Inclusion Criteria:  - 1. Panoramic radiographs and cone beam computed tomography of patients aged15-40 years.  2. Only patients with a documented date of birth.  Exclusion Criteria:  1. Asymmetry in OPG and CBCT images, unreadable ,unclear ,poor quality, gross pathology and magnification.  2. Panoramic radiographs with positioning errors which could cause distortions in the dimensions.  3. Hereditary facial asymmetries. 4. Images of completely edentulous patients. 5. Surgical intervention, patients with orthognathic surgeries. 6. Presence of pathologies such as fractures, impacted teeth, missing teeth, cleft lip or palate, cysts, tumors, osteomyelitis,severe osteoporosis in the mandible, periodontal lesion, and congenital craniofacial abnormalities, in the lower jaw, resorption in the mandibular arch that could affect the interpretation of radiographic image, 7. History of head trauma