Twist Technique in Press

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CRANIOMAXILLOFACIAL DEFORMITIES/COSMETIC SURGERY

J Oral Maxillofac Surgxx:xxx, 2012

Twist Technique for Pterygomaxillary

Dysjunction in Minimally Invasive

Le Fort I OsteotomyFederico Hernndez-Alfaro, MD, DDS, PhD,* and

Raquel Guijarro-Martnez, MD

Purpose: To present a new technique for effective, rapid, and safe pterygomaxillary dysjunction in thecontext of a minimally invasive Le Fort I protocol and to provide the authors preliminary experience.

Materials and Methods: In total, 1,297 consecutive patients underwent Le Fort I osteotomy as anisolated procedure or in combination with mandibular surgery. In all cases, the twist technique wasused to downfracture the maxilla. This method achieves pterygomaxillary dysjunction using a frontalapproach and a straight osteotome that is driven along the standard Le Fort I horizontal osteotomy towardthe pterygomaxillary junction. Downfracture is achieved by inwardly rotating the osteotome fixed at thezygomatic buttress.

Results: The studied sample consisted of 820 women and 477 men (mean age, 28.4 years). Meansurgical time of the maxillary procedure was 44 minutes. Mean incision length was 2.8 cm. No significantneurovascular complications or clinically evident iatrogenic fractures occurred. Mean maxillary advance-ment was 5.5 mm (range, 2.0 to 14.0 mm).

Conclusions: Compared with classic pterygomaxillary dysjunction, the twist technique uses a frontalapproach and a straight osteotome. This technical modification requires a substantially smaller incision,achieves an immediate effective separation of the maxilla, and enables adequate visualization of thepalatine neurovascular bundle. The authors preliminary experience in 1,297 patients shows the tech-niques safety and efficacy.

2012 American Association of Oral and Maxillofacial SurgeonsJ Oral Maxillofac Surg xx:xxx, 2012

In experienced hands, Le Fort I maxillary osteotomycurrently is a safe, reliable, and predictable proce-dure.1 The development of specific surgical instru-ments, an increased knowledge of the biology of thisparticular osteotomy, and optimal anesthesiology con-ditions have significantly decreased its former morbid-ity and duration.2-6

Successful mobilization of the maxilla during LeFort I osteotomy requires an effective separation ofthe maxilla from the pterygoid process of the sphe-noid bone. This dysjunction must be clean and pre-cise to avoid neurovascular complications and poten-tial skull base structures.4,7-9 The aim of this report isto present a new technique for effective, rapid, andsafe pterygomaxillary dysjunction in the context of aminimally invasive Le Fort I protocol and to describe

the authors preliminary experience with this proce-dure.

Materials and Methods

From January 2000 to January 2012, 1,297 consec-utive nonsyndromic patients underwent Le Fort I os-teotomy as an isolated procedure or in combinationwith mandibular surgery at the authors center. Aminimally invasive Le Fort I protocol was followed.This protocol is described in detail in the next sec-tion. In particular, the twist technique was used to

Received from the Institute of Maxillofacial Surgery, Teknon Med-

ical Center, Barcelona, Spain.

*Director; Clinical Professor, Department of Oral and Maxillofa-

cial Surgery, Universitat Internacional de Catalunya, Barcelona,

Spain.

Fellow.

Address correspondence and reprint requests to Dr Hernndez-

Alfaro: Institute of Maxillofacial Surgery, Teknon Medical Center

Barcelona, Vilana, 12, D-185, 08022 Barcelona, Spain; e-mail:

[email protected]

2012 American Association of Oral and Maxillofacial Surgeons

0278-2391/12/xx0x-0$36.00/0

http://dx.doi.org/10.1016/j.joms.2012.04.032

1
mailto:[email protected]:[email protected]:[email protected]:[email protected]://dx.doi.org/10.1016/j.joms.2012.04.032


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downfracture the maxilla in all cases. Patients inwhom significant scar tissue or abnormal anatomywas anticipated, such as cleft patients or syndromiccases, received a modified incision and were not in-cluded in this study. Guidelines from the Declarationof Helsinki were followed at all treatment phases.

After a 12-year period, a retrospective evaluation ofpatients who underwent this surgical protocol wasperformed. Being a retrospective analysis, the studywas exempt from institutional review board approval.

