Surgically assisted rapid palatal expansion

The surgically assisted rapid palatal expansion (SARPE) is a procedure designed for skeletal transverse widening of the basal maxilla, the palate, and the dental arch.

The widening itself is done with either a tooth born or bone born distraction device in the days following the osteotomy.

Various types of osteotomies have been described to facilitate maxillary and palatal expansion. Today, usually a subtotal Le Fort-I osteotomy (without downfracture) and a sagittal osteotomy of the maxilla and palate either on one or both sides of the septum is performed.

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For this procedure the buccal sulcus approach is used.

A periosteal elevator is inserted between the nasal mucosa and the lateral wall of the nose on one side. A curved retractor is inserted behind the maxillary tuberosity. A further instrument is used to retract upwards the lip and mucoperiosteal flap, exposing the lateral maxilla.

The horizontal osteotomy is usually made at the level of the nasal floor, a safe distance (~5 mm) from the apices of the teeth.

A curved pterygoid chisel is placed with the curvature pointing medially and inferiorly between the tuberosity and the pterygoid plates.

A mallet is used to drive the osteotome medially to complete the pterygomaxillary dysjunction. The position of the tip of the osteotome can be checked with a palpating finger.

Pitfall: An upward and posteriorly oriented osteotome will not reliably separate the maxilla from the pterygoid plates. It is also associated with increased risk of bleeding from the pterygoid plexus and internal maxillary artery.

The nasal septum has to be separated from the palate with either an osteotome or septum scissors.

Special "guarded" osteotomes are used for this purpose to protect the nasal mucosa.

The lateral nasal wall is then separated using a nasal osteotome or saw.

Special "guarded" osteotomes are used for this purpose to protect the nasal mucosa.

Pitfall: This osteotomy should end anteriorly to the greater palatine vessels and nerve to prevent bleeding.

The sagittal osteotomy is usually made between the roots of the central incisors. To avoid iatrogenic damage of those roots it is recommended to first mark the position and penetrate the outer cortex with a small burr or with a piezoelectric device.

The osteotomy is continued posteriorly through the alveolus and the palate, usually with a thin straight scaled osteotome. Care must be taken not to penetrate the palatal mucosa. The course of the chisel tip as it goes posteriorly is monitored with a palpating finger, which is difficult with a tooth borne expansion device in place.

After completion of the osteotomies, the mobility of the segments must be checked. The palatal expansion device can now be inserted, if not already in place.

A tooth borne expansion device is fixed to at least two teeth on either side of the palatal osteotomy.

A bone borne device is fixed to the palate on either side of the palatal osteotomy with screws or pins.

The expansion device is activated to assure that bilateral symmetric expansion occurs. The device is then deactivated (returned to starting position) prior to wound closure.

After a suitable latency period, the palate is distracted at a rate of 0.5 -1.0 mm per day.

During the distraction phase, a diastema will form between the two incisors (at the osteotomy site). Movement of the teeth into the regenerate will occur spontaneously unless the teeth are prevented from doing so by orthodontic appliances.

After reaching the desired expansion the device is left in place to retain the expansion and to allow for bone consolidation for at least 3 – 6 months before removal. Even after removal of the distraction device, it may be necessary to stabilize the expansion with an orthodontic appliance or an acrylic splint for an extended period of time.

Apply ice packs (may be effective in a short term to minimize edema).

The sterile dressing placed over the skin incisions is maintained for a minimum of 48 hours. Thereafter routine wound care should be instituted around the activation rod.

Antibiotic prophylaxis is continued for 1-5 days depending on the nature, complexity, and duration of the surgical procedure.

Patients with intraoral wounds must be instructed in appropriate oral hygiene procedures. A small soft toothbrush with toothpaste should be used. Antiseptic rinses can be used in the early postoperative period. If a Waterpik is used, care should be taken not to direct the jet stream directly over intraoral incisions to prevent wound dehiscence in the early postoperative phase.

Early post-operative x-rays are obtained to verify correct device placement. Additional postoperative imaging is performed as needed.

Remove sutures from skin after approximately 5 days if nonresorbable sutures have been used.

Regular follow up examinations to monitor healing and the postoperative occlusion are required.

Avoid sun exposure and tanning to skin incisions for several months.