Orthodontic diagnosis and treatment planning requires an extensive clinical evaluation that includes a detailed analysis of radiographic images. This chapter reviews traditional and contemporary hard and soft tissue imaging techniques used in orthodontic practice. Today, cephalometric radiographs remain a mainstay for orthodontic diagnostic purposes, treatment planning, and outcome assessment. These features become especially important in cases of impacted teeth where an exact determination of 3D root position is essential in order to formulate an appropriate treatment plan. Diagnostic evaluations and investigational projects on the airway were conducted with the use of 2D cephalometric radiographs. The use of these radiographs was associated with significant inaccuracies especially with the higher morphological variability of the airway that cannot be depicted accurately on a 2D image. Digital applications have significantly enhanced diagnosis and treatment planning in orthodontics. Treatment can be performed more efficiently with fewer complications.