SURGICAL TECHNIQUE

The procedure was performed under general anes-thesia and controlled hypotension. Through a mini-mally invasive incision from lateral incisor to lateralincisor, the nasal spine was osteotomized from themaxilla with a sharp 0.5-cm osteotome. After thissubspinal osteotomy, the nasal mucosa was detachedfrom the nasal floor with a periosteal elevator. Using

the latter, the nasal septum was luxated laterally toseparate it from the nasal crest of the maxilla. Subse-quently, standard Le Fort I horizontal osteotomieswere performed with a reciprocating saw with a 4-cmblade. Posteriorly, the cut was slanted slightly down-ward toward the maxillary tuberosity. The medialwalls of the maxillary sinuses were cut as the recip-rocating saw proceeded medially. Lateral osteotomieswere completed by driving a sharp, straight, 2-cmosteotome from the nasal crest of the maxilla to thepterygomaxillary junction (Fig 1). A classic pterygo-maxillary dysjunction from a lateral approach (ie, driv-

ing a curved osteotome at the pterygomaxillary fis-sure) was not performed. Instead, a straightosteotome was driven through the horizontal osteot-omy from the pyriform buttress back to the junction

of the posterior wall of the maxillary sinus to thepterygoid plates (Fig 2). Subsequently, once the os-teotome was fixed at the pterygomaxillary junctionand underneath the zygomatic buttress, it was rotatedinwardly, thus provoking downfracture of the maxilla(Fig 3). No mallet pressure was used during this ma-neuver. Rather, a swift twist of the chisel under con-trolled manual force led to an immediate verticalseparation of the maxilla from the cranial base. Oncethe pterygomaxillary dysjunction was completed atone side, the twist technique was repeated at thecontralateral side. For complete mobilization of the

maxilla, the palatine neurovascular bundles were lib-erated with the aid of a piezoelectric saw. Maxillaryrepositioning and fixation proceeded as usual (Fig 4).The technique is summarized in the supplementaryvideo file online.

FIGURE 1. The osteotome is driven from the nasal crest of themaxilla toward the pterygomaxillary junction. A narrow periostealelevator (left) is used to protect the nasal mucosa.

Hernndez-Alfaro and Guijarro-Martnez. Twist Technique in LeFort I Osteotomy. J Oral Maxillofac Surg 2012.

FIGURE 2. Skull base model. The osteotome progresses along thehorizontal osteotomy from the pyriform buttress back to the ptery-gomaxillary junction.


FIGURE 3. Immediate downfracture of the maxilla is achieved byinwardly rotating the osteotome (arrow).


2 TWIST TECHNIQUE IN LE FORT I OSTEOTOMY


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Results

The studied sample consisted of 820 women and477 men. Mean age at the time of surgery was 28.4years (range, 12 to 67 years).

In 985 cases, a bimaxillary surgery was performed;the remaining 312 cases underwent an isolated LeFort I maxillary osteotomy. In all cases, an effectivedownfracture of the maxilla was achieved with thetwist technique; there was no need for conversion tothe classic pterygomaxillary dysjunction. In total, 733patients required further maxillary segmentation in 3

to 4 pieces, which was successfully achieved usingthe same approach as in nonsegmented cases. Meansurgical time of the maxillary procedure (from inci-sion to last suture) was 44 minutes (range, 31 to 72min). Mean incision length was 2.8 cm (range, 2.2 to3.9 cm). Mean maxillary advancement was 5.5 mm(range, 2.0 to 14.0 mm). In total, 485 patients re-quired third molar extraction at the time of orthog-nathic surgery. In these cases, the third molars wereextracted using a standard occlusal approach beforeinitiating the Le Fort I osteotomy procedure.

Patients were discharged from the hospital withinan average period of 18 hours (range, 8 to 24 hr).

There was no need for blood transfusion. No postop-erative infectious complications occurred. Similarly,no clinically evident iatrogenic fractures or significantneurovascular complications were noted. However,488 patients reported temporary numbness of theinfraorbital nerve, which resolved within an averageperiod of 6 days (range, 3 to 15 days).

