## 3 Review
### Class III
#### 3.2.1 Study Design and Treatment Interventions
With the described approach, 72% of the sample were correctly classified in the pre-treatment stage. Interestingly, no difference was found in post-treatment soft-tissue measurements between the two groups and both treatments resulted in a satisfactory profile improvement. However, this study had various major limits, including a small sample size, a camouflage group that was limited to extraction cases, and the fact that different surgical procedures performed within the surgical group were not considered as a variable. In 2011, [PERSON] et al. [28] performed a similar cephalometric retrospective study. They improved the study design by adopting a larger sample size, adding an ethnic heterogeneity, and more selective recruitment criteria which gave priority to variables related to facial appearance, as well as to dento-alveolar and skeletal compensation. Post-treatment, all patients showed a three-dimensionally stable occlusion, a correct OVJ, and self-reported satisfactory facial esthetics. They found that the most predictive cephalometric value was the Holdaway Angle, with a threshold value of 7.2\({}^{\circ}\); subjects with a Holdaway Angle greater than 7.2\({}^{\circ}\) could be successfully treated with no need for orthognathic surgery. In 2017, [PERSON] et al. [16] performed a cross-sectional observational study to compare the variation of cephalometric parameters in adult patients with skeletal Class III malocclusions, treated with orthodontic camouflage (77), and with the combined orthodontic-surgical approach (79 patients, of which 30 underwent maxillary advancement, 16 mandibular setback, and 33 bimaxillary surgery). Statistically significant differences were found between the two groups for the Wits Appraisal Index, the lower incisor inclination, and the inter-incisal angle (\(p<0.05\)); the Wits Appraisal was identified as being an ideal parameter to determine the need for surgical treatment. In conclusion, in those patients who had undergone orthognathic surgery, an incomplete lower incisor decompensation resulted in an incomplete surgical correction of the jaws; a result that is reported in several other studies. A strong correlation was found between initial and final values, indicating that the treatment behaved in a remarkably equivalent way for all patients. For variables corresponding to antero-posterior skeletal analysis, the correlation was much greater in cases treated by orthodontics-only camouflage. Surgery produced changes in values that were more dependent on the treatment itself, rather than on the pre-treatment values. Lastly, in 2018, [PERSON] et al. [17] carried out a retrospective comparative study to delineate which cephalometric diagnostic measurements in adult borderline skeletal Class III cases (ANB of \(0^{\circ}\) to \(-4.5^{\circ}\); \(-8.5<\) Wits Appraisal \(<-1\) m) could determine the proper treatment modality. Treatment success was assessed by selecting patients (treated by camouflage or surgery) that were satisfied with the final esthetics. Results obtained by DA showed that the Holdaway Angle was the decisive parameter: the threshold value for the Holdaway Angle was \(10.3^{\circ}\) and it was \(-5.8\) mm for the Wits Appraisal Index. The Holdaway Angle quantifies the protrusion of the upper lip relative to soft tissue profile and it does not vary according to the skeletal discrepancy; it is, therefore, the perfect parameter for characterizing the profile of borderline surgical skeletal Class III, in whom esthetics and facial appearance might be of greater importance than occlusion or skeletal discrepancy. These values had a treatment prediction value of \(81.5\%\). The Influence of Different Biomechanics: Extraction versus Non-Extraction Treatment Plan to Reach Ideal Post-Treatment Condition  
In 2009, [PERSON] et al. [29] performed a retrospective cephalometric study aiming to find a significant correlation between incisor inclination and position, and orthodontics-only or orthodontic-surgical treatment of skeletal Class III malocclusion.