In this work, the investigators study the application of artificial intelligence systems on dental panoramic images for dental findings. An artificial intelligence system will be learned on an publicly available panoramic image dataset, and test against the investigators' local patient cohort as external test data. The investigators hypothesize the performance would be similar, if not identical to on the public data, and that the investigators' AI system is generalizable.

Exclusion Criteria:

• patients under 20 or with primary teeth
• patients with non-removable metal accessory above neck, such as tongue ring, nose ring etc.
• patients with mandible or maxilla deformation

all patients with panoramic image exposure and not with exclusion criteria