**5. SARME technique**

In our clinic, we perform the following protocol routinely. A horizontal incision is made through the mucoperiosteum above the mucogingival junction in the depth of the buccal vestibule, extending from the canine region to the mesial of the first molar. Keeping the incision more distally than the first molar region may cause damage to the pterygoid plexus or Bichat fat sometimes due to abnormal anatomic variations. Damage to pterygoid plexus may not be noticed intraoperatively. The vasoconstrictor effect of local anesthetics could curtail the bleeding during the operation and a postoperative bleeding may occur.

This incision is made in two layers as a safety precaution to any leak after suturing. Any gap or rupture of suture may cause exposure of the surgical bony area. The first layer incision is made on the epithelium and the periosteum is reached with dissection of connective tissue inferiorly, creating a pocket like formation of tissue. The second layer of the incision is then made on the periosteum 6-8 mm below the first layer. This technique forms a two level wound. Suturing this incisions layer by layer creates a more secure postoperative wound (Figure 1).

**Figure 1.** Dissection through the connective tissue from epithelial incision to periosteal incision beveled in order to cre‐ ate a pocket-like tissue wound.

Nasal mucosa should be elevated gently from the lateral nasal wall. Because the SARME is not a down fracture procedure, nasal bleeding can be easily controlled with nasal tampons which should be considered as a minor complication if patient has no coagulopathy. The maintenance of the blood supply requires an appropriate surgical procedure, with careful manipulation of soft tissues and ensuring the periosteum remains intact. [51]

A horizontal low-level osteotomy is made through the lateral wall of the maxilla 5-6 mm superior to the apices of the anterior and posterior teeth with tiny round burs (Figure 2) and then an osteotome, microsaw or piezo-surgery device, on the same level is used to make the bone cuts; the osteotomy extends from the inferolateral aspect of the pyriform rim posteriorly to the inferior aspect of the junction of the maxillary tuberosity and pterygoid plate (Figure 2). Working with piezo-surgery devices would clearly be more secure but take more operative time. At this point, retractors should be used gently to prevent infraorbital nerve damage.

**Figure 2.** After marking the osteotomy route with a tiny round bur

**5. SARME technique**

122 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

ate a pocket-like tissue wound.

In our clinic, we perform the following protocol routinely. A horizontal incision is made through the mucoperiosteum above the mucogingival junction in the depth of the buccal vestibule, extending from the canine region to the mesial of the first molar. Keeping the incision more distally than the first molar region may cause damage to the pterygoid plexus or Bichat fat sometimes due to abnormal anatomic variations. Damage to pterygoid plexus may not be noticed intraoperatively. The vasoconstrictor effect of local anesthetics could curtail the

This incision is made in two layers as a safety precaution to any leak after suturing. Any gap or rupture of suture may cause exposure of the surgical bony area. The first layer incision is made on the epithelium and the periosteum is reached with dissection of connective tissue inferiorly, creating a pocket like formation of tissue. The second layer of the incision is then made on the periosteum 6-8 mm below the first layer. This technique forms a two level wound. Suturing this incisions layer by layer creates a more secure postoperative wound (Figure 1).

**Figure 1.** Dissection through the connective tissue from epithelial incision to periosteal incision beveled in order to cre‐

bleeding during the operation and a postoperative bleeding may occur.

The maxilla is separated from the pterygoid plate with a curved osteotome (Figure 4).

The risk of bleeding increases if the pterygoid plates are separated from the maxilla. If the pterygoid plates are separated from the maxilla, the most common sources of hemorrhage after SARME are the terminal branches of the maxillary artery, especially the posterior superior alveolar artery, and the pterygoid venous plexus. Turvey and Fonseca showed that the mean distance from the most inferior part of the pterygomaxillary junction to the most inferior part of the internal maxillary artery is 25 mm. During pterygomaxillary separation, pterygoid osteotomes should be correctly positioned and variations of this anatomy should be taken into account. [52] The pterygoid region should always be packed with moistened gauzes until suturing to avoid excessive blood loss and less postoperative swelling or hematoma.

**Figure 3.** Osteotomy with an osteotome through the marked osteotomy line

**Figure 4.** Separation of the pterygoid plate with a curved osteotome. Note the position of the finger to feel the osteo‐ tome intraorally

In conjunction, a sagittal palatal osteotomy is carried out, running from the midline of the alveolar bone, between the central incisors, to the posterior nasal spine. First a vertical incision is made along the labial frenulum between the central incisors. Then an osteotome is positioned in the central incisor interradicular space and manipulated to achieve equal and symmetric mobilization of the anterior maxilla. The forefinger is positioned on the incisive papilla to feel the redirected osteotome as it transects the deeper portion of the midpalatal suture (Figure 5).

