Comparison of three-dimensional soft-tissue evaluations between skeletal and pseudo-class III malocclusions

Abstract

The aim of our study was to compare soft tissue measurements with 3D imaging methods in individuals with untreated skeletal and pseudo-Class III malocclusions. The study sample consisted of 75 patients (38 males, 37 females, mean age 12.41 ± 2.35 years) with pseudo- and true skeletal Class III malocclusions and skeletal Class I malocclusions. Soft tissue evaluations of all patients were performed using 3D stereophotogrammetric facial images. In our study, 26 landmarks, 17 linear measurements, 13 angular measurements, and 5 volume measurements were made using the 3dMD Vultus software. The significance was determined to be p < 0.05 in ANOVA, Tukey tests. No significant differences were found among the groups in terms of demographic data (p > 0.05). The skeletal Class I control group had a significantly more extended upper lip and vermillion length as compared to the Class III groups. The soft tissue convexity angle and upper nasal angle were found to be wider in the Class III malocclusion group compared to those in the Class I control group. While the pseudo-Class III group had a significantly lower midface volume, chin volume was significantly higher in the skeletal class group. Upper lip volume was significantly higher in the Class I group. Using 3dMD for guiding clinicians in the differential soft and hard tissue diagnosis of pseudo-Class III malocclusions, differences were revealed in Class I patients in the middle part of the face. In the differential diagnosis of true Class III malocclusions, chin volume was found to be different from that of Class I patients.

Early Treatment of a Class III Patient with Chincup: A Case Report

“…Positive DeNevreze maneuver 10 and skeletal Class I pattern showed us that this patient was in the Pseudo Class III group. 3 Treatment goals for this patient were to free the maxilla from confinement of the mandible, to create an ideal Angle class I molar relationship, and an ideal overjet and overbite.…”

“…The DeNevreze maneuver was positive and the patient was able to move the lower jaw head-on without external intervention. 10 (Figure 2)…”

Treatment of Class III Malocclusion and Anterior Crossbite with Aligners: A Case Report

“…In adult patients, it is essential to distinguish between the basal skeletal class III, for which surgical treatment is elective, and functional class III, or pseudo-class III, in which, due to a discrepancy between maximal intercuspation and centric occlusion, and therefore an occlusal interference, the patient in maximum intercuspation advances the mandible. In these cases, occlusal improvement can be achieved with orthodontic therapy alone [ 8 , 9 , 10 , 11 , 12 , 13 ]. Although the combination of orthognathic surgery and orthodontic therapy is considered the gold standard for class III malocclusion, if the patient decides not to undergo surgery, orthodontic treatment alone may help compensate for mild skeletal class III malocclusion.…”

Genetic architecture of non‐syndromic skeletal class III malocclusion

“…Skeletal Class III malocclusion is a heterogeneous, complex phenotype characterized by the mesial position of the mandible about the maxilla and/or cranial base (Chen et al, 2015). These can manifest as mandibular prognathism (MP), maxilla retrognathia (MR), or a combination of both these conditions (Kale & Buyukcavus, 2020; Figure 1).…”