Surgically assisted rapid maxillary expansion by almuzian

1. Surgically assisted rapid maxillary expansion (SARME)
Technique
 It is a part of distraction osteogenisis
 Most methods consider the zygomaticomaxillary junction the major site of resistance and
perform a corticotomy through the zygomatic buttress from the piriform rim to the
maxillopterygoid junction
 The midpalatal suture is historically considered the major place of resistance but this was
proven to be untrue by ISAACSON & INGRAM and KENNEDY et al.. Still many, but not all,
release the midpalatal suture by paramedical cut in order to:
1. Improve mobility and
2. Prevent deviation of the nasal septum to either side and thereby causing changes in nasal flow.
A tomographic study by Schwarz showed no significant change in nasal septum position in
SARME without sectioning of the nasal septum and an increase nasal airway space
 The pterygoid plates are also a considerable site of resistance but because of the increased risk
of injuring the pterygoid plexus by the osteotomy, some chose not to, without loosing much
mobility. By not releasing the pterygoid junction, the pattern of opening of the maxillary halves
is more V-shaped.
 An investigation by Shetty and coworkers attempted to give a biomechanical rational for the
choice of osteotomies by analyzing the internal stress response after SAME in a photoelastic
model fabricated from a human skull. A Hyrax appliance was placed and activated, and
sequential cuts were performed on the model. The alterations in the internal stresses of the skull
were recorded after each cut. All the bony buttresses of the maxilla contributed resistance to
expansion, but the midpalatal suture followed by the pterygomaxillary articulations were the
primary areas of resistance.
 The mandibular dentition should be decompensated before surgery to allow assessment of the
amount of transverse expansion necessary and to assist in preventing postexpansion relapse
with dental interdigitation.

2.  In addition, the maxillary expansion appliance must be placed preoperatively and the appliance
key must be present in the operating suite to allow intraoperative activation.
 Patient positioning in the operating room should be similar to that described for the Le Fort I
osteotomy. Nasal intubation is preferred. However, because maxillomandibular fixation is not
necessary for this surgical procedure, oral intubation can be used.
 Following SARPE, the maxilla should be allowed to remain stationary for five days prior to
initiation of expansion of the maxilla at 0.5mm/day (this allows capillary healing across the
osteotomy area- Ilizarov theory of distraction).
 During this procedure, the appliance is widened 3 to 4 mm and then turned back to a final
opening of 1 to 1.5 mm. During maximal expansion, the surgeon should check that both
maxillae are adequately mobile. If they are not, the osteotomies should be checked or more
surgery performed.
 SAME can also be used in cases of unilateral or asymmetric maxillary deformities. In this
situation, the osteotomies outlined earlier are created on only 1 side, thus allowing a differential
anchorage situation with more expansion on one side. As would be expected, on the
nonoperated side, buccal bone bending and dental tipping occur. After appliance removal,
almost complete relapse occurs on the nonoperated side.
 It is better to divert the root of the central to allow surgical cut
 Palatal tori can be a significant barrier to palatal expansion and the presence of a palatal torus
in this situation can be approached in 2 different ways.
1. The ideal treatment is to surgically remove the torus 4 to 6 months before the SAME
procedure.
2. Removal of the torus can be performed if the surgeon is willing to place the
expansion appliance intraoperatively. The appliance must be fabricated on a model
from which the torus has been removed. Because a midpalatal incision is necessary
to remove the torus, but this could compromise palatal blood supply, thus the
osteotomies should be performed through vertical incisions in the buccal mucosa
combined with subperiosteal tunneling.

3.  When performing SAME on patients with a skeletal open bite or open-bite tendency, care must
be taken to prevent worsening of the open bite with this procedure. Prevention of this problem
requires modification of the SAME technique to ensure that all osteotomies of the anterior and
lateral maxillary walls are parallel to the maxillary occlusal plane.
 If a secondary Le Fort I maxillary osteotomy is planned because of the existence of other
dentofacial deformities, the osteotomies for SAME should be placed in the location of the
planned osteotomy cut of the future Le Fort procedure. This strategy is because the osteotomies
in the anterior and lateral maxillary walls seldom completely heal after SAME, and this may
compromise future osteotomies or the ability to apply rigid fixation.
Postoperative care, rehabilitation, and recovery
 Routine follow-up care should be similar to that of the Le Fort I osteotomy, with the exception
that liquid diet is followed for only the first week and the diet is advanced from that time
forward.
 After the surgical procedure, the maxilla should remain stationary for at least
5 days before initiation of expansion at a rate of 0.5 mm/d (2 activations of the
jack screw appliance a day).
 The period of retention after expansion varies from 2 to 12 months. Generally, a period of 3
months is used.

