Engineering has not only developed in the field of medicine but has also become quite established in the field of dentistry, especially Orthodontics. Finite element analysis (FEA) is a computational procedure to calculate the stress in an element, which performs a model solution. This structural analysis allows the determination of stress resulting from external force, pressure, thermal change, and other factors. This method is extremely useful for indicating mechanical aspects of biomaterials and human tissues that can hardly be measured in vivo. The results obtained can then be studied using visualization software within the finite element method (FEM) to view a variety of parameters, and to fully identify implications of the analysis. This is a review to show the applications of FEM in Orthodontics. It is extremely important to verify what the purpose of the study is in order to correctly apply FEM.

Numerous cephalometric norms or standards have been given in past for various population in terms of age and ethinic origin. An accurate sagittal jaw relationship is critically important in orthodontic diagnosis and treatment planning. Various angular and linear measurements have been proposed that can be inaccurate because they depend on various factors. [1,2] For example Wits appraisal, ANB angle and nasion perpendicular are currently used by practitioners to diagnose the sagittal jaw relationship but all of these measurements have their limitations.McNamara's main goal in his analysis was to relate the teeth, jaws, and cranial bases to each other. [3] "Nasion Perpendicular to Frankfort Horizontal" is considered in his analysis but limitations include cases where the anteroposterior (A-P) position of nasion is more posterior thus nasion perpendicular is not accurate, and, therefore, an adjustment in the value should be made. [4] Jacobson's Wits appraisal is accurate for determining a discrepancy, but it is unable to determine which jaw is the discrepant. In his analysis accurate construction of the functional occlusal plane is of vital importance and the difficulty of accurately constructing results in a false appraisal of the jaw relationship, [4] also Chang reported that the Wits appraisal was found to evaluate the sagittal dental relationship along the occlusal plane and not the skeletal relationship. [5] Steiner proposed using nasion as the base for angular measurements to determine the position of the maxilla and mandible sagittally. [6] He used the ANB angle because it described the relationship between the maxilla and the mandible but

Introduction: It has been postulated that crown angulation and inclination has potential space implication within the arch. With the insight of space implication of the axial relations of teeth, cases of genuine tooth size discrepancies can be dealt with improved stability.Aim: This in vitro study was designed to investigate and quantify the influence of angulation and inclination of maxillary incisors on the effective arch perimeter. Materials and Methods:Acrylic teeth were arranged over typhodont frame with spaced maxillary anterior segment. Known value of tip and torque in increments were incorporated to maxillary incisors through bracket positioning and corresponding consumption of the interdental spaces were measured using coordinate measuring machine.Results: Study revealed that increase in maxillary incisor crown angulation by 1 o results in consumption of approximately 0.012 mm of arch perimeter. Similarly, there is a consumption of 0.021 mm of arch perimeter with each degree increase in labial crown inclination. Conclusion:The knowledge of the space implication can be included in the space analysis during the orthodontic treatment planning. Depending upon the amount of space discrepancy, an accurate degree of required alteration in the axial relation of one or more teeth can be planned.www.jcdr.net Megha Jain et al., Effect of Crown Angulation of Maxillary Incisor on Effective Arch Perimeter

The results of this study showed significant association between hand-wrist skeletal maturation levels and CA. Digital radiographic assessment of hand-wrist skeletal maturation can be used as a better choice for predicting average bone age of an individual because of its simplicity, reliability and lesser radiation exposure.