Table 1 List of the included studies

Matteini and Monnaerts; 2001

AJODO [26]

Prospective study

20 patients

Mean age: 20 years

NA

Le Fort I osteotomy

 + 

2-piece osteotomy

 + 

Pterygomaxillary disjunction (PD)

Clinical records and plaster casts

- before surgery

-2–3 weeks later

The most palatal points at the gingival margin of the first molars, the first premolars, and the canines;

The contact points on the mesial surface of the first molars;

The mesial surface of the first premolar;

The distal surface of the central incisors;

The most facial point of the most prominent central incisor.

Expansion averaged 29.9% at the level of the canines, 28.3% at the level of the first premolars, and 20.8% (SD 7.2) at the level of the first molars.

The expansion percentages must be related to the original widths at the different levels to learn the differential movement of the anterior and posterior parts of the segments. The average original intercanine and interpremolar distances were 75% and 77.7%, respectively, of the average original intermolar distance.

Fair

Babacan et al. 2006

Angle Orthod [27]

10 subjects

mean age: 18.70 ± 2.54 years

horizontal osteotomy

 + 

pterygomaxillary disjunction,

 + 

midpalatal suture separation

Acoustic rhinometry; occlusal radiograph

Mean follow-up: 6.19 ± 0.16

nasal volume (in cc) at the beginning of treatment (T1) and at the end of the retention period (T2);

Study casts at T1 and T2 to analyze changes in intermolar and intercanine width

All the subjects demonstrated sutural opening.

The mean intercanine expansion was 6.50 ± 1.97 mm for SARME. The mean intermolar expansion was 8.50 ± 3.82 mm for SARME.

A significant volume increase was observed between the T1 and T2 measurements.

Good

Goldenberg et al.; 2007

J Craniofacial Surgery [28]

Prospective study

15 patients; mean age: 24.47 ± 5.79; TMD > 5 mm, a maxilla-mandibular transverse differential index > 5 mm, and a crossbite

Le Fort I osteotomy

 + 

2-piece osteotomy

-

Pterygomaxillary disjunction (PD)

CT

before surgery

after surgery (6 months)

- Width of the nasal floor,

- Distance between the palatine process of the maxilla,

- Distance between the inferior margin of the maxillary alveolar process

- The distance between the greater palatine foramina

- The angle between the anterior nasal spine and the inferior margin of the alveolar bone

- The angle formed by anterior nasal spine and greater palatine foramina,

Mean appliance expansion was 11.47 + 1.65 mm.

The cross-sectional area of the maxilla was significantly increased. The angle between the anterior nasal spine and the inferior margin of the alveolar bone increased in a significant manner (P G 0.05).

A statistically significant increase in maxillary width was also observed in the intermediate portion of the maxilla. Measurements of the distance between the right and left greater palatine foramina, and the angle between the anterior nasal spine and the greater palatine foramina did not show differences that were statistically significant.

No complications; All patients spontaneously reported a clinically significant improvement in nasal airflow and breathing.

Fair

Landes et al.; 2009

JOMS [29]

Cohort study

50 patients

bipartite osteotomy (n = 28)

tripartite osteotomy (n = 22)

TMD

Le Fort I osteotomy

 + 

2-piece or 3-piece osteotomy

 + 

Pterygomaxillary disjunction (PD)

CT

- before surgery

- after surgery

- Transverse skeletal and dental expansion,

- Segmental skeletal inclination,

- Dental tipping

- Bone resorption

- Tooth inclination

Skeletal transverse widening: The biggest decrease in skeletal transverse widening from anterior to posterior was found in the tripartite, bone-borne, age older than 20 years, pterygoid osteotomy group.

Dental transverse widening: The greatest decline in dental transverse widening from anterior to posterior was found in the tripartite, bone-borne, age younger than 20 years, pterygoid osteotomy group.

Dental tipping: Outward rotation was seen in the tripartite, age older than 20 years, pterygoid osteotomy group, irrespective of the distractor used. Inward rotation was seen in the bipartite, bone borne, age older than 20 years, no pterygoid osteotomy group.

Bone resorption: The greatest loss in vestibular bone substance was detected in the bipartite, bone-borne, age younger than 20 years, no pterygoid osteotomy group in the molars and in the tripartite, age older than 20 years group in the premolars.

The palatal bone substance increased in the tripartite, tooth-borne group in the molars and in the tripartite, pterygoid osteotomy group in the premolars.

Good

Marchetti et al.; 2009

J Cranio Maxillofac Surg [30]

Retrospective study

20 patients:

SARME (n = 10)

Le Fort I bipartition (n = 10)

SARME: mean age of 23.5 years;

Le Fort I bipartition: mean age of 27.75 years

SARME: TMD > 6 mm;

Le Fort I bipartition: TMD < 6 mm

Le Fort I osteotomy

 + 

2-piece osteotomy

 + 

Pterygomaxillary disjunction (PD)

 ± 

Down fracture

- Plaster models of the maxilla

- pre-expansion (T1),

- post-expansion (T2),

- 2 years post-expansion (T3)

- Intercanine distance (from the cusp of the 1.3 tooth to the cusp of the 2.3 tooth)

- intermolar (from the 1.6 tooth mesio-palatine cusp to the 2.6 tooth mesio-palatine cusp)

In the SARPE group, the increase in the intercanine distance between T1 and T2 ranged from 4.5 to 10.5 mm, whereas the change from T2 to T3, or the relapse, ranged from + 1 to -6 mm. Similarly, the intermolar distance increased by 5–9.5 mm between T1 and T2, whereas the relapse ranged from + 3 to -3.5 mm

In the Le Fort I bipartition group, the increase in the intercanine distance ranged from 0 to 4.5 mm, which was smaller than that in the SARPE group, whereas the relapse ranged from + 3.5 to -2.5 mm. In contrast, the intermolar distance was increased by 2.5–7.5 mm, and the relapse ranged from 0 to -5 mm.

