On routine dental examination of a male patient, the following features were seen radiographically. What is the dental age of this patient?
At dental age 9, the maxillary lateral incisors have been in place for 1 year, and root formation on other incisors and first molars is nearly complete. Root development of the maxillary canines and all second premolars is just beginning, while about one third of the root of the mandibular canines and all of the first premolars have been completed. 
Since no teeth are erupting at that time, dental ages 9 and 10 must be distinguished by the extent of resorption of the primary canines and premolars and the extent of root development of their permanent successors. At dental age 9, the primary canines, first molars, and second molars are present. Approximately one third of the root of the mandibular canine and the mandibular first premolar is completed. Root development is just beginning, if it has started at all, on the mandibular second premolar. In the maxillary arch, root development has begun on the first premolar but is just beginning, if it is present at all, on both the canine and the second premolar.
Contemporary orthodontics, Proffit WR, Fields Jr HW, Sarver DM. 4th edition, Page 94
7 years
9 years
11 years
12 years