## 4 Discussion
The impact of the chin-cup on the lateral pterygoid muscle, which is very often constricted in Class III patients, relying on the slow lengthening of the muscle, facilitated functional, distal movement of the mandible [45; 46]. Figure 25: CBCTs of the incisors area of the described patients taken during follow-up. Another advantage of RME, according to a recent systematic review, is associated with a significant increase in nasal cavity and nasopharyngeal dimensions, as measured by CBCT [47]. Similarly, [PERSON] et al. (2023) have confirmed short-term improvements in upper airway dimensions [48]. Moreover, MARPE is associated with greater long-term skeletal maxillary expansion at the level of the nasal cavity in comparison to conventional RME [49]. The above studies confirm an early study by [PERSON] (1968), who compared pre and posttreatment airflow volume and stated that opening the palatal suture relieves nasal obstruction of the lower anterior part of the nasal cavity [50]. The fact that maxillary advancement was achieved in adolescent patients may be related to the influence of RME on the spheno-occipital synchondrosis (SOS) [51]. The CBCT research proved that RME procedures affect the SOS length in young individuals [52]. However, it should be kept in mind that the variation of the SOS fusion timing is extensive, and non-fusion was found in adults [51]. Therefore, screw activation of the acrylic expander might positively influence maxillary protraction in adolescents. Class III elastics with the force of 150-200 g per side applied round-the-clock to the dental arches, together with the extraoral elastics with the force of 400-600 g per side, both similar to the literature recommendations, produced positive changes in all patients (Table 1) [23; 25; 37; 38; 42]. An enhancement in the Wits appraisal, a small increase in the mandibular corpus length (Co-Gn), except for female patient 1 with endocrinological problems, and a small change in the mandibular angle (Ar-Go-Gn) (Table 1), despite the time-span of increased growth during the pubertal growth spurt and postpubertal stages, proved that the uncontrolled growth of the mandible can be modified. The smaller-than-expected increase in vertical dimensions was probably an effect of the vertical forces of the chin-cup and the acrylic splints of RME, which doubled the intrusion of the upper and lower molars. The residual growth of the mandible expected before growth cessation indicates the importance of further mandibular growth modification to avoid relapse, which can be performed with a chin-cup. The authors strongly emphasize that the chin-cup is the only extraoral appliance independent of intraoral constructions; thus, long-term use of it is possible after the completion of FA or RME therapy until the end of growth. The adaptation and response of the sutures to the traction decreases with age, but the full-day use of Class III elastics produced a continuous force that provided beneficial effects on the sutures, influenced the mandibular functional forward position, visible in most Class III patients as individual adaptation to dental discrepancies, and gradually changed the mandibular position in all patients confirmed by the positive changes in ANB and ANPg, despite the mandibular growth increment [3; 53; 54; 55; 56; 57]. Superimposition of the pre and posttreatment radiographs showed different beneficial changes in each patient. The same reported study based on 3D CBCT superimpositions were performed on prepubertal patients [58]. The success of the orthopedic/camouflage treatment relies greatly on patient compliance. The progressive improvement in facial appearance resulted in excellent cooperation.