The differences throughout T1-T3 for both treatments were significant (p < 0.001). The relapse in the intercanine and intermolar distances between T3 and T2 was smaller for Le Fort I bipartition than for SARPE.

Good

Laudemann et al.; 2009

Oral Maxillofac Surg [31]

Cohort study

50 patients;

retrospectively

(n = 38) prospectively

(n = 12)

SARME + PD (21 patients)

SARME -PD (29 patients)

Age: 13–50 years

TMD

Le Fort I osteotomy

 + 

2-piece or 3-piece osteotomy

 ± 

Pterygomaxillary disjunction (PD)

CT

- before surgery

- after surgery

- Mean follow-up: 15 months

- Skeletal internal and external maxillary widths;

- Dental width: the most prominent area of the buccal aspect of the posterior teeth (DA.E) and, on the other hand, at the level of the buccal cusp tips (DA.E);

- width between the teeth apices, the palatal root;

- The dental arch internal width measured at

- the most prominent area of the palatal aspect of the teeth (DA.I) as well as at the level of the lingual cusp tips (DA.I);

- distance between the buccal tooth apex down to the BAC was measured bilaterally (TA.BAC), then the distance between the buccal tooth apex and the external rim of the buccal alveolar bone (BTA.E).

- The distance between the lingual (palatal) tooth apex and the hard palate.

Bigger transverse widening tended to occur more

anteriorly directed (first premolar area) in the + PP group and more posteriorly directed (first molar area) in the − PP group.

In SARME − PP group there was more parallel distraction from molar level to pterygoid level increase in pterygoid widening and bigger lateral pterygoid bending.

For the + PP with BB devices in patients < 20 years, the biggest decline in transverse width along the dental arch was found.

For the + PP in BB devices, there was the biggest outward segmental inclination along the dental arch.

Biggest bone resorption at premolar level was found in the − PP with BB devices and biggest increase in vestibular bone plate thickness in the premolars (0.29 mm) in the + PP with BB devices.

Good

Seeberger, R. 2010

Journal of Cranio-Maxillo-Facial Surgery [32]

Retrospective clinical mono- centre study

13 patients

mean age: 31.23^6.11

TMD ≧ 5 mm

Le Fort I osteotomy

 + 

2-piece osteotomy

 ± 

Pterygomaxillary disjunction

Acoustic rhinometry

- One month before surgery

- 63 months after the operation

Volume of nasal airways divided in the different segments:

- Anterior segment of the nasal cavity,

- medium segment of the nasal cavity,

- posterior segment of the nasal cavity

- nasal isthmus

All patients showed a significant enlargement of the nasal volume as result of the palatal transverse distraction.

The volumes of the different segments indicate a V-shaped movement of the segments. The gain was greater in the anterior than in the medium and posterior segments.

No relapse of the maxillary expansion was observed. Stable orthognathic occlusions were observed 63 months after treatment.

All patients reported substantial improvement of nasal respiration.

Good

Hernandez-Alfaro et al.; 2010

JOMS [33]

Retrospective case series

283 patients;

Mean age: 18.3 years

Severe TMD

Minimally invasive SARPE with total liberation

of the anterior, lateral, posterior, and medial buttresses

Clinical evaluation

1-year follow-up

-Amount of dental expansion;

- Complications and relapse;

Mean expansion was 9.2 mm (range, 3.0 to 15 mm) at the level of the mesiovestibular cuspid of the first molar expansion.

Reintervention was necessary in 3 cases because of the lack of expansion on 1 side.

At the 1-year follow-up visit, mean expansion at the canines was 8.0 (range, 3.0 to 13.0), and at the mesiovestibular cuspid of the first molar, it was 8.9 (range, 2.0 to 14.2).

Good

De Assis et al. 2010

Oral and Maxillofacial surgery [34]

Prospective study

13 patients;

Mean age of 26.5 years old (from 18 to

38 years old)

TMD > 5 mm

subtotal Le Fort I

osteotomy, without nasal septum osteotomy, and

maxillary disjunction

Clinical follow-up using digital paquimeter:

- 2 months post-surgery

- 6 months post-surgery

- 24 months post-surgery

- 36 months post-surgery

Measurement of the alar base by  using a digital paquimeter, whose points were laid in the  lateral face of the alar insertions

No complications;

There was a discrete increase in the 2-month post-operative control period.

There was a statistical relevance (P < 0.05) in the crossing of the pre-operative period with the 6-, 24-, and 36-month post-operative periods.

There were no statistical significant results when the post-operative periods were compared among each other.

Good

Landim et al.; 2011

Int. J. Med. Sci [35]

Prospective cohort study

15 patients;

Mean age 23.8 years;

TMD

Le Fort I osteotomy

 + 

2-piece osteotomy

 + 

Pterygomaxillary disjunction (PD)

The frontal cephalometric radiograph

- before treatment (T0);

- during locking of expander 14 to 18 days following surgery (T1);

- at least six months following the locking of the expander (T2)

- Nose width

- Position of the nasal septum in relation to the left and right lateral walls of the pyriform aperture

No statistically differences were detected in these variables between sides or between evaluation periods (p > 0.05).

Fair

Laudemann et al.; 2011;

Journal of Oral Maxillofacial Surgery [36]

RCT

45 patients;

13–50 years

Transversal maxillary deficiency

Le Fort I osteotomy

 + (with)

2-piece or 3-piece osteotomy

 + (with) /- (without)

Pterygomaxillary disjunction (PD)

CT;

T0: preoperatively

T1: 2.87 ± 1.59 months after expansion

-Maxillary width;

-Buccal bone loss;

-Transverse width at pterygoid process;

- Bending of the pterygoid process.

A lower transverse widening and an increased buccal bone plate were recorded in SARME + PD, in patients younger than 20 years with bone-borne devices.

The greatest increase in transverse widening was found in patients with 3-piece osteotomy and tooth-borne devices.

