Tooth segmentation by low-dose CBCT for orthodontic treatment planning : Explorative ex vivo validation

Area of Science:

• Dentistry
• Radiology
• Medical Imaging

Background:

• Three-dimensional imaging is crucial in orthodontics, but standard high-dose cone-beam computed tomography (HD-CBCT) poses radiation risks.
• Advancements have led to low-dose CBCT (LD-CBCT) devices, aiming to reduce patient exposure.

Purpose of the Study:

• To evaluate the precision and reproducibility of LD-CBCT compared to HD-CBCT for dental imaging.
• To assess if LD-CBCT is as accurate as HD-CBCT in segmenting tooth roots and crowns and measuring tooth length.

Main Methods:

• HD-CBCT and LD-CBCT scans were acquired from four human cadaveric heads.
• Thirty single-rooted teeth were segmented twice by a single investigator, and tooth length was measured.
• Lin's concordance correlation coefficient (CCC) and intraclass correlation coefficient (ICC) were used to assess agreement and reliability.

Main Results:

• Excellent agreement was found between LD-CBCT and HD-CBCT for tooth length measurements (CCC = 0.991).
• Intrarater reliability for tooth length measurements was excellent for both modalities (ICC > 0.997).
• While volume measurements differed significantly (p < 0.001), agreement between modalities was excellent (CCC = 0.975) with high intrarater reliability (ICC > 0.997).

Conclusions:

• LD-CBCT is a valid alternative to HD-CBCT for measuring tooth length in orthodontic applications.
• The clinical significance of volume measurement differences between LD-CBCT and HD-CBCT requires further investigation through in vivo studies.