Distraction Osteogenesis VS Orthognathic Surgery

1. Distraction
osteogenesis
versus
Orthognathic surgery
-DR. NEEL GUPTA
PG RESIDENT (OMFS)

2. Contents
 Pre-operative
 Intra-operative
 Post-operative

3. Introduction
 Precious et al. remarks that, ‘‘Orthognathic
surgery consists of a constellation of
procedures that permit differential
alteration and repositioning of bone,
cartilage, muscle, teeth, gingiva, mucosa,
and skin’’, while distraction osteogenesis is
described as a biologic process of new
bone formation between the surfaces of
bone segments that are gradually
separated by incremental traction.

4. Pre-operative planning
Age-
 DO is versatile and can be performed at any
age, from neonates to adults as long as the
patient is physiologically capable to undergo
surgery.
 OGS are not performed in neonates and young
children and are generally recommended only
after the skeletal growth completion occurs
Weinzweig J (2010) Plastic surgery secrets plus e-book. Chapter 31: principles of distraction
osteogenesis.

5. An example of isolated Pierre Robin sequence. Note that along with micrognathia
apparent on facial profile, there is glossoptosis, with the tongue prolapsed into the
incomplete cleft in the palate.

7. Pre-operative Imaging and Planning
 DO warrants (CT) scanning for pre-op planning.
 Radiographs like OPG, lat. ceph. and PA cephalograms suffice in the treatment
planning for orthognathic surgeries, unless the procedure is planned with
(CAD/CAM) to fabricate customized splints, cutting guides and (PSI).
 DO doesn’t mandate complex virtual pre-operative planning to simulate (3D)
movements, whereas in case of osteotomies that involve 3D movements of
maxillomandibular complex, virtual planning software that incorporate DICOM
data are commonly employed, in recent times.
Kim SJ, Lee KJ, Yu HS, Jung YS, Baik HS (2015)
Threedimensional effect of pitch, roll, and yaw rotations on
maxillomandibular complex movement. J Cranio-Maxillofac
Surg 43(2):264–273

8. Movements
Quantum of Bone Movement
 In OGS advancements of more than 7 mm are not
advisable and those of more than 10 mm are considered
to be with an elevated risk of relapse.
 Distraction osteogenesis is a popular modality for larger
advancements of 10 mm or more, as it remains relatively
stable.
Bailey LT, Cevidanes LH, Proffit WR (2004) Stability and
predictability of orthognathic surgery. Am J Orthod
Dentofac Orthop 126(3):273–277

11. Prediction of Bone Movement
 Vector control is crucial in the planning for DO, where the placement
of the distractor dictates the primary vector.
 OGS offers, in most instances, predictable movements through
precise pre-operative planning and intra-operative usage of splints
to optimize the bone position.
Shirota T, Shiogama S, Asama Y, Tanaka M, Kurihara Y,
Ogura H, Kamatani T (2019) CAD/CAM splint and
surgical navigation allows accurate maxillary segment
positioning in Le Fort I osteotomy. Heliyon 5(7):e02123

12. Directions of Bone Movement
 A major drawback of distraction is that impaction,
setback or compression of bone is not possible.
 OGS provides the possibility of bone movements in
multiple directions in space, including retraction, and
correction of discrepancies like vertical maxillary excess.
Van Sickels JE (2000) Distraction osteogenesis versus
orthognathic surgery. Am J Orthod Dentofac Orthop
118(5):482–484

13. Three-Dimensional Bimaxillary
Movements
 OGS can offer complete movement of the entire maxillo-
mandibular complex, which acts as a rigid body with six
degrees of freedom in 3D space.
 It is difficult to manipulate 3D movements of the maxillo-
mandibular complex, in a single stage through DO.
Kim SJ, Lee KJ, Yu HS, Jung YS, Baik HS (2015)
Threedimensional effect of pitch, roll, and yaw rotations
on maxillomandibular complex movement. J Cranio-
Maxillofac Surg 43(2):264–273

