No abstract

Background:Commonly used parameters for anteroposterior assessment of the jaw relationship includes several analyses such as ANB, NA-Pog, AB-NPog, Wits appraisal, Harvold's unit length difference, Beta angle. Considering the fact that there are several parameters (with different range and values) which account for sagittal relation, and still the published literature for comparisons and correlation of these measurements is scarce. Therefore, the objective of this study was to correlate these values in subjects of Indian origin.Materials and Methods:The sample consisted of fifty adult individuals (age group 18-26 years) with equal number of males and females. The selection criteria included subjects with no previous history of orthodontic and/or orthognathic surgical treatment; orthognathic facial profile; Angle's Class I molar relation; clinical Frankfort Mandibular plane angle FMA of 30±5° and no gross facial asymmetry. The cephalograms were taken in natural head position (NHP). Seven sagittal skeletal parameters were measured in the cephalograms and subjected to statistical evaluation with Wits reading on the true horizontal as reference. A correlation coefficient analysis was done to assess the significance of association between these variables.Results:ANB angle showed statistically significant correlation for the total sample, though the values were insignificant for the individual groups and therefore may not be very accurate. Wits appraisal was seen to have a significant correlation only in the female sample group.Conclusions:If cephalograms cannot be recorded in a NHP, then the best indicator for recording A-P skeletal dimension would be angle AB-NPog, followed by Harvold's unit length difference. However, considering biologic variability, more than one reading should necessarily be used to verify the same.

Context: As lingual bonded retainers are required for long-term retention in the oral cavity, the wire-composite combination of choice may be the determining factor for the success of lingual bonded retainers. Aim: We compared the shear bond strength of different wire-composite combinations used for lingual bonded retainers and identified the combination of choice for lingual retention in terms of the shear bond strength. Materials and Methods: A total of 108 extracted human maxillary premolars in pairs were divided into 6 groups of 9 samples each. Three different types of retainer wires (namely, Respond [Ormco Corp., Orange, CA, USA], Leone Ligature Wire [Leone S.p.a., Firenze, Italy], and SRW™ Stranded Retention Wire [Ortho Classic Inc., USA]) were bonded to the teeth with the composites (G-aenial™ Universal Flo and Tetric N-Flow). The shear bond strength was measured on debonding using universal testing machine INSTRON. Results: The maximum shear bond strength (58.28 N) was observed in group IV (Respond wire with Tetric N-Flow), whereas the minimum (25.28 N) was observed in group VI (SRW™ Stranded Retention Wire with Tetric N-Flow). A highly significant difference was observed when the shear bond strength of group IV was compared with all the other groups. Conclusions: The maximum shear bond strength was observed in the wire-composite combination of Respond dead-soft wire with Tetric N-Flow composite. Therefore, it could be the wire-composite combination of choice for bonded lingual retainer.

Introduction: Cephalometric analysis forms the backbone of orthodontic diagnosis and treatment planning. However most of the angles used to assess antero-posterior jaw base discrepancy are based on landmarks that change with age, jaw rotation and orthodontic treatment. Walkers point is one landmark that has been suggested to be stable and easy to locate on radiograph.Objective: To derive SAR angle based on Walkers point, points M and G to assess true sagittal discrepancy. Materials & method:Sixty pretreatment lateral cephalograms of North Indian subjects were grouped in three classes of skeletal pattern based on fulfillment of any two of the three criteria: ANB angle, Witt's appraisal and Beta angle. The mean and SD for the SAR angle in three groups were calculated. ANOVA one-way of variance and Newman-Keuls tests were done to compare the groups. Result Conclusion:The SAR angle can be a reliable diagnostic aid to assess the sagittal jaw discrepancy more consistently.

Maxillary canines are known as the cornerstones of mouth. They are considered to be important for esthetics and for functional occlusion. Any disturbance in the eruption process leading to an aberrant position will hamper esthetics as well as function. Orthodontic tooth movement of total buccally blocked-out canine is usually difficult as it is related with the problems of severe crowding, midline deviation, involvement of long root movement and risk of gingival recession. Such conditions can be treated orthodontically in various ways, but this clinical innovation helps to correct the buccally placed canines into the arch with a precise control of the canine in all the Three-dimensions (3D) of space as well as providing maximum comfort to the patient by placing the canine loop on the palatal surface of the tooth, reducing soreness on the labial mucosa. It can be easily fabricated and activated at chairside for either simultaneous or sequential control in 3D.