Functional therapy in hemifacial microsomia: Therapeutic protocol for growing children

Purpose: This study evaluates the skeletal response to functional orthodontic therapy in growing children with hemifacial microsomia (HM). A method of classification for mandibular growth subsequent to treatment is also suggested. Materials and Methods: Sixteen growing children with unilateral HM were treated. Each patient was graded according to the skeletal, auricular, tissue (SAT) classification. Patients graded S-4-S-5 were excluded because the severity of the malformation made them unsuitable for functional orthodontic treatment. All patients initially underwent a period of treatment with an asymmetrical functional activator (AFA). Results: In 7 of 16 cases (43.7%) classified as S-1-S-2/T-1, regardless of the value of A, functional therapy brought about mandibular growth greater on the side of the malformation (G(3)-G(4)), re-establishing structural and functional harmony of the entire stomatognatic apparatus. Of the five cases (31.2%) classified as S-2/T-2, four required surgical intervention at about 10 years of age after an initial period of functional therapy that produced mandibular growth classified G(1)-G(2). In the other case, functional treatment was sufficient to correct the malformation. In four patients (25%) classified as S-3/T-3 or S-3/T-2, it was necessary to combine surgical treatment with functional therapy. Conclusion: Use of the AFA in growing children with HM makes it possible to induce harmonious maxillomandibular growth. Statistically, in S-1-S-2/T-2 cases, functional therapy brings about an overall resolution of the malformation whereas in more severe cases (S-2/T-2), it needs to be combined with orthodontics using fixed appliances and surgical intervention