14. Surgical Procedures
DO as Interim Procedure
 DO can be used as a part of a staged surgical treatment plan to achieve early
correction from childhood, to minimize the deformities in patients with severe
skeletal discrepancies. It does not induce permanent growth in the regions of
genetically determined growth centre deficits . Hence, it can be used to
minimize the quantum of deformity, providing a socially acceptable appearance.
 OGS has limitations and cannot be used as an interim procedure and is
preferred after growth completion. Osteotomies in the growing patients will
necessitate future interventions, as growth spurts would produce changes in the
final maxillo-mandibular relationship.
Liu Y, Khadka A, Li J, Hu J, Zhu S, Hsu Y, Wang Q, Wang D (2011) Sliding
reconstruction of the condyle using posterior border of mandibular ramus in
patients with temporomandibular joint ankylosis. Int J Oral Maxillofac Surg
40(11):1238–1245

15. Composite Distraction Versus
Multiple Osteotomies
 Multiple independent distraction of the bone segments in
the naso-maxillary zygomatic complex aren’t commonly
performed.
 OGS offers the possibility of movements of the bone
segments in the naso-maxillary zygomatic complex through
simultaneous LeFort I and LeFort III osteotomies, followed by
fixation separately.
Brown MS, Okada H, Valiathan M, Lakin GE (2015) 45
years of simultaneous Le Fort III and Le Fort I
osteotomies: a systematic literature review. Cleft Palate-
Craniofac J 52(4):471–479

16. Calvarial Deformity Correction
 While correcting calvarial deformities in paediatric patients with
osteotomies, there is an absolute necessity of intervening bone/cartilage
grafts and resorbable plates to be used, as indicated in brachycephaly and
craniosynostosis.
 Procedures like LeFort III distractions or frontoparietal (monobloc)
distractions , negate the use of interpositional grafts. Posterior cranial
vault distraction offers considerable advantage over posterior vault
osteotomies in craniosynostosis patients and the usage of internal,
resorbable distractors nullify the need for an additional surgery.
Maurice SM, Gachiani JM (2014) Posterior cranial vault
distraction with resorbable distraction devices. J
Craniofac Surg 25(4):1249–1251

17. Multiple Segmentations
 OGS offers the possibility to address the segmental
discrepancies of maxilla or midface, by separating them into
predetermined segments during surgery , and requires
intricate planning and intra-operative splints.
 Three or four pieces of segmentalization is not an option
while performing DO, because they will make the distraction
segments unstable.
Rachmiel A, Aizenbud D, Peled M (2005) Long-term
results in maxillary deficiency using intraoral devices. Int J
Oral Maxillofac Surg 34(5):473–479

18. Obstructive Sleep Apnoea
 Paediatric- In severe forms of syndromic mandibular deficiencies and maxillary hypoplasia,
distraction osteogenesis is the initial modality of treating (OSA).
 In TMJ ankylosis, pre-release distraction has been advocated to correct OSA for immediate
airway improvement and better vector control of distal mandibular segment against stable
proximal ankylosed ramus component.
 OGS don’t have a role in paediatric OSA management.
 Adults-Though maxillomandibular orthognathic rotation advancements are mostly preferred
for OSA correction, distraction of isolated mandible/maxillomandibular complex is performed
prior to ankylotic release similar to the paediatric group.
Heggie AA, Kumar R, Shand JM (2013) The role of distraction
osteogenesis in the management of craniofacial syndromes.
Ann Maxillofac Surg 3(1):4

19. Transverse Skeletal and Dental
Discrepancies
 DO is the best option for transverse skeletal
discrepancies, as it obviates the need for extractions &
proximal stripping, to gain space in the upper and lower
arches & to achieve facial fullness.
 OGS require transverse discrepancy management and
space gain before surgery; hence, extractions and
proximal stripping play a vital role in planning.
Van Sickels JE (2000) Distraction osteogenesis
versus orthognathic surgery. Am J Orthod Dentofac
Orthop 118(5):482–484

