On an OPG evaluation of a child, the following features were noted. Completion of the roots of the mandibular incisor teeth and near completion of the roots of the maxillary lateral incisors. Great amount of root resorption of the primary canines and molars and root development of their permanent successors. Approximately one half of the roots of the mandibular canine and mandibular first premolar have been completed. Nearly half the root of the upper first premolar was complete. Significant root development of the mandibular second premolar, maxillary canine, and maxillary second premolar. What is the dental age of this patient ?