The purpose of this study is to evaluate the position of the mandibular foramen and location and morphological characteristics of the mandibular lingula using Cone-Beam Computed Tomography (CBCT).Mandibular CBCT images of children aged 6 - 16 years were collected. A total of 180 patients were divided into 3 groups, 6 - 7, 10 - 11 and 15 - 16 years, with 30 male and female patients per group. Either side of the ramus was analyzed. The shortest distances from the anterior, posterior, superior and inferior border of the ramus to the mandibular lingula were measured. The shortest distance between the mandibular lingula and the mandibular foramen was also measured. The vertical distance from the mandibular lingula and the mandibular foramen to the occlusal plane was measured. The shapes of the mandibular lingula was classified into 4 types according to the criteria.The distances of the mandibular lingula from the anteroposterior and vertical reference points of the ramus increased in all directions with age. The distance between the mandibular lingula and the mandibular foramen also increased with age. The location of the mandibular lingula and the mandibular foramen in relation to the occlusal plane moved upwards with age. The most common shape of the mandibular lingula was triangular, followed by nodular, truncated and assimilated, and there was no difference in the shape according to age.It is recommended that the horizontal insertion point of the anesthesia from the anterior border of the ramus increased to 17 mm, 18 mm, and 19 mm according to the age groups. It is also suggested that the vertical insertion point increased by 2 - 3 mm, 5 - 6 mm and 9 - 10 mm above the occlusal plane according to the age groups.

The purpose of this study is to evaluate the morphological characteristics of the roots and roots canals of primary molar teeth using Cone-Beam Computed Tomography (CBCT).A total of 68 CBCT images of children aged 4 -5 years was used for this study. A total of 160 molar teeth were analyzed. Various parameters such as the number of roots and canals, length of root and root canal, and the angulation and shape of the roots were analyzed.All maxillary primary molars had 3 roots. The presence of 2 root canals in 1 root was only observed in the mesiobuccal root of maxillary primary second molars. Most mandibular primary molars had 2 roots, and most mesial roots had 2 root canals.Concerning the length of the roots, the palatal root of the maxillary primary molar was found to be longest whereas the distobuccal root was shortest. In mandibular primary molars, the mesial root was longer than the distal root. In maxillary primary molars, the palatal root had the greatest angulation whereas the distal root has the greatest in mandibular molars. The root and root canals of maxillary primary molars were more curved in shape whereas mandibular primary molars were straight. Abstract 25