Craniofacial Distraction, A Review

8/13/2019 Craniofacial Distraction, A Review

1/15

Int. J. Oral Maxillofac. Surg. 2001; 30: 89103

doi:10.1054/ijom.2000.0033, available online at http://www.idealibrary.com on

Invited review

Craniofacial distractionosteogenesis: a review of theliterature. Part 1: clinicalstudiesG. Swennen, H. Schliephake, R. Dempf, H. Schierle, C. Malevez: Craniofacial

distraction osteogenesis: a review of the literature. Int. J. Oral Maxillofac. Surg.

2001; 30: 89103. 2001 International Association of Oral and Maxillofacial

Surgeons

Abstract.A review of the literature dealing with distraction osteogenesis (DO) of

the craniofacial skeleton, provided by a PUBMED search (National Library of

Medicine, NCBI; revised 3 April 2000) from 1966 to December 1999 was

conducted. Key words used in the search were distraction, lengthening, mandible,

mandibular, maxilla, maxillary, midface, midfacial, monobloc, cranial, craniofacial

and maxillofacial. This search revealed 285 articles. One hundred and nine articles

were clinically orientated and were analysed in detail in this study. The type of

distraction, indications, age, type of surgery, distraction rates and rhythms, latency

and contention periods, amount of lengthening, follow-up period, relapse,complications and the nature of the distraction device were analysed. This review

revealed that 828 patients underwent DO of the craniofacial skeleton; 579

underwent mandibular DO, 129 maxillary DO, 24 simultaneous mandibular and

maxillary DO and 96 midfacial and/or cranial DO. Craniofacial DO has proven to

be a major advance for the treatment of numerous congenital and acquired

craniofacial deformities. Treatment protocols and success criteria for craniofacialDO are suggested on the basis of these results. There is still, however, a lack of

sufficient data, especially on follow-up and relapse, so that treatment strategieshave to be validated by long-term studies in the future.

Gwen Swennen1,2,Henning Schliephake1,Rupert Dempf1, Hannes Schierle1,3,Chantal Malevez2

1Department of Oral and Maxillofacial Surgery,Medizinische Hochschule Hannover,Hannover, Germany2Department of Oral and Maxillofacial Surgery,Childrens Hospital, University of Brussels,Belgium3Private Practice for Oral and MaxillofacialSurgery, Karlsruhe, Germany

Key words: distraction; mandible; maxilla;midface; cranial; treatment protocols; successcriteria.

Accepted for publication 20 November 2000

Distraction osteogenesis (DO) is the pro-cess of generating new bone in a gapbetween two bone segments in response

to the application of graduated tensilestress across the bone gap. The tech-

nique of bone lengthening by DO wasfirst described in 1905 by C13,when he reported lengthening of a

femur byaxial distraction forces. Otherreports1,2 also mention the concept of

bone lengthening in the tibia, but itremained undeveloped until Dr GavrielA. I5456, a Russian physician,

further developed the technique in the

1950s in Kurgan in West Siberia. Formore than 35 years he successfullyapplied the technique of DO to the

enchondral bone of the upper and lowerextremities. A unique feature of the

distraction technique is that bone regen-eration by DO is accompanied by simul-taneous expansion of the functional soft

tissue matrix, including blood vessels,nerves, muscles, skin, mucosa, fascia,

ligaments, cartilage and periosteum.These adaptive changes of the surround-ing soft tissues through the tension that

is generated by the distraction forces

applied onthebone, is called distractionhistogenesis22. Distraction osteogenesisseemed to be a promising new method in

the reconstruction of the membranousbones of the human craniofacial skel-

eton, when in 1992 MC et al.83

reported the first clinical application inthe Western literature of mandibular

lengthening by gradual distraction inpatients with hemifacial microsomia and

Nagers syndrome. Since then there hasbeen an explosion of reports in the lit-erature on DO in the craniofacial skel-

eton. In recent years, DO has become

0901-5027/01/020089+ 15 $35.00/0 2001 International Association of Oral and Maxillofacial Surgeons


2/15

increasingly popular and opened newtherapeutic perspectives for the treat-

ment of numerous congenital andacquired craniofacial skeletal anomalies.

Different treatment protocols, however,are applied by different groups. Despitethe growing body of literature on the

applications of craniofacial DO, import-ant parameters such as age, rhythm,

rate, latency period, contention periodare not rigidly established. Excellent

comprehensive reviews have been pub-lished4,22,24,82,133,134,137,145, however,

none of these provide an analysis ofthese parameters in detail. Therefore, theliterature dealing with DO of the cranio-

facial skeleton was reviewed comprehen-sively. The purpose of this review wastwo-fold: (1) to evaluate clinical indi-

cations and DO parameters by compar-ing different treatment protocols and

results obtained by different craniofacialteams; (2) to suggest treatment protocols

and success criteria for craniofacial DObased on clinical, experimental andscientific investigations to help provide

more objective data in the future.

Materials and methods

A review of the literature on DO of the

craniofacial skeleton, provided by aPUBMED search (National Library of

medicine, NCBI, New Pubmed System;revised 3 april 2000), was conductedfrom 1966 to December 1999. Key words

applied in the search were distraction,lengthening, mandible, mandibular,

maxilla, maxillary, midface, midfacial,monobloc, cranial, craniofacial and

maxillofacial. This initial search revealed285 articles. An additional three articles

relating to the subject were submitted tothe study. Of this total study sample of288 articles, 109 were clinical and 99

were experimental articles; 54 articleswere primarily on a scientific basis andwere excluded because they provided no

sufficient data; of the remaining articles,11 were excluded due to lack of appro-

priate data and 15 because they werewritten in languages, for which trans-

lation was not available (12 in Russian,two in Chinese and one in Hebrew)(Table 1). The study sample of this

review consisted of 109 articles that were

analysed in detail. Flow sheets weremade of each article with the specificparameters relative to DO. The author,

type of distraction, indications, numberof patients, age, type of surgery, distrac-

tion rates and rhythms, latency and con-tention periods, amount of lengthening,

follow-up period, relapse, complicationsand the nature of the device wererecorded for each article on the flow

sheets and analysed. The articles weredivided into four major groups accord-

ing to the site of distraction: mandible,maxilla, combined mandible and max-illa, and midface/cranium. Although

some authors have published results ofidentical patients in more publications,

this could not be verified in detail.For analysis, the data of all different

publications were used.

Results

A total of 109 articles were analysed; 74

(67.9%) were related to mandibular DO,16 to maxillary DO (14.7%), three to

simultaneous mandibular/maxillary DO(2.8%) and 23 to midfacial and/orcranial DO (21.1%); seven of these

articles were related to two or moreprocedures (Table 2). Indications for

craniofacial DO are shown in Table 3.

Mandibular distraction osteogenesis

A total of 579 patients (70.0%) under-went distraction procedures involving

the mandible(Table 3). These mandibu-lar DO procedures were divided intofour groups. Of the 579 patients, 430

(74.3%) underwent mandibular length-ening (Group 1), 38 patients (6.6%)

mandibular widening (Group 2), 16patients (2.8%) alveolar reconstruction(Group 3) and 95 patients (16.4%) bone

transport and compression DO (Group4). Results of mandibular DO par-

ameters for each group are shown inTable 4.

