Introduction: The zygoma may sometimes be divided into two parts by either a horizontal or a vertical suture. Such a bipartite bone has been given the name of os japonicum as it has been mostly observed in Japanese.
Material: In this study 1266 zygomatic bones in 633 Anatolian dry skulls and 1348 zygomatic bones in 674 plain cranium radiographs of adult patients have been examined.
Results: Os japonicum was present in 2.2% of female and 1.7% of male subjects. All of the 24 multipartite bones observed in the study were bipartite except one. In addition, of 690 female zygomatic bones examined radiologically 15 (2.2%), and 658 male bones 12 (1.8%) were bipartite or tripartite, a total of 674 plain cranium radiographs.
Conclusion: The results were compared with those of other populations. As a result evaluation of both dry skulls and plain radiographs as a single sample, our results were again closely similar to Main Island Japan and other East Asia groups.