ABSTRACT
Periodontal diseases affect 45.9\% of adults aged 30 or older in the United States. Current diagnostic methods for clinical assessment of these diseases are visual examination and bleeding on probing that are subjective, qualitative, and/or invasive. Thus, there is a critical need for research on noninvasive modalities for periodontal tissue characterization. Quantitative Ultrasound (QUS) has shown promising results in noninvasive characterization of various soft tissues; however, it has not been used in periodontics. This study is among initial investigations into the application of QUS for periodontal tissue characterization in the literature. Here, QUS analysis of oral soft tissues (alveolar mucosa and gingiva) is performed in an in vivo animal study including 10 swine. US scanning was performed at the first molar of all four oral quadrants, resulting in a total of 40 scans. We investigated first order speckle statistics of oral tissues by using the two-parameter Burr (power-law b and scale factor l) and Nakagami models (shape factor m and scale factor $\alpha$). Parametric imaging of these parameters was created using a sliding kernel method sweeping regions of interest with a kernel size of 10 wavelengths from a phantom study. Results showed that the difference between gingiva and alveolar mucosa were statistically significant using Burr and Nakagami parameters ($p-value<0.0001$). The Burr b and Nakagami m were higher in gingiva while the Burr l and Nakagami {$\alpha$} were higher in alveolar mucosa. Findings from QUS analyses agreed with observation from histology that showed denser stains for gingiva. Linear classifications of these tissues using 2D parameter spaces of the Burr and Nakagami models resulted in a segmentation accuracy of 93.51\% and 90.91\%, respectively. We propose that QUS holds promising potentials as an augmented tool for disease diagnosis in periodontology.
ABSTRACT
Successful bone augmentation relies on primary wound closure. Labial frenum is a soft tissue that connects the lip to alveolar mucosa or gingiva. However, frenum may exert biomechanical forces to the wound edge, causing wound instability. The aim of this study is to (1) review the frenum composition and classifications; (2) understand the significance of frenum in wound stability upon bone regeneration. An electronic search was conducted through the three online databases together with manual search on studies published until September 2022. A total of 300 articles were identified and 11 studies were included in this review. Two of the included six studies discovered that 35-37.5% of the labial frenum had muscle fibers. Other studies showed that labial frenum was mainly composed of connective tissue with elastic fibers. There are two widely used classifications for frenum based on morphology and position of attachment. No studies specifically evaluated the impact of frenum on bone regeneration. Frenum location intercorrelated with the amount of keratinized tissue, which could influence wound stability. A modified frenum classification for the edentulous ridge and a decision diagram to manage the frenum is proposed for research and evidenced practice.