Group 1: Mandibular lengthening

Of the 430 patients that underwentmandibular lengthening through DO,

345 (80.2%) had congenital micro-

gnathia8,11,14,16,19,2331,42,45,46,51,52,53,57,

59,62,63,6567,72,73,79,8385,87,88,94,98,101,102,

105,107,108,115,120,123,126,130,135,141,144 45

(10.5%) had acquired micro-

gnathia8,25,29,30,31,36,59,6264,66,84,88,91,98,

108,119,130,141,147 and 40(9.3%) had man-

dibular retrognathia26,31,91. Detailed

data regarding age were available in 156

patients (45.2%) with congenital micro-

gnathia and in 26 patients (57.8%) with

acquired micrognathia. In the congenital

micrognathia sample, age varied from 6

days to 19 years and most of the patientswere distracted in the age groups, 26

and 712 years. Patients with acquired

micrognathia were distracted at an age

varying from 1.5 to 64 years with most

of the patients distracted in the 712

years age group. Data regarding age

were available in 37 patients (92.5%)

with mandibular retrognathia; all

patients were distracted between the age

of 15 and 20 years. A total of 289

patients (83.8%) with congenital micro-

gnathia, 40 patients (88.9%) withacquired micrognathia and 40 patients

(100%) with retrognathia had infor-mation regarding the surgical technique.A complete osteotomy was performed in

166 patients (57.4%) with congenitalmicrognathia, while 123 (42.6%) under-

went a corticotomy. In the acquiredmicrognathia sample a total of 23patients (56.1%) underwent an osteo-

tomy, while 18 patients (43.9%) acorticotomy. A body osteotomy was per-

formed in all patients with mandibularretrognathia. Data regarding the distrac-tion rate were available in 300 patients

(86.9%) with congenital micrognathia,

37 (82.2%) with acquired micrognathiaand 40 (100%) with mandibular retrog-nathia. The distraction rate of 1 mm

daily was the most frequent for eachgroup. Data on distraction rhythm,varying from two to four times daily,

were reported in only 174 patients (58%)in the congenital micrognathia sample

and in 10 patients (27%) in the acquiredmicrognathia sample. All patients in theretrognathia sample had data on distrac-

tion rhythm, ranging from three times0.33 mm to twice 0.5 mm. A total of 325

Table 1. Articles on distraction osteogenesisof the craniofacial skeleton

Clinical DO 109Experimental DO 99Scientific DO 54Not relevant 11Other language 15Total 288

Table 2. Articles on clinical distraction osteogenesis

Mandibular DO 74 74Maxillary DO 16 4* 12Simultaneous mandibular/maxillary DO 3 3Midfacial and/or cranial DO 23 3** 20Total 109

*Of the 16 articles on maxillary DO, four concerned also mandibular DO.**Of the 23 articles on midfacial and/or cranial DO, three concerned also mandibular DO.

90 Swennen et al.


3/15

Table 3. Indications for distraction osteogenesis of the craniofacial skeleton

Number % %

Mandibular DOHemifacial microsomia (HFM)28,29,30,31,46,53,59,67,73,65,66,79,83,87,88,101,102,105,123,126,130,135 198 34.2Segmentalbone defect (trauma, tumor)6,9,76,113,116118,121,122 90 15.5Class II26,31,91 40 6.9Acquired micrognathia(trauma,TMJ ankylosis)8,25,29,30,31,59,64,65,66,85,88,97,98,108,141 39 6.7Transverse discrepancy41,60,142,143 35 6.0Craniofacial microsomia (CFM)11,13,14,84,85,98,108,130 32 5.5

Treacher-Collins Syndrome (TC)8,29,72,65,66,87,88,94,98,108,144

27 4.7Congenital micrognathia8,42,45,51,59,84,87,98,105 24 4.1Obstructive SleepApnoe Syndrome (OSAS)16,52,91 18 3.1Alveolar deficiency37,38,47,69,139 16 2.8Nager Syndrome59,79,83,87,108,115,144 10 1.7Pierre Robin Syndrome8,57,58,88,107,120 8 1.4Goldenhar Syndrome8,11,87,98,108 6 1.0Fibula36,119,147 6 1.0Arthrogryposis11,98 3 0.5Hypoglossia-hypodactyly Syndrome8,99 2 0.4Hanhart Syndrome29,73 2 0.4Post irradiation therapy8 2 0.4Condylar resorbtion124 2 0.4Moebius Syndrome62,63 2 0.4Histiocytose X121,122 2 0.4Rubinstein-Taybi Syndrome79 1 0.2Cerebro Costomandibular Syndrome79 1

Tessier cleft VII65

1Retrognathia/facial cleft65 1Plagiocephaly23 1Kampomele dysplasie115 1Trisomie 18115 1Morpheaform sleroderma23 1Amnionband Syndrome8 1Neurofibromatosis8 1Glossoptosis-micrognathia107 1Aglossia-micrognathia8 1Silver-RussellSyndrome61 1Facial skoliosis58 1Bilateral dysostosis mandibularis141 1Subtotal 579 100 70.0Maxillary DOOrofacial clefts 115 89.2

Unilateral cleft lip-palate (UCLP)3,34,70,89,106,127,128,141 55

Bilateral cleft lip-palate (BLCP)34,70,89,103,106,127,128,132,146

34Undefined clefts104 18Unilateral cleftpalate (UCP)70,89 8

Alveolar defect37 5 3.9NasomaxillaryDysplasia89 2 1.6Prognathism89 2 1.6Alveolar atrophy37,47 2 1.6Cleidocranial Dysostosis19 1 0.8Craniosynostosis (CST)70 1 0.8Oral-acral syndrome32 1 0.8Subtotal 129 100 15.6Simultaneous mandibular/maxillary DOHFM90,95,96 23 95.8TC96 1 4.2Subtotal 24 100 2.9Midfacial and/or cranial DOCraniosynostosis (CST) 86 90.0

Crouzons S5,10,12,19,20,21,27,68,125

36Aperts S5,10,12,18,19,20,27,77 19UndefinedCraniosynostosis77,81 15Pfeiffers S7,10,11,12,17,18,19,21,100 12Unilateral Coronal Synostosis71 1Bilateral CoronalSynostosis49 1Sagittal Synostosis125 1CarpentersS131 1

Midfacial cleft10,12 3 3.1UCLP15,19 3 3.1Unilateral CFM14,19 2 2.1BCLP/severe maxillary atrophy48 1 1.0Rare cleft19 1 1.0Subtotal 96 100 11.6

Total 828 100

Craniofacial distraction 91


4/15


5/15

respectively; only 62 patients (26.2%)were followed-up for 1 year or longer and

only six relapses (4.0%) were reported. Atotal of 26 patients (57.8%) in the ac-

quired micrognathia sample had data onfollow-up varying from 3 months to 4years; only nine patients (34.6%) were

followed-up for 1 year or longer. Data onrelapse were only available in 10 patients

(22.2%); none of these patients showedskeletal relapse. No data regardingfollow-up and relapse were reported in

the mandibular retrognathia sample.Data on complications were available for

311 patients (72.3%); a total of 86 compli-cations were reported(Table 5).

Based on these results, the commonstandard appears to be a distractionrate of 1 mm daily, a latency period of 57

days and a contention period of 68weeks for patients with congenital or ac-

quired micrognathia and retrognathiaundergoing mandibular lengthening. In

patients with congenital or acquiredmicrognathia, both surgical techniques(complete osteotomy/corticotomy) can be

performed and both devices (external orinternal) can be applied. In retrognatic

patients a complete osteotomy of themandibular body and bone-borne inter-nal devices are recommended(Table 6).

