Effect of Low-Intensity Pulsed Ultrasound on Functional Treatment of Class II Malocclusion

Studies of the etiologic factors of Class II malocclusions recognize that most Class II malocclusions are a result of mandibular deficiency and not of maxillary excess. For many patients, especially adults, optimal overall results are best obtained using a combined orthodontic-surgical approach. However, treating such cases early while the patient is still growing, using mandibular propulsive functional appliances, can produce satisfactory improvement in the facial esthetics, and minimizes the need for surgical intervention in many cases.

Ultrasound (US), a form of mechanical energy that is transmitted through and into biological tissues as an acoustic pressure wave at frequencies above the limit of human hearing, is used widely in medicine as a therapeutic, operative and diagnostic tool. Therapeutic US, and some operative US. Previous studies on animals have found that therapeutic ultrasound (US) can stimulate and enhance mandibular growth when applied during the active growth period.

This study will evaluate the effect of low-intensity pulsed ultrasound (LIPUS) on the growth of mandible and the duration of functional treatment.

Twin-block will be applied to the two groups. While the control group will receive the twin-block only, the experimental group will receive the twin-block combined with low-intensity pulsed ultrasound (LIPUS) on Temporomandibular joint (TMJ) region.

Cephalometric radiographs will be obtained before and after functional treatment to evaluate the dento-skeletal changes.

• Twin-block (Device): Functional treatment will be achieved using the Twinblock appliance
• LIPUS (Low-intensity pulsed ultrasound) (Other): Functional treatment will be combined with LIPUS (Low-intensity pulsed ultrasound )

Primary outcomes

• The duration of functional treatment [After functional treatment which will take approximately 8 months]: The duration of the functional treatment will be measured and compared between groups.

Secondary outcomes

• Dentoskeletal effects of the functional treatment [Changes will be evaluated before and after functional treatment which will take approximately 8 months]: Dentoskeletal changes before and after functional treatment combined with Low-level Laser compared with those of the control group (SNA, SNB, ANB, Overjet ,…etc) using lateral cephalometric radiographs.

Sex: All, ages: 11 Years to 14 Years

Inclusion Criteria:

* Angle class II malocclusion because of mandibular retrognathia
* O.J > 5 , SNB < 78
* Patient during growth spurt

Exclusion Criteria:

* TMJ disorders
* Poor oral hygiene
* Previous orthodontic treatment.
* Patients with syndromes, clefts, or craniofacial abnormalities.
* Reason of contraindication of functional treatment

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• Ghiath Mahmood, PhD., Study director, Department of Orthodontics, Faculty of Dentistry, Damascus University, Damascus, Syria