Inclusion Criteria:  good quality of panoramic radiographs, presence of all permanent mandibular and maxillar teeth except the third molars healthy children with normal eruption of teeth, children with similiar etnic origin and socio-economic status  Exclusion Criteria:  Children with any syndromes, congenital or developmental anomalies and systemic diseases, Children undergoing or with previous orthodontic treatment history, Children with tooth agenesis, dental trauma history