Group 2: Mandibular widening

A total of 38 patients underwent sym-physeal widening through DO41,60,61,98,

99,142,143. Detailed information on agewas given in 27 patients (71.1%); nine

patients (33.3%) were distracted between13 and 16 years, 14 patients (51.9%)older than 16 years and four patients

(14.8%) younger than 13 years. Further-more, mandibular widening was

reported in 10 patients with unspecifiedage between 13 and 31 years41. Thus, a

total of 33 patients (89.2%) were dis-tracted at an age older than 12 years andonly four patients (10.1%) at an age

between 212 years. Three of these fourpatients were syndromic cases. In all

patients a midline osteotomy was per-formed. A total of 12 patients were dis-tracted at 1 mm daily, while 26 were

distracted at less than 1 mm daily; 24were distracted at 0.75 mm daily (three

times 0.25 mm), one at 0.5 mm andanother at 0.33 mm. Latency periods

were reported in all patients. The 57day latency period was the most com-

mon. Data regarding the contentionperiod were given in 22 patients (57.8%).The 68 weeks contention period was

reported most frequently. A total of 23patients (60.5%) had data on the amountof symphyseal widening varying from

3.9 to 14 mm. Only 16 patients (42.1%)had follow-up data varying from 6 to

45 months and none of all patients hadinformation on relapse. Of the 38

patients that underwent mandibularwidening through DO, two (5.3%) hadexternal devices and 36 (94.7%) inter-

nal monodirectional devices; 33 weretooth-borne and three bone-borne

devices. Data on complications werereported in 37 patients (97.4%); a total

of 10 complications (29.7%) occurred(Table 5).

Thus, it is recommended to perform

mandibular widening from the age of 12years after a complete symphyseal

osteotomy using an internal device, adistraction rate ranging from 0.75 to1 mm daily, a 57 day latency period and

a 68 weeks contention period(Table 6).

Group 3: Alveolar reconstruction

In this group 16 patients underwentalveolar reconstruction through vertical

DO11,37,38,47,69,139. Data regarding agewere available in 15 patients (93.8%) andvaried from 17 to 69 years. A segmental

osteotomy was performed in all patients.

A total of 10 patients had a distractionrate of 1 mm, while six had a rate of0.5 mm. Data regarding distraction

rhythm were available for only ninepatients (56.3%); eight patients had arhythm of 0.5 mm twice a day while one

0.5 mm once daily. The 57 days latencyperiod and the 8 week contention period

were the most common. In group 3 alldevices that were used were intraoraldevices; nine patients (56.3%) had inter-

nal monodirectional devices and sevenpatients (43.8%) had implant-borne

Table 5. Complications of distraction osteogenesis of the craniofacial skeleton

Distraction procedure

Total %Length

Mandibular

Bone TMaxill.adv/alv

Mand/maxill.

Midf/cranialWiden. Alveol.

Complications

Mech. problems (pin loosening/accidental trauma) 34 1 1 1* 7 44 33.1Transient hypesthesia inferior alveolar nerve 15 15 11.3

Minor local infection 5 4 1 2 12 9.0Pin infection 5 1 1 4 11 8.3Premature consolidation 5 4 1 10 7.6Transient weakness r.marginalis facial nerve 9 9 6.7Limited skeletal advancement 6 6 4.6Hypertrophic scar 4 4 3.0Asymmetric advancement 3 3 2.3Ankylosis (zygoma-coronoid processus) 3 3 2.3Severe infection 3** 3 2.3Tooth damage 1 2 3 2.3Tooth mobility 2 2 1.5Incomplete osteotomy 2 2 1.5Loss of distraction implant 1 1 2 1.5Incorrect distraction vector 1 1 0.8Pseudarthrosis 1 1 0.8Haematoma 1 1 0.8

Periodontal pocket 1 1 0.886 10 1 7 3 1 25 133 100

*Loosening of IMF; **2 meningitis, 1 H.flu.pneumonia.



6/15

devices; six of these were used for pros-

thetic treatment after distraction wascompleted37,38, while one was removed

at the end of the activation period69.Data on the amount of lengthening werereported in 15 patients (93.8%) and varied

from 4 to 15 mm. Internal bone-bornedevices provided greater lengthening

(715 mm) compared to implant-borne

devices (4

8 mm). Follow-up was men-tioned in 14 cases (87.5%) and rangedfrom 1 to 13 months. None of these ar-ticles provided data on skeletal relapse.

Data on complications were only avail-able in six patients; only one complication

occurred (Table 5).It can be recommended to perform

mandibular alveolar reconstruction from

the age of 16 years after a segmentalosteotomy using a distraction rate of

1 mm daily, a latency period of 57 daysand a contention period of 8 weeks withan internal bone-borne device. A 0.5 mm

rate and a 46 months contention periodis recommended when a distraction

implant is used, that will serve for pros-thetic treatment after the contentionperiod(Table 6).

Group 4: Bone transport

Bone transport DO was performed in a

total of 50 patients. Six patients (12%)underwent bifocal bone transport DOfor reconstructionof a neocondyle (TMJ

sample)9,121,122,124, while 42 patients(84%) underwent bifocal bone trans-

port6,9,76,117,118 and 2 patients (4%) tri-

focal bone transport76,113 DO for

reconstruction of segmental defects due

to trauma or tumor resection. A total of

45 patients underwent reconstruction of

segmental defects through compression

DO116118. Detailed data on age were

reported in 41 patients (82%) who

underwent bone transport DO. A total

of 39 patients (95.1%) were distractedabove the age of 16 years, varying from

20 to 68 years. Data on age were only

available in seven of the patients (15.6%)

who underwent compression DO; they

all were distracted at an age varying

from 20 to 35 years. A reverse-L oste-

otomy was performed in all six patients

who had TMJ reconstruction, while an

osteotomy of the mandibular body was

made in 88 patients (98.9%), who had

reconstruction of segmental defects by

bifocal, trifocal or compression DO. All

patients in this group had a distraction

rate of 1 mm daily. In the TMJ sample,five patients had a distraction rhythm of

twice a day, and one patient once a day.

In 84 (94.4%) of the 89 patients who

underwent segmental bone reconstruc-

tion through bifocal, trifocal bone trans-

port DO or compression DO, distraction

rhythms varying 24 times a day were

used. Data regarding the latency period

were reported in 43 patients (97.7%) whohad bifocal or trifocal bone transport

DO for reconstruction of segmentaldefects; 37 patients (88.3%) had a

latency of 1012 days. Only one patient

in the TMJ sample had information on

the latency period, which was 5 days. All

patients who underwent compression

DO had a latency period of 1012 days.

