Abstract
Cone beam computed tomography (CBTCT) scans (n = 45) and digital dental casts (n = 45) were both used to measure the maxillary transverse dimensions in patients with impacted maxillary canines. The objectives were to explore the associations of these dimensions with the impaction and patient characteristics, and to compare the measurements between these techniques. The maxillary width was measured on scans and casts at the Walaridge, and the intermolar width and interpremolar width levels were measured at the first and second premolars (measured from the buccal grooves and the palatal cuspids, and the palatal and lingual amelocemental junctions). Two examiners independently compared the measurements between the control quadrants (without impaction) and the case quadrants (with impaction) in patients with unilateral impactions, and between the unilateral and bilateral impaction groups. The interclass correlation coefficient (ICC) was calculated to assess the interexaminer reliability and paired or independent Student’s t-tests and ANOVAs were used for comparisons. The ICCs were 0.887 and 0.919, globally, for the measurements on the CBCT scans and casts, respectively, which indicates the excellent interexaminer reliability. On the CBCT scans, statistically significant differences were found between the case and control quadrants in the transverse measurements at the lingual level on the upper first molars, and at the WALA ridge level on the upper second premolars (p < 0.05) in the unilateral impaction group. Significant differences were found between the case quadrants in the unilateral versus the bilateral groups at the WALA ridge on the second premolars in casts (p < 0.05), and at the lingual point on the first molars on the CBCT scans (p < 0.05). No statistically significant differences in the transverse measurements were observed between the impacted buccal and palatal canines on either the casts or CBCT scans. To the best of our knowledge, this is the first study to compare the transverse measurements between digital models and CBCT scans.
Highlights
The maxillary canines are the second most frequently impacted teeth after the third molars [1]
The interclass correlation coefficient (ICC) was higher for the measurements on the casts (0.919) than for those on the cone beam computed tomography (CBCT) scans in the present study, with the best reference point for the cast measurements being the lingual point on the first premolars (0.997), and the worst being the Walaridge on the upper first molars (0.6) (Table 2)
In terms of our main objective, we can conclude that there is no relationship between the maxillary canine impaction and the arch width measured by the quadrants at the dental, dentoalveolar, or skeletal levels
Summary
The maxillary canines are the second most frequently impacted teeth after the third molars [1] The etiology of their impaction is associated with local (high canine position in the maxillary arch and maxillary transverse dimension; and the agenesis, or microdontia, of the lateral incisors) and genetic factors [2,3,4]. Buccal canine displacement is most often associated with anterior maxillary transverse (dental and skeletal) deficiency and palatal displacement, with small or missing lateral incisors, which is consistent with the guidance theory [5]. Various authors have reported that patients with canine impactions have a maxillary transverse deficiency in the anterior portion of the dental arch, and that premaxillary skeletal deficiency is frequently associated with the buccal impaction of the maxillary canines [3,6]. Yan et al found that PDCs are largely associated with small or missing lateral incisors, which is in line with the guidance theory [10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
