adult 2 article 2 controlled study 2 maxilla micro-computed tomography 2 Anatomic Variation 1 Bone microstructure 1 Corticotomy 1 Dental Pulp Cavity 1 Female 1 Humans 1 Imaging, Three-Dimensional 1 In vitro study 1 Male 1 Maxilla 1 Maxillary first molars 1 Microcomputed tomography 1 Microcomputed tomography (micro-CT) 1 Molar 1 Prevalence 1 Radiography, Dental 1 Rapid maxillary expansion 1 Root Canal Therapy 1 Root canal orifices 1 Saudi Arabia 1 X-Ray Microtomography 1 analysis of variance 1 anatomical variation 1 anatomy and histology 1 animal experiment 1