The aim of this study was to clarify the arrangement of the anatomic courses and distribution of the intraosseous branch (IObr) of posterior superior alveolar artery. The anatomic variations in the topographic relationships were described to provide beneficial data to minimize injury to the IObr during surgical procedure of the buccal wall of the maxillary sinus. The IObrs in 42 hemifaces of embalmed Korean cadavers were examined. The courses of the IObr of the posterior superior alveolar artery were classified into 2 categories: the straight (type 1) and the U-shaped (type 2). The type 1 was the most common (78.1%), and the type 2 was observed in 21.9% of the specimens. The minimum mean height from the cervix to the IObr was 21.1 mm in the first molar region. The IObr ran at the lowest level from the maxillary sinus floor at the first premolar region. These anatomic findings in the current study could represent useful information for the various surgical procedures of the maxilla.

The platysma muscle is a thin superficial muscle that covers the entire neck and lower part of the face. The platysma muscle is the primary target muscle for botulinum neurotoxin injection therapy aimed at treating platysmal band and lower facial lifting. In the procedure of botulinum neurotoxin injection therapy, a lack of knowledge of the anatomy of the platysma muscle and the properties of botulinum neurotoxin can lead to side effects such as dysphagia, dysphonia, and weakness of the neck muscles. Anatomically safe injection sites have been proposed for the platysma muscle, and the appropriate injection technique has been reviewed. We proposed optimal injection sites based on the external anatomical features of the mandible. The aim of these proposal was to standardize the procedure for the effective use of botulinum neurotoxin injections by minimizing the dose unit and injection points and thereby preventing adverse events.