The greatest pterygoid lateral bending was found in patients with 2-piece osteotomy; the greatest pterygoid medial bending was found in patients with 3-piece osteotomy.

Good

Landes et al.; 2012

Oral Surg Oral Med Oral Pathol Oral Radiol [37]

Cohort study

77 patients:

2-piece (n = 22)

3-piece (n = 55);

Mean age of 24.3 ± 8.7 years;

TMD

Le Fort I osteotomy

 + 

2-piece or 3-piece osteotomy

 + 

Pterygomaxillary disjunction (PD)

CT

- before surgery

- after surgery

Mean follow-up: 20.5 months post-operatively

For transverse skeletal maxillary widening:

- the distance between the right and left vestibular gingival margins.

- the distance between the right and left palatal gingival margins

For transverse dental maxillary widening:

- the distance between the right and left vestibular cusp tips

- the distance between the right and left palatal cusp tips.

- vestibular attachment loss in clinical crown length on the central incisors, lateral incisors, canines, and first and second premolars.

- angulation of the central and lateral incisors and canines

3SO as well as 2SO increased transverse skeletal width along the dental arch; however, 3SO expanded more symmetrically and led to more general dental tipping. More increase in clinical crown length occurred in 2SO, however, except for the lateral incisors and canines at the osteotomy sites of 3SO. 3SO provoked more inward angulation in the central incisors and the canines and more outward angulation in the lateral incisors.

Good

Iodice et al.; 2013

J Craniofacial Surgery [38]

Prospective study

21 patients;

Median age 25.6 ± 6.3 years;

TMD > 5 mm

Le Fort I osteotomy

 + 

2-piece osteotomy

 + 

Pterygomaxillary disjunction (PD)

Lateral cephalogram before and 6 months after surgery

3 years

skeletal measurements:

- SNA (°),

- S–N-Sna angle (°),

- FH^NA angle (°),

- SN^PP angle (°),

- FH^PP angle (degrees),

- SNB (°),

- S–N-Pg angle (°),

- SN^GoGn angle (°),

- FMA (°),

- upper anterior facial height (UAFH)/total anterior facial height (TAFH) (numerical value),

- lower anterior facial height (LAFH)/ TAFH (numerical value),

- upper posterior facial height (UPFH)/ total posterior facial height (TPFH) (numerical value),

- TAFH/TPFH (numerical value),

- upper incisor (U1)^NA (°), U1^SN (°), U1^FH (°)

The skeletal vertical and sagittal changes did not reveal any variables with statistically significant results both in the maxilla and in the mandible.

The upper incisor changes after the SARPE. showed statistically significant alterations in U1^NA, indicating posterior inclination (P = 0.049); the others (U1^SN, U1^FH) confirmed the posterior inclination of the upper incisors but were not statistically significant (P = 0.1 and 0.08, respectively).

Fair

Antonios Sygouros et al. 2014

American Journal of Orthodontics and Dentofacial Orthopedics [39]

Retrospective study

20 patients

SARME -PD (10 patients; mean age,

19.2 years)

SARME 1PD (10 patients; mean age, 18.4 years)

TMD

Le Fort I osteotomy

 + 

2-piece osteotomy

 ± 

Pterygomaxillary disjunction

CBCT

- immediately before surgery

- 3 months after surgery

- 6 months after completion of the active expansion

Skeletal measurements

- Distance between the left and right piriform rims

- Distance between jugale points bilaterally

- Distance between the lateral pterygoid plates bilaterally

- Angles between the left and right lateral pterygoid plates and medial pterygoid plates

Dentoalveolar measurements

- Distance between the canine furcation points bilaterally

- Distance between the first premolar furcation points bilaterally.

- Distance between the second premolar furcation points bilaterally.

- Distance between the first molar furcation points bilaterally.

- Angulation of the alveolar crests.

Dental measurements

- Intercanine width

- Interpremolar width for first premolars

- Interpremolar width for second premolars

- Intermolar width.

- Canine angulation.

- First premolar angulation.

- Second premolar angulation.

- Molar angulation.

- Vertical molar movement.

Periodontal measurement

- Width of the buccal alveolar bone in the canine region.

- Width of the buccal alveolar bone in the first premolar region.

- Width of the buccal alveolar bone in the second premolar region.

- Alveolar bone height in the canine region.

- Alveolar bone height in the first premolar region.

- Alveolar bone height in the second premolar region.

- Alveolar bone height in the first molar region.

Anterior skeletal expansion was evident in both groups with no statistically significant differences between them.

At the dentoalveolar level, significant expansion was obtained between contralateral teeth (P0.01), with no significant differences between the 2 groups.

More pronounced tipping, without statistical significance, was reported in SARME + PD group.

On the dental level, all distances between cusps of the contralateral teeth increased significantly in both groups with no difference between the groups.

SARME resulted in buccal tipping of all posterior teethbut not of the canines.

On the periodontal level (Table VIII), the width of buccal alveolar bone decreased for all posterior teeth in both groups.

The height of the alveolar crest was reduced more in the SARME-PD group in the premolar area, but the difference did not reach statistical significance.

Fair

Habersack et al., 2014

JOMS [40]

Retrospective cohort study

24 patients:

2-piece (n = 12) 3-piece (n = 12)

Mean age: 27 ± 18.5 years

TMD > 5 mm

Le Fort I osteotomy

 + 

2-piece or 3-piece osteotomy

 + 

Pterygomaxillary disjunction (PD)

Postero-anerior cephalogram

- before surgery (T1)

- 6 weeks (T2) after surgery,

- 6 months (T3) after surgery,

- 12 months (T4) after surgery

- Interdental width changes at the intercanine level;

- interdental width changes at the level of the second molars;

- skeletal expansion between the bilateral maxillary jugulum landmarks.

There was a significant difference in the intercanine distance between the 2-piece and 3-piece SARME groups at T2, T3, and T4 (P < .001): 2-piece osteotomy showed higher values at any timings.

No significant difference between the 2-piece and 3-piece SARME groups was found in the inter-Second Molar Distancesat (P > .05).

