Evaluation of the availability of the closure of the sfenooccipital synchondrosis joint by agein cranial MR imagings and influence of antiepileptic drug use on closing time

Objective: Age estimation is an important parameter of identification, which is one of the primary applications of forensic medicine. The emphasis on age estimation studies employing radiological imaging methods has increased in recent years. Due to the ethical concerns about radiation exposure raised by computed tomography, which offers more comprehensive images than x-rays, studies on age assessment using magnetic resonance imaging have lately gained attention. The sphenooccipital synchondrosis joint has been studied multiple times in the literature using CT and x-rays, and it has been reported that MRI can also be used to assess it. In our study, sphenooccipital synchondrosis joint was examined on MRI and its applicability in forensic medicine age estimation was evaluated. Additionally, it was also investigated whether antiepileptic drug users differed from the general population. Materials and Methods: To study the involved sphenooccipital synchondrosis joint region retrospectively, cranial magnetic resonance images obtained by the Department of Radiology at the Ankara University Faculty of Medicine between 2015 and 2021 were assessed. The age range was determined as 8–25, and the images of individuals who met the inclusion criteria were examined in the T1 sequence and midsagittal section. A total of 1066 images were included in the study, of which 562 were of women and 504 were of men. 180 out of 1066 images belonged to individuals who use antiepileptic medication. To evaluate the sphenooccipital synchondrosis joint, the 5-stage definition system defined by Powell and Brodie and modified by Bassed et al. was used. Results: According to the information obtained from our study's 5 stage examination of the sphenooccipital synchondrosis joint closure; it was determined that in the healthy population the joint was completely open in both genders at the age of 8 years, the first sign of closure (stage 2) was observed in both genders at the age of 9 and the latest age at which the joint is completely open (stage 1) was 16 in women and 19 in men. It was also discovered that stage 3, which represents half closure, occurs between the ages of 11-17 in women and between the ages of 12-17 in men. Additionally; the earliest complete closure (stage 4) was observed at the age of 12 in women and at the age of 13 in men, and the joint was completely closed (stages 4 and 5) in all instances aged 18 years and over in women and 20 years and over in men. In the group with antiepileptic drug use, the joint was completely open (stage 1) at the age of 8-10 years in both sexes, and the first sign of closure (stage 2) was seen at the age of 11 in both women and men. Also, the latest age at which the joint is still open (stage 3) was 17 years in women and 18 years in men, and that the joint was completely closed (stage 4 and 5) in women above the age of 18. Age and stage were shown to be strongly positively correlated. The variable of health status was found to be insignificant in men and weakly associated in women. In addition, when the general population was evaluated, it was revealed that each increase in the stage for men demonstrated 2,671 years (2.648-2,873 in the 95% confidence interval), and the equation "age=7,667+2,761xStage" was developed based on this information. For women, this value was discovered to be 2,846 years (2.730-2,962 in the 95% confidence interval) and the age=6.479+2.846xStage equation was created. Conclusion: In terms of age estimation in forensic medicine, the margin of error should be minimized by increasing the evaluations done with a variety of techniques and multidisciplinary approaches. Based on MR imaging of the sphenooccipital synchondrosis joint, the age can be estimated with a 95% confidence interval. However, it should not be disregarded that there are extreme cases. There is a need for studies with a larger sample size, studies that demonstrate the impact of chronic diseases, and studies that take into account information like socioeconomic status, height-weight, and race, which are reported to have an impact on bone age. Keywords: forensic age estimation, magnetic resonanse imaging, sfenooccipital synchondrosis, identification, bone age.