Novel 3D segmentation for reliable volumetric assessment of the nasal airway: a CBCT study.

OBJECTIVE: Nasal airway obstruction affects up to one-third of Americans and is one of the most common complaints by patients to otolaryngologists. Nasal airway obstruction and obstructive sleep apnea syndrome (OSAS) are closely related. The aim of this study was to use the 3D imaging software, ITK-SNAP as a platform to define a gold standard for anatomically accurate boundaries of the nasal airway in 3D CBCT and to create a more reliable and precise 3D CBCT segmentation of the nasal airway for assisting diagnosis, treatment, and monitoring of nasal airway obstruction and OSAS. METHOD AND MATERIALS: After review of the literature to identify established parameters using CBCT and CT technology for the segmentation of the nasal airway, and the existing drawbacks, a gold standard for locating the anatomical boundaries of the nasal airway using CBCT is proposed. This new method aims at standardization of segmentation and quantification, allowing for more reliable comparison between studies. ITK-SNAP software was used to segment three CBCT samples of healthy patients aged 21 to 59 years, who were patients of record, with CBCT obtained for either orthodontic, endodontic, or prosthodontic treatment planning purposes.
Results: The literature search identified 11 studies describing nasal airway parameters utilizing CBCT and CT. A great variation was detected on where the anatomical boundaries for the nasal airway were selected. A new standard in the identification of anatomical boundaries of the nasal airway is proposed for consistent segmentation and quantification using 3D CBCT by using the following landmarks: the inferior ANS-PNS border, the anterior nares border, the posterior sella-PNS border, and superiorly the border in alignment with the base of the skull (excluding the ostia, frontal, ethmoidal, and sphenoidal air cells). The three segmented samples were volumetrically measured, and statistically analyzed. The mean average Hounsfield unit intensity using the CBCT samples in this study was 629 with a standard deviation of 190.
Conclusion: The literature indicates a lack of a gold standard using CBCT technology for the segmentation of the nasal airway. With the proposed standard in this study, it is possible to quantify the nasal airway volume and thereby its reduction. For the general dental practitioner, this is an important aspect during the evaluation of overall airway assessment. This information can be useful in the diagnosis and treatment of airway compromised dental patients. (Quintessence Int 2021;52:154-164; doi: 10.3290/j.qi.a45429).

Evaluation of diagnostic radiology acumen between 2 groups of clinical dental students.

PURPOSE: To evaluate and distinguish if an additional year of clinical experience increases the cognitive ability of dental students to accurately assess and interpret dental radiographs. METHODS: Radiological acuity was assessed between two groups of clinical dental students at Penn Dental Medicine (PDM). Group 1 was composed of 147 third-year dental students (D3), group 2 was composed of 145 fourth-year dental students (D4). A 65-question test comprising the length and breadth of radiographic anatomy and pathology was administered to both D3 and D4 students. The test was designed to test the participants' knowledge of radiographic technique, anatomy, and differential diagnosis. The null hypothesis was that there would be no significant differences between the two groups. RESULTS: STATA 15 software (StataCorp LLC, College Station, TX, USA) was used to statistically analyze the findings. Although, the mean correct score for group 1 was higher (60/65) than group 2 (59/65), there was no statistically significant difference between the performance of the groups. On average, group 1 outperformed the clinically more experienced group 2 on an individual question basis. The average overall number of correctly answered items compared to incorrectly answered items reflected this difference. CONCLUSION(S): An additional year of clinical dental education does not appear to correlate with any higher radiographic acumen. This may be due to tapering exposure to unique pathology and findings, as more routine findings are encountered daily and classroom instruction during the fourth year of dental school is limited. Early incorporation of new radiographic education tools that are clinically oriented may be one method to increase retention of knowledge accumulated in the initial didactic years of dental education.