Indications
 Failed orthodontic expansion
 Adult patient with skeletal maturity, Once skeletal maturity has been reached, orthodontic
treatment alone cannot pro- vide a stable widening of the constricted maxilla in cases of
deficiencies of more than 5 mm. The amount of distraction at the canine level mentioned varies
from 3.4 to 5.0 mm, in the first premolar region 4.7 to 5.9 mm and in the first molar region 3.4
to 8.0 mm.
 Sever maxillary transverse deficiency >5mm
 Extremely thin, delicate gingival tissue or presence of significant buccal gingival recession in
the canine-premolar region in the maxilla

4. Advantages of SARME (Koudstaal et al. 2005)
 Improvement of periodontal health;
 improved nasal air flow;
 elimination of the negative space i.e. cosmetic improvement of the buccal hollowing secondary
to post-expansion prominence at the site of the lateral wall osteotomy
 Tooth extractions for alignment of dental arches are often unnecessary
Evidence
 Surgical and non-surgical techniques: No significant difference in stability of expansion after
1 yr Berger et al., 1998. In summary, they reported on two groups of patients using both RME
and SARME with a hyrax expander. In the RME group the ages ranged from 6 to 12 years. In
the SARME group the ages ranged from 13 to 35 years. They concluded that there is no
difference in the stability of SARME and RME.
Problems
 PD damage at area of osteotomy
 Root damage at area of osteotomy
 Oronasal fistula
 Numbness of lip and palate due to osteotomy side effect
 Risk of nasal septum deviation
 Raely, life threatening epistaxis to a cerebrovascular accident, skullbase fracture with
reversible oculomotor nerve pareses and orbital compart- ment syndrome
 asymmetrical expansion, nasal septum deviation
Difference between SARME and segmental maxillary osteotomy
 SARME more stable than same day expansion 1-15% and 30-40% respectively. (Pogrel
and associates studied 12 patients 1 year after SAME (still in orthodontic appliances)
and found an 11.8% relapse at the maxillary first molar. Bays and Greco studied 19
patients who had undergone SAME who had completed orthodontic therapy more than
6 months previously and found an 8.8% relapse at the canines, 1% at the first bicuspid,
and 7.7% at the first maxillary molar. The reported relapse in the transverse component
of segmental maxillary osteotomies has been considerably higher. Stephens found a
30% and 23% relapse at the canine and molar regions, respectively, in 15 patients who

5. had undergone segmental maxillary osteotomies with an average follow-up of
47.5 months after debanding. Phillips and colleagues compared the transverse stability
in 39 patients who underwent either a 2-piece Le Fort osteotomy (n = 26) or a 3-piece
Le Fort osteotomy (n = 13). The postorthodontic follow-up was 14 to 47 months
(mean = 24.4 months). Significant transverse relapse in both groups was observed,
ranging from 11% at the canines to 47% at the second molar in the 2-piece group and
from 30% at the first premolar to 51% at the first molar in the 3-piece group.)
 The pattern of transverse expansion is different for SAME than for maxillary segmental
osteotomies. More expansion occurs at the canines and less at the molars after SAME.
In contrast, during segmental Le Fort maxillary osteotomy, more expansion is achieved
at the maxillary molars than at the canines. In the SAME procedure, all the maxillary
articulations are not osteotomized superiorly and posteriorly (lateral nasal wall and
palatine bone); therefore, the greater resistance to expansion in the posterior maxilla
accounts for less posterior expansion. The inelasticity of the palatal mucosa is a major
limiting factor for segmental Le Fort osteotomy. Widening of more than 6 mm is not
stable or feasible. Therefore, transverse expansion greater than 7 mm would be an
indication for SAME.
 Extraction and expansion: SAME is generally performed early in the treatment
sequence. Early expansion of the maxilla allows orthodontic alignment in the severely
crowded maxillary arch without the need to extract teeth. Treatment plans that include
a segmental maxillary osteotomy often include extraction of teeth with partial
orthodontic space closure to allow for safe performance of interdental osteotomies. In
nonextraction segmental osteotomies, the dentition requires buccal expansion before
surgery, which is unstable and prone to postoperative relapse.
 The segmental maxillary osteotomy is a more difficult, more technically sensitive, and
potentially more morbid procedure
 The major disadvantage of a treatment plan that includes SAME followed by a 1-piece
Le Fort maxillary osteotomy is that 2 surgical procedures are required. If a patient who
has had a SAME procedure requires a Le Fort osteotomy for correction of concomitant
dentofacial deformity, a second procedure must occur after orthodontic
decompensation of the maxillary and mandibular dentition. In contrast, a segmental
maxillary osteotomy attempts to correct the deformities in all planes of space during 1
surgical procedure.