Data regarding the contention period

were available in 43 patients (97.7%),

who underwent segmental bone recon-

struction through bifocal or trifocal DO;

4 weeks, 1.52.5 months and 3 monthscontention periods were reported in 5

(11.6%), 37 (86.1%) and 1 (2.3%) patient,

respectively. A total of 33 patients

(73.3%) in the compression DO series

h a d a 12 months contention period,

while 12 (26.7%) had one of 1.52.5

months. In the TMJ sample, data were

only available in three patients; they all

had a contention period of 56 weeks. In

the TMJ sample, all patients had exter-

nal devices; five had monodirectional

devices and one had a bidirectional

device. All patients who underwent seg-

mental bone reconstruction throughbifocal and trifocal DO had external

devices, however only nine (20%) had

further information on the type of

device; four patients had monodirec-

tional, three bidirectional devices and

two multidirectional devices. In the com-

pression DO sample, all patients had

external devices but no information

regarding the type of the device wasreported. The amount of lengthening

was mentioned in all patients whounderwent segmental reconstruction by

Table 6. Treatment protocols for mandibular distraction osteogenesis

Type of surgery Rate Latency Contention Device

Mandibular lengthening

Mandibular micrognathia16 y**** Corticotomy 1/d 57 d 68 w E

IOsteotomy 1/d 57 d 68 w E

IMandibular retrognathia

>14 y Body osteotomy 1/d 57 d 68 w IMandibular widening

>12 y Symphyseal osteotomy 0.751/d 57 d 68 w IMandibular alveolar reconstruction>16 y Segmental osteotomy 1/d 57 d 8 w I

0.5/d 57 d 46 m IMandibular bone transportTMJ reconstruction>16 y Reverse-L osteotomy 1/d 57 d 56 w E

ISegmental defect reconstruction>16 y Body osteotomy 1/d 1012 d 68 w E

*DO can be performed in newborns with upper airway obstruction who are tracheostomy-dependent.**Ideal age group to perform DO in patients with severe craniofacial anomalies.***DO should only be performed in severe anomalies who hadnt prior surgery or eventually a secondary distraction in case of growth deficiency

after a costochondral graft86

.****DO can be performed in cases with delayed treatment or residual postsurgical growth disturbance.Distraction implant that will be used for prosthetic treatment after the contention period.Physical therapy during the activation and contention period to induce functional remodeling for the creation of a neocondyl.

94 Swennen et al.


7/15


8/15

internal distraction device. One patient

underwent maxillary advancement byDO using the RED system with adistraction rate of more than 1 mm. In

the maxillary alveolar reconstructiongroup, two patients were distracted at

1 mm daily (twice 0.5 mm) using aninternal monodirectional distractiondevice andfive were distracted at 0.5 mm

daily through the use of a distractionimplant. The 45 day latency period was

the most frequent for maxillary advance-ment DO, while all patients who under-

went alveolar reconstruction had oneof 57 days. Of the 122 patients thatunderwent maxillary advancement, data

regarding the contention period werereported in 116 patients (95.1%); 56

patients (48.3%) had a contention periodof 23 months and 60 patients (51.7%) acontention period of 24 weeks. Of those

60 patients, however, maxillary DO wasperformed in 54 using a rigid external

distraction device followed by night-timeretention with a facial mask during

48 weeks, while the other six patientswere distracted using a facial mask fol-

lowed by further orthodontic contentionwith elastics for a period of 3 months. Inthe alveolar reconstruction group, the

five patients who were distracted with adistraction implant, had a contentionperiod of 46 months, while the two

patients who were distracted with an in-ternal monodirectional distraction device,

had a contention period of 23 months.Data regarding the amount of maxillary

advancement were available in 121patients (99.2%) varying from 1 to17 mm; 50 patients (41.3%) had a distrac-

tion distance of more than 6 mm (36 had

a complete and 14 an incomplete Le FortI osteotomy). All patients who underwentalveolar reconstruction had data on the

amount of lengthening varying from 3 to15 mm; the bone-borne distraction de-

vices provided greater lengthening (715 mm) compared to the implant-borne

devices (35 mm). Follow-up data werereported in 109 patients (84.5%) andranged from 3 months to 3 years, with 79

patients (61.2%) followed up for 6 monthsor more. Data on relapse were reported

in 65 patients (50.4%); two had skeletalrelapse. In 87 patients (67.4%) informa-tion regarding complications was given;

2 complications occurred(Table 5).Thus, it appears recommendable to

perform maxillary advancement fromthe age of 5 years after a complete LeFort I osteotomy using an internal or

external device, a 1 mm distraction rate,a 45 days latency period and a 23

months contention period. In the 513years age group, an incomplete Le Fort I

osteotomy can be performed and a facialmask can be used for mild deformities

(Table 8). Recommendations concerningthe parameters for maxillary expansion(Table 8) are based on the scientific

report of M93, while those formaxillary alveolar reconstruction arethe same as for mandibular alveolar

reconstruction(Table 5).

Simultaneous mandibular and maxillarydistraction osteotogenesis

In this group, 24 patients (2.9%) under-

went simultaneous mandibular andmaxillary DO90,95,96. Of the 24 distrac-

tion procedures, 23 (95.8%) were carried

out in HFM patients and one in a TCpatient. Data on age were available forall patients and ranged from 11 to 32

years. All 24 patients had mandibulardistraction procedures with simul-

taneous maxillary DO through IMF.Two different surgical techniques werereported: 21 patients (all HFM) under-

went a unilateral mandibular ramuscorticotomy in combination with a com-

plete Le Fort I osteotomy at the affectedsite and an incomplete Le Fort I oste-

otomy at the unaffected site90,95; threepatients, two HFM and one TC, under-went a unilateral and bilateral osteo-

tomy, respectively, of the mandibularramus combined with a bilateral com-

plete Le Fort I osteotomy96. All patientshad a distraction rate of 1 mm daily anda latency period of 5 days. Contention

periods of 46, 7 and 810 weeks werereported in eight (33.3%), one (4.2%)

and 15 patients (62.5%), respectively.Distraction of the mandibular ramus

was performed in 21 patients (87.5%)using an external monodirectional device

and in three patients (12.5%) usingan internal monodirectional device.Data on mandibular lengthening were

reported in all patients varying from 12to 28 mm, while only 21 patients haddata on the degree of maxillary rotation

varying from 12 to 18 degrees. Follow-up was only reported in nine cases

(37.5%) and ranged from 4 to 25months. Data regarding relapse wereonly mentioned in two patients (8.3%),

showing no skeletal relapse. Informationon complications was reported in

Table 8. Treatment protocols for maxillary distraction osteogenesis


Maxillary advancement

513 y Incomplete Le Fort I 700/900 g 45 d 23 m Facial mask*Complete Le Fort I 700/900 g 45 d 23 m Facial mask*

1/d 45 d 24 w** RED1/d 45 d 23 m I

1316 y Complete Le Fort I 1/d 45 d 24 w** RED1/d 45 d 23 m I

>16 y Complete Le Fort I 1/d 45 d 24 w** RED1/d 45 d 23 m I

Maxillary expansion

>14 y Incomplete Le Fort I*** 0.33/d 57 d 36 m I/bone0.251/d 57 d 36 m I/tooth

Maxillary alveolar reconstruction>16 y Segmental osteotomy 1/d 57 d 2 m I

0.5/d 57 d 46 m I

Complete Le Fort I: pterygomaxillary disjunction is performed/Incomplete Le Fort I: the pterygomaxillary suture and septal base remain intact.*A facial mask should only be used for mild deformities (anterior crossbite


9/15

only eight patients (33.3%); only onecomplication occurred (Table 5).

This procedure can be performedfrom the age of 12 years using a 1 mm

distraction rate, a 5 day latency period,a 2 month contention period and anexternal or internal mandibular device in

combination with IMF. We further sug-gest that a mandibular device can be

combined with an internal maxillarydevice, instead of IMF. Both surgical

procedures can be performed(Table 9).

