This study aimed to evaluate the reliability and accuracy of an intraoral ultrasound(US) device to evaluate alveolar bone by comparing it between different raters and to microCT (µCT) measurements. 38 teeth distributed across three human cadavers were prepared by placing two notches on the facial enamel surface. The maxillary and mandibular teeth were imaged with a custom-designed intraoral 20MHz ultrasound and µCT with 0.03mm voxel size. µCT was considered the reference standard for this study. For each sample, the distance from the inferior border of the most apical notch to the tip of the alveolar bone crest on the facial aspect of the teeth was measured from the US and µCT images. Intraclass correlation coefficient (ICC) and standard deviation were calculated. The intra-examiner and inter-examiner reliability for both the µCT and US alveolar bone measurements were found to be excellent (intra-examiner ICC was 0.998 for µCT and 0.997 for US, inter-examiner ICC was 0.996 for µCT and between 0.947 and 0.950 for US). The accuracy of the US was found to be good compared to µCT (ICC between 0.885 and 0.894). The study demonstrated that intraoral ultrasound is highly reliable and accurate compared to the µCT reference standard for evaluating facial alveolar bone height.