Rozita Hassan

Effect of 940 nm low-level laser therapy on osteogenesis in vitro

Abstract. Bone regeneration is essential in medical treatment, such as in surgical bone healing and orthodontics. The aim of this study is to examine the effect of different powers of 940 nm diode low-level laser treatment (LLLT) on osteoblast cells during their proliferation and differentiation stages. A human fetal osteoblast cell line was cultured and treated with LLLT. The cells were divided into experimental groups according to the power delivered and periods of exposure per day for each laser power. The (3-(4,5-dimethylthiazol-2yl)-2,5 diphenyl tetrazolium bromide) (MTT) assay was used to determine cell proliferation. Both alkaline phosphatase and osteocalcin activity assays were assessed for cell differentiation. All treatment groups showed a significant increase in cell proliferation and differentiation compared to the control group. Regarding the exposure time, the subgroups treated with the LLLT for 6 min showed higher proliferation and differentiation rates for the powers delivered, the 300-mW LLLT group significantly increased the amount of cell proliferation. By contrast, the 100 and 200 mW groups showed significantly greater amounts of cell differentiation. These results suggest that the use of LLLT may play an important role in stimulating osteoblast cells for improved bone formation.

Tooth size and dental arch dimensions: a stereophotogrammetric study in Southeast Asian Malays

OBJECTIVE To investigate tooth size and dental arch dimensions in Malays using a stereophotogrammetric system. SETTING AND SAMPLE POPULATION The sample consisted of 252 subjects with ages ranged from 13 to 30 years. MATERIALS AND METHODS Images of dental casts were captured by stereophotogrammetry and selected variables were measured using a three-dimensional (3D) imaging system. Sex differences and changes associated with age were assessed, and interrelationships between different variables were explored within the study group. RESULTS Men had significantly larger mesio-distal crown widths and dental arch dimensions than women (p < 0.05). None of the dental arch dimensions or mesio-distal crown widths showed a significant change because of age except the widths of the upper canine, lower first molar and central incisor. Significant correlations of tooth size with dental arch dimensions were found, particularly with arch lengths and perimeters. A principal component analysis showed interrelationships between the majority of tooth size variables with inter-canine width, arch length and perimeter distances. CONCLUSION This study has established new reference data for tooth size and arch dimensions in Malays and demonstrated patterns of variation that are relevant to anthropologists interested in making comparisons within and between different populations and also to clinicians developing treatment plans for their patients. The study confirmed the accuracy of the 3D photogrammetric method for measuring dental casts.

Facial dimensions of Malay children with repaired unilateral cleft lip and palate: a three dimensional analysis

This comparative cross-sectional study assessed the facial surface dimensions of a group of Malay children with unilateral cleft lip and palate (UCLP) and compared them with a control group. 30 Malay children with UCLP aged 8-10 years and 30 unaffected age-matched children were voluntarily recruited from the Orthodontic Specialist Clinic in Hospital Universiti Sains Malaysia (HUSM). For the cleft group, lip and palate were repaired and assessment was performed prior to alveolar bone grafting and orthodontic treatment. The investigation was carried out using 3D digital stereophotogrammetry. 23 variables and two ratios were compared three-dimensionally between both groups. Statistically significant dimensional differences (P<0.05) were found between the UCLP Malay group and the control group mainly in the nasolabial region. These include increased alar base and alar base root width, shorter upper lip length, and increased nose base/mouth width ratio in the UCLP group. There were significant differences between the facial surface morphology of UCLP Malay children and control subjects. Particular surgical procedures performed during primary surgeries may contribute to these differences and negatively affect the surgical outcome.

Dentoalveolar Relationships of Malay Children With Unilateral Cleft Lip and Palate

Objective: To determine the treatment outcome based on dentoalveolar relationships among Malay children born with nonsyndromic complete unilateral cleft lip and palate (UCLP). Design: Retrospective cohort study. Setting and Sample Population: The Department of Orthodontics at the School of Dental Science and the Reconstructive Sciences Unit, School of Medical Science, Universiti Sains Malaysia. Dental study models of 82 UCLP Malay children aged 8 to 10 years were evaluated. All subjects had their cleft lip and palate repaired, but no alveolar bone graft or any orthodontic treatment was performed. Outcome Measure: The outcome of dental arch relationships was assessed using the Goslon Yardstick Index: a dental measure with outcomes ranked on a scale ranging from 1 to 5. Agreement of rating was assessed with weighted kappa statistics; both intraexaminer and interexaminer agreements were high, indicating good reproducibility. Results: A total of 2.4% of the sample was in grade 1, 24.4% in grade 2, 35.4% in grade 3, 31.7% in grade 4, and 6.1% in grade 5. The mean Goslon index score was 3.15. Conclusion: Dentoalveolar relationship outcomes of UCLP Malay children are intermediate according to the Goslon Yardstick. Interpretation of results should consider the ethnic differences in the craniofacial complex.

Overview of non-invasive factors (low level laser and low intensity pulsed ultrasound) accelerating tooth movement during orthodontic treatment

The need for orthodontic treatment is increasing all the time. As the treatment is time consuming ranging from a year to several years, any method of reducing the period of treatment and increasing the quality of the tissue will be beneficial to patients. The use of non-invasive techniques such as low level laser therapy and low intensity pulsed ultasound in accelerating orthodontic tooth movement are promising. Thus, this overview study will help to generate more understanding about the background information and the possible applications of them in daily orthodontics, depending on previous literature searching for reviews and original research articles.