Midfacial and/or cranial distractionosteogenesis

A total of 96 patients (11.6%) underwentDO procedures involving the midface

and/or cranium5,7,1012,14,15,1721,27,48,49,68,71,77,81,100,125,131,136 (Table 3). Resultsof midfacial and/or cranial DO par-

ameters are shown inTable 10.Data onage were reported in 88 patients and

varied from 3 months to 35 years; 32patients were distracted at 47 yearswhile 28 patients underwent DO of the

midface and/or cranium under the age of4 years; 19 of those were distracted

under the age of 1.5 years. A total of 62patients (64.6%) had midfacial advance-ments, while 25 had monobloc (MB)

advancements after a MB osteotomy.Below the age of 4 years MB DO was the

most performed surgical technique in atotal of 19 patients (12 were below the

age of 1.5 years), while in the other agegroups the Le Fort III procedure wasthe most frequent. Three patients

with Aperts Syndrome underwent com-bined MB and facial bipartition (FB)

Table 9. Treatment protocols for simultaneous mandibular and maxillary distraction osteo-genesis


>12 y Ramus corticotomy 1/d 5 d 2 m E/monoLe Fort I osteotomy* IMF

Ramus osteotomy 1/d 5 d 2 m I/monoLe Fort I osteotomy** IMF

*Complete Le Fort I osteotomy at the affected site, and incompleted Le Fort I osteotomy at the

unaffected site.**Complete Le Fort I osteotomy at both the affected and unaffected site.

Table 10. Midfacial and/or cranial DO: DO parameters related to indication

Crouzons Aperts PfeiffersOtherCST Clefts UniCFM Total %

Age

12 y 4 3 1 1 9 10.288 100

Surgical technique

Monobloc osteotomy 2 8 8 7 25 26.0Fronto-orbital osteotomy 2 3 5 5.2Coronal craniectomy 1 2 3 3.1Bitemporal parietal craniotomy 1 1 1.0

Le Fort III 31 7 4 8 5 2 57 59.0Modified midfacial osteotomy* 2 2 2.1Le Fort II 1 1 1.0No osteotomy 2 2 2.1

96 100Distraction rate

1 mm/d 7 6 5 15 5 1 39 40.6>1 mm/d 27 11 7 1 3 1 50 52.1


10/15

procedures through DO below the age of

4 years18,20. Different distraction rateswere used; 39 patients were distracted at

1 mm daily, 50 patients at more than1 mm (1.53 mm/d) and 7 patients at less

than 1 mm (0.50.8 mm/d). In the agegroup below 4 years of age, 1 mm dailywas the most frequent distraction rate,

while in all other age groups usually adistraction rate of more than 1 mm daily

was used. Data on distraction rhythmwere reported in only 47 cases (49.0%);

five patients had a rhythm of 1 mm once

and nine a rhythm of 0.5 mm twice, while

with a distraction rate of more than 1 mmdaily, activation was performed alwaystwo or three times daily. Two patients

who underwent cranial DO through theuse of implantable springs had a continu-

ous distraction rhythm77. Latency periodswere reported in 82 cases and ranged from07 days. A total of 44 patients had a

latency period of 0 days while 25 patientshad a latency period of 57 days. In the

age group below 4 years, a total of 15patients had a latency period of 57 days,

while in all other age groups no latencyperiod was the most common. Data re-lated to the contention period were men-

tioned in 76 patients and ranged from 3weeks to 6 months; 38 patients had a con-

tention period of 6 months and 28 patientshad one of 23 months. In the age groupbelow 4 years of age, the 23 month con-

tention period was the most frequent,while in all other age groups the 6 month

contention period was the most common.

In three patients (3.1%) immediate osteo-synthesis was made at the end of the acti-vation period. Data on the obtaineddistraction distance were reported in 76

patients (79.2%) and varied from 7.5 to35 mm; 74 patients were distracted more

than 10 mm. A total of 13 patients (13.5%)were distracted through the use of externaldevices; 10 had monodirectional, 3 multi-

directional devices. In 83 patients (86.5%)internal devices were used; 80 had mono-

directional, one a bidirectional device andtwo implantable springs. Length of follow-

up was reported in 58 patients (60.4%) and

ranged from 2 months to 4 years, with only36 cases (37.5%) followed-up for 1 year or

longer. Data on relapse were only reported

in 19 cases (19.8%); 17 had no relapse

and two had mild relapse. Information

regarding complications was mentionedin 87 patients (90.6%); 25 complicationsoccurred (Table 5).

Under the age of 4 years, it appearsthat MB DO is mostly indicated as aresult of functional reasons (respiratory

problems, severe exophthalmos) andcan be performed after a complete MB

osteotomy using internal or externaldevices, a 1 mm distraction rate, a 57latency period and a 23 month conten-

tion period. Midfacial DO is indicatedfrom the age of 4 years in patients who

underwent early conventional fronto-cranial remodeling and advancement,after a complete Le Fort III osteotomy

using the same parameters as the mono-bloc procedure or using the con-

tinuous rapid midface DO parameters(Table 11).

Other types of DO of the craniofacialskeleton

Occasional reports on other types of DOof the craniofacial skeleton include

zygoma distraction21; orbital distrac-tion14, Le Fort II distraction48, nasal

bone distraction in hypertelorism74 anddistraction of scarred soft tissue beforesecondary bone grafting148.

Discussion

Craniofacial DO is a rapidly growing fieldof craniofacial reconstruction that has be-

come a accepted method worldwide forthe treatment of numerous congenital andacquired craniofacial anomalies. Clinical

parameters that affect treatment outcomeof craniofacial DO, include: (1) age; (2)

surgical technique; (3) distraction rate andrhythm; (4) latency period; (5) contentionperiod and (6) distraction device. Distrac-

tion osteogenesis, parameters, however,are not rigidly established and consider-

able variation exists between differentcraniofacial groups. In this article we have

attempted to provide standards for thesevariables and to develop treatment proto-cols for each type of craniofacial DO

based on the review of clinical and ex-perimental investigations reported in the

literature.Craniofacial DO has been reported

successfully in the paediatric, adolescent

and adult patient population. Patient ageat the time of distraction is the most im-portant single variable with potentially

the mostprofound effect on the outcome

of DO51. The human face does not de-

velop as an individual unit but as one

functional unit with growth of one area

depending on growth of the remaining

areas33. C& S8, showed in their

study of mandibular DO in 14 childrenwith a follow-up of 36 years that cranio-facial growth postdistraction was vari-

able; this was also observed by othercraniofacial teams39,51,75. The growth pat-

tern is modulated by both the originalgenetic predispostion of the native boneas well as the accompanying soft tissue

functional matrix39,40. Although the issueof overcorrection remains controversial,

overcorrection seems to be necessary ingrowing patients and younger patients

with greater future growth potential re-quire a greater amountof overcorrectionthan older patients39,40,86.

One of the most critical components ofDO is the surgical separation of thebony

fragments. The original I5456

concept of necessity of preserving endos-teum and periosteum has proved not to be

essential in DO of the human craniofacialskeleton. The literature on craniofacial

DO, however, is sometimes confusingregarding the terms corticotomy/osteo-

tomy, especially concerning mandibularlengthening procedures. Corticotomy isfrequently used, while in reality a com-

plete division of the bone is performed.Therefore, we interpreted the technique of

performing a corticotomy of the buccalcortex with a bicortical notch followed by

a peroperative greenstick fracture as acomplete separation of two bone seg-ments and hence as an osteotomy. In

patients with congenital and acquiredmandibular micrognathia, both an osteo-tomy and a corticotomy have been per-

formed successfully; 189 patients under-went an osteotomy (57.3%) and 141

(42.7%) a corticotomy. We suggest thata complete osteotomy will make the

distraction procedure more reliable,predictable and comfortable for thepatient.