20. Segmental Defects
 Transport DO offers the possibility of reconstructing continuity
defects of the maxillofacial region. It can be achieved through
incremental movement of one (bifocal distraction), two (trifocal
distraction) or three (quadrifocal distraction) viable bone segments
across a defect.
 OGS cannot replicate this movement and are not indicated for
bridging segmental defects.
Zapata U, Elsalanty ME, Dechow PC, Opperman LA
(2010) Biomechanical configurations of mandibular
transport distraction osteogenesis devices. Tissue Eng
Part B Rev 16(3):273–283

21. Irradiated Cases
 DO has been successfully performed in conditions with
compromised vascularity like irradiated mandibles.
Confirmation of bone viability and the condition of
surrounding soft tissues are vital parameters in ensuring
the success of distraction in irradiated cases.
Barrera A, Salinas F, San Martin F (2011) Orthognathic
surgery in irradiated patient: a case report and literature
review. Int J Oral Maxillofac Surg 10(40):1202

22. Compromised Bone Quality
 Bone regeneration has been observed after DO, in suboptimal
clinical situations like scarred tissues wherein the native periosteum
had been destroyed.
 OGS can be performed only in situations, wherein there are no
disruptions of periosteum & with healthy soft tissue cover.
Osteotomy cuts raise the risk of unfavourable fractures and bad
splits in patients with low bone mineral density disorders like
osteoporosis.
Barrera A, Salinas F, San Martin F (2011) Orthognathic
surgery in irradiated patient: a case report and
literature review. Int J Oral Maxillofac Surg 10(40):1202

23. Condylar
Hyperplasia/Hypertrophy
 DO has no role in managing situations like condylar
hypertrophy/hyperplasia, as it doesn’t influence the growth
centre, which is actually the etiological factor.
 Surgical interventions for condylar hyperplasia either in
isolation or with maxillomandibular osteotomies are the
treatment of choice in such pathologies at appropriate age.
Almeida LE, Zacharias J, Pierce S (2015) Condylar
hyperplasia: an updated review of the literature. Korean J
Orthod 45(6):333–340

24. Neo-condyle Rehabilitation
 In TMJ ankylosis, after resection of the ankylotic segment, reconstruction can be done with
neocondyle distraction using ramus segment.
 The biomechanical properties of neo-condyle, under functional loading are equal to that of
physiologic condyle. Histological analysis has revealed the distraction gap filled with collagen
fibrous tissue gets gradually replaced by mature bone after 24 weeks postdistraction. A
pseudo-meniscus is formed by the fibrocartilaginous cap at the advancing front of distraction,
replicating a normal anatomic form.
 OGS can also be employed to achieve this by vertical sliding ramus osteotomies, where the
stump of the posterior ramus can replace the condyle; however, there is no formation of a
fibrocartilaginous cap which will act as a pseudo-meniscus.
Sharma R, Manikandhan R, Sneha P, Parameswaran A, Kumar
JN, Sailer HF (2017) Neocondyle distraction osteogenesis in
the management of temporomandibular joint ankylosis:
report of five cases with review of literature. Indian J Dent
Res 28(3):269

25. Intra-operative Factors-
Osteotomy Design
 DO involves linear bicortical osteotomy separation but it can
also be performed in certain instances with cortical scoring,
like in neonatal distraction of Pierre Robin sequence or
Treacher Collins syndrome, to serve the purpose of
emergency airway improvement.
 In OGS, specifically designed osteotomy cuts are done, for
complete mobilization and movement of the osteotomized
segments in different planes.
Faria R, Valladares S (2016) Distraction osteogenesis in
Pierre Robin sequence. Austin J Otolaryngol 3(2):1074

