Thirty-eight patients requiring extraction of maxillary first premolars will participate in the study. They will be divided randomly into two groups: an en-masse retraction group and a two-step group. In each group, anterior teeth retraction will be initiated after completion of the leveling and alignment phase via closed nickel-titanium coil springs applying 150 g of force per side, Mini-implants will be used as an anchor unit in the en-masse retraction group, and TPA in the two-step's retraction group.

The levels of pain, discomfort, and functional impairments will be self-reported using a validated questionnaire with a 4-points Likert scale.

Pain associated with orthodontic treatment is one of the undesirable complications, which negatively affects the patient's cooperation. Pain may occur due to the pressure on the periodontal ligaments induced by orthodontic forces. The perception of pain is affected by many factors related to the patient, such as age, gender, and any previous treatment experiences, which are negatively or positively reflected in the patient's cooperation. As for the factors related to the type of orthodontic treatment provided.

The levels of pain and discomfort vary with the different anchorage systems used during orthodontic treatment.

Several methods have been proposed to assure good anchorages, such as headgear, transpalatal arch (TPA) with or without a Nance button, lingual arches, bonding of second molars, or intermaxillary elastics, and recently mini-implants.

The use of mini-implants has recently become more common. The mini-implants have been used to secure absolute anchorage in en-mass retraction, canine retraction, total arch distalization, and anterior teeth intrusion. The most common usage is en-mass retraction of anterior teeth.

Inclusion Criteria:

1. Adult healthy patients, Male and female, Age range: 17-27 years.

2. Class II Division 1 malocclusion:

   • Mild / moderate skeletal Class II (sagittal discrepancy angle 4< ANB<10)
   • Overjet more than 5 mm.
   • Normal overbite (more than 0 mm and less than 4 mm)
   • Normal or increased anterior facial height (Clinically and then cephalometrically assessed using these three angles: mandibular/cranial base angle, maxillary/mandibular plane angle, and facial axis angle)
   • well-aligned maxillary teeth with minimal crowding (≤ 4 mm according to Little's index), 3- Complete permanent dentition (except for the third molars).

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 conditions that affect tooth movement (corticosteroid, nonsteroidal anti-inflammatory drugs (NSAIDs), …)
2. Presence of primary teeth in the maxillary arch
3. Any craniofacial syndromes.
4. Poor oral hygiene or Current periodontal disease:
5. The patient had previous orthodontic treatment