1) Conclusions: BWR is an accurate diagnostic method for approximal caries in present clinic practice.

2) Chapter 3 is about an approximal algorithm for misclassification minimization , which is one of the common problems in machine learning.

3) Methods On 100 cranial bones according to specified methods using vernier to measure the subcutaneous segment of each bone suture that is made by zygomatic bone and approximal bone.

4) Results The lesions located at distal femur in 7 cases, at approximal tibia in 3 cases, at distal humerus, approximal femur, thoracic vertebrae and sacrum in 1 case respectively.

5) Conclusions: BWR is an accurate diagnostic method for initial posterior approximal caries in present clinic practice.