Table 11. Treatment protocols for midfacial and/or cranial distraction osteogenesis


12 y Le Fort III 1/d 57 d 23 m I/E

>1/d** 0/d** 6 m** IMonobloc* 1/d 57 d 23 m I/E

*Monobloc (MB) osteotomy consists of a Le Fort III osteotomy and frontal osteotomy and canbe combined with facial bipartition (FB) in case hypertelorbitism and brachcephaly with facial

flatness.**Continuous rapid midface DO according to Chin and Toth12,136: intraoperative advance-ment up to 10 mm, followed by immediate distraction over 3 to 5 days and a prolongedcontention period.

98 Swennen et al.


11/15

The optimal rate of distraction, ac-

cording to adult orthopedic DO, is 1 mm

daily for each callusfield. Faster distrac-tion rates in enchondral bone result in

local ischaemia in the distraction gapand delayed ossification or pseudarthro-

sis, whereas slower distraction rates re-sult in premature ossification and

consolidation

56

. It has been suggested thatthe membranous bone of the craniofacial

skeleton behaves differently and that there

is a risk for premature consolidation if the

distraction rate is too slow, especially in

very young children where faster distrac-

tion rates comparing to DO of the enchon-

dral bones could be necessary136. This

review showed that a distraction rate of

1 mm daily remains the standard for man-

dibular lengthening, bone transport and

compression DO and for maxillary ad-

vancement and simultaneous mandibular/

maxillary DO procedures. A total of 451

patients who underwent these procedures

had data on complications; only six

patients (1.3%) had premature consoli-

dation. Although a distraction rate of

1 mm daily is effective in mandibular wid-

ening procedures, most patients (68.4%)

had a rate inferior to 1 mm (0.751 mm/d);

four premature consolidation occurred, al-

though not due to the slower distraction

rate but owing to a failure of the distrac-

tion device. Of the 23 patients that under-

went alveolar reconstruction procedures, a

total of 12 (52.2%) had a distraction rate of

1 mm daily, while 11 (47.8%) had a rate of

0.5 mm daily. None of these patients had

premature consolidation. Furthermore,

this review showed that in midfacial and/or

cranial DO, a distraction rate of 1 mm was

the most frequent in patients under the age

of 4, while in all other age groups, faster

distraction rates (1.53 mm/d) were re-

ported. Pseudarthrosis occurred in none of

the 87 patients who had data on compli-

cations. Success of DO not only depends

on the rate of distraction, but also on the

rhythm. I56 showed that osteo-

genic activity was greater when DO was

performed at 0.25 mm four times per day,

as opposed to 1 mm once a day, and even

greater when an autodistractor was usedthat allowed continuous distraction. Based

on our analysis of clinical articles on DO,

no conclusions could be made because of

lack of appropriate data regarding distrac-

tion rhythm. We suggest that several acti-

vations (24) a day, however, are certainly

more comfortable for thepatient.

According to I54,55 success ofDO depends on the response of the initial

callus to tensile stress. Therefore, in theenchondral bone, a latency period of 57days after surgery is necessary to allow

time for initial callus formation and heal-

ing of soft tissues5456. The membranous

bones of the craniofacial skeleton, which

are thin and have a rich blood supply aresignificantly different. Therefore, shorterlatency periods could be acceptable. This

review also showed that in craniofacialDO the 57 day latency period was the

most frequent. Even longer latencyperiods (712 days) were mentioned inpatients who underwent bone transport

and compression DO. On the contrary,shorter latency periods were reported in

maxillary, midfacial and cranial advance-ment DO procedures. A 45 day latency

period was most common reported formaxillary advancement. In the midfacialand cranial DO group a latency period of

57 days was the most reported in the agegroup below 4 years, while in all other age

groups distraction was most frequentlyimmediately started. However, 38 (63.3%)of those patients underwent continuous

rapid midface DO after a Le Fort IIIosteotomy and were all reported by the

same craniofacial team10,12,136. The highfrequency emission of the latency periodis thus not a widely agreed standard, but

results from the high numbers of casescontributed by a single team. We suggest

that a latency period to allow initial callusformation and healing of the soft tissues is

also necessary in DO of the craniofacialmembranous bones.

After the active period of distraction,the distraction appliances are left in placefor adequate consolidation and matur-

ation of the bony callus. This review re-vealed that the 68 week contention pe-

riod was the most appropriate for allmandibular lengthening and expansion

DO procedures and for the reconstructionof segmental defects by bone transport orcompression DO. Longer contention

periods were reported in maxillary (23months), midfacial and/or cranial DO

(23, 6 months). We suggest that despitethe good vascularization of the midfacialcomplex, longer contention periods are

necessary compared to the mandibleowing to the thin structure of the bone at

the distraction sites.Distraction devices used range from

traditional extraoral monodirectional

appliances as introduced byMCet al.83 tobidirectional6466,88 and multi-directional67,68,85,103,104 devices that per-

mit interceptive distraction. Continuedresearch has lead to the development

of intraoral devices, that can betooth26,41,60,61,142, implant37,38,69, orbone11,29,30,41,47,9193,140, supported,

and subcutaneous15,1719 devices used inmidfacial and cranial DO. It is crucial

for the device to be chosen with consid-

eration to the type of skeletal deficiency

and the patients needs. Devices withideal bone-device and bone-tooth move-

ment ratios of 1:1 are recommended.Craniofacial DO was found to be a

procedure with low peroperative andpostoperative morbidity. Data on com-

plications were mentioned in 604(73.0%) of the 828 patients who under-went craniofacial DO procedures.

Although a total of 133 patients (22.0%)had complications, most of these were

mechanical problems due to the distrac-tion appliance or minor local infections(Table 5). Only four hypertrophic scars

due to external devices and one pseudar-throsis were reported. It was remarkable

that only two (8%) cases of meningitiswere reported in monobloc DO proce-

dures. All authors noted that this was incontrast to conventional MBprocedureswhere the morbidity is higher17,18,20,136.

The growing body of literature oncraniofacial DO means that there is a

need for success criteria to provideobjective data in the future. In thisarticle we attempted to establish such

criteria that should be adequate fordeterming long-term functional and

aesthetic results, responding to the needsof our patients (Table 12). The literatureprovides a wide spectrum of useful

tools that can help to increase success,such as stereolithographic models112,130,

3D-cephalometric treatment plan-ning75,135, geometric models78,110,111,

114,129, computer-aided surgery141, ultra-sound35,36,58,80 and endoscopy109,138.The key to success for each type of

craniofacial DO, however, is carefultreatment planning39,40,111. Callus

manipulation can be helpful because itpermits fine-tuning of the occlusionduring distraction44,50,86.

Craniofacial DO has had an enormous

impact and will probably play a major rolein the future in the treatment of congenitaland acquired deformities of the craniofa-

cial skeleton. Through the use of DO,craniofacial deformities can be treated less

invasively. Because there is no need for asecond surgical site to harvest bone, oper-ating time, risk for blood transfusion,

postoperative morbidity and hospital-ization time are reduced. In addition, sim-

ultaneous expansion of the soft tissuefunctional matrix may improve long-term

skeletal stability. The literature dealingwith DO of the craniofacial skeleton, how-ever, shows a lack of long-term data, es-

pecially regarding skeletal relapse. Only479 patients (57.9%) had data on

follow-up and in only 248 patients (30%)



12/15


13/15

LD, L PF, P B, P RM,

T LA. Gradual bone distrac-

tion in craniosynostosis. Preliminary

results in seven cases. Scand J Plast

Reconstr Surg Hand Surg 1997: 31:

2537.28. D PA, K E, M H,

V MP. Intraoral distraction for

mandibular lengthening: a technical

innovation. J Craniomaxillofac Surg1996: 24: 9295.