No significant difference between the 2-piece and 3-piece SARME groups was found in the Skeletal Jugulum Distance (P > .05).

Good

Daif 2014

IJOMS [5]

Prospective study

30 patients;

Age 20 to 29 years,

mean age 24 years;

TMD > 5 mm

Le Fort I osteotomy

 + 

2-piece osteotomy

-

Pterygomaxillary disjunction (PD)

CT

- before surgery

- 6 months after surgery

Palatine process of the maxilla (C1)

Inferior palatine margin of the alveolar process of the maxilla (C2)

Greatest convexity of the medial walls of maxillary sinus (A1) greater palatine foramen (A2)

Maxillary expansion was higher at C2 than C1, this indicates tilting of the expanded segment outward at the C2 level

Maxillary expansion was higher at A1 than at A2, this indicates tilting of the expanded segment outward at the A1 level

No complications;

Good

Adolphs et al.; 2014

Journal of Cranio Maxillo Facial Surgery [41]

Retrospective case series

50 patients

Mean age: 24.6 years

TMD could not be corrected by orthodontic appliances alone

modified subtotal Le Fort I osteotomy

 + 

median maxillary split

- pterygomaxillary disjunction

- Photo documentation,

- distraction protocols,

- rhinomanometry

- dental casts

- DICOM datasets

Follow-up after device removal is more than 6 months

-Amount of dental expansion;

-Complications and relapse;

-Pain

Maxillary expansion improved nasal breathing in all patients (28/50) in whom pre- and postoperative rhinomanometry was performed routinely.

No palatal relapse consisting in a reduction of the initially achieved widening was observed.

In one patient, infraction of the vestibular alveolar process occurred during median splitting of the maxilla.

Low

William Yao et al. 2015

Craniomaxillofacial deformities/cosmetic surgery [42]

Prospective longitudinal study

13 patients

MULTIPIECES OSTEOTOMY GROUP

(9 patients)

SARPE

(4 patients)

17 – 23 Years

TMD

SARPE GROUP

Le Fort I osteotomy

 + 

2-piece osteotomy

 + 

Pterygomaxillary disjunction

MULTIPIECES OSTEOTOMY GROUP

Le Fort I

 + 

2- or 3-piece osteotomy

 + 

Pterygomaxillary disjunction

CBCT

SARPE

GROUP

- preoperatively (T0),

- after expansion in retention (T1),

- at least 6 months after expansion (T2)

MULTIPIECES OSTEOTOMY GROUP

- preopera-tively (T0),

- within 1 month postoperatively (T1),

- at least 6 months postoperatively (T2)

Posterior skeletal width: measured from the most posterior point of the greater palatine canal in the axial view at the level of the nasal floor, bilaterally

Anterior skeletal width: measured from the left recess point to the right recess point of the piriform rim Posterior dentoalveolar width: from the medial of the left maxillary first molar crown to the medial of the right maxillary first molar crown

Anterior dentoalveolar width: measured from the medial of the left maxillary canine crown to the medial of the right maxillary canine crown

All patients showed an increase in posterior and anterior skeletal width from T0 to T1.

A greater variation in the amount of expansion in the anterior maxilla compared with the posterior maxilla was noted both in the Le Fort group and in the SARPE group.

The SARPE group showed a significantly greater amount of dental expansion. A greater increase at the molars respect to the canines was showed in both group from T0 to T1.

From T1 to T2, the Le Fort group showed a greater dental relapse at the molars than at the canines.

Low

Seeberger, R. 2010

Journal of Cranio-Maxillo-Facial Surgery [32]

Retrospective clinical mono- centre study

13 patients

mean age: 31.23^6.11

TMD ≧ 5 mm

Le Fort I osteotomy

 + 

2-piece osteotomy

 ± 

Pterygomaxillary disjunction

Acoustic rhinometry

- One month before surgery

- 63 months after the operation

Volume of nasal airways divided in the different segments:

- Anterior segment of the nasal cavity,

- medium segment of the nasal cavity,

- posterior segment of the nasal cavity

- nasal isthmus

All patients showed a significant enlargement of the nasal volume as result of the palatal transverse distraction.

The volumes of the different segments indicate a V-shaped movement of the segments. The gain was greater in the anterior than in the medium and posterior segments.

No relapse of the maxillary expansion was observed. Stable orthognathic occlusions were observed 63 months after treatment.

All patients reported substantial improvement of nasal respiration.

Good

Dergin et al.; 2015

Oral Surg Oral Med Oral Pathol Oral Radiol [43]

Retrospective clinical study

60 patients;

17–26 years;

TMD > 5 mm

Le Fort I osteotomy

 + 

2-piece osteotomy

 + 

Pterygomaxillary disjunction (PD)

CT

Assessment of post-operative discomfort and complications after 6 months

Nasal bleeding occurred in 12 of 60 patients (20%);

Eleven patients reported paresthesia of the infraorbital nerve and related branches;

Seven patients suffered prolonged pain during the distraction procedure.

Eight patients suffered from headaches

One patient developed a large hematoma in the cheek;

One patient complained of tinnitus;

Three patients reported excessive lacrimation;

Fair

Zandi et al. 2016

Journal of Cranio-Maxillo-Facial Surgery [44]

Double-blind, historical, controlled, clinical trial

30 patients

SARME-PD

15 prospective patients

 + 

SARME + PD

15 retrospective

patients

15 to 28 years

TMD

Le Fort I osteotomy

 + 

2-piece osteotomy

 ± 

Pterygomaxillary disjunction

CBCT

- before treatment (BT)

- immediately after the end of the consolidation period (AT)

Nasal floor width measured at the area of the first premolars, and the first molars (NFW4)

Palatal bone width measured at the level of a line connecting the palatal root apex of the first premolars and the first molars (PBW4).

The distance between the palatal root apex of the right and left first premolars and first molars (IRD4)

The distance between the mesiopalatal cusp tip of the right and left first premolars and of the right and left first molars (ICD4).

