Objects: Recently, plasmamicroRNAs (miRNAs) emerging as newpotential molecular biomarkers in various fields of research and have significant effects in disease formation. In this study, we hypothesized that plasma miRNAs may play an important role in maxillary deficiency (MD), and would be excellent biomarkers for this disease. Methods: Two cohorts were examined in this study. Cohort one comprised three MD cases and three controls with normal Class I occlusion. Cohort two comprised 31 cases and 31 controls. We first used a microarray assay to examine the miRNA expression profiles in cohort one to identify candidate miRNAs. Secondly, the candidate miRNAs were validated by qRT-PCR in cohort two. Finally, ROC analysis was performed to identify potential biomarkers inMD diagnosis. Results: Themicroarray assay identified sevenmiRNAs with a p-value < 0.05; in which those showing a fold change > 2 were chosen as candidate disease biomarkers. At the validation stage, miR- 4505 was showing a satisfactory diagnostic capacity, with an AUC of 0.844 and sensitivity and specificity of 84.0% and 71.2%, respectively. Conclusion: Plasma miRNAs are associated with MD and may be useful biomarkers forMDearly diagnosis and assistant inMD linicalmanagement.