The document discusses various 3D imaging techniques used in dentistry, including magnetic resonance imaging (MRI), 3D facial imaging using laser scanning, obtaining 3D dental models through destructive and non-destructive scanning, 3D craniofacial skeletal imaging using computed tomography and cone beam computed tomography. It also describes software used for orthodontic diagnosis and treatment planning, and Invisalign treatment which uses clear removable aligners to straighten teeth without wires or brackets.