No significant difference was observed between the groups.

Surgical time from incision to last suture was significantly (P < 0.05) shorter in the SARME-PD group.

Mean Hyrax opening in the SARME-PD and SARME + PD groups was no statistically significant different.

Mild extrusion of an anchor first premolar occurred in a patients in the SARME + PD group.

The amount and pattern of maxillary expansion were not significantly different between the SARME-PD and SARME + PD groups.

In both the SARME-PD and SARME + PD groups, the greatest expansion occurred at the dental arch, followed by palatal bone and nasal floor level, all the differences were statistically significant (P < 0.0001).

In both the SARME-PD and SARME + PD groups, the amount of expansion achieved at the first premolar and molar areas was comparable, indicating a parallel widening of maxilla postero-anteriorly.

Fair

Oliveira et al.; 2016

Ijoms [45]

Retrospective study

30 patients: Group 1 (16 patients) Group 2

(14 patients)

Mean age: group 1: 30.4 years;

group 2: 24.2 years

TMD > 5 mm with crossbite

Le Fort I osteotomy

 + 

2-piece osteotomy

 + 

Pterygomaxillary disjunction (PD)

 + 

Two different maxillary lateral osteotomy:

- group 1: lateral osteotomy performed in a horizontal straight fashion;

-group 2: lateral osteotomy performed in parallel to the occlusal plane with a step at the zygomatic buttress

CBCT

- before surgery (T1),

- immediately after expansion (T2),

- at 6 months after expansion (T3)

Linear and angular measurements were performed on the coronal slices at the level of the upper first molars and upper pre-molars to determine

- nasal floor width,

- maxillary width,

- distance between the palatal root apices,

- distance between the buccal cusps

- tooth tipping

No differences were found between the groups in the expansion of dental and skeletal measurements (P > 0.05).

However, changes over time were significant for all measures (P < 0.001). Significant differences between time points T2 and T3 were found for the distance between the palatal root apices in molars, intermolar angle, nasal floor width at the level of premolars, and interpremolar angle. A recurrence of nasal floor width (0.29 mm) was observed between T2 and T3.

The distance of the root apices of the first molars increased by 1.28 mm during the retention period (P < 0.001).

Increases of tooth tipping were observed after expansion of molars and premolars as a result of SARME, with a decrease in these angles was observed between T2 and T3 (P < 0.05).

The amount of expansion in the cusps of the first molars was similar to that obtained in the cusps of the first premolars (P = 0.632), with a parallel expansion occurred when evaluated at the coronal level of the teeth supporting the appliance. Similar results were found for measurements at the level of the palatal root apex (P = 0.315).

The results revealed greater expansion in the lowest region of the maxilla; these results translate to a tilt of the maxillary segment.

Fair

Jensen et Rodrigo-Domingo.; 2017

Oral Surg Oral Med Oral Pathol Oral Radiol [46]

Retrospective cohort study

20 patients: Releasing of the nasal

Septum (n = 10),

No releasing of the nasal septum (n = 10)

Releasing of the nasal

Septum: mean age 18 years;

No releasing of the nasal

Septum: mean age 23 years

TMD > 5 mm

Le Fort I osteotomy

 + 

2-piece osteotomy

 + 

Pterygomaxillary disjunction (PD)

 ± 

Release of the nasal septum from the palatal base

CBCT

- Immediately postoperatively (T1),

- at the end of the distraction phase (T2),

- 6 months after SARME (T3)

Using a calliper was measured

- the distance (mm) between the contact point of the central incisors,

- the distance (mm) between the vestibular cusp tips of the first premolars,

- the distance (mm) between the mesiobuccal cusp tips of the first molars.

Nasal septum deviation was evaluated by measuring the angle obtained between the traced median reference line and the intersection line between the superior orbital rim.

Moreover, objective evidence of nasal septum deviation was not observed in any of the patients in the two groups.

No significant difference in dental expansion was found between the two groups (P = 0 .46).

No statistically significant differences between groups were found at any time point.

Good

M.Verquin et al. 2017

Clinical Paper Orthognathic Surgery [47]

Retrospective study

55 patients

13 to 47 Years

TMD

Le Fort I osteotomy

 + 

2-piece osteotomy

 + 

Pterygomaxillary disjunction

 + 

Disengagement of the nasal septum

Baseline radiographic and clinical imaging

- Nerve injury

- Haemorrhage

- Intraoral bleeding

- Dental and periodontal problems

- Pain

- Inadequate/asymmetrical expansion

- Other complications

Paresthesia of the infraorbital nerve and related branches was observed in 16 patients.

Six patients presented with postoperative bleeding

Dental complications were seen in a total of five patients.

Four patients suffered from severe postoperative pain at the surgical site.

Three cases of asymmetrical expansion were encountered.

Fair

Alves et al.; 2017

IJOMS [48]

Retrospective study

19 patients: group 1 (n = 9) group 2 (n = 10);

Mean age of group 1: 23.1 years (19.5– 29.4 years);

mean age group 2: 30.3 years (18.7–39.7 years)

TMD > 5 mm;

-Group 1:

Le Fort I

 + alar base cinch

-Group 2:

subtotal Le Fort I

 + V-shaped incision at the maxillary midline in the labial frenulum region, without alar base cinch

CBCT

- before surgery (T1)

- 6 months after expansion (T2)

- superior alar width,

- alar base width,

- nasal width,

- alar angle,

- nasal length,

- nasal projection,

- upper lip length

Mean maxillary expansion had no significant difference between the groups (P = 0.64).

In both groups, a significant increase in nasal width (superior alar width, alar base width, and nose width) after maxillary expansion was observed (P < 0.001).

Nasal length and projection had no significant changes Alar angle was significantly different pre- and post-surgery only in group 2 (P = 0.013).

No statistically significant difference was found between groups, except for the post-operative upper alar width, significantly higher in group 1.

