Patient and population (P) All adult patients (> 17 years) with a transverse maxillary hypoplasia requiring orthognatic surgery.
Intervention (I) Segmental Le Fort I osteotomy.
Comparator or control group (C) Surgically assisted rapid maxillary expansion
Outcomes (O) Transverse dentoalveolar and skeletal expansion and relapse, total dentoalveolar expansion, frequency of complications and patient-related outcome measure.
Study design (S) Human studies, including randomized controlled trials, controlled clinical trials and retrospective studies, with the aim of comparing transverse dental and skeletal expansion and relapse after segmental Le Fort I osteotomy compare to surgically assisted rapid maxillary expansion.
Focused question Are there any differences in the transverse maxillary dentoalveolar and skeletal expansion and relapse between segmental Le Fort I osteotomy and surgically assisted rapid maxillary expansion?