Association between palatally displaced maxillary central incisors and lateral incisors: A retrospective cone-beam computed tomographic study

The evaluation of lateral incisor adjacent to treated labial inversely impacted maxillary central incisor: A retrospective follow-up study

INTRODUCTION

This retrospective study aimed to evaluate the further development of the lateral incisor and its associated periodontium adjacent to the treated labial inversely impacted maxillary central incisor.

METHODS

We enrolled 23 participants (average age, 8.24 ± 1.43 years) undergoing a mean follow-up period of 31.10 ± 13.05 months. Each participant had an unimpacted lateral incisor and a successfully treated unilateral labial inversely impacted maxillary central incisor. The contralateral lateral incisors served as controls. Cone-beam computed tomography data were available for treatment completion and follow-up stages. The variables (including root length, dental age, root canal width, root-crown angulation, and alveolar bone loss and thickness) were evaluated with Dolphin Imaging software (version 11.95; Dolphin Imaging and Management Solutions, Chatsworth, Calif).

RESULTS

At the follow-up stage, the lateral incisors in the impacted side had significantly longer root lengths, smaller root canal widths, and thinner labial bone widths at the apex than at the posttreatment stage (P <0.001, P = 0.036, and P = 0.001, respectively). A significant lateral incisor root length reduction was noted when comparing the impacted and contralateral sides, although no variation was observed in root canal width. Similarly, crown-root angulation of the lateral incisor on the impacted side was significantly larger than that of the contralateral lateral incisor. The lateral incisor on the impacted side also had thicker labial and thinner lingual bone widths at the apex than the contralateral lateral incisor.

CONCLUSIONS

The lateral incisor adjacent to the successfully treated labial inversely impacted maxillary central incisor showed continuous growth during follow-up stages, exhibiting a similar morphology and alveolar bone quality but shorter root length, larger root angulation, and thinner lingual bone width at the apex than those of the contralateral lateral incisors.

The position and morphology characteristics of multiple impacted anterior teeth in the unilateral maxillary area: A retrospective study based on cone-beam computed tomography

INTRODUCTION

This study investigated the position and morphologic characteristics of multiple impacted anterior teeth in the unilateral maxillary area.

METHODS

Cone-beam computed tomography images of 21 patients (11 males and 10 females; median age 9.42 years [9.08-11.29]) with multiple teeth impacted were collected and imported into Dolphin Imaging software (Dolphin Imaging and Management Solutions, Chatsworth, Calif). The vertical height, crown orientation, twist direction, and root curvature of each impacted tooth were described. The crown length, root length, and root canal width of impacted and homonym teeth were measured.

RESULTS

The positions of the impacted lateral incisors are lower than that of the other 2 anterior teeth. Most crowns of impacted central incisors are positioned distally, labial surfaces in mesial torsion, with most roots, bent toward the distal and labial. Crowns of impacted lateral incisors are positioned mesiolabially, with labial surfaces mostly in distal torsion, and most roots bent toward the mesial and labial. Crowns of impacted canines are mostly positioned mesiolabially, with labial surfaces in mesial torsion. The crowns and roots of the impacted central and lateral incisors were shorter than those of the homonym (P <0.05); however, the difference in crown length is clinically negligible, and there was no difference in root canal widths. There was no difference in the comparison of parameters for the canine group.

CONCLUSIONS

There are certain rules in the vertical height, crown orientation, twist direction, and root curvature of multiple impacted anterior teeth in the unilateral maxillary area. Root development of impacted central and lateral incisors was restricted.