Good

Cakarer et al. 2017

J Stomatol Oral Maxillofac Surg [49]

Retrospective case series

40 patients;

23.67 ± 5.23

bilateral TMD > 5 mm

Le Fort I;

PMS was not performed but bilateral nasal osteotomies were created

Clinical examination

During the 6 months after surgery

Intra- and postoperative complications

During operation, the osteotome became displaced from the palatal mucosa in three patients. The mucosa was sutured and no postoperative dehiscence was observed. No hemorrhagic problem was noted.

One patient experienced epistaxis 5 days after surgery. Hemostasis was attained by applying an anterior nasal pack.

One patient developed a maxillary sinus infection 2 weeks after surgery and four complained of numbness of the anterior maxilla.

One patient with cleft lip-palate (CLP) syndrome developed a fistula at the site of the prior palatal cleft.

One patient exhibited wound dehiscence at the anterior maxilla 1 week after surgery

No asymmetric/inadequate expansion, and no dental or periodontal problem was noted in any patient

Fair

Romulo de Medeiros et al.; 2017;

International Journal of Oral and Maxillofacial Surgery [50]

RCT

25 patients;

17—49 years

Skeletal transversal maxillary deficiency > 5 mm, with unilateral or bilateral skeletal crossbite

Le Fort I osteotomy

 + (with)

2-piece osteotomy

 + (with) /- (without)

Pterygomaxillary disjunction (PD)

CBCT;

T1 (preoperatively),

T2 (after the activation period post-SARME)

T3 (after 6 months of Hyrax screw stabilization)

-Nasal cavity volume (NCV);

-Right (RMSV) and left (LMSV) maxillary sinus volume;

-Nasopharynx volume (NPV);

-Oropharynx volume (OPV);

-Oropharynx minimum cross-sectional area (OMCSA)

A statistically significant difference was observed only for NPV (p = 0.003),

OPV (p = 0.007), and

OMCSA (P = 0.001) in SARME + PD group

The sum of the

NCV, RMSV, LMSV, NPV, and OPV did not differ significantly between SARME + PD and SARME –PD (p = 0.983).

Unclear

Kim et al.; 2018

K Journal of Orthod [51]

Prospective study

61 patients: Control group (n = 25)

Experimental group (n = 36)

Mean age:

CTR group 22.48 ± 3.81 years; Experimental group 24.50 ± 6.19

Years;

Le Fort I osteotomy (control group) ± segmental osteotomy (experimental group)

 + 

Pterygomaxillary disjunction (PD)

CBCT

- before (T1)

- after surgery (T2)

- at the end of treatment (T3)

- Measurement of the skeletal width

Measurement of the distance between the right and left greater palatine foramina on a coronal cone-beam computed tomography image

- Measurement of the dental width

Measurement of the distance between the right and left mesiolingual cusps of the first molars on a coronal cone-beam computed tomography image

The amount of change in the dental width after surgery was small in the control group; a significant expansion was achieved in the experimental group. There was no significant difference in the width at T2 between the two groups; this was maintained up to T3.

The amount of change in the skeletal width after surgery was very small in the control group; a significant expansion was achieved in the experimental group. The width at T2 was significantly greater in the experimental group than in the control group.

During the postoperative orthodontic treatment period, the  experimental group exhibited a significant decrease in the skeletal width (− 0.67 ± 0.72 mm), unlike the control group (0.30 ± 0.87 mm).

Fair

Krzysztof et al.; 2018 [52]

Prospective study

78 patients

Mean age:

16.86 ± 2.65;

TMD > 4 mm

Le Fort I osteotomy

 + 

2-piece osteotomy

 + 

Pterygomaxillary disjunction (PD)

CBCT

 + 

Lateral cephalogram

- Before

- 3 months after surgery

Using gypsum models, measurements in millimetres (mm) were performed:

- distance between points on the cusp tips of the canines;

- distance between points on the buccal cusp tips of the first maxillary premolars,

- distance between points on the cusp tips of the first maxillary molars

The following were assessed on CBCT:

- distance between points located the most laterally on the internal

- bone surface of the nasal cavity at the level of the first maxillary molars

- distance between palatal cusps of the first maxillary molars

- distance between the skeletal margins from the palatal side of the first maxillary molars

- palate height measured at the level of the first maxillary molars

The intercanine dimension, between the cusp tips of the  maxillary canines T1-T2 was 7.68 ± 3.78 (p  < 0.05).

The anterior arch width, between the palatal cusp tips of the first maxillary premolars T1-T2 was 8.26 ± 3.08.

The posterior arch width, between the palatal cusp tips of the first maxillary premolars T1-T2 was 5.98 ± 2.60.

Nose floor did not change significantly after surgery.

Fair

Huizinga et al.; 2018

J Cranio Maxillofacial Surgery [6]

Retrospective case series

20 patients;

Mean age: 24.5 years;

TMD

Le Fort I osteotomy

 + 

2-piece osteotomy

 + 

Pterygomaxillary disjunction (PD)

CBCT and 3D reconstruction of the cone beam computed tomography (CBCT) scans

- predistraction model

- postdistraction model (5 months after)

Differences in lateral expansion between right and left maxillary

segments were calculated in three ways:

1) anteriorly, at the level of the central incisor;

2) posteriorly, at the level of the first molar inferiorly and at the level of the first molar superiorly

Clinical relevant asymmetries (> 3.0 mm) were found in 11 patients (55%). Five patients had an asymmetry of > 5.0 mm in one or two directions.

Among asymmetric lateral expansions, most of them occurred in the anterior-inferior component (48.8%). Only 24.1% of asymmetric expansion occurred in the inferior-posterior component. Caudal expansion was larger than cranial one.

