The general superimposition observed on the anterior cranial base at Sella indicates that there has been substantial vertical development throughout therapy. The general vertical development of the face complex appeared to keep proceeding inferiorly and posteriorly, indicating a degree of posterior growth rotation. The anterior modifications included soft tissue remodeling and maturation.

The maxillary superimpositions on the palatal dome and maxillary plane demonstrated that the upper incisors had been retroclined, resulting in bony remodeling at A-point.

Mandibular superimpositions on Björks' stable structures resulted in mandible lengthening. The growth modifications seen throughout the fixed orthodontic appliance treatment period appeared to be restricted to remodeling of the ascending ramus as well as gonial angle. The lower molars moved to a more mesial and extruded position. The lower incisor location showed a little amount of proclination.

Discussion

Class II correction might be attributable to functional appliance (growth modification) and favorable forward skeletal development. Growth modification causes correction primarily through skeletal and dental changes, such as upper incisor retroclination, lower incisor proclination, upper molar distalization, lower molar extrusion and mesial drifting, maxillary growth restriction, and mandibular growth acceleration. The lower molars' extrusion is often compensated for by vertical development in the ramus. O'Brien et al. (2003) attributed around 60% of overjet correction to dental alterations and 30-40% to bone modifications. In this example, the mandibular superimposition revealed backward and upward mandibular development, resulting in downward and forward mandibular translation, as represented in the overall superimposition. Furthermore, higher incisors retroclined while lower incisors proclined, resulting in overjet correction. All of the adjustments described above explained the Class II correction; however, none of them explained how the room for the lost central incisor was created.

Summary

Orthodontic Treatment Analysis

• Superimposition on anterior cranial base at Sella indicates significant vertical development throughout therapy.
• The face complex's vertical development continues inferiorly and posteriorly, indicating posterior growth rotation.
• Anterior modifications include soft tissue remodeling and maturation.
• Maxillary superimpositions on palatal dome and maxillary plane show upper incisors retroclined, causing bony remodeling at A-point.
• Mandibular superimpositions on Björks' stable structures result in mandible lengthening.
• Growth modifications restricted to remodeling of ascending ramus and gonial angle.
• Lower molars moved to a more mesial and extruded position.
• Class II correction attributed to functional appliance (growth modification) and favorable forward skeletal development.
• Overjet correction attributed to dental alterations and bone modifications.
• Mandibular superimposition revealed backward and upward mandibular development, resulting in downward and forward mandibular translation.