In some embodiments, an apparatus comprises a housing, an emitter, and an electronic circuit. The housing is configured to fit within a patient's mouth. The emitter is at least partially encased within the housing. The emitter is configured to emit an effective amount of light to the alveolar soft tissue when the housing is disposed within the mouth. The electronic circuit is operatively coupled to the emitter. The electronic circuit is configured to control the emitter when the housing is disposed within the mouth and the apparatus is in use during orthodontic treatment. The apparatus and its use for regulating tooth movement or maintaining or improving oral tissue health are disclosed herein.