Heritability of thirty cephalometric parameters on monozygotic and dizygotic twins: twin study method.

Genetic mechanisms are already predominant during embryonic craniofacial morphogenesis, but environment is also thought to influence dentofacial morphology postnatally, particularly during facial growth. A better understanding of the relative effects of genes and environment on dentofacial and occlusal parameters should improve our knowledge on the etiology of orthodontic disorders and therefore also on the possibilities and limitations of the orthodontic treatment and treatment planning. The aim of the present study is to explore the genetic and environmental influence on craniofacial dimensions in a group of 19 pairs of twins using the twin study method. The twin study carried out here clearly indicates that craniofacial matrix is under substantial genetic control and the redirection of a basic growth pattern may be modified only within biological limits which are harmonious for the patient.

Comparison of shear bond strength of resin reinforced chemical cure glass ionomer, conventional chemical cure glass ionomer and chemical cure composite resin in direct bonding systems: an in vitro study.

The acid pretreatment and use of composite resins as the bonding medium has disadvantages like scratching and loss of surface enamel, decalcification, etc. To overcome disadvantages of composite resins, glass ionomers and its modifications are being used for bonding. The study was conducted to evaluate the efficiency of resin reinforced glass ionomer as a direct bonding system with conventional glass ionomer cement and composite resin. The study showed that shear bond strength of composite resin has the higher value than both resin reinforced glass ionomer and conventional glass ionomer cement in both 1 and 24 hours duration and it increased from 1 to 24 hours in all groups. The shear bond strength of resin reinforced glass ionomer cement was higher than the conventional glass ionomer cement in both 1 and 24 hours duration. Conditioning with polyacrylic acid improved the bond strength of resin reinforced glass ionomer cement significantly but not statistically significant in the case of conventional glass ionomer cement.

Dental Aesthetic Index of school students in Telangana region - An epidemiological study.

BACKGROUND: Malocclusion should be identified at its earliest before it produces any detrimental effects. The objective of this study is to evaluate the orthodontic status and treatment need of school children in Telangana region, Andhra Pradesh, using Dental Aesthetic Index. MATERIALS & METHODS: One thousand children in the age group of 12 - 14 years who fulfilled the inclusion and exclusion criteria were considered. The demographic details of the students along with the information on the orthodontic status were collected using a predesigned questionnaire by a single orthodontist. The information on orthodontic status was obtained using Dentofacial Anomalies with the criteria of Dental Aesthetic Index (W H O Oral Health Assessment form 1997). RESULTS: RESULTS were subjected to ANOVA, Tukeys test and chi square test using SPSS, version 16. 86.1% of the subjects had DAI score of less than 25, suggesting 'no treatment'; 10% had DAI score of 26-30, suggesting 'elective treatment'; 3% had DAI score of 31-35, suggesting 'highly desirable treatment'; 0.9% had DAI score of >36, indicating 'mandatory treatment'; Higher prevalence of malocclusion among females than males. CONCLUSION: It is necessary to identify this abnormality at its earliest before it produces detrimental effects. It is also essential to know the prevalence of malocclusion in any society, as it reveals the true extent of the problem and guides in overcoming it. The general public can, then, be educated on widespread occurrence of malocclusion and its deleterious effects, so that appropriate preventive and corrective measures can be instituted. How to cite this article: Anita G, Kumar GA, Reddy V, Reddy TP, Rao MS, Wankhade SB. Dental Aesthetic Index of school students in Telangana region - An epidemiological study. J Int Oral Health 2013; 5(6):55-60 .

Comparative evaluation of the fracture resistance of teeth prepared with rotary system, filled with single cone gutta-percha and laterally condensed with zinc oxide eugenol and resin based (AH26) sealers to that of Resilon.

AIM AND OBJECTIVE: To compare the fracture resistance of teeth prepared with rotary system and filled with single cone guttapercha followed by lateral condensation with different sealers like zinc oxide eugenol and resin based (AH26) to that of resilon. MATERIALS AND METHODS: A total number of 70 extracted intact human permanent maxillary incisors were selected. All prepared samples were divided into one control group (n = 10) and three experimental groups (n = 20 per group). Group 1 control. This group received no obturation; the root canal opening was sealed with a temporary filling material (Cavit, Premier Dental Products, Plymouth Meeting, PA) Group 2: Gutta-Percha and zinc oxide Eugenol sealer. Group 3: Gutta-Percha and AH26 sealer. (DiaDent, Korea) dipped in AH26 sealer. Group 4: Resilon cones and RealSeal Resin Sealer. Obturation was accomplished using a 0.06 taper size 40 gutta-percha master point. All the root samples were stored in 100% humidity at 37 °C for 2 weeks to allow the sealer to set completely. The root samples were then prepared for mechanical testing and the data was recorded and analyzed statistically. RESULTS: One-way ANOVA and Post hoc test (Duncan Multiple range test) were employed to determine possible statistical variation among the groups tested in this study. The force for group 2 was significantly greater than that for the control group 1 (no obturation).The force for group 3 was significantly greater than that for group 2. The force for group 4 was significantly greater than that for group 3. All other groupwise comparisons were not significant at 5% level. Group 4 seemed to have the greatest force among the three groups of interest in the study. CONCLUSION: Root canals filled with Resilon increased the in vitro resistance of single canal extracted teeth compared to other experimental groups. The mean fracture resistance value for the experimental groups in ascending order was as follows: Root canals instrumented but not filled, filled with gutta-percha and zinc oxide eugenol sealer, filled with gutta-percha and AH26 sealer and filled with Resilon. CLINICAL SIGNIFICANCE: Resilon is a promising material for reinforcement of endodontically treated teeth.

Comparison of orthopantomography and computed tomography image for assessing the relationship between impacted mandibular third molar and mandibular canal.

BACKGROUND: Permanent mandibular third molar are most commonly impacted teeth. In planning the surgical removal of mandibular third molar, correct diagnosis requires not only their precise spatial location, but also a thorough and accurate assessment of the intimate relationship with adjacent anatomical structures. Various imaging modalities have been used for localizing the mandibular third molar but not satisfactorily. AIM: This prospective study of 30 patients with 42 impacted mandibular third molars was carried out with the aim of finding evidence for justifying the use of computed tomography and orthopantomography as a diagnostic modality, prior to surgical intervention of impacted mandibular third molar. MATERIALS AND METHODS: Subjective evaluation of the CT and OPG images by two observed had shown that there was significant difference between the CT and OPG for radiographic visibility of mandibular canal in relation to third molar. RESULTS: Data analysis was done with Chi-square test (X(2)) and z-test to find the significant difference between the two radiographic modalities OPG and CT in localizing special relationship of impacted mandibular third molar. The comparison of OPG and CT showed z-value >1.5 in darkening of roots (1.98), deflection of root (2.00) interruption of z-value = 0 in narrowing of canal and dark, bifid apexes. Also it showed p-value <0.05 in all the radiographic signs except narrowing of mandibular canal and and dark and bifid apexes. CONCLUSION: The spiral CT image provides a unique opportunity to determine the exact position of impacted mandibular third molar and their relationship to adjacent structure in all three planes. CLINICAL SIGNIFICANCE: Computed tomography is highly instrumental in depicting the relationship of mandibular third molar with inferior alveolar nerve canal before treatment and accurate appraisal of the several aspects can be made regarding prognosis.