Reinforcement of poly(vinyl alcohol) hydrogel with halloysite nanotubes as potential biomedical materials

ABSTRACT This work reports the reinforcement of poly(vinyl alcohol) (PVA) hydrogel with halloysite nanotubes (HNT) as potential biomedical materials. The nanocomposite hydrogel was prepared using the facile and harmless process of freeze–thawing. Mechanical properties of the hydrogels were optimum at 2 wt% of HNT loading. Morphological and topographic analysis of the PVA/HNT hydrogel revealed excellent filler dispersion and smoothing of surface due to good compatibility between the components. Immersion of the PVA/HNT hydrogel in simulated body fluid for 7 days resulted in the formation of fully covered apatite layers on the surface. This is a good indication of bioactivity for artificial cartilage material.

Leukaemia screening based on fuzzy ARTMAP and simplified fuzzy ARTMAP neural networks

Leukaemia is a life threatening disease that has caused many deaths for the patients below 20 years of age compared to the other types of cancer. The accurate and early detection of leukaemia are the main keys to cure this disease effectively. Therefore, the need for analyzing the blood cells promptly is essential for leukaemia screening. Currently, the procedure for leukaemia screening is performed by haematologists by analyzing the blood cells under the microscope. Since the recognition of the blood cells has been performed manually, it is a time consuming and effortful procedure. As a step to provide the solution to this problem, this paper presents the classification of three different types of white blood cells (WBCs) which are lymphoblast, myeloblast and normal cell inside the Acute Lymphoblastic Leukaemia (ALL), Acute Myelogenous Leukaemia (AML) and normal blood samples by using the Fuzzy ARTMAP (FAM) and Simplified Fuzzy ARTMAP (SFAM) neural networks. Here, an overall of 24 extracted input features that cover the size, shape and colour features have been obtained from each WBC nucleus and fed to both FAM and SFAM networks. Comparison of performance has been made for finding the best classifier that is capable of classifying the WBCs with an optimum result. Overall, the results indicate that SFAM network has produced the highest testing accuracy with classification result of 92.00% by using the overall extracted features compared to the FAM network with classification result of 90.63%.

Skeletal, dentoalveolar, and soft tissue cephalometric measurements of Malay transfusion-dependent thalassaemia patients

Thalassaemia is a public health problem in Malaysia. It is known to cause skeletal deformity. The purpose of this study was to compare the skeletal, dentoalveolar, and soft tissue features of Malay transfusion-dependent thalassaemia (TDT) patients with a Malay control group. Lateral cephalometric radiographs of 30 Malay (14 males and 16 females aged 6.4-21.8 years) TDT patients and 60 normal Malays matched for chronological age and gender were analysed and compared using an independent t-test. The TDT group showed a similar sagittal relationship to the control group but with a significantly increased (P < 0.01) mandibular plane inclination. They also showed a significantly shorter (P ≤ 0.001) mandibular body, ramus length, and posterior face height and consequently a smaller ratio of posterior to anterior face height (P < 0.01). The upper and lower lips were significantly procumbent (P < 0.001) in the TDT group together with a significantly smaller nasolabial angle (P < 0.05). Dentoalveolar measurements showed less proclined maxillary teeth in the TDT group compared with the controls (P < 0.05). The cephalometric features of Malay TDT patients were characterized by a mild Class II skeletal pattern, prominent vertical growth direction of the mandible, and protruded upper and lower lips.

Stereophotogrammetric analysis of nasolabial morphology among Asian Malays: Influence of age and sex

Objective It is clear that population-specific norms should be used when planning plastic and reconstructive surgery for selected patients. In this study, we aimed to generate nasal and labial reference values by applying a stereophotogrammetric technique. A further aim was to investigate the effect of sexual dimorphism, age-related changes, and the interrelation between nasal and labial morphology. Design Cross-sectional study. Setting The data were collected from different locations on the Malaysian peninsula. Participants A total of 276 Asian Malays (138 males and 138 females) were included in this study, and a three-dimensional system was used for capturing data. The sample was divided into three age groups: 13 to 14, 15 to 17, and 18 to 36 years. Main Outcome Measure(s) Twenty-five dimensions of the nose and lips were measured and analyzed separately in males and females. Results Significant differences between males and females were identified in 11 distances, and significant effects of age were found in most of the dimensions (p < .05). Significant correlations between the nasal and labial dimensions were recorded, particularly between lateral lip height and width of the ala insertion. A principal component analysis showed interrelationships between the nasal width distances and upper lip height. Conclusion This study has provided a new three-dimensional database for nose and lip morphology in Malays and demonstrated patterns of variation that can be used by surgeons to make comparisons within and between different human populations and also to develop treatment plans for their patients.

Influence of citric acid on the physical and biomineralization ability of freeze/thaw poly(vinyl alcohol) hydrogel:

This work reports the modification of freeze/thaw poly(vinyl alcohol) hydrogel using citric acid as the bioactive molecule for hydroxyapatite formation in simulated body fluid. Inclusion of 1.3 mM citric acid into the poly(vinyl alcohol) hydrogel showed that the mechanical strength, crystalline phase, functional groups and swelling ability were still intact. Adding citric acid at higher concentrations (1.8 and 2.3 mM), however, resulted in physically poor hydrogels. Presence of 1.3 mM of citric acid showed the growth of porous hydroxyapatite crystals on the poly(vinyl alcohol) surface just after one day of immersion in simulated body fluid. Meanwhile, a fully covered apatite layer on the poly(vinyl alcohol) surface plus the evidence of apatite forming within the hydrogel were observed after soaking for seven days. Gel strength of the soaked poly(vinyl alcohol)/citric acid-1.3 mM hydrogel revealed that the load resistance was enhanced compared to that of the neat poly(vinyl alcohol) hydrogel. This facile method of inducing rapid growth of hydroxyapatite on the hydrogel surface as well as within the hydrogel network can be useful for guided bone regenerative materials.