DEFINITIONS OF ORTHODONTICS 

🔹MALOCCLUSION: Any deviation from normal occlusion.

🔹MOMENT (of a force): The tendency of a force to cause rotation.

🔹NANCE PALATAL ARCH: A maxillary fixed anchorage reinforcing appliance consisting of a wire soldered onto the first molar bands connected to an acrylic button contacting the anterior palatal surface.

🔹NASOLABIAL ANGLE: The angle between a line drawn tangent to the columella of the nose and a line connecting subnasale to the mucocutaneous border of the upper lip.

🔹NATURAL HEAD POSITION: A standardised reproducible head position used for dento-skeletal assessment.