Jitendra Sharan

Bio-functionalization of grade V titanium alloy with type I human collagen for enhancing and promoting human periodontal fibroblast cell adhesion – an in-vitro study

Surface modification of medical grade V titanium alloy (Ti-6Al-4V) with biomolecules is an important and vital step for tailoring it for various biomedical applications. Present study investigates theinfluence of type I human collagen (T1HC) bio-conjugation through a three stage process. Polished grade V titanium alloy discs were functionalizedwith free OH group by means of controlled heat and alkali treatment followed by coating of 3-aminopropyltriethoxy (APTES) silane couplingagent. T1HC were bio-conjugated through 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride N-hydroxysuccinimide (EDCNHS)coupling reaction. At each stage, grade V titanium alloy surfaces were characterized by atomic force microscopy (AFM), scanning electronmicroscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Xrayphotoelectron spectroscopy (XPS). FTIR and XPS studies confirms thecovalent attachment of APTES with titanium alloy surface while terminalamine groups of APTES remained free for further attachment of T1HCthrough covalent bond. Aqueous stability of bio-conjugated titanium discsat various pH and time intervals (i.e. at pH of 5.5, 6.8 and 8.0 at timeinterval of 27 and 48h) confirmed the stability of T1HC bioconjugated collagen on titanium surface. Further human periodontalfibroblast cell line (HPdlF) culture revealed enhanced adhesion on theT1HC bio-conjugated surface compared to the polystyrene and polishedgrade V titanium alloy surfaces.

Bimaxillary protrusion trait in the Indian population: A cephalometric study of the morphological features and treatment considerations

Abstract Purpose The orthodontic literature is discordant with the diagnosis of bimaxillary protrusion with no single anatomic answer and the anomaly has been referred in the literature with protean characteristics. The trait denotes a particular facial configuration and its cephalometric representation in certain ethnic and racial groups revealed a mixed pattern with individual variations. The present study was aimed at analyzing the dento-skeletal characteristics of bimaxillary protrusion in a sample of Indian men and women. Materials and methods Forty-six Indian subjects (28 women and 18 men; 19 ± 3.6 years of age) with Class I malocclusion and interincisal angle ≤110°, who attended orthodontic clinics for a comprehensive fixed orthodontic treatment were included for the study. The lateral films were hand traced and 27 parameters were measured. The data were imported to SPSS version 13 US package and statistical manipulation included means, standard deviation, and coefficient of variation (%). Male and female data were compared by Students t-test (unpaired). Correlation and regression analysis were performed to assess any relationship between different parameters. Results There was a marked increase in proclination of the maxillary incisors both to the maxillary plane (125.3 ± 5.7°), the NA line (35.1 ± 5.0°) and to sella–nasion (117.7 ± 5.5°). The positional relationship of the mandible to the maxilla with reference to the cranial base was within the normal limits (ANB = 3.1 ± 1.3°) and the skeletal pattern was Class I. The effective lengths of maxilla and mandible did not correlate significantly with sagittal skeletal discrepancy. Conclusion Unlike in other ethnic and racial groups, bimaxillary protrusion in Indian subjects is likely a bidental protrusion over normal dento-alveolar bases. The skeletal characteristics suggested a normal relationship of the functional components of the face. The condition could be treated successfully with orthodontic mechanotherapy alone.

Assessment of hyoid bone position among different skeletal patterns

Abstract Purpose To determine the hyoid bone position in subjects with various skeletal patterns. Materials and methods Conventional pre-treatment lateral cephalograms of 100 subjects aged 18–25 years were selected from the files of orthodontic patients based on anteroposterior skeletal pattern and facial divergence pattern. Subjects with Class I skeletal pattern (ANB 1–4°) were categorized into group A and group B depending on the measurements of Frankfort Mandibular Plane Angle (FMA) of 22–30° (normo divergence) and greater than 30° (hyper divergence) respectively. Likewise subjects with Class II skeletal pattern (ANB >4°) were categorized into group C and D, based on the above same divergence. The angular and linear measurements were recorded and measured. Statistical assessments include unpaired Student t-test and one-way analysis of variance (ANOVA). Results The vertical position of hyoid bone was not affected by nature of horizontal or vertical growth pattern of the face. The mean anteroposterior position of the hyoid bone among the 4 groups of subjects was statistically significant (p < 0.05). The position of hyoid bone in group D was significantly backward compared with the subjects in group A (p < 0.05) or group C (p < 0.05). The mean hyoid axis angle among subjects in the hyper divergent group (group B and group D) was high but insignificant. Conclusion The position of hyoid bone was most posterior in subjects with skeletal Class II malocclusion associated with mandibular retrognathism.

Ultraviolet photofunctionalization of orthodontic miniscrews

We commend Dr Tabuchi et al for their study on ultraviolet (UV) photofunctionalization of orthodontic miniscrews (Tabuchi M, Ikeda T, Nakagawa K, Hirota M, Park M, Miyazawa K, et.al. Ultraviolet photofunctionalization increases removal torque values and horizontal stability of orthodontic miniscrews. Am J Orthod Dentofacial Orthop 2015;148:274-82). The article provides the latest and an easy way to improve the removal torque of orthodontic miniscrews in use. However, we have a few concerns related to the implementation of the study and seek clarifications regarding these.