Dental appliances for treating sleep disorders

A method of preparing a dental appliance for treating a patient having obstructive sleep apnea or hypopnea, the method comprising the steps of:

• (i) identifying in the patient a mandibular dentition, a maxillary dentition, a tongue, an airway, and an epiglottis, in which the mandibular dentition has a central incisor and a mandibular central point located at the tip of the central incisor,
• (ii) optionally sedating the patient,
• (iii) locating a reference position (0,0) of the mandibular central point when the maxillary dentition and the mandibular dentition fit together in maximum interdigitation,
• (i) scanning the mandibular dentition and the maxillary dentition to obtain a set of digital data,
• (ii) determining a target position (Xtp, Ytp) of the mandibular central point, into which the mandibular dentition moves so that the airway and epiglottis of the patient are open, and
• (iii) constructing the dental appliance according to the set of digital data and the target position (Xtp, Ytp), in which the dental appliance has a lower arch section, an upper arch section, and a connection section linking the lower arch section and the upper arch section, the lower arch section conforms to the mandibular dentition, the upper arch section conforms to the maxillary dentition, and the lower arch section is in a position corresponding to the target position (Xtp, Ytp),
• wherein
• Xtp is the horizontal distance between the target position (Xtp, Ytp) and the reference position (0,0),
• Ytp is the vertical distance between the target position (Xtp, Ytp) and the reference position (0,0),
• Ytp=bXtp, b being 1 to 10,
• Ytp=mYmax, m being 5% to 70%,
• Xtp=nXmax, n being 5% to 80%,
• Xmax is the horizontal distance between the reference position (0,0) and a maximum protrusive position (Xmax), the maximum protrusive position being the position into which the mandibular dentition is protruded maximally to its maximum, and
• Ymax is the vertical distance between the reference position (0,0) and a maximum mouth opening position (Ymax), the maximum mouth opening position being the position into which the mandibular dentition is opened vertically to its maximum.