Factors associated with occlusal plane inclination

INTRODUCTION: The inclination of the occlusal plane (OP) is a crucial parameter in achieving optimal dental and facial harmony. The occlusal plane serves as a horizontal reference line used to assess the relationship between the upper and lower teeth during occlusion, playing a pivotal role in determining the overall aesthetics and functionality of a patient’s smile. The aim of this review is to understand the concept of occlusal plane inclination, examining its significance in orthodontic practice, its relationship with different skeletal frames, and the clinical implications for treatment planning. We will explore the variations in occlusal plane inclination in different malocclusions, such as Class I, Class II, and Class III, and how orthodontic interventions can influence this inclination to correct misalignments.EVIDENCE ACQUISITION: An electronic search was conducted on PubMed, Cochrane Library, EBSCO databases, EMBASE, Web of Science, UpToDate, and MEDLINE. After excluding systematic reviews, duplicated articles, and meta-analyses, 22 articles were included in our review.EVIDENCE SYNTHESIS: A steepened OP is associated with Class II dental occlusions, while a rotated upward and forward (flattened) OP is associated with Class III dental occlusions. Hyperdivergent profiles tend to have steeper occlusal plane inclinations, whereas hypodivergent profiles tend to have flatter inclinations. The inclination of the Curve of Spee contributes to the development of both open and deep bite malocclusions.CONCLUSIONS: Occlusal plane inclination varies according to vertical and sagittal skeletal patterns, and there is a significant correlation between OP inclination and maxillary incisor inclination. Given its importance in orthodontic therapy, a more comprehensive analysis of OP as a diagnostic parameter is needed for more effective and efficient treatments.