Deciduous teeth first teeth seen in the mouth are the mandibular centrals and the last are the maxillary second molars. The primary teeth are made up of central incisors, lateral incisors, canines, first molars, and secondary molars; there is one in each quadrant, making a total of four of each tooth. All of these are gradually replaced with a permanent counterpart except for the primary first and second molars; they are replaced by premolars. The replacement of primary teeth begins around age six, when the permanent teeth start to appear in the mouth, resulting in mixed dentition. The erupting permanent teeth cause
Deciduous teeth to develop. Teething age of primary teeth: Primary teeth are essential in the development of the mouth. The primary teeth maintain the arch length within the jaw, the bone and the permanent teeth replacements develop from the same tooth germs as the primary teeth. The primary teeth provide guides for the eruption pathway of the permanent teeth. Also the muscles of the jaw and the formation of the jaw bones depend on the primary teeth to maintain proper spacing for permanent teeth. The roots of primary teeth provide an opening for the permanent teeth to erupt. The primary teeth are