Titanium Particles Modulate Lymphocyte and Macrophage Polarization in Peri-Implant Gingival Tissues.

Titanium dental implants are one of the modalities to replace missing teeth. The release of titanium particles from the implant's surface may modulate the immune cells, resulting in implant failure. However, little is known about the immune microenvironment that plays a role in peri-implant inflammation as a consequence of titanium particles. In this study, the peri-implant gingival tissues were collected from patients with failed implants, successful implants and no implants, and then a whole transcriptome analysis was performed. The gene set enrichment analysis confirmed that macrophage M1/M2 polarization and lymphocyte proliferation were differentially expressed between the study groups. The functional clustering and pathway analysis of the differentially expressed genes between the failed implants and successful implants versus no implants revealed that the immune response pathways were the most common in both comparisons, implying the critical role of infiltrating immune cells in the peri-implant tissues. The H&E and IHC staining confirmed the presence of titanium particles and immune cells in the tissue samples, with an increase in the infiltration of lymphocytes and macrophages in the failed implant samples. The in vitro validation showed a significant increase in the level of IL-1ß, IL-8 and IL-18 expression by macrophages. Our findings showed evidence that titanium particles modulate lymphocyte and macrophage polarization in peri-implant gingival tissues, which can help in the understanding of the imbalance in osteoblast-osteoclast activity and failure of dental implant osseointegration.

Optimization of scanning electron microscope technique for amniotic membrane investigation: A preliminary study.

OBJECTIVE: The objective of this study was to evaluate and compare the two scanning electron microscope (SEM) preparation protocols and determine the better SEM preparation technique to study stem cells on human amniotic membrane (hAM) scaffold. MATERIALS AND METHODS: Formaldehyde-based protocol and glutaraldehyde-based protocol were compared to evaluate the quality of SEM images for stem cells cultured on hAM scaffold. RESULTS: The results suggested that formaldehyde-based protocol is better than glutaraldehyde-based protocol in terms of showing clearer topography of the membrane as well as the boarders of the cells. To provide intact surface of the SEM sample and avoid possible ruptures of the hAM or the thin cell layer, it is recommended to perform the dehydration step using graded alcohol concentrations of 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%, one time for each and twice in 100% for 10 min each. Gold sputter-coating step is not recommended as it does not improve the image quality. CONCLUSIONS: To obtain clear SEM images, it is recommended to run a preliminary study to determine the better chemicals and conditions of sample preparation even when following preexisting protocols.

Rapid growth and osteogenic differentiation of mesenchymal stem cells isolated from human bone marrow.

Mesenchymal stem cells (MSCs) are involved in bone formation in the embryo, bone repair and remodeling. The differentiation of these cells is a complex multistep pathway that involves discrete cellular transitions and is similar to that which occurs during hematopoiesis. MSCs have self-renewal capacity without differentiation in long-term culture. In the present study, MSCs were isolated from human bone marrow and characterized by the presence of cluster of differentiation 105 marker using the labeled streptavidin biotin method. The MSCs were cultured in Dulbecco's modified Eagle's medium supplemented with fetal bovine serum, ascorbic acid, ß-glycerol phosphate and dexamethasone to differentiate into osteoblasts. Biological in vitro analysis showed the rapid proliferation of the MSCs. Further evaluation of specific osteogenic markers using von Kossa staining and the alkaline phosphate assay demonstrated that the MSCs were stimulated to differentiate into osteoblast-lineage cells. This mesengenic potential indicated that the bone marrow-derived cells were multipotent MSCs. The findings of this study show that bone marrow can be a legitimate source of MSCs for the production of osteoblasts for utilization in bone replacement therapy.

In vitro cytotoxic evaluation of processed natural coral in human osteoblasts.

