Is there really a relationship between maxillary and mandibular incisor inclination and the amount of surrounding cortical alveolar bone? A systematic review

Abstract

Background: For orthodontists, the position of the incisors is a key factor in setting treatment goals. Achieving maximum stability requires that they be positioned in the medullary portion of the alveolar bone, balanced with the lingual and labial musculature. Incorrect orthodontic movements can result in root resorption, dehiscences, or even fenestrations. Methods: A systematic review of the bibliography was conducted in accordance with PRISMA recommendations. Searches were made in PubMed, Scopus, and Cochrane Library databases, using the same search terms in each, with no limitation on publication data, up to July 1st, 2024. The review accepted articles in any language. Randomized controlled trials, case-control studies, and cohort studies were included, both retrospective and prospective. Systematic reviews, meta-analyses, case reports, case series, literature reviews, and editorials were excluded. The quality of the articles was determined according to the CONSORT criteria. Results: The initial database search identified 167 articles: 89 in PubMed, 74 in Scopus, and 4 in the Cochrane Library. Of these, 75 were duplicates, leaving 92. After applying the inclusion criteria, a total of 8 articles were included in this systematic review. Conclusions: This systematic review highlights the significant relationship between alveolar bone thickness and incisor inclination as assessed by CBCT. The bone thickness varies regionally, with the maxilla generally having thicker palatal bone and the mandible having thinner labial bone. CBCT is indispensable for evaluating cases involving severe skeletal discrepancies, preexisting bone defects, or planned movements beyond the alveolar limits, while traditional methods may suffice for less complex cases. Standardizing methodologies and conducting longitudinal studies with diverse populations are crucial for improving clinical guidelines and ensuring safe, effective treatment planning.