This case report demonstrates a different method of using miniplates to treat an 11-year-old boy with a skeletal Class III malocclusion and maxillary deficiency. This treatment was found to be an acceptable alternative to the use of extraoral appliances such as facemasks and major surgery.
Diagnosis and Etiology
The patient was an 11-year-old boy who was referred for treatment of maxillary deficiency. He had no medical problems, and there were no signs of temporomandibular joint dysfunction. The patient had a skeletal Class III malocclusion and maxillary deficiency. His parents had no Class III characteristics. The facial photographs showed a Class III appearance with a concave profile because of maxillary deficiency. The pretreatment intraoral photographs and dental casts showed Class III relationship of the central incisors and anterior crossbite. The patient had a Class III molar relationship on the right and Class I on the left side.
Extraoral appliances, such as protraction facemask, Class III functional appliance, any modified maxillary protraction devices, and orthognathic surgery, were considered as alternative treatments for the correction of this Class III malocclusion. However, the patient refused the use of extraoral appliances and major surgery. Therefore, in this case, it was decided to use miniplates to protract the maxilla by application of Class III elastics.
In this pateint plates for orthodontic anchorage were placed under local anaesthesia in the canine areas of the mandible by a maxillofacial surgeon. The ideal position for miniplates insertion was evaluated by using a panoramic radiograph in order to avoid damage to the roots of the adjacent teeth and mental foramen. A tightly fitting and well-retained upper removable appliance (image is shown below) was fabricated with two Adams clasps on the upper first permanent molars. Each of the Adams clasps had a loop which was used for retaining the elastics. A labial bow was also used on the anterior teeth for retention. A maxillary posterior bite plate was used to disclude the upper and lower jaws.
Orthodontic latex elastics (3/16 heavy size) were connected from the hooks of the miniplates to the Adams clasps of the removable appliance to generate approximately 500 g of anterior retraction. The patient was instructed to wear the appliance full-time except for eating contact sports, and tooth brushing; he was also told to change the elastics every day. In order to retain these elastics,the Adams clasps on the molars were bent to form loops.
In this image you can see the removable appliance in the upper jaw:
After 10 months of active treatment a positive overjet and Class I buccal segments were achieved and the anterior crossbite was corrected.