Evaluation of the Anchorage Loss During En-masse Retraction in Orthodontic Patients With Maxillary Protrusion

Evaluation of the Anchorage Loss During En-masse Retraction in Orthodontic Patients With Maxillary Protrusion Using Friction Versus Frictionless Mechanics: A Randomized Clinical Trial

There is scarcity in literature regarding the effectiveness of friction and frictionless mechanics during ''En-masse retraction''technique on anchorage loss of posterior segment in orthodontic patients with maxillary protrusion. Moreover there is deficiency in studies measuring the patient pain and satisfaction regarding the different techniques of retraction.

The aim of the current study is to evaluate the effects of friction versus frictionless mechanics, implemented during "En-masse retraction", on anchorage loss. Additionally, assessment of both techniques regarding their rates, effects on root resorption as well as patient satisfaction.

One of the most common complaints of orthodontic patients is proclination of anterior teeth where there is an increase in facial convexity and as well as incompetent lips. Bimaxillary dentoalveolar protrusion and class II division I cases always have this appearance. Frequently this situation requires extraction of the first premolars followed by fixed orthodontic appliance for space closure and retraction of anterior teeth. Different techniques are used including "Two-step retraction" where canines are retracted as a first step followed by anterior four incisors as a second step and "En-masse retraction" where anterior teeth are retracted as one unit. However, the method of "En-masse retraction" is controversial - whether to use frictionless or friction mechanics.

Inclusion Criteria:

1. Orthodontic patients (both genders)
2. Age range (14-24)
3. Patients requiring 1st premolars extraction followed by ''En-masse retraction'' (Bimaxillary Protrusion or Class II division 1 cases).
4. Patients with fully erupted permanent teeth (not necessarily including the 3rd molar).
5. Cases requiring maximum anchorage during anterior segment retraction.
6. Cases with minimal crowding (2-3) mm

Exclusion Criteria:

1. Patients suffering from any systemic diseases interfering with tooth movement.
2. Patients with extracted or missing permanent teeth. (except for third molars).
3. Patients with badly decayed teeth.
4. Patients with any parafunctional habits (i.e. Bruxism, tongue thrusting, mouth breathing, etc....).
5. Patients with previous orthodontic treatment