Which order corresponds to movements in the horizontal (occlusal) plane?

In orthodontics, the classification of movement orders refers to the type of displacement that dental arches or teeth can undergo. The first order corresponds specifically to movements in the horizontal or occlusal plane, which involves the lateral and anteroposterior movements of the dental arch.

This order is particularly focused on the way teeth shift side to side or forward and backward relative to the occlusal plane when forces are applied. Understanding the first order is crucial for orthodontic treatment as it directly pertains to aligning the teeth to achieve proper occlusion and aesthetics.

In contrast, the second order involves vertical movements, the third order encompasses tipping movements, such as the inclination of teeth, and the fourth order relates to rotational movements. Each order corresponds to different planes of movement and is essential for comprehensively understanding orthodontic force applications and mechanics.