Surgically Assisted Rapid Palatal Expansion (SARPE)

Omri Emodi

Nezar Watted

Adi Rachmiel

DEFINITION

Maxillary transverse deficiency can be treated either orthodontically or surgically using rapid palatal expansion (RPE). This technique, which involves enlarging the maxillary dental arch and the palate (roof of the mouth) to reestablish balance between the width of the jaws through use of an orthodontic device, forces open the palatal bones via a screw mechanism that is turned daily.¹^,²
In children and adolescents, conventional orthodontic RPE has been successful when applied prior to palatal suture closure.³
In skeletally mature patients, the possibility of successful maxillary expansion decreases as sutures close and resistance to mechanical forces increase.⁴
Indications for RPE include⁵^,⁶ the following:
- To increase maxillary arch width, which corrects a posterior crossbite
- To widen the maxillary arch as a preliminary procedure prior to LeFort I advancement
- To provide space for crowded maxillary dentition
- To widen maxillary hypoplasia associated with clefts of the palate prior to bone grafting¹^,²^,³

ANATOMY

Relevant anatomic regions that contribute to resistance:
- Anteriorly—piriform aperture pillar
- Laterally—zygomatic buttress
- Posteriorly—pterygoid junction
- Medially—midpalatal suture
Important anatomical landmarks:
- Greater palatine neurovascular bundle—passes through the palatine bone in the posteromedial wall of the maxillary sinus
- Nasal mucosa—located medially and should be preserved
- Root of the canine—apex of the root is more superiorly positioned compared to other teeth and should be avoided when performing the horizontal osteotomy.

PATIENT HISTORY AND PHYSICAL FINDINGS

Physical examination reveals a constricted upper arch, with a narrow and high palatal vault.
Maxillary dental crowding is present in combination with midface hypoplasia.

IMAGING AND OTHER DIAGNOSTIC STUDIES

Posteroanterior cephalogram (interjugal distance, intermolar width)

FIG 1 • Cone-beam computer tomography showing maxillary transverse deficiency.
Cone-beam computer tomography (CBCT; FIG 1)
Cast models of the upper and lower jaws: In cases of maxillary transverse deficiency, a deep curve of Wilson in the lower dentition may mask the maxillary transverse constriction.
Assessing the models in the articulator