Treatment of Skeletal Class II Malocclusion With Modified Twin-Block Appliance With Clear Plates

There are two group:

1. a group of patients in which participants will be undergo to Modified Twin-Block Appliance with Clear Plates.
2. a group of patients in which participants will be undergo to the traditional Twin-Block Appliance.

phase Intervention/treatment Condition or disease

Not applicable Other:

Modified Twin-Block Appliance with Clear Plates.

Other:

Traditional Twin-Block Appliance. Skeletal class II Malocclusion

• Modified Twin-Block Appliance with Clear Plates. (Device): Clear plates technique A group of patients in which participants will be undergo to clear plates treatment will be applied to the upper and lower arch 17 hours daily
• Traditional Twin-Block appliance (Device): Traditional Twin-Block appliance A group of patients in which participants will undergo to the Traditional Twin-Block appliance Treatment, appliances will be applied to the upper and lower arch 17 hours daily

Primary outcomes

• Change in the SNA angle[ [: T0:1 day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)]: This angle the represents the position of the upper jaw in the cephalometric analysis in the anteroposterior direction. Lateral cephalograms will be taken and this angle is going to be measured in degrees.
• change in the SNB angle [ [: T0:1 day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)]: This angle the represents the position of the lower jaw in the cephalometric analysis in the anteroposterior direction. Lateral cephalograms will be taken and this angle is going to be measured in degrees.
• change in the mandibular length [T0: 1day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)]: Amount of distance measured from the Co point to Gn point in the cephalometric analysis. Lateral cephalograms will be taken and this angle is going to be measured in degrees.
• change in overjet [T0: 1 day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)]: Represents The distance between the most anterior point on the lower incisor to the most anterior point on the upper incisor in the cephalometric analysis.
• change in the vertical position of incisors [: T0: 1 day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)]: The vertical distance from the edge of the lower incisor to the mandibular plane.

Sex: All, ages: 10 Years to 13 Years

Inclusion Criteria:

* \- Patients with mixed dentition at age 10.5-13 years.
* The patient has Skeletal class II malocclusion caused by mandibular retraction ANB > 5, 8 mm >O.J> 5 mm, SNB<78, angle (NSAr) ≥ ° 125 and normal placement of the upper jaw.
* The patient is willing to accept treatment with a removable device.
* No previous orthodontic treatment
* the growth model is within the normal or horizontal maxillary opening angle of 30 >MM or angle of 400 > Björk
* patients do not have an upper alveolar dental protrusion.

Exclusion Criteria:

* -Patients with periodontal disease.
* patients with a neuromuscular disorder.
* patients of class I or III of malocclusion.
* Patients with temporomandibular joint disorder.
* Patients with Skeletal open bite.
* Patients with poor oral and gingival health
* the presence of a unilateral or bilateral posterior crossbite.
* patients who have upper jaw stenosis and need to be prepared by expansion before functional treatment.
* any patient who does not meet one or more of the Inclusion criteria will be removed from the study.

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• Rabab Alsabbagh,, DDS MSc PhD, Study director, Professor of Orthodontics, University of Hama Dental School, Hama, Syria.
• ANAS FAKHOURI, Principal investigator, Student in Orthodontics, University of Hama Dental School, Hama.