Salivary levels of disease-related biomarkers in the early stages of Parkinson's and Alzheimer's disease: A cross-sectional study.

Introduction: Finding a non-invasive and repeatable tool has been recommended to make an accurate diagnosis of Alzheimer's disease (AD) and Parkinson's disease (PD). Methods: 70 volunteers participated in three groups: 24 with mild dementia of AD, 24 in the first and second stages of PD, and 22 healthy controls. After valuing the scores of cognitive tests, the salivary levels of phosphorylated tau (p-tau), total alpha-synuclein (α-syn), and beta-amyloid 1-42 (Aß) proteins have been evaluated. Finally, the cutoff points, receiver operating characteristic (ROC), sensitivity, and specificity have been calculated to find accurate and detectable biomarkers. Results: Findings showed that the salivary level of Aß was higher in both PD (p < 0.01) and AD (p < 0.001) patients than in controls. Moreover, the level of α-syn in both PD and AD patients was similarly lower than in controls (p < 0.05). However, the level of p-tau was only higher in the AD group than in the control (p < 0.01). Salivary Aß 1-42 level at a 60.3 pg/ml cutoff point revealed an excellent performance for diagnosing AD (AUC: 0.81). Conclusion: Evaluation of p-tau, α-syn, and Aß 1-42 levels in the saliva of AD and PD patients could help the early diagnosis. The p-tau level might be valuable for differentiation between AD and PD. Therefore, these hopeful investigations could be done to reduce the usage of invasive diagnostic methods, which alone is a success in alleviating the suffering of AD and PD patients. Moreover, introducing accurate salivary biomarkers according to the pathophysiology of AD and PD should be encouraged.

Investigation of the Relationship Between Mandibular Morphology and Upper Airway Dimensions.

INTRODUCTION: In this study, the authors aimed to perform a novel and extensive analysis, based on the most applicable correlations between the mandibular and upper airway parameters, using cone beam computed tomography across all malocclusion classes. The authors also focused on gender-dependent differences in an Iranian population. MATERIALS AND METHODS: Images were acquired from adult patients using cone beam computed tomography. The patients were classified into three groups of malocclusion classes (class I: 13 males and 27 females, class II: 13 males and 27 females, and class III: 25 males and 15 females). For each patient, 10 parameters for the mandible and 23 parameters for the pharynx, pyriform aperture, and nasal cavity were evaluated in the images. RESULTS: Pearson's correlation coefficient showed significant correlations between the mandibular morphology and upper airway dimensions in each malocclusion class. In females, the menton angle had a significant correlation with pharyngeal dimensions in all malocclusion classes. In males, the bigonial width, bicondylar width, and symphyseal height of the mandible were correlated with pharyngeal dimensions in all classes. The greatest correlation between the mandible and upper airways was observed in class III malocclusions, and the lowest correlation was observed in class I malocclusions. In addition, the mandibular parameters had relationships with the nasal cavity and pyriform aperture. CONCLUSION: It is important to consider the knowledge of the relationship between some characteristics of the mandible and airways in various clinical approaches.