Abdul Rani Samsudin

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.

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 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.

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.

3D CT Imaging for Craniofacial Analysis Based on Anatomical Regions

The development of a craniofacial database is a multidisciplinary initiative that will provide an important reference for community, security, social and medical applications. A method of landmark identifications and measurements in 3D on craniofacial patients is described. Anatomical regions such as mandible, orbits, zygoma and maxilla are located, created and stored as templates of 3D CAD files for subsequent analysis. Data from these images were tested for accuracy and repeatability by comparing with direct measurements using caliper and CMM. The landmark points are reproducible in CAD system for further analysis. It was found that the approach provides a fast, accurate and efficient method for landmarks identification of the craniofacial areas in database development

Effect of exogenous nitric oxide on the proliferation of a human osteoblast (HOS) cell line induced by hydroxyapatite

AIM The aim of this study was to test the hypothesis that the proliferation of hydroxyapatite (HA)-induced human osteoblast cell line (HOS cells) may be up-regulated by exogenous nitric oxide (NO). METHODS HOS cells were cultured on the surface of HA with or without the presence of a NO donor, S-nitroso acetyl penicillamine (SNAP) or nitroso acetyl penicillamine (NAP). 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) known as carboxy PTIO, a NO scavenger, was added in the cell cultures with or without the presence of SNAP. The cells were also pre-treated with L-N5-(1-iminoethyl)orthinine hydrochloride (L-NIO), an endothelial nitric oxide synthase (eNOS) inhibitor, or anti-integrin alphaV antibody before culturing on HA surfaces with or without the presence of SNAP. Medium, cells alone or cells pretreated with these inhibitors or antibodies was used as the controls. Cell proliferation was assessed by colorimetric assay. RESULTS The results showed that SNAP, but not NAP, augmented HA-induced HOS cell proliferation. This modulatory effect of SNAP on HA-induced HOS cell proliferation was abolished by carboxy PTIO or anti-integrin alphaV antibody, but only partially reduced by L-NIO. CONCLUSION Therefore, the results of this study suggest that exogenous NO alone may up-regulate the proliferation of HOS cells attached on HA surfaces via integrin alphaV molecules.

The Efficacy of Immediate Implant Placement in Extraction Sockets for Alveolar Bone Preservation: A Clinical Evaluation Using Three-dimensional Cone Beam Computerized Tomography and Resonance Frequency Analysis Value.

Abstract The aim of this study was to determine the efficacy of immediate implant placement with alveolar bone augmentation on socket preservation following atraumatic tooth extraction and comparing it with a tooth alveolar socket that was allowed to heal in a conventional way. Twenty medically fit patients (8 males and 12 females aged between 18 and 40 years) who needed noncomplicated tooth extraction of mandibular premolar teeth were divided randomly and equally into 2 groups. In Group I, the empty extraction socket was left untreated and allowed to heal in a conventional way. In Group II, the immediate implant was placed and the gap between the implant and the inner buccal plate surface of the socket wall was filled with lyophilized bovine bone granules and the wound was covered with pericardium membrane. The patients were followed up clinically and radiologically for regular reviews at 1 week, 3 months, and 9 months postoperative. Cone beam computerized tomography images of the alveolar ridge and socket were analyzed to determine the structural changes of the alveolar ridge. Resonance frequency analysis was measured at 9 months for Group II to assess the degree of secondary stability of the implants by using Osstell machine. A significant difference of bone resorption of 1.49 mm (confidence interval, CI 95%, 0.63–2.35) was observed within the control group at 3 months, and 1.84 mm (P ⩽ 0.05) at 9 months intervals. No significant changes of bone resorption were observed in Group II. Comparison between groups showed a highly significant difference at 3 months; 2.56 mm (CI 95% 4.22–0.90) and at 9 months intervals; 3.2 mm (CI 95%, 4.70–1.62) P ⩽ 0.001 between Group I and II. High resonance frequency analysis values were observed at 9 months postoperative in Group II. In conclusion, the insertion of immediate implants in fresh extraction sockets together with grafting the circumferential gap between the bony socket wall and the implant surface with bovine bone granules was able to preserve a greater amount of alveolar ridge volume when compared with an extraction socket that was left to heal in a conventional way.

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.

3D Modelling and Evaluation of the Morphology of Hyoid Bone

The hyoid bone, a small U-shaped bone in the upper neck above the thyroid cartilage is a unique structure in humans as it has no bony articulation. The lack of data on morphology and position of hyoid bone is due to a large extent to difficulty in visualizing the hyoid bone using conventional radiographic techniques. Lateral cephalometry has significant limitations such as superimposition of structures, difficulty in identifying landmarks and poor visualization of structures. The aim of this study is to compare morphological and positional variations of the hyoid bone in patients who had undergone CT scans. CT scan images are modeled in MIMICS and using anthropometric analysis module, several measurements of hyoids are obtained. Hyoid bone angle was measured from the most superior medial point on the surface of the body to the base of the skull. 3D visualization of hyoid bone helps to locate the most inferior point of the anterior aspect of the foramen magnum in the mid-sagittal plane (basion) and the most inferior point of the spheno-occipital synchondrosis (SOS) on the sphenoid bone. Data collected using 3D images are used to compare the position of the hyoid bone and epiglottis in relation to the cervical vertebrae and cranial base.