26. Bone Grafting
 As DO eliminates the need for autogenous bone harvesting and grafting at the site of bone
movement, there is no donor site morbidity. The only indication for bone grafting after
distraction will be in cases of transverse deficiencies, specifically in areas of mandibular ramus
or zygoma, to achieve optimal symmetry, if warranted.
 In orthognathic maxillary advancements of more than 7 mm, bone grafts are desirable to
stabilize the osteotomized segments. This autogenous bone grafting has disadvantages like
donor site morbidity, infection of the bone graft, resorption and subsequent relapse due to
resorption. Immediate bone grafting or the usage of synthetic substitutes for augmentation is
an advantage of OGS over DO, as fixation of those can be done simultaneously.
Precious DS (2007) Treatment of retruded maxilla in cleft lip
and palate—orthognathic surgery versus distraction
osteogenesis: the case for orthognathic surgery. J Oral
Maxillofac Surg 65(4):758–761

27. Need for Overcorrection
 For growing patients with facial asymmetry, who undergo
distraction, mild overcorrection of the segments is advised,
to catch up with the growth of unaffected side and also to
reduce the later discrepancies that might occur during
growth.
 Overcorrection is not practised for orthognathic surgery
patients, as they are operated after growth cessation with
final planned occlusion in mind.
Molina F (2009) Mandibular distraction osteogenesis: a
clinical experience of the last 17 years. J Craniofac Surg
20(8):1794–1800

28. Necessity for Surgical Splints
 When osteotomy cuts are placed in orthognathic surgery, it
is imperative to use splints, which serve as an intra-operative
guide to establish a pre-surgically planned occlusion.
 Surgical splints are not essential in distraction cases, as it
only involves the mobilization of segments, followed by
fixation of the devices.
Bachelet JT, Cliet JY, Chauvel-Picard J, Bouletreau P (2016)
Observations on the role of surgical splints In
orthognathic surgery. J Dentofac Anom Orthod 19(2):207

29. Role for Transfusion
 Distraction procedures are less invasive with a lower
necessity for post-operative blood transfusion, due to
minimal manipulation of hard and soft tissues.
 Bimaxillary orthognathic procedures have an increased
propensity for post-operative blood transfusions.
Sammanbds N, Cheung LK, Tong AC, Tideman H
(1996) Blood loss and transfusion requirements in
orthognathic surgery. J Oral Maxillofac Surg
54(1):21–24

30. Duration of Surgery
 Incision to closure time for a distraction procedure for
maxilla or mandible is lower than a similar procedure
performed as an OGS.
Van Strijen PJ, Breuning KH, Becking AG, Perdijk FB,
Tuinzing DB (2003) Cost, operation and hospitalization
times in distraction osteogenesis versus sagittal split
osteotomy. J Cranio-Maxillofac Surg 31(1):42–4

31. Post-operative Issues
Biomechanics of Bone Healing
 Histologically, the healing process in sites of distraction osteogenesis differs from osteotomy
in two basic aspects. There is an advantage of having a controlled microtrauma and an
intramembranous ossification. The controlled microtrauma present during the activation
phase of distraction stimulates osteoblast proliferation, bone extracellular matrix (ECM)
synthesis and induces growth factors.
 In orthognathic osteotomy sites, the healing is produced by endochondral processes, similar
to fracture healing.
Hegab AF, Shuman MA (2012) Distraction osteogenesis of
the maxillofacial skeleton: biomechanics and clinical
implications. Sci Rep 1(11):509
Olate S, Va´squez B, Sandoval C, Vasconcellos A, Alister JP,
Del Sol M (2019) Histological analysis of bone repair in
mandibular body osteotomy using internal fixation system in
three different gaps without bone graft in an animal model.
Biomed Res Int 2019:8043510

