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Inicio Revista Mexicana de Ortodoncia Osteogenic mandibular distraction in Nager’s Syndrome. Case report
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Vol. 1. Núm. 1.
Páginas e44-e53 (Octubre - Diciembre 2013)
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2937
Vol. 1. Núm. 1.
Páginas e44-e53 (Octubre - Diciembre 2013)
DOI: 10.1016/S2395-9215(16)30120-9
Open Access
Osteogenic mandibular distraction in Nager’s Syndrome. Case report
Distracción osteogénica mandibular en síndrome de Nager. Reporte de un caso
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...
Nubia Yadira Prado Bernal
, Norma Villanueva§, Héctor Rincón
* Former resident maxillofacial surgery «Federico Gómez» Children’s Hospital, Mexico City
§ Attending Maxillofacial Surgeon «Federico Gómez» Children’s Hospital, Mexico City
Chief of Maxillofacial Surgery «Federico Gómez» Children’s Hospital, Mexico City
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Table I. Nager’s syndrome associated malformations compared with others with similar phenotype.
Table II. Cephalometric tracing measurements, multiple authors (Rickets, Jarabak, Steiner, Epker).
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Abstract

Osteogenic distraction is used nowadays for tissuelengtheningdue to the bone formation that occurs during the progressive segment separation after corticotomy, being very useful in dentofacial anomalies, especially in severe hypoplasia. We present the case report of a patient with Nager’s syndrome, acrofacial dysostosis of the preaxial type, severe mandibular hypoplasia and oligodonthia who was treated by means of distraction osteogenesiswith ramus osteotomies to lengthen the mandible. He was treated with a Spring Bite-type orthopaedic appliance after the osteotomies. We conclude that treatment with mandibular distraction should be comprehensive and supported with the use of miofuncional advices.

Key words:
Nager’s syndrome
postaxial acrofacial dysostosis
mandibular distraction
mandibular hypoplasia and oligodonthia
Resumen

La distracción osteogénica es actualmente utilizada para el elongamiento tisular, gracias a la neoformación ósea que ocurre durante la separación progresiva de los segmentos después de la corticotomia de los mismos. Se ha utilizado con excelentes resultados en anomalías dentofaciales especialmente en hipoplasias mandibulares severas. Reportamos un paciente con síndrome de Nager, disostosis acrofacial del tipo preaxial con hipoplasia mandibular severa y agenesias dentales, quien fue tratado con distracción mandibular a través de corticotomías en ramas mandibulares y posterior manejo ortopédico funcional con aparatología tipo Spring Bite. Con la presentación de este caso podemos sugerir que el manejo de la distracción mandibular debiera ser apoyado con el uso de aparatología miofuncional.

Palabras clave:
Síndrome de Nager
acrofacial disostosis preaxial
distraccion mandibular
hipoplasia mandibular
oligodoncia
Texto completo

Nager’s syndrome was described for the first time by Nager and De Reynier in 1948; there have been 100 cases reported in the literature up to now.1–3

It belongs to the vast group of otofacialmandibular disostosis such as the Treacher Collins Syndrome, Nager’s Syndrome, Pierre Robin Anomaly, Hemifacial Microsomia, among others. These are malformations associated with a hypoplasia or agenesis of the earlobe and mandibular hypoplasia among other facial deformities which can be found isolated or in association with other malformations.3,4

Nager’s syndrome is a preaxial acrofacial disostosis that consists in facial malformations associated with radial effects (absence of the radial or tibial axisfirst metacarpian and first toe).1–5 It has a recessive autosomal genetic pattern and an alteration of the 9q32 chromosome, 1q12q21 deletion with an average neonatal birth rate of 20%, growth delay of 10% and usually normal intelligence.2–4