29. D PA, K EM, V MP.

Mandibular distraction. Ann Chir Plast

Esthet 1997: 42: 547555.

30. D PA, K E, M H,

V MP. Submerged intraoral

device for mandibular lengthening.

J Craniomaxillofac Surg 1997: 25: 116

123.

31. D PA, T C, S V,

M H, V MP. Intraoral

mandibular distraction: indications,

technique and long-term results. Ann

Acad Med Singaport 1999: 28: 634641.

32. D P, N E, U I. Oral-acral syndrome and its correction using

maxillary bone distraction osteogenesis.

J Craniofac Surg 1998: 9: 123126.

33. E DH, H MG. Essentials of

facial growth. Philadelphia: W. B.

Saunders 1996: 117.

34. F AA, P JW. Manage-ment of severe cleft maxillary deficiency

with distraction osteogenesis: procedure

and results. Am J Orthod Dentofacial

Orthop 1999: 115: 112.

35. F RE, H D, P

K, S R. Ultrasound of seg-ment distraction and callus formation in

reconstruction of the mandible. Value of

surgical ultrasound of callus distractionof vascularized ilial crest transplants and

mandibular segments in a previously

irradiated area. Ultraschall Med 1997:

18: 177181.36. F RE, H D, P

K, S R. Application of B-scan

ultrasonography for analysis of callus

distraction in vascularized fibular grafts

of the mandible: a report of three

patients. J Oral Maxillofac Surg 1997:

55: 635640.37. G A, S G, K H.

Distraction implants: a new operative

technique for alveolar ridge augmen-

tation. J Craniomaxillofac Surg 1999:

27: 214221.

38. G A, S G, K H.Distraction implantsa new possibility

for augmentative treatment of the eden-

tulous atrophic mandible: case report.

Br J Oral Maxillofac Surg 1999: 37:

481485.

39. GBH, MCS, S

PE, MC JG. Vector of deviceplacement and trajectory of mandibular

distraction. J Craniofacial Surg 1997: 8:

473482.

40. G BH, S PE. Treatment

planning and biomechanics of distrac-

tion osteogenesis from an orthodontic

perspective. Semin Orthod 1999: 5:

924.

41. GCA, BWH, C GI,

R AM. Mandibular widening

by intraoral distraction osteogenesis. Br

J Oral Maxillofac Surg 1997: 35: 383

392.

42. H MB. New bone formation by

biological rhythmic distraction. JCraniofac Surg 1994: 5: 344347.

43. H MB. A future domain distractor

for the facial skeleton. J Craniofac Surg

1995: 6: 414416.

44. H PR, M MB. Orthodon-

tic management of the patient undergo-

ing mandibular distraction osteogenesis.

Semin Orthod 1999: 5: 2534.

45. H RJ, B SP. Mandibular

distraction lengthening in the severely

hypoplastic mandible: a problematic

case with tongue aplasia. J Craniofac

Surg 1994: 5: 305312.

46. H A A, S PA. Distraction

osteogenesis in a patient with micro-gnathia and a rare facial clefting

syndrome. Aust Orthod J 1998: 15: 200

205.

47. HJ, L F, Z JE. Initial

outcome of vertical distraction osteo-

genesis of the atrophic alveolar ridge.

Mund Kiefer Gesichtschir 1999: 3: S79

83.

48. H T, H A. Callus distrac-

tion of the midface in the severely atro-

phied maxilla-a case report. Cleft Palate

Craniofac J 1999: 36: 457461.

49. H S, SY, S

A, H K, P S. Frontoorbital

advancement by gradual distraction.

Technical note. J Neurosurg 1998: 89:

10581061.

50. H B, MCH, WKD.

The floating bone concept in intraoral

mandibular distraction. J Craniomaxil-

lofac Surg 1998: 26: S76.

51. H LH, K JH, G B,

MC MG. Mandibular growth

after distraction in patients under 48

months of age. Plast Reconstr Surg

1999: 103: 13611370.

52. H C, S MF,

S B. Feeding complications

in a six-week-old infant secondary to

distraction osteogenesis for airway

obstruction: a case report. J OralMaxillofac Surg 1999: 57: 14651468.

53. HCS, KWC, LWY, LEJ,

H KF, C YR. Mandibular

lengthening by distraction osteogenesis

in childrena one-year follow-up study.

Cleft Palate Craniofac J 1999: 36: 269

274.

54. I GA. The principles of the

Ilizarov method. Bull Hosp J Dis Orhop

Inst 1988: 48: 111.

55. I GA. The tension-stress effect

on the genesis and growth of tissues:

Part I. The influence of stability of fix-

ation and soft-tissue preservation. Clin

Orthop 1989: 238: 249281.

56. I GA. The tension-stress effect

on the genesis and growth of tissues:

Part II. The influence of the rate and

frequency of distraction. Clin Orthop

1989: 239: 263285.

57. J B, HD, RFL. Man-

dibular distraction osteogenesis in a

neonate. Arch Otolaryngol Head NeckSurg 1999: 125: 10291032.

58. J TH, K V,

H HP. Standardized ultrasound

follow-up of callus distraction of the

mandible. Mund Kiefer Gesichtschir

1999: 2: 331335.

59. J TH, K V,

H HP. Application of ultra-

sound in callus distraction of the hypo-

plastic mandible: an additional method

for the follow-up. J Craniomaxillofac

Surg 1999: 27: 160167.

60. K GF, V S JE. Long-

term effect of mandibular midline dis-

traction osteogenesis on the status of thetemporomandibular Joint, teeth, peri-

odontal structures, and neurosensory

funtion. J Oral Maxillofac Surg 1999:

57: 14191425.

61. K RS, F SD, E BN.

Distraction osteogenesis in Silver

Russell syndrome to expand the man-

dible. Am J Orthod Dentofacial Orthop

1999: 116: 2530.

62. K C. Ilizarov bone lengthening

for treatment of mandibular micro-

gnathism in childhood. Fortschr KieferGesichtschir 1994: 39: 150152.

63. KC, H HP. Lengthening of

the hypoplastic mandible by gradual dis-

traction in childhood-a preliminaryreport. J Craniomaxillofac Surg 1995:

23: 6874.

64. K C, H HP. Mandibularmicrognathism as a sequela of early

childhood capitulum fractures and their

treatment using distraction osteogenesis.

Fortschr Kiefer Gesichtschir 1996: 41:

147151.

65. K C, H HP. Correctionof mandibular hypoplasia by means

of bidirectional callus distraction.


66. K C, H HP. Mandibular

distraction osteogenesis as first step in

the early treatment of severe dysgnathiain childhood. J Orofac Orthop 1996: 57:4654.

67. K C. Multidimensional distraction

osteogenesis for profile correction in

severe facial asymmetries. Mund Kiefer

Gesichtschir 1997: 1: S98101.68. KC. Midfacial callus distraction in a

patient with Crouzon syndrome. MundKiefer Gesichtschir 1998: 2: S5257.

69. K C, P M, K A,

C JE. Initial experiences with a

new distraction implant system for

alveolar ridge augmentation. Mund

Kiefer Gesichtschir 1999: 3: S7478.



