Comparing Labial and Lingual Orthodontic Appliances on Root Resorption and Bone Height

CBCT-based Assessment of Apical Root Resorption and Alveolar Bone Height Following Orthodontic Treatment of Moderate Crowding With Labial vs. Lingual Fixed Appliances: A Randomized Controlled Trial

Patients who have moderate crowding that could be treated on a non-extraction will be treated in this study. The apical root resorption and alveolar bone height of the lingual and labial fixed appliances will be assessed. All patients will receive a cone-beam computed tomography (CBCT) scan at two different times (T0: Before treatment, T1: After treatment).

There are two groups: The first group (Experimental): The patients in this group will be treated using Lingual Fixed Orthodontic Appliances. The second group (Control): The patients in this group will be treated using Labial Fixed Orthodontic Appliances.

Recently, the therapeutic results of lingual orthodontics have become similar to those produced by labial orthodontics. However, lingual appliances act differently. The application of force near the center of resistance and the distance between the lingual brackets leads to an increase in friction and, thus, an increase in the force applied during treatment. In addition, the contact of the lower incisors with the brackets of the upper incisors in the lingual technique can lead to the intrusion of these incisors. Therefore, these factors can be potential risks for apical root resorption and alveolar bone height in lingual orthodontics.

2D radiographs may not accurately depict the true amount of root resorption due to magnification errors and difficulties in obtaining repeatable images. Besides, conventional two-dimensional radiographs cannot accurately assess alveolar bone height in the anterior region. CBCT has proven to be valuable in diagnosing root resorption due to its capability to produce distortion-free images, as well as its ability to maintain a high level of reproducibility despite changes in tooth positions after treatment, with high sensitivity and specificity. On the other hand, the use of CBCT allows for an evaluation of alveolar bone height in the anterior region with high accuracy and precision.

Inclusion Criteria:

1. Class I molar and canine relationships on both sides.
2. Moderate crowding of both arches of about 4 to 6 mm treated on a non-extraction basis.
3. Age from 18 to 25 years.
4. The presence of permanent dentition (except third molars).

Exclusion Criteria:

1. The existence of craniofacial syndromes, cleft lip and/or palate (soft and/or hard).
2. Skeletal or dental crossbite.
3. Patients with missing teeth or periodontal diseases.
4. Previous orthodontic treatment.