[Evaluation of the treatment results of anterior crossbite in the mixed dentition].

As an evaluation of treatment for anterior crossbite (Class I Malocclusion) in the mixed dentition, relationships were examined between the results of cluster analysis on the measured values before treatment and those on the changes caused by treatment. The following were the results of the present investigation. 1. The results of cluster analysis on the measured values before treatment were summed up into three groups; A1, A2, and A3. 1) Group A1 showing retrusion of the Maxilla and lingual version and lingual inclination of Maxillary anterior teeth. 2) Group A2 showing protrusion of the Mandible, lingual version of Maxillary anterior teeth, and lingual inclination of Mandibular anterior teeth. 3) Group A3 showing lingual version of Maxillary anterior teeth and labial version of Mandibular anterior teeth. 2. The results of cluster analysis on the changes caused by treatment were classified into three groups; V1, V2, and V3. 1) Group V1 showing labial version and labial inclination of Maxillary anterior teeth and lingual version and lingual inclination of Mandibular anterior teeth. 2) Group V2 showing protrusion of the Maxilla, labial version of Maxillary anterior teeth, and lingual version and lingual inclination of Mandibular anterior teeth. 3) Group V3 showing retrusion of the Mandible and labial version and labial inclination of Maxillary anterior teeth. 3. Relationships between Groups A1, A2, and A3 and those of V1, V2, and V3 may be summarized in the following. 1) Group A1 shows healing trend of Group V2. 2) Group A2 shows healing trend of either Group V1 or Group V3. 3) Group A3 shows healing trend of Group V1. The results shown above indicate that healing process is dependent upon many factors including a problem of mixed dentition, a problem of constructing dental arch and individual growth characteristics. Therefore, it is important for us to recognize the findings described above when treating anterior crossbite in the mixed dentition.