With craniofacial characteristics in 25% of the cases, it presents cygomatic and maxillaryhypoplasia, severe mandibular micrognathia, outwards and downwards palpebral fissures, absence of the lower lid eyelashes, lower lid coloboma, broad nasal bridge, depressed tip of the nose, limited mandibular movements secondary to alterations in the mandibular ramus and the temporomandibular joint, macrostomia, cleft lip and palate, soft palate agenesis, short soft palate, high and narrow palate, dysplasic earlobes, atresia of theear meatus, conductive deafness, enamel hypoplasia and oligodonthia. In the muscular skeletal system, it is characterized by radial anomalies, 75% of them being radial hypoplasia or aplasia, sinostosis of the carpal bones, absence of the 5th metacarpian, agenesis of toes and anomalies of pelvic limbs. Cardiovascular anomalies such as Fallot tetralogy and/or ventricular septum defect may be present.1–5 It can also be associated with vesicoureteral reflux or renal agenesis.3

Acral deformities associated with a facial disostosis allow it to be differentiated from the Treacher Collins syndrome, the Nager syndrome and other dysplasiasof the 1st and 2nd facial arch (Table I).3,4

Table I.

Nager’s syndrome associated malformations compared with others with similar phenotype.

Malformation  Propositus  Sx Nager  Sx Miller  Sx. 1 and 2 brachial arch 
Cranium  yes  25%  yes  10% plagiocephalic 
Zygomatic bone, maxillary and mandibular hypoplasia  yes,mandible  yes,mandible  yes zygomatic,mandibular  65% skeletal asymmetry Temporal, zygomatic, ramus y condilar hypoplasia 
Ectropion  no  no  yes  Blepharoptosis 
Long philtrum  yes  no  yes  no 
Inclined palpebral fissures  yes  100%  no  Narrow palpebral fissures 
Lack of eyelashes  no  80%  no  35% epibulbar Tumors 
Lower lid coloboma  no  50%  yes  20% lower lid coloboma 
Broad nasal bridge with descended tip of the nose  yes  constant  no  no 
Mandibular Ankylosis  no  25%  no  yes 
Macrostomia  no  20%  no  yes 
Cleft palate  no  60%  no  15% 
Soft palate agenesis or partial agenesis  no  60%  no  no 
Short soft palate  yes  60%  constant  35% paralysis VF insufficiency 
High and narrow palate  yes  60%  constant  no 
Submucous cleft palate  no  60%  constant  no 
Bifid uvula  no  60%  constant  no 
Cleft lip  no  10%  constant  no 
Hypoplasia oligodonthia  yes  constant  No  no 
Dysplasic earlobes  yes  80%  constant wine-glass shape  65% dysmorphic earlobes, microthia, 
Hypoplasia, helix and tragus  no  constant  constant  anothia, preauricular 
CAE Atresia  yes  85%  constant  appendicis o fissures 
Conductive deafness  yes  85%  constant  15% 
Muscular skeletal system Radial abnormalities  yes  75%  no  10% 
Radial hypoplasia or aplasia  no  25%    no 
Carpal bones synostosis  no  constant  yes  yes 
Absence of the 5 metacarpian  no  no  yes  no 
Toe agenesis  no  no  constant  no 
Pelvic abnormalities  yes  constant  yes   
Growth delay  yes  10%  no   
Cardiovascular System        5 a 58% 
Fallot Tetralogy  no  frequent  no  65% 
Ventricular-septal defect  no  frequent  no  yes 
Genitourinary System  no  frequent  no  no 
Vesicular uretral reflux  no  frequent  no  yes 
Renal agenesis  no  frequent  no  no 
Central Nervous System        Facial paralysis 
Normal Intelligence  yes  yes  no  5 a 15% Mental deficiency 
Learning difficulties  yes  constant  no  yes 
Cervical vertebrae fussion  no  no  no  60% 
Costal abnormalities  no  no  no  30% 
Genetics    9q32 deletion 1q12-q21    5p del 6 q, trisomy 7 mosaicism, del 8q 
Osteogenic distraction

Osteogenic distraction is a method for bone lengthening that allows the correction of deformities and bone deficiencies with the subsequent correction of the soft tissues6 by means of a distracting appliance.

