Soft tissue paradigm based Treatment planning in skeletal class III.

Objectives: 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.

Materials and methods: 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.

Results: 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.

Conclusions: 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.

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