Effects of different surgical techniques and displacement distances on the soft tissue profile via orthodontic-orthognathic treatment of class II and class III malocclusions

Abstract

Background Orthognathic surgery can be carried out using isolated mandibular or maxillary movement and bimaxillary procedures. In cases of moderate skeletal malocclusion, camouflage treatment by premolar extraction is another treatment option. All these surgical procedures can have a different impact on the soft tissue profile. Methods The changes in the soft tissue profile of 187 patients (Class II: 53, Class III: 134) were investigated. The treatment approaches were differentiated as follows: Class II: mandible advancement (MnA), bimaxillary surgery (MxS/MnA), upper extraction (UpEX), or Class III: maxillary advancement (MxA), mandible setback (MnS), bimaxillary surgery (MxA/MnS), and lower extraction (LowEX) as well as the extent of skeletal deviation (moderate Wits appraisal: − 7 mm to 7 mm, pronounced: Wits <− 7 mm, > 7 mm, respectively). This resulted in five groups for Class II treatment and seven groups for Class III treatment. Results In the Class II patients, a statistically significant difference (p ≤ 0.05) between UpEX and moderate MnA was found for facial profile (N′-Prn-Pog’), soft tissue profile (N′-Sn-Pog’), and mentolabial angle (Pog’-B′-Li). In the Class III patients, a statistically significant differences (p ≤ 0.05) occurred between LowEX and moderate MxA for facial profile (N′-Prn-Pog’), soft tissue profile (N′-Sn-Pog’), upper and lower lip distacne to esthetic line (Ls/Li-E-line), and lower lip length (Sto-Gn’). Only isolated significant differences (p < 0.05) were recognized between the moderate surgical Class II and III treatments as well between the pronounced Class III surgeries. No statistical differences were noticed between moderate and pronounced orthognathic surgery. Conclusions When surgery is required, the influence of orthognathic surgical techniques on the profile seems to be less significant. However, it must be carefully considered if orthognathic or camouflage treatment should be done in moderate malocclusions as a moderate mandibular advancement in Class II therapy will straighten the soft tissue profile much more by increasing the facial and soft tissue profile angle and reducing the mentolabial angle than camouflage treatment. In contrast, moderate maxillary advancement in Class III therapy led to a significantly more convex facial and soft tissue profile by decreasing distances of the lips to the E-Line as well as the lower lip length.

Comparison of soft tissue simulations between two planning software programs for orthognathic surgery

“…These findings were also reported in former investigations 29 – 31 . In this context, recently, Möhlhenrich et al investigated the effects of different surgical techniques and displacement distances on the soft tissue profile retrospectively 32 . They found that for the mandibular setback in class III patients, only a slight increase in nasolabial angle (up to 2.13° ± 4.78°) and distance Ls-E-Line (up to 1.69 ± 2.12 mm) occurred.…”

Cirugía ortognática y camuflaje ortodóncico de la maloclusión clase II división 1: Revisión narrativa

“…La mejor manera de afrontar la maloclusión Clase II división 1 severa, es el tratamiento quirúrgico (Gumiela M. et al 2019) pero existe la alternativa de un camuflaje ortodóncico. (Möhlhenrich S. et al, 2021) En su estudio retrospectivo se centró en pacientes límite que claramente requerían cirugía ortognática sin una alternativa de tratamiento únicamente de ortodoncia. El objetivo era determinar la influencia de estos diferentes enfoques.…”

Severe Bilateral Mandibular Hyperplasia and Angle’s Class III Malocclusion in Indonesia: A Case Report

“…We found that soft tissue behavior differed between the maxillary advancements combined with mandibular setback or bimaxillary procedures, which were more equal to each other. 5 Thus, after some consideration, the Le Fort I osteotomy and mandibular bilateral sagittal split and anterior subapical osteotomies were chosen.…”