Cephalometric Changes Following Retraction of the Upper Anterior Teeth Stimulated by Low-intensity Electrical Current

Thirty-six patients requiring extraction of maxillary first premolars and en-masse retraction of upper anterior teeth will participate in the study. They will be randomly assigned into two groups: low-intensity electrical stimulation group (LIES) and traditional retraction group (TRAD) after the leveling and alignment phase is completed. En-masse retraction will be initiated in both groups via closed nickel-titanium coil springs that applying 250 g of force on each side, Mini-implants will be inserted to provide the highest level of anchorage. The skeletal, dental, and soft tissue changes will be detected using lateral cephalometric radiographs, which will be obtained pretreatment, pre-, and post-en-masse retraction of the anterior teeth.

All candidate patients will be examined to determine the orthodontic treatment plan. Written informed consent will be obtained from all patients who accept to participate in the trial. Self-drilling mini-screws (1.6mm diameter and 8mm length) will be used to provide anchorage. They will be inserted bilaterally 8-10 mm above the level of the interdental papilla, between the second premolars and the first molar. Then, the maxillary first premolar will be extracted. Leveling and alignment of the upper dental arch will be done using a pre-adjusted orthodontic appliance: MBT™, 0.022 × 0.028-inch slots-size brackets. The removable electrical stimulation device utilized in the Shaadouh et al. study to provide the electrical stimulation will be used in this trial for the same purpose. Each patient in the low-intensity electrical stimulation group will be asked to wear a removable device for five hours daily until the completion of the retraction of the upper anterior teeth.

The en-masse retraction will be done by applying 250 g force on each side using two NiTi springs attached between the mini-implants and the crimpable hooks in a direction approximately parallel to the occlusal plane. The force will be calibrated every two weeks. The en-masse retraction will continue until a class I canine relationship and a correct incisor relationship, which will consider the endpoint of this phase.

Lateral cephalometric radiographs will be obtained pretreatment, pre-, and post-en-masse retraction of the anterior teeth to assess the skeletal, dental, and soft tissue changes. The duration of retraction will be calculated by calculating the time required to achieve complete retraction of the upper anterior teeth through clinical examination.

Eligibility Criteria:
Inclusion Criteria:

1. Adult healthy patients, Male and female, Aged 18-25 years.
2. Class II Division 1 malocclusion :

   * Mild/moderate skeletal Class II (ANB= 5-7 degrees)
   * Overjet ≤10
   * Normal or excessive facial height (Clinically and then cephalometrically assessed using these three angles: mandibular/cranial base angle, maxillary/mandibular plane angle, and facial axis angle)
   * Mild to moderate crowding ≤ 4
3. Permanent occlusion.
4. Existence of all the upper teeth (except third molars).
5. Good oral and periodontal health:

   * Probing depth \< 4 mm
   * No radiographic evidence of bone loss.
   * Gingival index ≤ 1
   * Plaque index ≤ 1

Exclusion Criteria:

1. Medical problems that affect tooth movement (corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs), ...)
2. Presence of primary teeth in the maxillary arch
3. Missing permanent maxillary teeth (except third molars).
4. Poor oral hygiene or Current periodontal disease:

   Probing depth ≥ 4 mm Radiographic evidence of bone loss Gingival index \> 1 Plaque index \> 1
5. Patient had previous orthodontic treatment