14/15

70. K EW, F AA, G TW,

P JW, L WR. Velopharyngeal

changes after maxillary advancement in

cleft patients with distraction osteogen-

esis using a rigid external distraction

device: a 1-year cephalometric follow-

up. J Craniofac Surg 1999: 10: 312

320.

71. K S, H T, S A,

K K. Unilateral coronal synos-tosis treated by internal forehead dis-

traction. J Craniofac Surg 1999: 10:

467472.

72. K O, L G, E

Y, E A. Repeated mandibular

lengthening in Treacher Collins syn-

drome: a case report. Int J Oral Maxil-

lofac Surg 1995: 24: 406408.

73. K EM, D PA, V MP,

A G, P M. Bone distrac-

tion using an external fixator: a new

mandibular lengthening technic. A pre-

liminary study apropos of 2 cases of

children with mandibular hypoplasia.

Rev Stomatol Chir Maxillofac 1994: 95:411416.

74. K Y, A T, K M,

OK. Histological examination of

regenerated bone through craniofacial

bone distraction in clinical studies. J

Craniofac Surg 1999: 10: 308311.

75. KB, FAA, PJW.A longitudinal three-dimensional evalu-

ation of the growth pattern in hemifacial

microsomia treated by mandibular dis-

traction osteogenesis: a preliminary re-

port. J Craniofac Surg 1999: 10: 480486.

76. L D, B MB, KE, C JF. Mandibular reconstruc-

tion of gunshot wounds by progressive

bone distraction. Report of five cases.Ann Chir Plast Esthet 1998: 43: 141

148.

77. L C, S Y,K O, O R. Spring

mediated dynamic craniofacial re-

shaping. Case report. Scand J Plast

Reconstr Surg Hand Surg 1998: 32: 331

338.

78. L HW, P GT, T D,

C DW. Geometric evaluation ofmandibular distraction. J Craniofac

Surg 1995: 6: 395400.

79. L HW, P GT, L

SA, W T. Planning mandibular

distraction: preliminary report. Cleft

Palate Craniofac J 1995: 32: 7176.

80. L R, C Y, B P,F M. The value of ultrasono-

graphic monitoring in mandibular

lengthening using the Ilizarov principle.

Rev Stomatol Chir Maxillofac 1996: 97:

313320.

81. M D, AE. Distraction ofthe maxilla. Ann Chir Plast Esthet 1997:

42: 557563.

82. M DJ. Review of devices for dis-

traction osteogenesis of the cranio-

facial complex. Semin Orthod 1999: 5:

6473.

83. MC JG, S J, K N,

T CH, G BH. Lengthen-

ing the human mandible by gradual

distraction. Plast Reconstr Surg 1992:

89: 110.

84. MC JG. The role of distraction

osteogenesis in the reconstruction of the

mandible in unilateral craniofacial

microsomia. Clin Plast Surg 1994: 21:

625631.85. MCJG, W JK, G

BH, C JS. Controlled multipla-

nar distraction of the mandible: device

development and clinical application.


86. MCJG, S EJ, G

BH. Distraction osteogenesis of the

mandible: a ten-year experience. Semin

Orthod 1999: 5: 38.

87. MC SU, G BH,

MC JG, S D. Effect

of mandibular distraction on the tempo-

romandibular joint: Part 2, Clinical

study. J Craniofac Surg 1995: 6: 364367.

88. M F, O-M F. Man-dibular elongation and remodeling by

distraction: a farewell to major osteo-

tomies. Plast Reconstr Surg 1995: 96:

825842.

89. M F, O-M F,

PA M, B J. Maxillary

distraction: aesthetic and functional

benefits in cleft lip-palate and prog-

nathic patients during mixed dentition.

Plast Reconstr Surg 1998: 101: 951

963.

90. M F. Combined maxillary and

mandibular distraction osteogenesis.

Semin Orthod 1999: 5: 4145.

91. M MY, JW, J

N. Mandibular distraction using a

dynamic osteosynthesis system:

MD-DOS. Concept and surgical tech-

nique. Rev Stomatol Chir Maxillofac

1998: 99: 223230.

92. M MY. Horizontal anchorage

in the ascending ramusa technical

note. Int J Adult Orthodon Orthognath

Surg 1998: 13: 5965.

93. M MY. Transpalatal distrac-

tion as a method of maxillary expansion.

Br J Oral Maxillofac Surg 1999: 37:

26872.

94. M MH, G-S G,

P TW, A AH,

N DJ, DDJ. Mandibularlengthening by distraction for airway

obstruction in Treacher-Collins syn-

drome. J Craniofac Surg 1994: 5: 2225.

95. O-M F, M F,

AL, R C, A JS.

Simultaneous mandibular and maxillary

distraction in hemifacial microsomia in

adults: avoiding occlusal disasters. Plast

Reconstr Surg 1997: 100: 852861.

96. P BL, K GJ, T R,

T M, M JB, K LB.

Simultaneous maxillary and mandibular

distraction osteogenesis with a semi-

buried device. Int J Oral Maxillofac

Surg 1999: 28: 28.

97. P MB, A C. Sim-

ultaneous mandibular distraction and

arthroplasty in a patient with temporo-

mandibular joint ankylosis and man-

dibular hypoplasia. J Oral Maxillofac

Surg 1999: 57: 328333.

98. PJM, GDP, LB,

C NC. Skeletal distraction of thehypoplastic mandible. Ann Plast Surg

1995: 34: 130137.

99. P DH, BR, V K,

K LB. Use of a skeletal distraction

device to widen the mandible: a case

report. J Oral Maxillofac Surg 1993: 51:

435439.

100. P JW, F AA, C

FT, B R, R D, C

M. Monobloc craniomaxillofacial dis-

traction osteogenesis in a newborn with

severe craniofacial synostosis: a prelimi-

nary report. J Craniofac Surg 1995: 6:

421423.

101. P JW, B GL,R S, F AA, C

M. Simultaneous distraction osteo-

genesis and microsurgical reconstruction

for facial asymmetry. J Craniofac Surg

1996: 7: 469472.

102. P JW, FAA. Distractionosteogenesis: its application in severe

mandibular deformities in hemifacial

microsomia. J Craniofac Surg 1997: 8:

422430.

103. P JW, F AA. Manage-

ment of severe maxillary deficiency in

childhood and adolescence through dis-traction osteogenesis with an external,

adjustable, rigid distraction device.

J Craniofac Surg 1997: 8: 181186.104. P JW, FAA. Rigid exter-

nal distraction: its application in cleft

maxillary deformities. Plast Reconstr

Surg 1998: 102: 13601372.105. R A, L M, L D.

Lengthening of the mandible by distrac-

tion osteogenesis: report of cases. J Oral

Maxillofac Surg 1995: 53: 838846.

106. R A. Surgically-assisted ortho-

pedic protraction of the maxilla in cleftlip and palate patients. Int J Oral

Maxillofac Surg 1999: 28: 914.

107. R JC, D P. Man-

dibular distraction in glossoptosis-

micrognathic association: preliminary

report. J Craniofac Surg 1998: 9: 127

129.108. RDA, GAK, MCJG,

S MA, L DR, G

BH. A CT scan technique for quantitative

volumetric assessment of the mandible

after distraction osteogenesis. Plast

Reconstr Surg 1997: 99: 12371250.109. R JP, P JC, Y

MJ. Role of endoscopic and distraction

techniques in facial and reconstructive

surgery: new technology or improved

results. J Craniofac Surg 1998: 9: 285

299.

102 Swennen et al.


15/15

Documents

Craniofacial Distraction, A Review