Good

Ferraro-Bezerra et al.; 2018;

Journal of Oral and Maxillofacial Surgery [53]

RCT

24 patients;

17—49 years

Skeletal transversal maxillary deficiency > 5 mm, with unilateral or bilateral skeletal crossbite

Le Fort I osteotomy

 + (with)

2-piece osteotomy

 + (with) /- (without)

Pterygomaxillary disjunction (PD)

CBCT;

T0 (preoperatively)

T1 (at the end of the expansion)

T2 (6 months after the final activation and before the hyrax removal)

- Skeletal and dental expansion at the posterior maxillary region;

- Skeletal and dental expansion at the anterior maxillary region;

- Molar tipping

In both groups, all of the measurements significantly increased between T0 and T2, except for maxillary width at the molar region.

Although without significant difference, between T1 and T2, greater posterior palatine bone expansion was found in SARME + PD group and greater molar dental expansion in SARME -PD group.

Good

Mohlhenrich et al.; 2020

Oral Surg Oral Med Oral Pathol Oral Radiol [54]

Retrospective study

27 patients:

SARME + PD

(n = 15) SARME-PD

(n = 12)

Mean age:

SARME + PD (26.3 years);

SARME-PD

(26.3 years);

TMD

Le Fort I osteotomy

 + 

2-piece osteotomy

 ± 

Pterygomaxillary disjunction (PD)

Plaster casts before and after surgery

Mean follow-up: 24.6 months

The maxillary dental arch width measured as:

- distance between the vestibular and palatal cusp tips of the canine and the first and second premolars

- distance between the mesiobuccal and mesiopalatal cusp tips of the first and second molars

For evaluation of transverse asymmetry, the distance between the right side of the arch width and the raphe palatina line was measured and subtracted from the distance on the left side

The palatal gingival depth measured as shortest distance from the midpalate raphe to the connecting line between the gingival crests adjacent to the first molars

The palatal vault angle measured

a) between the tangential lines to the middle two-thirds of the right and left palatal surfaces

b) between the intersecting lines drawn across the mesial buccal and mesial lingual cusp tips of the right and left first molars was measured to determine the axial angulation of the maxillary first and second premolars and the first and second molars

Significant changes in the dental arch width were observed in all pre- and posttreatment transverse measurements.

No significant differences between both groups in the mean changes (T1_T0) were found. No significant differences in the expansion pattern were found.

An increase in crown height was measured in nearly all teeth in both groups, but this increase was not significant. The increase was less or negative in the group with PMD

Statistically significant differences in the pre- and post-treatment conditions were found in the palatal gingival width (C) and midpalate width (D). No significant  differences were detected in the treatment difference  values (T1 _ T0), although they were descriptively  larger in the ( +) PMD group than in the (_) PMD  group. Only the difference in the mean overall changes on the oral side of the right alveolar ridge, that is, _1.96 mm (SD 0.72) for (_) PMD and _2.69 mm (SD 1.02) for ( +) PMD, was statistically significant. Almost no changes were measured in the hard palate, about _0.18 mm (SD 0.52) for (_) PMD and _0.07 mm (SD 0.26) for ( +) PMD.

Fair

Keskin et al.; 2020

J Stomat Oral Maxillofac Surg [55]

Prospective study

18 patients;

Mean age 15–33 years;

TMD > 5 mm

Le Fort I osteotomy

 + 

2-piece osteotomy

-

Pterygomaxillary disjunction (PD)

CBCT

- before surgery

- 6 months after surgery

On digital dental records

- Arc circumference (AC),

- arc length (AL),

- arc depth (AD),

- intercanine width,

- intermolar width

On the CBCT

- The volume of the area over the ANS-PNS plane located between the lateral nasal wall and the nasal base in the coronal section

- The pre-op and post-op minimum transverse diameters of the bony nasolacrimal duct (BNLD-TD)

Lower anterior nasal volume showed statistically significant increase. Significant dental and skeletal changes in CBCT occurred before and after expansion. BNLD-TD showed statistically significant decrease

Fair

Gürsoytrak et al.; 2021

Meandros Med Dental J [56]

Retrospective study

38 patients:

SARME + PD (17 patients);

SARME-PD

(17 patients)

Mean age:19.68

TMD > 5 mm

Le Fort I osteotomy

 + 

2-piece osteotomy

 ± 

Pterygomaxillary disjunction (PD)

Clinical evaluation

Intraoperative and post-operative 6-month complications were evaluated in the group with and without PMD

Intraoperative hemorrhage: 2 patients in the with PMD group and 1 patient in the without PMD group. In the with PMD group, post-operative hematoma was observed in 2 patients following intraoperative hemorrhage,

Post-operative asymmetric expansion in 2 patients of SARME + PD, and post-operative unilateral transient paresthesia in 1 patient

In the without PMD group, 1 patient developed epistaxis after intraoperative hemorrhage

The average age was found to be higher in the groups with complications

Good

Da Costa et al. 2021

JOMS [57]

Retrospective study

61 patients:

3-piece (n = 32) 2-piece (n = 29);

mean

age 24.5 y;

2-piece: moderate TMD;

3-piece: moderate to large TMD with unilateral or bilateral cross bite

Le Fort I osteotomy

 + 

2-piece or 3-piece osteotomy

 + 

Pterygomaxillary disjunction (PD)

CBCT

- 1 week postoperatively,

- 6 months postoperatively,

- 1 year postoperatively

- Skeletal expansion (distance between the right and left maxillary points);

- Dental expansion (width between the most buccal points of the maxillary molars);

- Pain;

- Postoperative complications;

- Relapse;

No statistical differences in skeletal maxillary expansion (P = .775) between the 2 treatment groups;

Significantly more dental expansion following SARPE (P = .009);

Complications: 3 patients (9.4%) showed bone resorption following 3-piece osteotomy; tooth discoloration and gingival recession was present in respectively 2 (4.8%) and 1 (2.4%) patient of the 2-stage treatment; severe apical resorption was reported in 53.1% of the 2-piece and 66.7% of the 3-piece. This difference was not significant (P = 0 .311). Asymmetrical expansion was noticed in 2 patients (4.8%) after the SARPE procedure. Three patients (9.4%) reported mucosal or maxillary sinus infection after 3-piece and 4 patients (12.5%) underwent removal of osteosynthesis hardware due to infection