It was first used by Dr. Codevilla in 1905, when he performed femur osteotomies. This technique remained forgotten for several decades until Dr. Ilizarov in 1950 made it popular in the field of trauma and orthopedics.8,9 Its clinical and systematic application in craniofacial deformities began with McCarthy in 19929–11 mainly by using it in children with hemifacial microsomias for mandibular distraction.11–14Its indications have broadened for the correction of facial asymmetries of diverse etiologies such as severe maxillaryand mandibular retrognathias.9,10

Osteogenic distraction is a biological procedure of new bone formation by applying constant traction forces during a period of time. These forces are applied with a distraction device on a bone area that has been previously weakened by corticotomy.6–8 Thedistraction device is an expansion screw that has been universally graduated in such a way that every 360 degree turn will provide a 0.5mm18,19 movement; all this process is under biological principles such as: vascular preservation, adequatelatency period, distraction rhythm and consolidation period. During this last phase the objective is to keep the bone segment immobile to achieve a correct organization and condensation of the elements that will offer the characteristics of resistance to the newly formed tissue.6,7,18

Physiologically, the process of distraction begins when the loading stimulus is detected by the osteoblast thus triggering a fast and continuous signaling cascade; in this process the bone growth and differentiation is established, the osteoblastic proliferation is followed by cell differentiation and finally by the mineralization of the extracellular matrix; also, specific factors have been identified associated with the beta 1 transforming growth factor (TGFB-1), the insulinic growth factor(IGF-1) and the E2 prostaglandin (PGE2). The created bone gap is initially filled by fibrillar connective tissue with collagen fibers oriented parallel to the force vector of the distraction forces.6–8

Once the tissue neoformation objective has been accomplished, a tissue regeneration phase of this newly formed tissue follows.18,19

The success of the distraction will depend on numerous factors such as: small incisions, preservation of the periostium and vascularity, latency period without distraction of 5 to 7 days, an expansion rhythm of 1mm once a day, a stabilization period or consolidating phase of 8 to 12 weeks and finally, a remodeling period.18

On this last period one can have more certainty on the formation of new bone tissue as well as in the histodistraction; in this stage the distraction appliance may be removed. Equally important is to verify this process by periodical image techniques to monitor the correct function and evolution of the distraction.19–22

Difficulties have been found such as the distractor selection, the determination of the direction of the vector, the site for the osteotomy and patient cooperation.23,24

The orthodontist should be present during the complete process of study and treatment of these patients, playing an important role in the diagnosis, treatment planning and postsurgical management.

The wide variety of mandibular anomalies associated with a syndromic deformity makes it difficult to predict the treatmentresult, in spite of the surgical, orthodontic and physiotherapeutic management. Alsorelapse appears to be inevitable and overcorrection may not compensate central growthalterationsand poor muscular function.Nevertheless, osteogenic distraction has proved to be the most useful method for solving breathing and swallowing problems in patients with severe mandibular hypoplasia asides of improving facial esthetics.9,10

In mandibular retrognathias there is a severe hypoplasia of the mandibular ramus, body and chin so by creating new bone in the posterior part of the mandible (body and ramus) a more anterior positioning of the mandible is obtained,however a moreeffective chin is not always obtained.13,14Once growth has ended the convenience of performing only a mentoplasty or mandibular osteotomies must be reconsidered to achieve the esthetic results.

It is so that osteogenic distraction has quickly become the treatment of choice in craniofacial syndromes with severe mandibular deformities because it is possible to perform during childhood opposite to conventional treatments which may only be performed upon completion of growth; this statement has been controversial due to the fact that multiple studies also report successful results by performing mandibular osteotomies in children.8,19,25

Finally, inaddition to being controversial it is difficult to predict that a mandibular distraction during childhood will definitely substitute an advancement osteotomy in the adult.10,11,13

Mandibular osteotomies

Poswillo and Obwegeser in 1974 stated that surgical trauma in children may alter the mandibular functional matrix and interfere insubsequent facial growth.26,27 However, Converse, Horowitz, Coccaro and Woodsmith in 1973 recommended mandibularsurgery in children pursuing the following objectives:

  • 1.

    To improve mandibular symmetry by performing bilateral osteotomies in the ramus during the mixed dentition.

  • 2.

    To provide maxillary growth in response to mandibular growth.

  • 3.

    To provide an adequate height of the ramus by using an interocclusal splint.

  • 4.