Discussion

Unlike classic pterygomaxillary dysjunction, whichentails a lateral approach to the pterygomaxillary fis-

sure with a curved osteotome, the twist techniqueseeks to achieve pterygomaxillary dysjunction from afrontal approach with a straight osteotome. Down-fracture is achieved by inwardly rotating the os-teotome that has been previously fixed at the zygo-matic buttress by sliding the osteotome backwardalong the lateral osteotomies. Separation of the max-illa is completed instantly. Successful maxillary sepa-ration from the cranial base can be verified underexcellent direct vision and the greater palatine neu-rovascular bundle may be dissected easily. Lateralvision is adequate to enable an equilibrated elimina-tion of bony interferences and assure good bone-to-bone contact.

This modified approach enables a substantiallysmaller soft tissue incision (2.8 cm on average) thanthe classic molar-to-molar exposure. The risk ofischemic events is minimized by the preservation ofmost of the vascular supply to the bone through the

buccal corridors. In addition, the final visible scar onthe buccal mucosa is significantly smaller. Despitethis minimally invasive approach, the present resultsindicated that the procedure is perfectly feasible un-der the required conditions of patient safety and tech-nical accuracy, including cases in which maxillarysegmentation is required. It must be noted, however,that decreasing the incision length should be consid-ered a technical progression from the classic ap-proach and not a primary goal for the inexperiencedorthognathic surgeon. That said, the twist techniqueis technically undemanding and is taught at the au-

thors center as a standard method for pterygomaxil-lary dysjunction. Similarly, in cases in which signifi-cant scar tissue or abnormal anatomy is anticipated,such as patients with cleft or syndromic cases, awider incision is recommended, although maxillarymobilization can still be achieved safely and effi-ciently with the twist technique.

Potentially severe complications after pterygomax-illary dysjunction have been reported in the scientificliterature.2,4,7-10 Many of these complications havebeen caused by malpositioning the osteotome or byaccidental fractures during maxillary downfracture.4

Although several technical modifications have been

proposed to minimize the risk of pterygoid processfracture,7,11-18 studies of strain distribution with dif-ferent osteotome designs have indicated that ptery-goid plate fractures are likely to occur regardless ofthe type of osteotome used.19 Similarly, they occurirrespective of the use or nonuse of a pterygoidchisel.10At any rate, a pterygoid plate fracture cannotbe considered a complication because it is not neces-sarily the cause of hemorrhage or nerve injury.4,10 Infact, intentional fracturing of the pterygoid process isoccasionally necessary when maxillary repositioningis hindered by interference with the pterygoid pro-

FIGURE 4. The procedure is successfully completed through aminimally invasive incision.


HERNNDEZ-ALFARO AND GUIJARRO-MARTNEZ 3


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cess.4 Despite the authors clinically favorable re-sults with no significant complications in a longseries of patients, an ongoing study will try tospecify the particular radiologic characteristicsifanyof pterygomaxillary dysjunction as achievedby the twist technique.

Regarding the limitations of the minimally invasiveLe Fort I procedure described in this report, theauthors differentiate two aspects: incision length andtwist technique maneuver. In cases in which signifi-cant scar tissue or an abnormal anatomy is expected,such as patients with cleft or syndromic cases, awider incision is preferred for safety reasons. In addi-tion, although the authors minimally invasive incisionposes no limitations to the magnitude of maxillaryadvancement or clockwise rotation, significant anti-clockwise maxillary rotation is managed with poste-rior plating and, hence, requires 1 to 2 cm broadeningof the incision to enable proper access to the zygo-

maticomaxillary buttress. It must be noted that, whenindicated, third molar extraction is always performedfrom an occlusal approach before the Le Fort I pro-cedure. The twist technique of pterygomaxillary dys-junction is a safe, efficient, technical modification formaxillary downfracture. In the authors experience,no particular limitations or contraindications must beacknowledged.

Compared with classic pterygomaxillary dysjunc-tion, the twist technique uses a frontal approach anda straight osteotome. Downfracture is achieved byinwardly rotating the osteotome that has been fixed at

the zygomatic buttress. This modified approachenables a substantially smaller soft tissue incision,achieves an immediate effective separation of themaxilla, and enables adequate visualization of thegreater palatine neurovascular bundle. Preliminary ex-perience in more than 1,200 patients indicates theprocedure meets the necessary requirements of safetyand technical accuracy.

