# Sandibular Molar Distalization in Class III Malocclusion: A Systematic Review
## 4 Discussion
### MMD with Clear Aligners  
Currently, there is a shortage of research in the literature regarding MMD performed with aligners, however, there is evidence of the effectiveness of aligners in distalizing the upper molar by more than 2.7 mm with aligners. MMD requires significant force to move the tooth backward, but aligners are primarily designed to apply light and controlled forces for tooth movement [60; 61; 62]. In the study by [PERSON] et al., clinicians implemented a compensatory orthodontic treatment for a patient with TCM who had refused orthognathic surgery. The sequential distalization protocol was used, which consists of initially moving most distal teeth while keeping the rest of the arch anchored. Subsequently, the mesial teeth were moved, and the entire arch was repositioned distally (Figure 9). In this way, the distalization is guided tooth by tooth; the patient's cooperation in wearing the templates and the elastics of the third is obviously essential for the resolution of the case [2]. In the study by [PERSON] et al., the effectiveness of the Invisalign system regarding MMD was analyzed. A standardized protocol of sequential MMD, like that used for the upper arch, was also used in this study. The results showed that although the aligner-only method is effective for MMD, the movement that is mainly achieved is not a body movement of the tooth but a tipping movement [32]. This can be explained by the fact that the lower molar has a complex root morphology and greater bone density, which makes it difficult to achieve effective distalization with aligners alone [63]. In a recent study by [PERSON], however, the authors described how they planned an inferior distalization movement of more than 3 mm in two TCM patients using aligners and the assistance of mini-implants in the retromal area. In these patients, the distalization method was proposed to resolve malocclusion and moderate crowding without premolar extractions [64]. The studies highlight the use of sequential distalization protocols and the potential for incorporating mini-implants in the retromolar area to assist with distalization. Further research is needed to explore the efficacy of aligners for MMD and to develop optimal protocols that can achieve successful outcomes in these cases. Comparing the methods, fixed appliances provide various mechanics with good outcomes, but success relies on patient compliance and orthodontist expertise [36,37]. Skeletal anchorage methods (TADs, mini-plates, and ramal plates) offer stable anchorage, eliminating the need for patient cooperation, and have shown promising results in achieving MMD in various TCM cases [27,29,30]. Clear aligners have limited evidence for MMD but offer benefits like aesthetics and patient comfort; however, their effectiveness in significant distalization remains a challenge [32]. This systematic review may have some limitations, even though MMD seems to be an additional orthodontic strategy for treating TCM in adult patients. First, the validity and representativeness of the results may be impacted by the small number of research papers that are currently available for this topic. Furthermore, the lack of a control group in certain studies makes it challenging to draw clear conclusions regarding the effectiveness of MMD procedures in comparison to other therapies. Furthermore, different research designs and treatment protocols may have been used in the numerous studies included in the review, making it challenging to directly compare and analyze data uniformly. The possibility of publication bias, wherein studies with positive results are more likely to be published than those with negative or insignificant results, as well as the risk of bias and confounding factors in specific studies, a lack of uniformity in reported data, among other issues, could also be limitations. Finally, the variability in patient characteristics, treatments, and evaluation criteria used in the included studies, could affect the generalizability of results for different populations of patients with TCM.