*2.1.1 Demirjian's method*

According to the criteria, the maturity of the seven mandibular teeth on the left side (excluding the third molar) was determined by comparing their radiographic appearances with a sequence of reference radiographs and diagrams, and description of formation stages. If any of the mandibular left teeth was missing, or its image was unclear, the contra-lateral tooth was used [9].

Each tooth was divided into eight formative stages (A to H), and each stage was allocated a score depending on the gender. The scores for all seven teeth were then added to give the maturity score which can be converted directly into dental age by reading off a percentile curve the age at which the 50th centile attains the maturity score value, or by using a table which had been constructed.
