels increased significantly over time, whereas the sham control groups showed no fluctuation. Additionally, the expression levels of matrix metalloproteinase-13 (MMP-13) and cysteinyl aspartate specific proteinase-3 (Caspase-3) in the experiment groups increased in a time-dependent manner compared with the matched sham control groups. In conclusion, our results indicated that the Ihh signaling pathway may activate the occurrence of TMJOA by mediating the hypertrophy of chondrocytes, which may be an important regulatory mechanism and potential therapeutic target in the repair of condylar cartilage.

Effect of phosphorylation and methylation on the function of the p16INK4a protein in non-small cell lung cancer A549 cells.

The p16INK4a protein (p16) has been reported to be a tumor suppressor gene that suppresses the proliferation of cells through the direct inhibition of cell cycle progression. Accordingly, p16 is a potential target for cancer gene therapy. In the present study, the arginine 22, 131 and 138 residues of p16 were found to be methylation sites, as the mutation of these arginine residues to lysine resulted in the hypomethylation of p16. Furthermore, the protein arginine methyltransferases (PRMTs), such as PRMT1, PRMT4 and PRMT6, were determined to be involved in the methylation of the p16 arginine residues. PRMT6 effectively reduced the intensity of the association between p16 and CDK4, and also weakened the function of p16 in preventing cell proliferation. In addition, the p16 protein was found to be phosphorylated in various cell lines, and mutations in the serine residues weakened the cell cycle arrest and induction of apoptosis mediated by p16. Preliminarily, the crosstalk between the phosphorylation and arginine methylation modification of p16 was examined. These findings predict a role for serine phosphorylation against arginine methylation of p16.

[Effect of periodontal initial therapy on teeth with chronic periodontitis and secondary occlusal trauma].

OBJECTIVE: To evaluate the effect of subgingival scaling/root planning (SRP) and occlusal adjustment on clinical and occlusal parameters in teeth with chronic periodontitis and secondary occlusal trauma. METHODS: Eighteen patients with chronic periodontitis and occlusal trauma were included and randomly divided into group A and group B. On day 0, group A was treated by full-mouth subgingival scaling and root planning, and group B was treated by occlusal adjustment in occlusal trauma site. On day 28, group A was treated by occlusal adjustment in occlusal trauma site, and group B was treated by full-mouth subgingival scaling and root planning. Probing depth (PD), attachment loss (AL), bleeding index (BI) were evaluated on 0, 28 and 56 d, and the occlusal time (OT) and the percentage of occlusal force were evaluated on 0, 28 and 56 d in occlusal trauma site. The data was statistically analyzed. RESULTS: In baseline, the PD[(4.42 ± 1.41) mm vs (4.36 ± 1.38) mm], AL [(2.75 ± 1.32) mm vs (2.63 ± 1.37) mm] and BI [(2.20 ± 0.81) vs (2.24 ± 0.89)] of the full-mouth showed no significant difference between the two groups (P > 0.05). There was no significant difference in PD [(5.21 ± 1.21) mm vs (5.08 ± 1.12) mm], AL [(4.94 ± 1.47) mm vs (4.89 ± 1.32) mm], BI [(2.61 ± 0.92) vs 2.50 ± 0.79)], OT [(1.29 ± 0.39) s vs (1.34 ± 0.35) s] and the percentage of occlusal force [(6.8 ± 2.1)% vs (7.4 ± 1.7)%] in occlusal trauma site between the two groups(P > 0.05). After SRP therapy, the PD,AL,BI and OT were significantly decreased (P < 0.05).The clinical parameters exhibited no significant difference after only occlusal adjustment(P > 0.05).On 56 d, the reduction in clinical parameters was not significantly different between the two groups(P > 0.05),however the reduction of OT and the change of the percentage of occlusal force in group A [(0.85 ± 0.41) s, (2.2 ± 2.2)%] were more significant than those in group B [(0.70 ± 0.38) s; (1.5 ± 1.6)%] (P < 0.05). After occlusal adjustment, the increase of OT in group A [(0.21 ± 0.11) s] was lower than that in group B [(0.67 ± 0.37) s]through the 28-day observation period (P < 0.05). CONCLUSIONS: Occlusal adjustment alone is inadequate for control and management of periodontitis.SRP therapy can eliminate the inflammation and decrease the OT of tooth with occlusal trauma.The combination of SRP and occlusal adjustment may achieve more stable results.

[Influence of transfection with human transforming growth factor-beta1 gene on the osteogenic potential of the cultured human gingival fibroblast].

OBJECTIVE: To study the influence of transfection with human transforming growth factor-beta1 (hTGF-beta1) gene on the osteogenic potential and differentiation of the cultured human gingival fibroblast (GF). METHODS: Enzyme kinetics method was used to measure the effects of the transfection on the alkaline phosphatase (ALP) activity. Immunohistochemistry stain and image analysis were applied to evaluate the alteration of the content of osteopontin (OPN), bone sialoprotein (BSP), osteonectin (ON), osteocalcin (OC) in the GF with transfection. Mineralization nodules formation in vitro was also used. RESULTS: The ALP activity of the GF after transfection was higher than the GF without transfection significantly (P<0.05), and was close to that of the PDLCs (P>0.05). The content of OC in GF was not improved after transfection, was similar with that of PDLCs (P>0.05). Under immunohistochemistry stain, the contents of OPN, ON, BSP expressed in GF with transfection were higher than those of GF without transfection (P<0.05), but similar to those of PDLCs (P>0.05). In the mineralized cultured medium, the nodules were observed in the GF with transfection and PDLCs after 21 days and 24 days alternatively. After von Kossa stain, purple mineralization nodules were observed. CONCLUSION: The GF transfected with pcDNA3-hTGF-beta1 could express some osteogenic characters, though these characters are restricted.

[Effects of gingival fibroblasts transfected with human transform growth factor-beta1 gene on improving the periodontal tissue regeneration].

OBJECTIVE: To evaluate the effects of gingival fibroblasts (GF) transfected with hTGF-beta1 gene on improving the periodontal tissue regeneration for the repair of degree II artificial furcation defects. METHODS: The gingival fibroblasts transfected with hTGF-beta1 gene was compounded to the cuttlebone-transformed nanometer hydroxyapatite (CBHA) material from the cuttlefish in vitro, the degree II furcation defects on the premolars of dogs were produced surgically, and the compound was to implanted into the defect (transfected group), and compared with the compound of periodontal ligament cells (PDLC) with nanometer HA material and the compound of untransfected GF with HA. The results were examined histologically 8 weeks after operation. RESULTS: In the transfected group and the positive control group, more new attachment was found compared with the negative control (P < 0.01), and the NC, NB and NC of the transfected group and the positive control group were: (2.97 +/- 0.50), (4.29 +/- 0.26) and (4.73 +/- 0.06) mm; (3.09 +/- 0.26), (4.46 +/- 0.25) and (4.69 +/- 0.10) mm, respectively. There was no significant difference between the two groups (P > 0.05). Although the alveolar bone regeneration was found in the untransfected group [NB = (3.46 +/- 0.32) mm], the root resorption was observed. The tracing experiment showed that the transfected GF were found in the new alveolar bone and the periodontal membrane. CONCLUSIONS: GF transfected with hTGF-beta1 gene can significantly improve the periodontal tissue regeneration in treatment of degree II furcation defects and is involved in the formation of the new alveolar bone and the new periodontal membrane.