Pain was significantly more reported in the 2-piece group (P = .038)

Relapse: unilateral posterior crossbite in 2 patients (6.2%) in the 3-piece and 2 patients (4.8%) in the 2-piece at 1 year postoperatively

Fair

Prado et al.; 2021;

Journal of the American Society of Plastic Surgeons [58]

RCT

32 patients;

16—50 years

Transversal maxillary deficiency greater than or equal to 5 mm

Le Fort I osteotomy

 + (with)

2-piece or 3-piece osteotomy

 + (with)

Pterygomaxillary disjunction

TC and Facial Scanning

T0: before SARME

T1: end of maxillary expansion

T2: removal of expanding device

T3: 6 months after T2

T4: 10 months after T1

-Asymmetry of maxillary expansion;

-Stability of the area and volume of the palate after expansion;

-Changes in nose width and paranasal region

Two-piece osteotomy produced a larger mean increase in nose width (2.73 mm); however, 3-piece technique produced a larger displacement of the paranasal areas (p = 0.014)

The symmetry of maxillary expansion did not differ between the 2-piece or 3-piece osteotomies. Relapse of palatal area and volume was similar in the two study groups

Fair

Pereira et al. 2022

Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology [59]

Pilot prospective study

19 patients:

10 2-S osteotomy

9 3-S osteotomy

Mean age: 25.7 years (18–33 years)

TMD ≧ 6.0 mm

Le Fort I osteotomy

 + 

2-piece or 3-piece osteotomy

 + 

Pterygomaxillary disjunction

CBCT

- before surgery

- after expansion completion,

- 2 months after surgery

Palatal expansion:

- distance (mm) between the bone segments bordering the osteotomy gap in 2-piece and the sum of the 2 distances between the bone segments bordering the 2 osteotomy gaps in 3-piece;

- distance (mm) between the mesio-palatal cusp tips of the maxillary first molars;

- the angle formed between a line connecting the apex of the maxillary first molar’s palatine root with the mesio-palatal cusp, and a line perpendicular to the horizontal plane

The interradicular space:

- distance between the central incisors in 2-piece and between the lateral incisors and canines in group 3-piece

Periodontal probing: performed immediately before surgery and 2 months after maxillary expansions on buccal, palatal, mesial, and distal surfaces of the teeth adjacent to the osteotomy

Cosmetic perception: using a colored visual analog scale (VAS), in which 0 was the worst aesthetic result and 10 was the best

The 3-piece osteotomy had statistically significant (P = .016) values of increased bone expansion

The mean increase in the distance between the tips of the mesiopalatal cusps of the maxillary first molars was greater in the 3-piece, with no significant differences between them

The first molar had greater bucco-palatine angulation values in the 2-piece, with significance only on the right side (P = 0.028)

In the 2-piece test, patients were clearly dissatisfied compared with the 3-piece test, the mean score was 7.68 ± 1.77 (P = 0.000)

The periodontal survey revealed that 100% of postoperative measurements remained compatible with periodontal health

Good

Orion et al. 2022

J Cranio Maxillo-Fac Surg [60]

Prospective study

11 patients

Mean age of 38.89 years

TMD

MISMARPE: Le Fort I osteotomy

 + 

2-piece osteotomy

-

Pterygomaxillary disjunction (PD)

CBCT

- before expansion (T0)

- at the end of the activation period (T1)

(D1): Posterior maxilla distance;

(D2): Posterior midpalatal suture distance;

(D3): Anterior maxilla distance;

(D4): Anterior midpalatal suture distance;

(D5): Posterior alveolar process distance;

(D6): Anterior alveolar process distance;

(D7): Posterior dental crown distance;

(D8): Posterior dental root distance;

(A1): Angle UR6;

(A2): Angle UL6

Greater expansion was observed in the anterior region than in the posterior region

In the posterior region, a greater expansion was seen in the maxilla than in the alveolar process

Fair

Felipe et al.; 2022

Research, Society and Development [61]

Retrospective and observational study

19 patients;

SARME + PD

(6 patients);

SARME – PD

(13 patients)

Mean age: 28.94 ± 8.38 years

TMD

Le Fort I osteotomy

 + 

2-piece osteotomy

 ± 

Pterygomaxillary disjunction

CBCT

- one month before surgery (T0)

- six to eight months after surgery (T1)

On a plaster model

- the distance from the palatal cusp of the right first molar to the palatal cusp of the left first molar

On the CBCT:

- the thickness of buccal alveolar bone and the height of buccal alveolar bone were measured in the upper canines, maxillary first and second premolar, and maxillary first molar

- the angle between the alveolus and the long axis of the tooth

In each tooth and on both sides of the maxilla, there were no significant differences in the variables between groups SARME + PD and SARME-PD

On the left side, there were differences between the group with PMD and the group without PMD, where the second premolar and first molar showed increased angulation of the alveolus

The greater the amount of expansion, the greater the bone level and the thickness loss

Fair

Carvalho et al. 2023

Oral and Maxillofacial Surgery [62]

Retrospective observational study

24 patients: SARME + PD (n = 13);

SARME-PD (n = 11)

mean

age 27.2 ± 1.6

NA

Le Fort I osteotomy

 + 

2-piece osteotomy

 ± Pterygomaxillary disjunction (PD)

CBCT

- Before surgery(T1)

- Postsurgery (T2), after the activation period)- Postsurgery (T3), 6 months after Hyrax screw stabilization

Sagittal and vertical maxilla-mandibular measurements after SARME using Linear and angular cephalometric parameters

Significant maxillary displacements in the right-left component in both groups

Regarding the anteroposterior orientation, a significant reduction was observed in the PD group at T3 (p = 0.022)

Craniocaudal N-Pg (p = 0.018) and N-Pg (3D) (p = 0.016) varied significantly at T2 and returned to baseline at T3 in the PD group

Good