Volunteer patient

The volunteer was a 21-year-old woman with chief complaints of malocclusion, crossbite and deciduous tooth retention. Intraoral examination revealed deciduous tooth retention, and mixed dentition with class-III malocclusion. The overjet was − 5 mm and overbite was − 3 mm. The dental formula is shown in Fig. 2.

The dental formula of our volunteer

Miniscrew-assisted rapid palatal expansion (MARPE) involves application of a force directly to the maxilla using miniscrews and a skeletal anchorage expander. MARPE was selected for skeletal maxillary expansion. However, the volunteer’s palatal suture was fused. In addition, patients with cleidocranial dysplasia have been reported to have more dense and compact alveolar bone, which indicates that their facial skeleton provides greater resistance to expansion than that of healthy people. Accordingly, MARPE failed to overcome greater resistance or an open, fused midline palatal suture after 30 days of treatment.

According to FEA results, lateral osteotomy-assisted maxillary palatal expansion was selected, and was completed under local anesthesia in a clinic. Hence, corticotomy-facilitated MARPE was deemed to be the most suitable treatment modality. With regard to the maxilla expander, a custom-made bone-borne device was newly designed to cut costs and reduce invasion. Hence, a new method of corticotomy-facilitated MARPE was developed to resolve maxillary dysplasia while minimizing the side-effects of the procedure. Our treatment plan combined surgery and modified techniques to meet the requirements of our volunteer. The procedure was designed to be more efficacious and less invasive. The patient accepted the option of corticotomy-facilitated MARPE (Fig. 3).

Miniscrew-assisted rapid palatal expansion (MARPE). a Fixation of four miniscrews in the palate. b Custom-made appliance. c Lateral cortiotomy. d Mid-palatal cortiotomy