ISW for the treatment of adult anterior crossbite with non-extraction

Abstract

Diagnosis of adult peedoskeletal class III with facial asymmetry is usually a challenge to the orthodontist. Careful clinical evaluation of Class III malocclusion always requires checking anterior and posterior dental relationships with the mandible in centric relation.1Anterior crossbite and reversed over jet are constantly present due to the anterior mandibular displacement. Usually, the soft tissues tend to camouflage the skeletal discrepancy and the patient’s profile appears normal or slightly concave in centric occlusion. Different aetiological factors have been suggested in pseudo-Class III malocclusion.2 The patient had functional class III malocclusion and facial asymmetry, orthognathic surgery combined with orthodontic treatment may be the better choice. But the patient refused the surgery. Before the orthodontic treatment was performed, differentially diagnosing a facial asymmetry case by dental/functional/skeletal is very crucial.3–7 Sometimes a case may combine two or more. For instance, this case showed both functional and skeletal problems.It was important to locate functional interferencein a facial asymmetrycase. Sometimes a functional wax bite was helpful. This case showed possibility of functional interference around the anterior teeth. With ISW (developed by the Tokyo Medical and Dental University) curve technique and class III intermaxillary elastics (IME), functional interference was relieved. ISW MEAW was used not only for space creation, it can further upright the second molar due to its distal tipping effect.8–12 Finally, when using ISW MEAW on the upper arch and Class IIintermaxillary elastics (IME) was also performed, the control of excess over jet resulting from the upper anterior leveling can be achieved. MEAW on the upper arch and Class II intermaxillary elastics (IME) can bilaterally tip and intrude from canines to second molars so as to gain extra space for anterior retraction and to facilitate canine relationship. Moreover, “MEAW” can efficiently prevent profile from deteriorating.