Novel anatomical guidelines for botulinum neurotoxin injection in the mentalis muscle:a review / 대한해부학회지

The mentalis muscle is a paired muscle originating from the alveolar bone of the mandible. This muscle is the main target muscle for botulinum neurotoxin (BoNT) injection therapy, which aims to treat cobblestone chin caused by mentalis hyperactivity. However, a lack of knowledge on the anatomy of the mentalis muscle and the properties of BoNT can lead to side effects, such as mouth closure insufficiency and smile asymmetry due to ptosis of the lower lip after BoNT injection procedures. Therefore, we have reviewed the anatomical properties associated with BoNT injection into the mentalis muscle.An up-to-date understanding of the localization of the BoNT injection point according to mandibular anatomy leads to better injection localization into the mentalis muscle. Optimal injection sites have been provided for the mentalis muscle and a proper injection technique has been described. We have suggested optimal injection sites based on the external anatomical landmarks of the mandible. The aim of these guidelines is to maximize the effects of BoNT therapy by minimizing the deleterious effects, which can be very useful in clinical settings.

Intramuscular neural distribution of the teres minor muscle using Sihler’s stain: application to botulinum neurotoxin injection / 대한해부학회지

The aim of this study was to elucidate the intramuscular arborization of the teres minor muslce for effective botulinum neurotoxin injection. Twelve specimens from 6 adult Korean cadavers (3 males and 3 females, age ranging from 66 to 78 years) were used in the study. The reference line between the 2/3 point of the axillary border of the scapula (0/5), where the muscle originates ant the insertion point of the greater tubercle of the humerus (5/5). The most intramuscular neural distribution was located on 1/5–3/5 of the muscle. The tendinous portion was observed in the 3/5–5/5. The result suggests the botulinum neurotoxin should be delivered in the 1/5–3/5 area of the teres minor muscle.

Novel anatomical proposal for botulinum neurotoxin injection targeting depressor anguli oris for treating drooping mouth corner / 대한해부학회지

The depressor anguli oris (DAO) muscle is a thin, superficial muscle located below the corner of the mouth. It is the target for botulinum neurotoxin (BoNT) injection therapy, aimed at treating drooping mouth corners. Hyperactivity of the DAO muscle can lead to a sad, tired, or angry appearance in some patients. However, it is difficult to inject BoNT into the DAO muscle because its medial border overlaps with the depressor labii inferioris and its lateral border is adjacent to the risorius, zygomaticus major, and platysma muscles. Moreover, a lack of knowledge of the anatomy of the DAO muscle and the properties of BoNT can lead to side effects, such as asymmetrical smiles. Anatomical-based injection sites were provided for the DAO muscle, and the proper injection technique was reviewed. We proposed optimal injection sites based on the external anatomical landmarks of the face. The aim of these guidelines is to standardize the procedure and maximize the effects of BoNT injections while minimizing adverse events, all by reducing the dose unit and injection points.

Influence of Area-Level Characteristics on the Suicide Rate in Korean Adolescents

OBJECTIVE: We aimed to investigate the influence of area-level factors on adolescent suicide and to determine which variables differ according to age and sex.METHODS: We selected variables that were available for collection through an online database from 2005 to 2015 in the Korean Statistical Information Service and the Korea Labor Institute. We used administrative districts of Korea in 2017 for geographical classification. We examined the relationships between regional suicide rates and area-level variables in male and female subjects aged 10–14 years and 15–19 years. In addition, we analyzed area-level variables in adolescents aged 15–19 years according to sex.RESULTS: Our findings indicated that several area-level variables affected adolescent suicide rates, varying according to age and sex. Economic problems were shown to be more associated with suicide in male adolescents than in female adolescents. On the other hand, social fragmentation and health services were shown to be more associated with suicide in females.CONCLUSION: Suicide in adolescents was attributable to area-level factors such as economic status, social fragmentation, and community health services. By identifying area-level variables affecting adolescent suicide rates, we will be able to contribute to implement mental health policies related to adolescent suicide.