Forensic age estimation based on ultrasound, ulna and sesamoid bone evaluation

Purpose Forensic age estimation is necessary in many cases concerning criminal or civil law. Especially in situations that are not suitable for using classical age estimation methods such as pregnancy. For this cases we believe it is necessary to evaluation of sesamoid and ulnar bone by ultrasound. In the available literature, no study was found for ultrasonographic evaluation of the ulna for age determination. In our study, it was aimed to investigate at what ages and developmental levels of ulna and sesamoid bones by using ultrasound. Material method In our study, we evaluated the volunteers between the ages of 4-21 who applied to Düzce University Training and Research Hospital for various reasons between March 2019 and April 2020. Cases with a chronic disease, a history of bone fractures in left wrist, those with a history of obesity (those with a weight percentile value above 97) or a history of pregnancy, and patients with chronic medication use for a year or more were excluded. Evaluation was made on 216 (107 girls, 109 boys) volunteer cases that met the criteria. Ultrasonographic evaluation was performed for the sesamoid bone of the fist Metacarpophalangeal (MKP) joint and distal epiphysis of the ulna. For this purpose we created a classification for ulna development including six stages and determine whether the sesamoid bone is ossified. Findings Development of stage 5 ulna epiphysis was not seen in any female or male gender under 12 years of age. Development of stage 6 ulna was not seen in any female or male gender under the age of 15. Stage 2 was first seen at the age of 6,4 for boys 4,7 for girls stage 3 was first seen at 8,2 years old for boys and 7,5 years old for girls, stage 4 was first seen at 9,5 years old for boys and 8,6 years old for girls, stage 5 was first seen at the age of 13,8 for boys and 12,0 for girls, stage 6 was first seen at the age of 17,2 for boys and 15,2 for boys. Median age values were found to be 6.9 for girls and 8.7 for boys for stage two, 9,1 for girls and 10,7 for boys for stage tree, 11,2 for girls and 13,4 for boys for stage four, 15,4 for girls and 16,9 for boys for stage five, 18,9 for girls and 19,1 for boys for stage six. The P50 value (method of probits) corresponded to the chronological age at which 50% of the population had a visible sesamoid. It was 12.7 years for boys 7 and 10.2 years for girls. Ulna and sesamoid bone examinations of the volunteers were done by a single researcher. In addition, 149 randomly selected individuals (69%) were evaluated for ulna and sesamoid bone by second researcher. There was a significant and good level of aggrement for ulna (ICC=0,941 p<0,001) and substantial aggrement for the sesamoid (Kappa=0,784) between the two researchers. Discussion and conclusions In our study, it was thought that the sesamoid bone corresponds to a certain stage in the development of the ulna epiphysis and that the ulna epiphysis stage 4 can actually divide into two parts whether sesamoid bone was seen. However, according to the results we obtained, it was thought that the sesamoid bone could not be used as a definite indicator in age determination due to its occurrence in a very wide time interval. In addition, no stage five were seen under the age of 12 and no stage six were seen under the age of 15. This can be used to evaluate 12 and 15 years of age, which are important age limits for forensic medicine. Ultrasonographic evaluation is a convenient tool for age determination because it is easily accessible, it is suitable for evaluating bones in different parts of the body in a short time, it can be applied to pregnant women and it does not contain radiation. For this reason, more studies are needed in this area.