32. Post-surgical Imaging
 DO mandates, regular monitoring of the progress of the distraction
regenerate consolidation, direction and dimension of movement,
through serial radiographs.
 Orthognathic procedures require post-operative radiographs to
assess the degree of movement and fixation and will require further
investigation when a complication arise.
Andrade N, Aggrawal N, Jadhav G, Sahu V, Mathai PC
(2018) To determine the efficacy of ultrasonography in
the evaluation of bone fill at the regenerate site for
mandibular distraction osteogenesis over clinical and
radiographic assessment: an in vivo prospective study.
J Oral Biol Craniofac Res 8(2):89–93

33. Assessment of Post-operative
Changes
Occlusion
 DO has a tendency to cause mild to severe occlusal discrepancies as
the movements are planned at basal bone level.
 OGS relies on planning and predictability. The patient undergoes
presurgical orthodontics and the intra operative final position is
determined by the splint. After the surgical procedure, the patient is
referred to the orthodontist to correct the expected post-operative
changes in occlusion.
Ow A, Cheung LK (2009) Skeletal stability and
complications of bilateral sagittal split osteotomies
and mandibular distraction osteogenesis: an evidence-
based review. J Oral Maxillofac Sur 67(11):2344–2353

34. Condylar Position
 The BSSOis notorious for producing inadequate condylar positioning
and displacement, which had led to condylar resorption and
subsequent internal derangement
 DO, which is performed for either anteroposterior or transverse
discrepancies of the mandible, has lesser incidences of TMJ
complications when compared with procedures like BSSO or with
vertical symphyseal step osteotomies.
Ow A, Cheung LK (2009) Skeletal stability and
complications of bilateral sagittal split osteotomies
and mandibular distraction osteogenesis: an evidence-
based review. J Oral Maxillofac Sur 67(11):2344–2353

35. Velopharyngeal Changes
 In patients undergoing maxillary advancement for moderate cleft
maxillary hypoplasia of less than 10 mm, DO has no significant advantage
over OGS in preventing velopharyngeal incompetence (VPI) or speech
disturbances.
 In patients with severe cleft maxillary hypoplasia of more than 10 mm,
performing a Le Fort I osteotomy increases VPI in patients with pre-
existing borderline VPI , but maxillary advancements achieved through
DO have markedly minimal effects on velopharyngeal competence.
Chua HD, Whitehill TL, Samman N, Cheung LK (2010)
Maxillary distraction versus orthognathic surgery in
cleft lip and palate patients: effects on speech and
velopharyngeal function. Int J Oral Maxillofac Surg
39(7):633–640

36. Concomitant Histogenesis
 One of the major advantages of distraction osteogenesis is the concurring
distraction histogenesis. This phenomenon explains the simultaneous
expansion of the soft tissues, including skeletal muscles, nerves,
ligaments, fat, skin and gingiva, in concert with the lengthened bone,
thereby producing excellent aesthetic and functional results
 In OGS, as the facial bones are advanced in an acute fashion and fixed in
its new planned position, the adjacent soft tissues are stretched and they
tend to displace the bony segments back to their previous positions to a
certain degree.
Rachmiel A (2007) Treatment of maxillary cleft palate:
distraction osteogenesis versus orthognathic
surgery—part one: maxillary distraction. J Oral
Maxillofac Surg 65(4):753–757

37. Additional Interventions
 In patients with internal submerged distraction devices, an
additional surgery is necessary, to remove the device and to
excise the hypertrophic scarred tissue at the site of activation
arm.
 As OGS is usually a definitive single stage procedure, the
necessity for additional surgeries is rare.
Scott AR (2016) Surgical management of Pierre Robin
sequence: using mandibular distraction osteogenesis to
address hypoventilation and failure to thrive in infancy.
Facial Plast Surg 32(02):177–187

38. Patient Compliance
 OGS, unlike distraction, is almost entirely an intraoral
procedure which is generally well tolerated with superior
patient compliance. The overall satisfaction rate of
patients, after orthognathic surgeries, is very high
Soh CL, Narayanan V (2013) Quality of life assessment in
patients with dentofacial deformity undergoing orthognathic
surgery—a systematic review. Int J Oral Maxillofac Surg
42(8):974–980

