The correction of Class II malocclusion is one of the most common problems facing the orthodontist, with an estimated one-third of all orthodontic patients treated for this condition. Many strategies are available for Class II treatment on growing patients, and most orthodontists tend to choose a treatment protocol based on what part of the craniofacial deformity they believe the appliance will affect the most. A number of authors have described the dentoalveolar and skeletal changes induced by the Herbst appliance. The dentoalveolar effects consist of distalization of the maxillary molars and forward movement of the mandibular dentition. The main skeletal change "mandibular stimulation" is acceleration of a patient's inherent mandibular growth rather than increased growth beyond what would occur without treatment. Maxillary molar distalization, is one of the Class II treatment. Mini-implants have become popular in recent years, and various kinds of mini-implant-borne distalization approaches have been described. Because Class II correction appears to be achievable with either appliance, a follow-up question is whether there is a difference in the esthetic outcomes. However, because of the complexity of the human face and the subjectivity of facial beauty, a simple set of measures of lines or angles cannot quantify facial beauty. With the advances in 3-dimensional imaging, it is now possible to capture and superimpose digital images and measure the changes in the soft tissues from 3-dimensional images. Such advances in facial imaging allow a more thorough investigation of changes in 3 dimensions and prevent the inherent loss of information that results from 2-dimensional imaging. Optical scanners with short shutter speeds are convenient for clinicians and patients for capturing soft-tissue records. Bearing in mind that the aim of orthodontic treatment is to achieve facial harmony along with excellent occlusion, one of the most important objectives of an orthodontist should be the improvement of facial appearance. Therefore, it is important to gain a better understanding of how or whether orthodontic procedures affect the appearance of the soft tissues. Thus, the aim of this clinical trial is three dimensional evaluation of soft tissue facial changes on late mixed dentition patients following maxillary arch distalization with palatal screws one group and acrylic split herbst patients on other group and to compare these changes.

The correction of Class II malocclusion is one of the most common problems facing the orthodontist, with an estimated one-third of all orthodontic patients treated for this condition.

Many strategies are available for Class II treatment on growing patients, and most orthodontists tend to choose a treatment protocol based on what part of the craniofacial deformity they believe the appliance will affect the most.

A number of authors have described the dentoalveolar and skeletal changes induced by the Herbst appliance. The dentoalveolar effects consist of distalization of the maxillary molars and forward movement of the mandibular dentition. The main skeletal change "mandibular stimulation" is acceleration of a patient's inherent mandibular growth rather than increased growth beyond what would occur without treatment.

Maxillary molar distalization, is one of the Class II treatment. Mini-implants have become popular in recent years, and various kinds of mini-implant-borne distalization approaches have been described.

Because Class II correction appears to be achievable with either appliance, a follow-up question is whether there is a difference in the esthetic outcomes. However, because of the complexity of the human face and the subjectivity of facial beauty, a simple set of measures of lines or angles cannot quantify facial beauty.

Being the principle quantifiable diagnostic tool, the use of lateral head films lead orthodontists to have thought primarily in two dimensions. With the advances in 3-dimensional imaging, it is now possible to capture and superimpose digital images and measure the changes in the soft tissues from 3-dimensional images. Such advances in facial imaging allow a more thorough investigation of changes in 3 dimensions and prevent the inherent loss of information that results from 2-dimensional imaging. Optical scanners with short shutter speeds are convenient for clinicians and patients for capturing soft-tissue records.

Bearing in mind that the aim of orthodontic treatment is to achieve facial harmony along with excellent occlusion, one of the most important objectives of an orthodontist should be the improvement of facial appearance. Therefore, it is important to gain a better understanding of how or whether orthodontic procedures affect the appearance of the soft tissues. Thus, the aim of this clinical trial is three dimensional evaluation of soft tissue facial changes on late mixed dentition patients following maxillary arch distalization with palatal screws one group and acrylic split herbst patients on other group and to compare these changes.

Inclusion Criteria:

Angle Class II molar relation, Skeletal Class II depends on mandibular retrognathia , Crowding less than 4 mm, Normal growth pattern, No systematic or oral disease, No previous orthodontic treatment

Exclusion Criteria:

Missing teeth, Severe facial asymmetry, Poor oral hygiene