**Figure 5.** An easy way of traction of midline incision to reach and perform midpalatal osteotomy

Releasing the anterior nasal spine to improve mobility and to prevent deviation of the nasal septum is useful. Lateral nasal walls on both sides should be checked and released with osteotomes. A lateral nasal wall osteotomy might cause damage to the descending palatine artery and this could be minimized by limiting the extent of the osteotomy posterior to the pyriform rim to 35 mm in men and 30 mm in women [52].

Before the osteotomies the Hyrax appliance is activated to obtain easy palatal separation for about 8-10 turns, for maximum aperture and diastema formation. An immediate gap between central incisors should be observed intraoperatively after the osteotomies are performed. This is followed by immediate regression, leaving a 1 mm gap. Patients should receive postopera‐ tive prophylactic antibiotics and analgesics for 7 days postoperatively (Figure 6).

A surgically assisted maxillary expansion procedure is essentially a combination of osteogenic distraction with controlled expansion of soft tissues. Some principles must be followed to ensure that bone repair occurs in osteogenic distraction namely:


In conjunction, a sagittal palatal osteotomy is carried out, running from the midline of the alveolar bone, between the central incisors, to the posterior nasal spine. First a vertical incision is made along the labial frenulum between the central incisors. Then an osteotome is positioned

**Figure 4.** Separation of the pterygoid plate with a curved osteotome. Note the position of the finger to feel the osteo‐

**Figure 3.** Osteotomy with an osteotome through the marked osteotomy line

124 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

tome intraorally


**Figure 6.** View of a completed osteotomy. Also zygomatic retention plates are implemented for orthodontic purposes.

The technique is based on a 5-day period of rest after corticotomy before the expansion starts. This gives the tissue time to form the first callus but is too short for consolidation.

**Four phases of new bone formation** can be described.


When the distraction is performed too fast, the collagen fibers lose contact and there is no ingrowth of new bone, causing nonunion or malunion. In cases of a too slow distraction premature consolidation can occur and the required elongation cannot be reached [53].

**Latency** is considered to be the time interval between osteotomy and the appliance start-up and varies from 0 to 14 days in experimental and clinical studies. [54-56]

**Activation rate** is the amount of daily bone distraction (in millimeters); it varies from 0.25 to 1.0 mm.

**Frequency** represents the number of times the appliance is activated per day. [57] De Freitas et al recommend the expansion procedure with an overexpansion index of 23% above the desired measurements to compensate for relapse [58].

**Retention period** at the end of the distraction is necessary for the neoformed bone tissue to acquire the necessary resistance to bear the tipping forces. In experimental and clinical studies this period can vary from one to six months. [54, 59]

SARME procedures have traditionally been reported to have low morbidity especially when compared with other orthognathic surgical procedures. However, many complications have been reported in the literature varying from life-threatening epistaxis to a cerebrovascular accident, skull base fracture with reversible oculomotor nerve paresis and orbital compartment syndrome. [60-64]

Rapid maxillary expansion can produce unwanted effects when used in a skeletally mature patients, including lateral tipping of posterior teeth, extrusion, periodontal membrane compression, buccal root resorption, alveolar bone bending, fenestration of the buccal cortex, palatal tissue necrosis, inability to open the midpalatal suture, pain, and instability of the expansion. [6-8,10-15,17,28,46]

**Complications** associated with SARME reported in the literature also include significant hemorrhage, gingival recession, injury to the branches of the maxillary nerve, infection, pain, devitalization of teeth and altered pulpal blood flow, periodontal breakdown, sinus infection, alar base flaring, extrusion of teeth attached to the appliance, relapse, and unilateral expansion. [60,61,65-73] Postoperative bleeding starting on the third week due to the rupture of greater palatine artery, rupture of inferior nasal mucosa or any damage of venous plexus during the expansion procedure may even be observed. Segments or sharp prominences of bone in the intrapalatinal region could be considered to abrade or lacerate these tissues while the expan‐ sion procedure is processed. Moreover postoperative hemorrhage, pain, sinusitis, palatal tissue irritation/ulceration, asymmetrical expansion, nasal septum deviation, periodontal problems and relapse were reported as minor complications; and although SARME is consid‐ ered a procedure with little risk of serious complications, several complications were dis‐ cussed.
