Bone forms the basic framework of the body and it consists of bone cells, ground substance and collagen fibres. The bone undergoes alternate deposition and resorption to withstand the biomechanical forces exerted. Osteoclasts, osteoblasts, osteocytes secrete numerous enzymes, cytokines, growth factors which interact among one another to perform the physiological activities taking place in bone. This article emphasizes on the secretions of osteoblast that interacts with the osteoclast precursor involved in osteoclastic stimulation and inhibition and vice versa osteoclastic activity on bone can trigger osteoblastic formation or inhibition. This interaction is explained based on 3 different modes: Direct cell-cell contact, gap junctions, diffusion of paracrine factors and the 3 phases of bone remodelling.

Conventional radiographs provide only a 2 dimensional view of complicated three dimensional structures.  The proximity, angulations, location of impacted teeth, related to the IAN can be adequately determined using conventional 2-D periodical and panoramic radiographs. Computed tomography necessitates the administration of a high dose radiation, especially when the slice width is shortened to increased cost are the negative aspects of computed tomography compared with conventional imaging. Cone beam computed tomographies are becoming more readily available for use in maxilla facial applications. CBCT provides better image quality of teeth and their surrounding structures, compared with conventional CT and offers high spatial resolution. CBCT seems to be more accurate data about inferior alveolar canal. Hence the present study was undertaken to assess and select roots of third molar with close proximity to inferior dental canal in panoramic radiograph having radiographic signs of darkening of root, disruption of canal cortex and canal deviation and to evaluate the same roots with CBCT using trans axial and coronal sections which is angulated parallel to long axis to tooth, axial and coronal sections for proximity of inferior dental canal with the apices of third molar root. Keywords: CBCT, IAN