    By expanding the facial skeleton early,the soft tissues will respond adequately.26,27

In 1941 Converse and Rushton reported the first mandibular osteotomies in children using horizontal osteotomies performed superior to the inferior dental nerve and placing interpositional iliac grafts after the placement of interocclusal splints that increased vertical dimension and thus the augmentation of the mandibular ramus.26

Osborne supported the benefits of mandibular osteotomies performed prior to six years of age. He stated that an early surgery on the mandible provides an opportunity for normal development of the maxilla which is also affected by a hypoplasic mandible.26–28

In 1970 Delaire recommended mandibular surgeries even at an earlier stage, between the ages of 4 to 6 elongating a short ramus with inverted L osteotomies and placing a rib interpositional graft.26–29

Case report

We present an eight-year-old male patient diagnosed with acrofacial dysplasia compatible with Nager’s syndrome with characteristic phenotype and the following relevant findings: inclined palpebral fissures, broad nasal bridge, severe mandibular hypoplasia, atresia of the acoustic meatus, conductive deafness, protruded earlobes, oligodonthia, excessively short soft palate, brachydactilia and pes cavus (claw foot) (Figure 1).2,4,5

Figure 1a.

Initial phase. Notice the characteristic face of Nager’a Syndrome. 1b. Profile view. 1c. Post mandibular distraction control 1 year later. 1d. Profile view 1 year later. 1e. Post mandibular distracion control 2 years later. 1f. Profile view 2 years later.

(0,41MB).

An interdisciplinary consult with our serviceis performed for the evaluation and management of the severe mandibular hypoplasia and the oral hypometria of 20mm.

A complete study of the case is performed with a clinical facial esthetic analysis and lateral cefalometry in which a severe mandibular hypoplasia with a delayed growth is evident. Temporomandibular joint pathology is discarded (Figure 2).

Figure 2.

Radiographic study where the short mandibular, ramus and the oligodonthia can be observed. 2a. Panoramic radiograph. 2b. PA radiograph. 2c. Lateral cephalogram.

(0,15MB).

The patient enters a protocol for mandibular osteogenic distraction in which placement of bilateral extraoral mandibular distractors is suggested. A distraction for a total mandibular advancement of 25mm is planned (Figure 3).

Figure 3.

Surgical procedure. 3a. Corticotomy of the ramus. 3b. Extraoral distractors in position. 3c. PA radiograph with full distraction. 3d. Panoramic radiograph before distractors removal.

(0,21MB).
Surgical technique

The procedure is begun under balanced general anesthesia. The patient presented a difficult airway so the use of nasofibroendoscopy was required for an optimum nasotracheal intubation.

Asepsis of the intervention area was performed and sterile fields were placed.

Throughan intraoral approach, a 2 cm incision was performedin the oblique line region, a mucoperiosteal flap was dissected and ramus corticotomies were marked using an oscillating saw (Stryker Corporation, Kalamazoo, Mich. USA). On both sides of the osteotomy two 2.4×30mm bicortical intraosseous screws (w. Lorenz-Bioment Microfixation HTX-Drive JacksonvilleFL)were placed percutaneously and attached to the external one-way distractor (25mm. Eby fix w. Lorenz-Bioment Microfixation HTX-Drive Jacksonville FL). The same procedure is performed on the other side (Figure 3).

The position of the screws was determined prior to the surgical procedure taking underconsideration the degree of mandibular shortening, the location of the tooth germ and the prediction for mandibular growth (Figure 3b).

The distraction process is begun on the 5th day post-surgery, at a 1mm per day rate for 21 days with a consolidation period of 8 weeks.

Mandibular growth, occlusion and facial symmetry were assessed and regular radiographic controls were performed as well. Myofunctional therapy was continued due to the oral hypometria an also the management with excursive movements with a spring bite-type appliance (Figures 4and5).

Figure 4.

Postsurgical radiographic control.

(0,16MB).
Figure 5.

Cephalometric tracings. 5a. Initial. 5b. Final.

(0,11MB).
Results

The final result was assessed at the endof the distraction period, upon removal of the distractor, 1 year and 2 years after the procedure (Figure 1). Cephalometric tracings were performed and they showed an overall improvement of the mandibular position. An important mandibular advancement was obtained until a 4mm overjet was reached (Figure 5).

