The aim of this study is to analyze the skeletal and dentoalveolar morphological characteristics of the maxillary in subjects with a unilateral palatally impacted canine using Cone Beam Computed Tomography (CBCT). A retrospective clinical study was conducted of 100 adult patients divided into two groups: one consisting of patients with a unilaterally palatally impacted maxillary canine (GI), with the subgroups in the right and left hemiarches (GI-R and GI-L), and the second, without impacted canine, as the control group (CG). The CBCT measured skeletal variables (maxillary basal width and alveolar crest height) and dentoalveolar variables (inclination of the upper incisor, tooth lengths of incisors and canines, arch length, tooth size and bone dental discrepancy). In skeletal variables, statistically significant differences were found in alveolar crest height (ACH) in all groups and subgroups (p < 0.01). In the dentoalveolar variables, there were differences in the angle of the upper incisor (II) and lateral incisor length (LLIL) between the GI and GC and the angle of the upper incisor (II′), arch length (AL′) and arch length-tooth size discrepancy (ATD′) among the GI subgroups (p < 0.01). There are skeletal and dentoalveolar differences in patients with unilateral palatally impacted maxillary canines, with lower angular and linear measurements compared with patients without impaction.

The molecules deposited outside the nerve root, nerve root cuffs or nerve need to cross several structures before reaching the axons. The diffusion occurs initially through the tissue surrounding the nervous structures, then crossing and distributing among the intraneural area such as endoneurium, pia mater, arachnoid lamina, dura mater, fat tissue and transitional epithelium inside nerve root cuffs, epineurium, perineurium and endoneurium of peripheral nerve. The morphological characteristics of the tissue surrounding and protecting axons may change depending on the area and can influence the diffusion of local anesthetics to reach axons. The study of these morphological variables in depth will be of help to choose the best area of injection, according to the type of surgery and to analyze any possible complications.