Reid's base line

Reid's baseline is an anatomical reference line used in various fields, particularly in dentistry and orthodontics. It is defined as a plane that runs horizontally through the center of the external auditory meatus (the ear canal) and the lower border of the eye socket (the infraorbital rim). In other contexts, it can also refer to a guideline used in maxillofacial surgery for establishing the orientation of the maxilla in relation to the cranium.