The duration of orthodontic treatment is one of the exacerbation causes of orthodontic pain. Several methods have been suggested to reduce the duration of orthodontic treatment classified to surgical and non-surgical methods.

Researchers used minimally invasive surgical methods like corticision, piezocision, micro-osteoperforation, and piezopuncture indicated that most of these methods can accelerate dental movement by 20 - 40%.

The effect of corticision as a minimally invasive procedure on root resorption and dehiscence formation during orthodontic tooth movement has not been studied yet.

Applying corticision on the lower anterior teeth using a surgical blade and a hammer may accelerate tooth alignment during orthodontic treatment. This study consists of two groups, patients will be randomly assigned to one of these two groups.

Orthodontically induced external root resorption accompanying orthodontic treatment is defined as a microscopic loss of root tissue as a result of the inflammatory reaction that occurs in the area of application of orthodontic force. It can be diagnosed and measured using conventional radiography or cone-beam computed tomography (CBCT).

Dehiscence is a loss of alveolar bone on the facial (rarely lingual) aspect of a tooth that leaves a characteristic v-shaped, root-exposed defect from the cementoenamel junction apically. Bone dehiscence cannot be detected through conventional radiography or clinical examination. Actually, CBCT can be considered the best accessible technique providing 3D data.

Corticision is one of the minimally invasive surgical procedures that is not associated with flap lifting. It was used to accelerate tooth movement in animals and case report studies. Its application on humans may aggravate their fear and anxiety towards the pain that may accompany this technique.

No randomized controlled trial (RCT) has compared flapless corticision in the non-extraction-based orthodontic decrowding of lower anterior teeth (LAT) with the conventional treatment in terms of external apical root resorption (EARR) and dehiscence formation (DF).

Inclusion Criteria:

1. Age range between 18 and 24 years
2. Completion permanent dentition (except third molars)
3. Mild to moderate crowding (2-6 mm according to Little's index)
4. Absence of medications intake that interferes with pain perception for at least one week before the beginning of the treatment

Exclusion Criteria:

1. Medical conditions that would affect tooth movement.
2. Cases which contraindication to oral surgery.
3. Previous orthodontic treatments.