This study aimed to evaluate the in vitro cytotoxic effects of locally produced processed natural coral (PNC) using human osteoblasts (HOS). Cytotoxicity was not observed when HOS cells were cultured with PNC, as assessed by (3-(4,5-dimethylthiazol-2-yl)-2-5-diphenyl tetrazolium bromide; MTT) and Neutral Red (NR) assays at concentration up 200 mg/mL for up to 72 hours. Flow cytometry (FCM) analysis showed that PNC (200 mg/mL) did not decrease viability of HOS cells after 48 and 72 hours of treatment. In a cell attachment study, the HOS cells attached to the edge of the PNC disc, and later grew into the pores of the PNC disc. All results from these studies indicate that locally produced PNC material is noncytotoxic and favors the growth of HOS cells.

The role of nitric oxide on the proliferation of a human osteoblast cell line stimulated with hydroxyapatite.

The aim of the present study was to test the hypothesis that the proliferation of a human osteoblast cell line (HOS cells) stimulated with hydroxyapatite (HA) may be regulated by nitric oxide (NO). The cells were cultured on the surface of HA. Medium or cells alone were used as controls. L-arginine, D-arginine, 7-NI (an nNOS inhibitor), L-NIL (an iNOS inhibitor), L-NIO (an eNOS inhibitor) or carboxy PTIO, a NO scavenger, was added in the HA-exposed cell cultures. The cells were also precoated with anti-human integrin alphaV antibody. The levels of nitrite were determined spectrophotometrically. Cell proliferation was assessed by colorimetric assay. The results showed increased nitrite production and cell proliferation by HA-stimulated HOS cells up to day 3 of cultures. Anti-integrin alphaV antibody, L-NIO, or carboxy PTIO suppressed, but L-arginine enhanced, nitrite production and cell proliferation of HA-stimulated HOS cells. The results of the present study suggest, therefore, that interaction between HA and HOS cell surface integrin alphaV molecule may activate eNOS to catalyze NO production which, in turn, may regulate the cell proliferation in an autocrine fashion.

Comparison of two methods of dental age estimation in 7-15-year-old Malays.

BACKGROUND: Numerous methods of age estimation have been proposed. The Demirjian method is the most frequently used, which was first applied in a French Canadian population in 1973. The Willems method is a modification of the above and was applied in a Belgian population in 2002. OBJECTIVES: The objectives of this study were to test the applicability of the two methods, namely Demirjian and Willems, for age estimation in a Malay population, and to find the correlation between body mass index and the difference between the dental age and the chronological age. MATERIALS AND METHODS: A cross-sectional study involving 214 boys and 214 girls, selected by a simple stratified random sampling method was carried out. The orthopantomograph was used to score the seven left mandibular teeth, and the calculated maturity score was used to obtain the Demirjian dental age. Willems dental age was estimated using the tables proposed in the Willems method. Results. The Demirjian method overestimated the age by 0.75 and 0.61 years, while the Willems method overestimated the age by 0.55 and 0.41 years among boys and girls, respectively. In boys, the body mass index was significantly correlated to the difference in age using the Willems method. CONCLUSION: Further modification of either method is indicated for dental age estimation among the Malay population.

Chondrosarcoma of the mandible: a case report.

Chondrosarcomas are malignant tumours of cartilaginous origin. They range from a well-differentiated growth resembling a benign cartilage tumour to a high-grade malignancy with aggressive local behaviour and the potential to metastasize. Only 5% to 10% of chondrosarcomas are known to occur in the head and neck region. A case of chondrosarcoma of the anterior region of the mandible is presented, along with a review of the relevant literature.

Arteriovenous malformation of the mandible: a rare but life-threatening disease.

AVM in the mandible is rare. It may present with recurrent episodes of unexplained gingival haemorrhage, bony swelling, tooth mobility or facial asymmetry. We reported our experience in managing a case of a 15 year old Malay girl who presented with a life threatening bleeding from her mandible.

A three-dimensional computed tomographic analysis of the cervical spine in unoperated infants with cleft lip and palate.

