Effect of mandibular third molars on crowding of mandibular teeth in patients with or without previous orthodontic treatment: a systematic review and meta-analysis.

OBJECTIVES: To assess the scientific evidence related to the role of the mandibular third molars on the late crowding of the lower anterior teeth in patients with or without previous orthodontic treatment. The secondary outcomes included changes in mandibular arch width and arch length. MATERIALS AND METHODS: The databases PubMed, Scopus, ProQuest, and Google Scholar were searched from inception until April 2022. The included papers were studies evaluating the role of mandibular third molars on crowding of mandibular anterior teeth in patients of any age and gender, with mandibular third molars impacted or semi-impacted or erupted. Predetermined and prepiloted data collection forms were used to record the necessary information. RESULTS: Thirteen observational studies were included in the present systematic review. Most of them were assigned an overall risk of bias of moderate risk while the rest of them were at high risk. Four studies found an association between the presence of mandibular third molar and mandibular incisor crowding. Finally, seven studies were included in the quantitative analysis. Three different meta-analyses were conducted: for patients (a) with or (b) without previous orthodontic treatment and (c) in combination for patients with and without previous orthodontic treatment. According to the pooled results of all three meta-analyses, random effects model yielded a significant benefit for those without third molars compared to those with third molars regarding crowding, mean Little's irregularity index and mean arch length. CONCLUSIONS: Lower third molars may contribute to mandibular crowding and lower arch constriction. Further prospective research of high quality is needed to clarify the impact of third molars on anterior mandibular crowding.

Evaluation of Lateral Incisor Resorption Caused by Impacted Maxillary Canines Based on CBCT: A Systematic Review and Meta-Analysis.

BACKGROUND: Root resorption (RR) of the adjacent teeth due to upper canine impaction requires an appropriate modification of the orthodontic treatment plan and the mechanotherapy used. AIM: The aim of this review was to assess scientific evidence published during the last decade, concerning the prevalence of lateral incisor RR caused by impacted maxillary canines, based only on cone-beam computed tomography (CBCT). The location of RR on this tooth, as well as the prevalence of RR on the other adjacent teeth, were additionally evaluated. METHODS: This review followed the criteria specified by the PRISMA statement. Four databases were searched for articles published between January 2008 and June 2021. Predefined and piloted data collection forms were used to record the necessary information. RESULTS: A total of 5098 records were initially screened. Only seven articles were finally eligible for further analysis. A total number of 540 participants (176 males and 364 females) was derived from the included studies. RR of maxillary lateral incisors was common (50%). RR of mild severity was more common (62%), more frequently located in the middle (52%) and apical (42%) thirds of the root. CONCLUSIONS: Further research with more homogeneous groups is required.

The effect of facemask in patients with unilateral cleft lip and palate: a systematic review and meta-analysis.

BACKGROUND: Patients with cleft lip and palate usually present a Class III skeletal pattern. Facemask (FM) is one of the conventional orthodontic treatment modalities used to address the skeletal discrepancy in cleft patients. OBJECTIVE: To investigate the potential effectiveness of FM in unilateral cleft lip and palate (UCLP) patients. SEARCH METHODS: Search without restrictions except language in seven databases since inception and hand searching until January 2019 was conducted. Detailed search strategies were developed for each database which were based on the PubMed strategy and adapted accordingly. SELECTION CRITERIA: Controlled studies assessing the effect of FM in UCLP patients were to be included. DATA COLLECTION AND ANALYSIS: After retrieval and selection of the studies, data extraction was performed. Both angular and linear cephalometric measurements were collected. Weighted mean differences (WMDs) and 95% confidence intervals (CΙs) between treated and untreated UCLP patients concerning the pre- and post-treatment angular measurements of each group were calculated using a random-effects meta-analysis model. The risk of bias in individual studies was assessed using the ROBINS-I tool. RESULTS: From nine eligible studies, five were included in the meta-analysis investigating the use of FM in patients and controls with UCLP (with and without maxillary expansion). Statistically significant differences were evident for SNA/S-N-ss, SNB/S-N-sm, ANB/ss-N-sm, and SN-MP. FM was found to induce an increase of SNA (WMD = 2.12 degrees, 95% CI: 1.58 to 2.66), ANB (WMD = 4.17 degrees, 95% CI: 3.60 to 4.74), and SN-MP angles (WMD = 2.60 degrees, 95% CI: 1.10 to 4.10) and a decrease of SNB angle (WMD = -1.94 degrees, 95% CI: -2.48 to -1.40) in UCLP patients. Low to moderate heterogeneity was observed. LIMITATIONS: They emerge due to risk of bias, exclusion of non-English papers and methodological characteristics of the included papers. CONCLUSIONS: According to the available data, FM seems to improve the sagittal skeletal relationships in UCLP patients, increasing the SNA and ANB angles and decreasing the SNB angle. Moreover, in the vertical dimension, FM increases the SN-MP angle. Regarding dental measurements, there are controversial results. More high-quality studies need to be conducted in order to further clarify the impact of FM on UCLP patients. REGISTRATION NUMBER: PROSPERO: CRD42019131619.

Two Rare Cases of Non-Syndromic Paramolars with Family Occurrence and a Review of Literature.

Supernumerary teeth (or hyperdontia) are teeth that exceed the normal number of deciduous or permanent teeth in the oral cavity. The occurrence of supernumerary teeth without any associated syndrome has been frequently reported and many case reports have been published. This article reports two rare cases of familial occurrence of multiple paramolars without the presence of any other syndrome for two consecutive generations. Limited cases of bilateral maxillary or mandibular paramolars have been reported. In addition, prevalence, classification, etiology, complications, diagnosis and therapeutic strategies that may be adopted when supernumeraries occur are discussed. A review of similar cases published in the literature is included as well.