Soft tissue paradigm based Treatment planning in skeletal class III

This study aimed to propose guidelines for the indications of non-extraction, extraction camouflage treatment, and orthognathic surgery by comparing the degree of soft tissue improvement effects. This comparison focused on changes in CKHA, a soft tissue indicator corresponding to the major hard tissue indicator, ANB.

Sixty-six patients, 25 males and 41 females, aged between 18 and 50 years and diagnosed with skeletal Class III malocclusion (ANB < 0°), were enrolled in the study. Participants were categorized into three groups based on the treatment approach: G1, non-extraction (n = 20); G2, extraction (n = 20); and G3, orthognathic surgery (n = 26). To assess variations in treatment outcomes, measurements derived from lateral cephalometric radiographs obtained before and after treatment were analyzed and compared across the different treatment methods.

Significant differences were observed in the ANB between the G1 and G2/G3 groups. However, no significant differences were observed in CKHA levels after treatment. Furthermore, in G2, the CKHA approached the normal range at -1.8° (normal range: -2.0°), suggesting that soft tissue responses can normalize despite minimal changes in the skeletal structure.

Although surgery resulted in the most significant skeletal changes, both camouflage groups demonstrated distinct advantages in the soft tissue paradigm. In G2, a noticeable posterior movement of the lower lip was observed along with a corresponding posterior shift in the soft tissue B point.

This study provides guidelines for non-extraction, extraction and surgical treatment selection aimed at achieving soft tissue objectives.