Evidence-based selection of orthodontic miniscrews, increasing their success rate in the mandibular buccal shelf. A randomized, prospective clinical trial.

BACKGROUND: Skeletal anchorage has made it possible to perform complex orthodontic tooth movements that are difficult or even impossible to achieve with conventional orthodontic treatment. Mandibular buccal shelf miniscrews, used for distalization, play a particularly important role in treatment of Class III malocclusion. Unfortunately, stability of the miniscrews placed in the mandible is still considered at higher risk of failure compared to other intraoral locations. The aim of our study was to determine the influence of the miniscrew size on their long-term stability, occurrence of oral mucosa inflammation and pain lasting over 48 h after implantation. METHODS: 184 Absoanchor® miniscrews (Dentos, South Korea) in two sizes: SH2018-10 (length 10 mm, ø 1.8-2.0 mm) and SH1514-08 (length 8 mm, ø 1.4-1.5 mm) were inserted in the mandibular buccal shelf in 92 Caucasians aged 20-50 years, diagnosed with Class III malocclusion that required en-masse distalization of the mandibular dentition. Data was statistically analyzed with the level of significance set at p = .05. RESULTS: 91.3% of the SH2018-10 and 75% of the SH1514-08 miniscrews were stable, and this difference was statistically significant (p < .05). Inflammation of the oral mucosa was noticed around both types of miniscrews and affected 50% of the SH2018-10 and 26.09% of the SH1514-08 group (p < .05). Pain lasting longer than 48 h after implantation was related to 60.87% and 20.65% of the SH2018-10 and the SH1514-08 miniscrews (p < .05), respectively. Inflammation associated with larger SH2018-10 miniscrews did not affect their stability (p > .05), contrary to the SH1514-08 ones (p < .05). When inflammation was present, the overall success rate declined to 64.29%, from 94.74% noted for TADs without inflammation. According to the log-rank test, smaller TADs failed significantly sooner than the larger ones (p = .002). CONCLUSION: Larger SH2018-10 miniscrews are the anchorage of choice for the mandibular buccal shelf, despite triggering inflammation and long-lasting pain significantly more often than the smaller ones. Therefore, this issue should be discussed with every patient prior to miniscrew use. Trial registration ID: ClinicalTrials.gov Identifier: NCT05280678 Date of Registration: 15/03/2022. Retrospectively registered.

Changes in the Mandible Following Rapid Maxillary Expansion in Children with Class II Malocclusion: A Systematic Review.

OBJECTIVE: The aim of this systematic review was to determine whether rapid maxillary expansion (RME) allows favorable changes in the mandible during the treatment of class II malocclusion before the growth spurt. METHODS: A search of Pubmed/Medline, the Science Direct, and the Google Scholar database was performed. The keywords used were: orthodontics, rapid maxillary expansion, class II, and growing patients. Relevant articles were assessed for quality according to Cochrane guidelines, and then changes in SNA, SNB, ANB, NL-NSL (or SN-SNP.SNA), and ML-NSL (or SN-Go-Gn) relationships were analyzed. RESULTS: The selection process brought forth five articles, including 162 patients (91 females, 71 males) for detailed analysis. The quality of the evidence (GRADE) for comparisons and outcomes was assessed as moderate for SNB and ANB and as low or very low for other variables. CONCLUSIONS: The results of this systematic review showed that there is a small body of moderate-quality evidence for statistically and clinically favorable changes in SNB and ANB angles and a small body of low-quality evidence for changes in vertical parameters after RME.

Factors influencing an eruption of teeth associated with a dentigerous cyst: a systematic review and meta-analysis.

BACKGROUND: A dentigerous cyst (DC) is a pathology embracing the crown of an unerupted tooth at risk of malignant transformation. The causal tooth is usually removed together with the cyst. However, if there are orthodontic contraindications for extraction, two questions arise. (1) Which factors favor spontaneous eruption? (2) Which factors imply the necessity of applying orthodontic traction? This systematic review aimed to identify factors conducive/inconducive to the spontaneous eruption of teeth after dentigerous cyst marsupialization. METHODS: In accordance with the PRISMA guidelines, the main research question was defined in the PICO format (P: patients with dentigerous cysts; I: spontaneous tooth eruption after surgical DC treatment; C: lack of a spontaneous tooth eruption after surgical DC treatment; O: determining factors potentially influencing spontaneous tooth eruption). The MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases were searched for keywords combining dentigerous/odontogenic/follicular cysts with teeth and/or orthodontics, as well as human teeth and eruption patterns/intervals/periods/durations. The following data were extracted from the qualified articles (4 out of 3005 found initially): the rate of tooth eruption after surgical treatment of the cyst, the age and sex of the patients, the perpendicular projection distance between the top of the tooth cusp and the edge of the alveolar process, tooth angulation, the root formation stage, the cyst area, and the eruption space. The articles were subjected to risk of bias and quality analyses with the ROBINS-I protocol and the modified Newcastle-Ottawa QAS, respectively. Meta-analyses were performed with both fixed and random effects models. The GRADE approach was used to evaluate the quality of the evidence. The systematic review was registered in PROSPERO under ID CRD42020189044. RESULTS: Nearly 62% of DC-associated premolars erupted spontaneously after cyst marsupialization/decompression. Young age (mean = 10 years) and root formation not exceeding 1/2 of its fully developed length were the factors likely to favor spontaneous eruption. CONCLUSION: The small number of published studies, as well as their heterogeneity and the critical risk of bias, did not allow the creation of evidence-based protocols for managing teeth with DC after marsupialization. More high-quality research is needed to draw more reliable conclusions.