Morphological Analysis of the Anatomical Mandibular Lingual Concavity Using Cone Beam Computed Tomography Scans in East Asian Population—A Retrospective Study oleh Hee-Ju Ahn, Soo-Hwan Byun, Sung-Ah Che, Sang-Yoon Park, Sang-Min Yi, In-Young Park, Sung-Woon On, Byoung-Eun Yang