A profile improvement was accomplished, obtaining a mandibular advancement of 20mm and a 36mm mouth opening. Due to the use ofmyofunctional appliances astimulus for mandibular growth was evident and an adequatevertical dimension was obtained. By doing so, horizontal growth was accomplished despite the use of a one-way distraction in the ramus and the fact that the patient presented dental agenesias which prevented an adequate interocclusal relationship (Figures 1e and f, 6).

Figure 6.

Final occlussion control. 6a y b. Monomaxillary and bimaxillary Spring bite. 6c. Overjet and overbite

(0,32MB).

Facial characteristics and interocclusal relationship as well as the anterior guidance were satisfying, contributing to the esthetic improvement of the patient (Figures 1 c, d, f, and6) Table II).

Table II.

Cephalometric tracing measurements, multiple authors (Rickets, Jarabak, Steiner, Epker).

Cephalometry
  RANK  June 20, 2005  Sep 22,2007 
Maxillary depth  90±3o  84  85 
Mandibular depth  88±3o  82  87 
Facial depth  86±3o  83  86 
Facial axis angle  90±3o  83  87 
Mandibular body length 71mm±64  76   
Ramus length  44±21  26 
SNA  82o  70  71 
SNB  80o  65  69 
ANB  2o 
Overjet  2mm  12 
Overbite  2mm 

The patient remains under growth and development control with the intention of overcorrecting his overjet, stimulating mandibular growth and trying to create more interarch space foreseeing the subsequent rehabilitation by means of endoosseous dental implants thus achieving a normal vertical dimension and restoring masticatory function.

Discussion

Mandibular hypoplasia is the most commonly found dentofacial deformity.11,13,14

Severe mandibular deficiency maybe nonsyndromic, an isolated finding or a morphological component of some dentofacial anomaly, in this case specifically, Nager’s syndrome among others.1–5

Functional consequences of severe mandibular hypoplasia includeairway obstruction, obstructive sleep apnea, speech and feeding difficulties and many times, lack of psychosocial adaptation.11,13,14

On the long term, children who are affected by this condition may suffer a delay in growth, cardiopulmonary changes, (pulmonary hypertension and rightcardiac failure) and in some cases, death.9,10

For many years this dentofacial deformity has been treated withosteotomies of the mandibular body and ramus and interpositional graft placement with acceptable results although some authors state that such osteotomies may alter the functional matrix of the mandible.26,17,28,29Additionally, it is known that mandibular advancements of more than 10mm. with sagittal and inverted L osteotomy techniques are unpredictable and their long term stability may be compromised.25,30

Since its introduction, osteogenic distraction hasprovedto possess many advantages for the treatment of severe mandibular hypoplasias, especially when it comes to patients with syndromic-type dysgnathias in whom structural anatomy is altered18,19 and the magnitude of the corrective treatment is far greater. In the same manner, the postsurgical stability favored by distraction, which is not only of the bones but of the soft tissues as well, could be superior to that of osteotomies in some specific cases.9,10

A disadvantage of maxillofacial distraction is its incapacity to achieve precise movements just as the ones achieved with bilateral distractors as well as the management of vectors.23,24

In the case report hereby presented, the following were achieved: increase in mandibular body and ramus length in addition to the soft tissues, all thanks to the use of osteogenic distraction and orthopedic therapy, promoting a counterclockwise rotation of the mandible and thus achieving a better interocclusal relationship.

Nevertheless, using osteogenic distraction as the only method for achieving a functional and harmonic occlusion is still a controversy.15,17

It has also been reported that one of the late complications of osteogenic distractionis the correct management of vectors, with an incidence between 7.2 to 8.8% and even more with the use of a one-way distractor.23,24

In children younger than six years old, osteogenic distraction techniques have been able to achieve very satisfying mandibular advancements that could have been very difficult to accomplish previously.

