ABSTRACT
Background: Orofacial cleft is the most common congenital defect of the maxillofacial region. Its non-syndromic type is multi-factorial, and several genes are involved in its occurrence. This study aimed to assess the interaction effect of Rsal and BamHI polymorphisms of Transforming Growth Factor-alpha [TGFa] gene and Bone Morphogenetic Protein-2 [BMP2] and BMP4 variants on the occurrence of Non-Syndromic Cleft Lip and Palate [NSCLP] in the Iranian population
Methods: This case-control study was conducted on 120 children with NSCLP and 215 healthy children. Genotyping of the TGFA/BamHI [rs11466297], TGFA/RsaI [rs3732248], BMP4 [rs17563] and BMP2 [rs235768] was performed by Polymerase Chain Reaction [PCR] and Restriction Fragment Length Polymorphism [RFLP] methods. Logistic regression was applied to determine the effective factors and the interaction effect of different variants on the occurrence of NSCLP
Results: Gender of patients had no significant association with the occurrence of NSCLP [p=0.335]. Multiple logistic regression showed that the interaction effect of the aforementioned polymorphisms on the occurrence of NSCLP was not statistically significant [p=1.000]
Conclusion: Although the individual effect of each of the BMP4, BMP2, RsaI and BamHI variants on the occurrence of NSCLP in the Iranian population has been previously confirmed, their interaction does not play a role in this respect
ABSTRACT
Objective: Root resorption is a complication of orthodontic treatment and till date, there is a dearth of information regarding this issue. The aim of this study was to determine whether the expression of transforming growth factor-beta 1 [TGF-beta 1, an inflammatory cytokine] is related to orthodontic force. Moreover, if associated, the expression level may be helpful in differential diagnosis, control and ultimate treatment of the disease
Materials and Methods: In this experimental study, a total of 24 eight-week-old male Wistar rats were selected randomly. On day 0, an orthodontic appliance, which consisted of a closed coil spring, was ligated to the upper right first molar and incisor. The upper left first molar in these animals was not placed under orthodontic force, thus serving as the control group. On day 21, after anesthesia, the animals were sacrificed. The rats were then divided into two equal groups where the first group was subjected to histological evaluation and the second group to reverse transcriptase-polymerase chain reaction [RT-PCR]. Orthodontic tooth movement was measured in both groups to determine the influence of the applied force
Results: Statistical analysis of data showed a significant root resorption between the experimental group and control group [P<0.05], however, there was no significant difference in the expression level of the inflammatory cytokine, TGF-beta 1
Conclusion: Based on the findings of this study, we suggest that there is a direct relationship between orthodontic force and orthodontic induced inflammatory root resorption. In addition, no relationship is likely to exist between root resorption and TGF-beta 1 expression in the resorptive lacunae
ABSTRACT
Objectives: the purpose of this study was to evaluate whether intra-canal application of controlled direct electric current [DEC] could accelerate the amount of orthodontic tooth movement [OTM] in young adult mixed breed dogs
Methods: fourth premolars of both jaws of five young adult mixed breed dogs were divided into two groups of control and experimental groups. Orthodontic force was applied to both groups using an active NiTi push coil spring. Direct electric stimulation [15µA DC] was conducted by intra-canal usage of electric potential [1.5v]. The experimental teeth were compared with controls in terms of clinical OTM results measured with an electronic caliper every two weeks [four time intervals]. The animals were sacrificed one month [T2] or two months [T4] after initiation; and tissue sections were decalcified for histological evaluation. The data were analyzed using SPSS 16, Shapiro-Wilk test and paired t-test
Results: measurements revealed a statistically significant increase in OTM at electrically stimulated sites compared to the control sites in just one time interval [T3: after four weeks] [P< 0.05]. Histological sections also showed increased osteoblastic and osteoclastic activity at tension and compression sides of the experimental group compared to the control group, respectively at both time intervals [T2 and T4]
Conclusion: direct intra-canal electric current applied by a miniature electric device is effective for increasing the rate and amount of OTM in canine experimental model
ABSTRACT
The relationship between IQ score and malocclusion is a subject that has been the focus of attention in the field of orthodontics. The present study aimed at determining the IQ score of patients with dentoskeletal malocclusions presenting to the Orthodontic Department of Shahid Beheshti Dental School during 2008-2009. This descriptive cross-sectional study was conducted on 160 patients aged 12-18 yrs. who were receiving orthodontic treatment. A questionnaire was designed containing 3 sections of demographic characteristics, general information and orthodontic treatment. The questionnaire was completed by the patient and senior dental students and patients were asked to take the Cattell Culture Fair III IQ test on the computer and the obtained IQ score was recorded. Data were analyzed using linear regression analysis. The mean IQ score of the understudy population was 98 +/- 16. IQ score had a significant correlation with level of education [P<0.001], age [P<0.001] and socioeconomic status [P<0.001]. However, type of skeletal malocclusion and facial growth pattern were not correlated with the IQ score. The obtained results showed no association between type of skeletal malocclusion or facial growth pattern and the IQ score