OBJECTIVE: To investigate anatomical variations and abnormalities of cervical spine morphology in unoperated infants with cleft lip and palate. DESIGN: Retrospective cross-sectional investigation of infants born with nonsyndromic cleft lip and palate using computed tomography scans acquired for investigation of a spectrum of clinical conditions. SETTING: Computed tomography scan data were obtained from 29 unoperated cleft lip and palate infants and 12 noncleft infants of Malay origin, ages 0 to 12 months. METHODS: Observational study of cervical spine computed tomography scans. Heights of cervical vertebral bodies (C2-C7) and intervertebral spaces were measured from landmarks identified from computed tomography reformats and three-dimensional computed tomography reconstructions. Linear modeling of heights and spaces, with age as a covariate, was undertaken to identify differences between the samples. RESULTS: Anomalous features observed in the cleft lip and palate sample included short posterior arch of C1 (2/29), abnormal development of the anterior arch of C1 (2/29), and fusions of the posterior arch of C2 and C3 (2/29). No anomalies of the cervical spine were observed in the noncleft sample. Although the heights of three cervical vertebral bodies were significantly smaller and two intervertebral spaces were significantly larger in infants with cleft lip and palate compared with noncleft infants (p < .05), overall length of the cervical spine did not differ significantly between the samples. CONCLUSION: There was evidence for subtle upper spinal anomalies in the infant cleft lip and palate population. Our finding of reduced size of some cervical vertebral bodies may reflect delayed upper spinal development in infants with cleft lip and palate.

The hyoid bone in malay infants with cleft lip and palate.

OBJECTIVE: To compare morphological and positional variations of the hyoid bone in unoperated infants with cleft lip and palate (CL/P) with those in noncleft infants. DESIGN: Retrospective, cross sectional. PATIENTS AND METHODS: Three-dimensional computed tomography scans were obtained from 29 unoperated CL/P infants of Malay origin aged between 0 and 12 months and from 12 noncleft infants in the same age range. Observations were made and measurements were obtained with a software package developed at the Australian Craniofacial Unit. The sizes of the hyoid bones and the position of the hyoid body and epiglottis in relation to the cervical spine were measured. Anatomical anomalies of the hyoid and prevalence of aspiration pneumonia were also documented. RESULTS: The hyoid bones and epiglottis were found to be located more inferiorly in CL/P infants compared with the noncleft infants. Also, 17% (5/29) of the CL/P infants had nonossified hyoid bodies. CONCLUSION: The results suggest that there are differences in the location and genesis of the hyoid bone in infants with CL/P that warrant further investigation.

Dental anomalies and facial profile abnormality of the non-syndromic cleft lip and palate children in kelantan.

This study was done to determine the prevalence of dental anomalies and facial profile abnormality and its association with the non-syndromic cleft lip and palate (CLP) as compared to the non-cleft children. A comparative cross sectional study was conducted where the case group consist of 98 non-syndromic CLP children-unilateral (UCLP) and bilateral (BCLP) who attended the Combined Clinic at Kota Bharu Dental Clinic (KBDC) while the comparison group comprised of 109 non-cleft children who attended the outpatient clinic at KBDC. Their ages were between 3 to 12 years old. Clinical oral and facial profile examinations were carried out to look for dental anomalies (morphology, number and alignment of teeth) and facial profile abnormality. The prevalence of anomalies in morphology of teeth in CLP (24.5%) and non-cleft (10.1%), number of teeth in CLP (44.9%) and non-cleft (7.3%), mal-alignment in CLP (79.6%) and non-cleft (27.5%) and facial profile abnormality in CLP (26.5%) and non-cleft (9.1 %). There was a significant association between CLP and anomalies in morphology, number, mal-alignment and abnormality in facial profile; (p < 0.05). Therefore, there was a high prevalence and risk of dental anomalies and facial profile abnormality in the CLP children compared to the non-cleft children.

Hyalinizing clear cell carcinoma of minor salivary gland: case report.

Hyalinizing clear cell carcinoma is a low-grade neoplasm of the minor salivary gland composed exclusively of epithelial cells and not myoepithelial cells. It predominantly affects the oral cavity of adult females. It is microscopically characterized by hyalinizing stroma and clear cells, which are typically positive for cytokeratin markers and negative for S 100 and smooth muscle actin (SMA). Cystic degeneration can also be present. Pathologists should be aware of this new entity so as not to misdiagnose otherwise. To our knowledge, this is the first case report of its kind from Malaysia.