Osteogenic distraction and conventional osteotomies may be viable options for mandibular advancement depending on the specific case to treat. Therefore, it is necessary to take under consideration other factors such as mandibular morphology, bone quality, the surrounding soft tissue and the developing dentition.9–14,30

Finally, this patient obtained an improvement in oral hypometria due to the increase in the ramus growth and a better positioning of the mandibular body and secondly, the effect on muscular relationships. Still, the effect of myofunctional appliances over muscular relationshipsremains controversial.15–17

In the same manner, mandibular advancement during early childhood does not eliminate the need for orthognatic surgery when the patient has reached its skeletal maturity, thus it is necessary to reevaluate the case once the last peak of growth has ended.9,10,30

Conclusions

At present there are very well known protocols that describe the process of osteogenic distraction, establishing its latency period, rate,frequency and remodeling period. Still there are no treatment protocols which include the use of myofunctional appliances at an early stage after performing the mandibular distractions.

This type of treatment must be considered in patients with severe mandibular deficiencies, significant oral hypometria, oligodonthia and lack of appropriate interocclusal relationships that would allow an adequate vertical dimension. All of these factors contribute to a more difficult direction of the vector, even more if we are dealing with one-way distractors.23,24

In this specific case, the patient will remain under growth and development control so that once the last peak of growth has concluded we can reassess the mandibular projection and determine the need for mandibularadvancement osteotomies or just a sliding mentoplasty for better chinprojection.Equally importantis the need for an adequate interocclusal relationship so that endoosseous dental implants can be placed.

Acknowledgements

To all of my teachers and a special recognition to Dr. Juan Carlos López Noriega and Dr. Rafael Ruiz for their invaluable support during the entire process of my professional education.

