Objective To classify skeletal Class Ⅲ malocclusion samples into specific skeletal types and to analyze the differences between the soft and hard tissue profile in different facial types. Methods Three hundred and forty-four patients between 18 to 25 years old of skeletal Class Ⅲ malocclusion were selected. 22 variables describing soft tissue and hard tissue profile were measured on each cephalograph. Cluster analysis was then used to classify the skeletal patterns. To study the characteristics of subgroups and relationship between soft tissue and hard tissue profile. Results Cluster analysis was used to classify the skeletal patterns into ten types. The disharmony between the soft and hard tissue profile was found in 40% of the skeletal Class Ⅲ malocclusion. There were about 50% of the skeletal Class Ⅲ malocclusion with straight profile mainly included in subgroups of maxillary retrusion with normal mandibular and a combination of mandibular and maxillary retrusion. Conclusion Hard tissue profile is the basis of the soft tissue profile. It is different of the soft tissue integument of the the skeletal Class Ⅲ malocclusion subgroups.