39. Follow-Up Visits
 Constant post-operative follow-up visits are mandatory
following distraction procedures, to check for regularity
in activation, and also to note the occurrence of
complications, if any.
 Numerous visits are not necessary after an orthognathic
surgical procedure.
Van Strijen PJ, Breuning KH, Becking AG, Perdijk FB,
Tuinzing DB (2003) Cost, operation and hospitalization
times in distraction osteogenesis versus sagittal split
osteotomy. J Cranio-Maxillofac Surg 31(1):42–45

40. Duration of Treatment
 DO entails a prolonged treatment time, lasting at least 3
months.
 OGS are single step procedures, and only the adjuvant
orthodontic treatment might cause an increase in the
treatment duration.
Onger ME, Bereket C, Sener I, Ozkan N, Senel E, Polat AV
(2017) Is it possible to change of the duration of
consolidation period in the distraction osteogenesis with the
repetition of extracorporeal shock waves? Med Oral Patol
Oral 22(2):e251

41. Complications
Relapse
 DO has lower relapse rates with larger advancements, as there is decreased
force needed to lengthen the bone due to the phenomenon of distraction
histogenesis.
 In OGS, advancements of more than 10 mm in any direction are considered
to be with an elevated risk of relapse.
Van Strijen PJ, Breuning KH, Becking AG, Tuinzing DB (2004) Stability
after distraction osteogenesis to lengthen the mandible: results in
50 patients. J Oral Maxillofac Surg 62(3):304–307

42. Post-operative Infection
 The distraction rods that penetrate the oral mucosa are
portals of entry for infection.
 The infection rates in orthognathic surgery patients are
very minimal or even nil, if proper antibiotic regimen is
followed.
Cheung LK, Chua HD, Ha¨gg MB (2006) Cleft maxillary
distraction versus orthognathic surgery: clinical
morbidities and surgical relapse. Plast Reconstr Surg
118(4):996–1008

43. Extra Oral Scarring
 External distraction devices anchored by transcutaneous pins
are used to transport and stabilize the skeletal fragments.
Though there are numerous advantages like less infection
rate, easy adjustment of vector and easy removal, these pins
are prone to cause scarring of the skin.
 OGS has no extra oral scarring as the approaches are always
made transorally, barring a few procedures like extraoral
ramus osteotomies and Lefort III osteotomies
Chin M, Toth BA (1996) Distraction osteogenesis in
maxillofacial surgery using internal devices: review of five
cases. J Oral Maxillofac Surg 54(1):45–53

44. Neurological Deficits
 The larger incidences of persistent long-term inferior alveolar nerve
(IAN) disturbances have been reported following (BSSO).
 Mandibular distraction has lower incidences of persistent sensory
nerve disturbances when compared to OGS, between 6 and 10 mm
of distraction.
Makarov MR, Harper RP, Cope JB, Samchukov ML (1998)
Evaluation of inferior alveolar nerve function during
distraction osteogenesis in the dog. J Oral Maxillofac Surg
56(12):1417–1423
Van Strijen PJ, Breuning KH, Becking AG, Perdijk FB, Tuinzing
DB (2003) Cost, operation and hospitalization times in
distraction osteogenesis versus sagittal split osteotomy. J
Cranio-Maxillofac Surg 31(1):42–45

45. Complications in Specific Craniofacial
Procedures
 Frequent and severe complications like cerebrospinal fluid
leakage, meningitis, subgaleal haematoma, transection of the
infraorbital nerve, strabismus and ptosis have a higher
incidence in patients undergoing LeFort III osteotomy than
those undergoing LeFort III distraction.
Bradley JP, Gabbay JS, Taub PJ, Heller JB, O’Hara CM,
Benhaim P, Kawamoto HK Jr (2006) Monobloc advancement
by distraction osteogenesis decreases morbidity and relapse.
Plast Reconstr Surg 118(7):1585–1597

46. Summary