References1. Hoffman GR, Islam S: The difficult Le Fort I osteotomy and

downfracture: A review with consideration given to an atypical

maxillary morphology. J Plast Reconstr Aesthet Surg 61:1029,2008

2. Lanigan DT, Hey JH, West RA: Major vascular complications oforthognathic surgery: Hemorrhage associated with Le Fort Iosteotomies. J Oral Maxillofac Surg 48:561, 1990

3. Ueki K, Hashiba Y, Marukawa K, et al: Assessment of pterygo-maxillary separation in Le Fort I osteotomy in Class III patients.J Oral Maxillofac Surg 67:833, 2009

4. Ueki K, Nakagawa K, Marukawa K, et al: Le Fort I osteotomyusing an ultrasonic bone curette to fracture the pterygoidplates. J Craniomaxillofac Surg 32:381, 2004

5. Bell WH, Fonseca RJ, Kenneky JW, et al: Bone healing andrevascularization after total maxillary osteotomy. J Oral Surg33:253, 1975

6. Epker BN: Vascular considerations in orthognathic surgery. II.Maxillary osteotomies. Oral Surg Oral Med Oral Pathol 57:473,1984

7. Precious DS, Morrison A, Ricard D: Pterygomaxillary separationwithout the use of an osteotome. J Oral Maxillofac Surg 49:98,1991

8. Robinson PP, Hendy CW: Pterygoid plate fractures caused bythe Le Fort I osteotomy. Br J Oral Maxillofac Surg 24:198, 1986

9. Cruz AA, dos Santos AC: Blindness after Le Fort I osteotomy: Apossible complication associated with pterygomaxillary sepa-ration. J Craniomaxillofac Surg 34:210, 2006

10. Precious DS, Goodday RH, Bourget L, et al: Pterygoid platefracture in Le Fort I osteotomy with and without pterygoidchisel: A computed tomography scan evaluation of 58 patients.J Oral Maxillofac Surg 51:151, 1993

11. Dupont C, Ciaburro TH, Prvost Y: Simplifying the Le Fort I

type of maxillary osteotomy. Plast Reconstr Surg 54:142, 197412. Trimble LD, Tideman H, Stoelinga PJ: A modification of thepterygoid plate separation in low-level maxillary osteotomies.J Oral Maxillofac Surg 41:544, 1983

13. Wikkeling OM, Tacoma J: Osteotomy of the pterygomaxillaryjunction. Int J Oral Surg 4:99, 1975

14. Cheng LH, Robinson PP: Evaluation of a swans neck os-teotome for pterygomaxillary dysjunction in the Le Fort I os-teotomy. Br J Oral Maxillofac Surg 31:52, 1993

15. Juniper RP, Stajcic Z: Pterygoid plate separation using an oscil-lating saw in Le Fort I osteotomy. Technical note. J Craniomax-illofac Surg 19:153, 1991

16. Laster Z, Ardekian L, Rachmiel A, et al: Use of the shark-finosteotome in separation of the pterygomaxillary junction in LeFort I osteotomy: A clinical and computerized tomographystudy. Int J Oral Maxillofac Surg 31:100, 2002

17. Stajcic Z: Altering the angulation of a curved osteotomeDoes

it have effects on the type of pterygomaxillary disjunction in LeFort I osteotomy? An experimental study. Int J Oral MaxillofacSurg 20:301, 1991

18. Lanigan DT, Loewy J: Postoperative computed tomographyscan study of the pterygomaxillary separation during the LeFort I osteotomy using a micro-oscillating saw. J Oral Maxillo-fac Surg 53:1161, 1995

19. Hiranuma Y, Yamamoto Y, Iizuka T: Strain distribution duringseparation of the pterygomaxillary suture by osteotomes. Com-parison between Obwegesers osteotome and swans neckosteotome. J Craniomaxillofac Surg 16:13, 1988

Appendix

Supplementary Data

Supplementary data associated with this article canbe found, in the online version, at http://dx.doi.org/10.1016/j.joms.2012.04.032.

4 TWIST TECHNIQUE IN LE FORT I OSTEOTOMY
http://dx.doi.org/10.1016/j.joms.2012.04.032http://dx.doi.org/10.1016/j.joms.2012.04.032http://dx.doi.org/10.1016/j.joms.2012.04.032http://dx.doi.org/10.1016/j.joms.2012.04.032http://dx.doi.org/10.1016/j.joms.2012.04.032

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