Skeletal and dentoalveolar effects of class II malocclusion treatment using bi-maxillary skeletal anchorage: a systematic review

Abstract

Background The goal of this systematic review was to assess the available evidence regarding the skeletal and dentoalveolar effects of bi-maxillary skeletal anchorage devices (BMSADs) used in treating growing class II malocclusion patients. Methods A comprehensive search was conducted on PubMed, Scopus, Science Direct, Web of Science, Cochrane, and LILACS up to November 2021, which was augmented by a manual search. The studies included were clinical trials (RCTs) and/or follow-up observational studies (retrospective and prospective). The outcomes of interest were the skeletal, dentoalveolar, and occlusal treatment-induced changes obtained from pre- and post-cephalometric measurements. The risks of bias of the included studies were assessed using an assessment tool from previous publications. Results Out of 742 screened articles, only 4 were eligible and thus included in the qualitative synthesis. They showed a moderate overall risk of bias. The results are presented as mean changes in both the study and control groups. All studies reported retrusion of the maxillary base and advancement of the mandible (meaning reduced ANB angle). Three of the included studies reported an increase in the vertical jaw relation, which was contrary to what the fourth study reported. Three studies reported an increase in the maxillary incisors’ inclination or position, while one study reported their retroclination. Proclination of the mandibular incisors happened in two studies, whereas the other two studies reported retroclination. The overjet was reduced in all included studies. Conclusion Apart from the protrusive effects on the mandible, retrusive effects on the maxilla, and the consequent reduction of the overjet, BMSADs results in inconsistent skeletal and dentoalveolar effects. However, the current evidence is limited due to the variability in the biomechanics of the intermaxillary components, type of anchorage, and comparable groups in the included studies. Further RCTs with more standardized methodologies are highly encouraged. Clinical relevance BMSADs (using miniscrews or miniplates on both jaws) induces more skeletal than dentoalveolar effects. However, this must be practiced with caution, based on the benefit to risk (surgical insertion) ratio, and the limited evidence available in hand so far. Registration The protocol for this systematic review was registered at the International Prospective Register of Systematic Reviews (PROSPERO, No.: CRD42020199601).

Biomechanical analysis of the effect of aligner overtreatment on molar distalization with clear aligners: a finite-element study

“…Fortunately, Class II elastic traction is a biomechanical solution counteract incisor proclination during molar distalization by exerting a retraction force on upper anterior teeth [16,17]. However, the biomechanical superiority of the two traction modes (canine precision cut vs. canine button) is yet to be determined [14,18]. Moreover, although the predictability of molar distalization at the distalization stage was as high as 88%, it dropped down to 42% following anterior retraction [11,19].…”

“…Thus, upper molar distalization, achieved by "pushing" force exerted on molars, is one of the most predictable tooth movements with clear aligner [12,13]. However, labial movement of anterior teeth occurs during molar distalization due to its reciprocal force, posing periodontal threats to those with inadequate periodontal support [14,15]. Fortunately, Class II elastic traction is a biomechanical solution counteract incisor proclination during molar distalization by exerting a retraction force on upper anterior teeth [16,17].…”

Evaluation of Effects of Bimaxillary Anchored Fixed Functional Appliance on Temporomandibular Joint and Maxillomandibular Complex in Late Adolescents: An MRI Study

“…[4][5][6] However, these designs limited the use of miniplates only on mandibular symphysis and failed to provide substantial evidence to prove the superior skeletal effects attained. 7,8 A recent systematic review 9 also concluded that FFA supported by bi-maxillary anchorage failed to control the proclination of mandibular incisors.…”