Functional therapy in hemifacial microsomia: therapeutic protocol for growing children

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.

Sixteen growing children with unilateral HM were treated. Each patient was graded according to the skeletal, auricular, tissue (SAT) classification. Patients graded S4-S5 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).

In 7 of 16 cases (43.7%) classified as S1-S2/T1, regardless of the value of A, functional therapy brought about mandibular growth greater on the side of the malformation (G3-G4), re-establishing structural and functional harmony of the entire stomatognathic apparatus. Of the five cases (31.2%) classified as S2/T2, four required surgical intervention at about 10 years of age after an initial period of functional therapy that produced mandibular growth classified G1-G2. In the other case, functional treatment was sufficient to correct the malformation. In four patients (25%) classified as S3/T3 or S3/T2, it was necessary to combine surgical treatment with functional therapy.

Use of the AFA in growing children with HM makes it possible to induce harmonious maxillomandibular growth. Statistically, in S1-S2/T2 cases, functional therapy brings about an overall resolution of the malformation whereas in more severe cases (S2/T2), it needs to be combined with orthodontics using fixed appliances and surgical intervention.