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References
[1.]
P. Bowen, F. Harley.
Mandibulo-facial dysostosis with limb malformations (Nager’s acrofacial dysostosis).
Birth Defects Orig Ail Ser, X (1974), pp. 109-115
[2.]
R. Zori, B. Gray, A. Bent-Williams, J. Zackowski.
Preaxial acrofacial dysostosis (Nager syndrome) associated with an inherited and apparently balanced X;9 translocation: prenatal and postnatal late replication studies.
Am J Med Genet, 46 (1993), pp. 379-383
[3.]
R.J. Gorlin, M. Cohen.
Syndromes of the head and neck.
4ta Ed, OXFORD, University Press, (2001),
[4.]
L. Burglen, V. Soupre, M. Diner.
Dysplasies oto-mandibulaires : génétique et nomenclature des formes syndromiques.
Ann Chir Plast Esthét, 46 (2001), pp. 400-409
[5.]
B. Herrmann, R. Karzon, D. Molter.
Otologic and audiologic features of Nager acrofacial dysostosis.
International Journal of Pediatric Otorhinolaryngology, 69 (2005), pp. 1053-1059
[6.]
S. Swennen, R. Dempf.
Cranio-Facial Distraction Osteogenesis: A review of the literature Part II Experimental Studies.
Int J Oral Maxillofac Surg, 31 (2002), pp. 89-103
[7.]
P. Kessler, F. Neukama, B. Wilfang.
Effects Of Distraction On Bony Regeneration.
British J Oral Maxillofac Surg, 43 (2005), pp. 392-398
[8.]
M. Milloro.
Peterson’s Principies of Oral and Maxillofacial Surgery.
2da Ed, Bc Decker Inc, (2004),
[9.]
R. Ruiz, T. Turvey, B. Costello.
Mandibular Distraction Osteogenesis in Children.
Oral Maxillofacial Surg Clin N Am, 17 (2005), pp. 475-484
[10.]
M.A. Sancho, F. Parri, F. Rivera.
Elongación ósea progresiva del área máxilo-facial: Distracción mandibular.
Cir Pediatr, 13 (2000), pp. 167-169
[11.]
A. Fuente del Campo, M. Castro, M. Yudovich.
Distracción osteogénica de la mandíbula Principios e indicaciones.
Rev Hosp Gral Dr. M Gea González, Vol3 (2000), pp. 7-12
Enero-Marzo
[12.]
F. Molina.
Combined Maxillary and Mandibular Distraction Osteogenesis.
Seminars in Orthodontics, Vol 5 (1999), pp. 41-45
(March)
[13.]
R. Kisnisci, S. Fowel, N. Epker Bruce.
Distraction osteogenesis in Silver Russell syndrome to expand the mandible.
Am J Orthod Dentofacial Orthop, 116 (1999), pp. 25-30
[14.]
R. Friedrich, F. Hermann.
Seven years clinical experience with mandibular distraction in children.
Journal of Cranio-Maxillofacial Surgery, 26 (1998), pp. 197-198
[15.]
Kevin O’Brien, Jean Wright.
Effectiveness of early orthodontic treatment with the Twin-block appliance: A multicenter, randomized, controlled trial Part 1: Dental and skeletal effects.
Am J Orthod Dentofacial Orthop, 124 (2003), pp. 234-243
[16.]
A. Kumar, R. Duggal, J. Parkashc.
Skeletal and dentoalveolar effects of Twinblock and bionator appliances in the treatment of Class II malocclusion: A comparative study.
Am J Orthod Dentofacial Orthop, 130 (2006), pp. 594-602
[17.]
J. Trenouth.
Ortopedia funcional de los maxilares con el aparato Twin Block (Bloques Gemelos).
Ortodoncia Clinica, 4 (2001), pp. 86-93
[18.]
M. Suhr, Th. Kreusch.
Technical considerations in distraction osteogenesis.
Int J Oral Maxillofac Surg, 33 (2004), pp. 89-94
[19.]
M. Ulrich, J. Kleinheinz.
Biomechanical and Clinical Implications of Distraction Osteogenesis in Craniofacial Surgery.
Journal of Cranio-Maxillo-Facial Surgery, 32 (2005), pp. 140-149
[20.]
J. Wiens, R. Forte, J. Wien.
The use of distraction osteogenesis to treat hemifacial microsomia:A clinical report.
J Prosthet Dent, 89 (2003), pp. 11-14
[21.]
G.R. Swennen, C. Euzler, F. Schutser.
Assement Of the Distraction Regenerate Using Three Dimensional Quantitative Computer Tomography.
Int J Oral Maxillofac Surg, 34 (2005), pp. 64-73
[22.]
F. Pcer, M. Alavanse, H. Wangerin.
Distraction Osteogenesis of the Mandible: Evaluation Of Callus Distraction by Scan Ultrasonography.
Journal of Cranio-Maxillo- Facial Surgery, 30 (2002), pp. 286-291
[23.]
B. Juson, L. Milkhail.
Biomechanics of Mandibular distractor Orientation: An animal Model Analysis.
J Oral Maxillofacial Surg, 57 (1999), pp. 952-962
[24.]
E. Demann, R. Haug.
Do posicion And Soft Tissue Affect Distraction Vector? An in Vitro Investigation.
J Oral Maxillofacial Surg, 60 (2002), pp. 149-155
[25.]
W.R. Proffit, T.A. Turvey, C. Phillips.
Orthognathic surgery: a hierarchy of stability.
Int J Adult Orthod Orthogn Surg, 11 (1996), pp. 191-204
[26.]
M. Converse, J. Mc Carthy.
Reconstructive Plastic Surgery Vol 4.
2 Ed, W.B. Saunders. N.Y, (1977),
[27.]
L. Kaban, B. Padwa, J. Mulliken.
Surgical correction of Mandibular Hypoplasia in Hemifacial Microsomia.
J Oral Maxillofacial Surg, 56 (1998), pp. 628-638
[28.]
Jc. Posnik.
Surgical Correction Of Mandibular Hypoplasia In Hemifacial Microsomia.
J Oral Maxillofacial Surg, 56 (1998), pp. 639-650
[29.]
B. Svensson, G. Feldmann, A. Rindler.
Early surgical-orthodontic treatment of the mandibular hypoplasia in juvenile chronic arthritis.
Journal of Cranio-Maxillo- Facial Surgery, 21 (1993), pp. 67-75
[30.]
P.J. Van Strijen, K.H. Breuning, A.G. Becking.
Cost, operation and hospitalization times in distraction osteogenesis versus sagittal split osteotomy.
Journal of Cranio-Maxillofacial Surgery, 31 (2003), pp. 42-45
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