Evaluation of the skeletal, dental and soft tissue effects of class III splints (clinical study)

Objective: The aim of this study was to evaluate the skeletal, dental and soft tissue effects of using Class III splints in the treatment of skeletal Class III malocclusion in growing patients. Materials and Methods: The appliance was tested on ten growing skeletal Class III patients with an anterior crossbite. Digital lateral cephalometric radiographs were taken before treatment and after crossbite correction. The pre and post radiographs were traced and skeletal, dental and soft tissue measurements were calculated with the use of the computer software FACAD. Evaluation of the effects was by statistical comparison of the pre and post treatment measurements. Results: There was a marked clinical improvement in the form of correction of the anterior crossbite and improvement of the patient’s profile, which raised the self esteem of the patients. The statistical analysis showed skeletal effects in the form of an increase in the ANB difference, Wits appraisal, mandibular plane to Frankfort horizontal plane angle and convexity angle, and a significant decrease in the occlusal plane to Frankfort horizontal plane angle. Dental effects were in the form of an upper incisor proclination, lower incisor retroclination, upper molar proclination and lower molar retroclination, an increase in the overjet and molar relation, and a decrease in the overbite. Soft tissue effects were in the form of a backward movement of the soft tissue chin and the lower lip, and a forward movement of the upper lip. Conclusion: Class III splints can be used in the treatment of growing skeletal Class III malocclusion that is due to a combination of maxillary retrusion and mandibular protrusion. It is more indicated though with deep bite cases, unless it will be followed with phase II extraction or with the use of high pull head gear.