<%server.execute "isdev.asp"%> Management of hypertelorism Pellerin P - J Pediatr Neurosci
home : about us : ahead of print : current issue : archives search instructions : subscriptionLogin 
Users online: 251      Small font sizeDefault font sizeIncrease font size Print this page Email this page

  Table of Contents    
Year : 2022  |  Volume : 17  |  Issue : 5  |  Page : 4-13

Management of hypertelorism

Department of Plastic and Reconstructive Surgery, Lille University Hospital, Lille, France

Date of Submission01-Apr-2022
Date of Acceptance01-Apr-2022
Date of Web Publication19-Sep-2022

Correspondence Address:
Prof. Philippe Pellerin
Department of Plastic and Reconstructive Surgery, Lille University Hospital, 18 rue de la Carnoy, 59130, Lambersart
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jpn.JPN_43_22

Rights and Permissions



Aim: To summarize the experience of the author with the treatment of hypertelorism. Settings and Design: The author has been heading a high-caseload department of craniofacial surgery for 38 years; the research is based on his experience with this pathology by this time. Materials and Methods: The charts of 38 patients were used for this research. Statistical Analysis Used: No statistic was used; the author has just given his personal insights as the result of a professional life devoted to the problem. Results: Most of the hypertelorism cases requiring surgical correction are rare interorbital clefts (Tessier’s 14–12). Among the syndromic ones, cranio-fronto orbital dysplasia is the most demanding for surgery because it is associated with craniosynostosis, which has to be addressed at the same time. Among the technics published for hypertelorism correction, craniofacial bipartition has our preference for several reasons: easily done and redone when necessary, safer to the vascularization, and trophicity of displaced parts of the skeleton. Conclusions: Complex craniofacial conditions such as hypertelorism have to be treated only in specialized craniofacial centers by a multidisciplinary team. The caseload has to be high, and the follow-up is very strict to get the benefits of experience to improve the results.

Keywords: hypertelorism, telorbitism, rare clefts, cleft 14, cleft 13, cleft 12, interorbital clefts, craniofacial surgery, encephalocele, cranio facial bipartition

How to cite this article:
Pellerin P. Management of hypertelorism. J Pediatr Neurosci 2022;17, Suppl S1:4-13

How to cite this URL:
Pellerin P. Management of hypertelorism. J Pediatr Neurosci [serial online] 2022 [cited 2023 Dec 5];17, Suppl S1:4-13. Available from: https://www.pediatricneurosciences.com/text.asp?2022/17/5/4/356363

   History Top

Greig and the origin of the term

It was in 1924 that David Greig[1] published the article where he created and explained the newly created term “hypertelorism” by combining three Greek words: “υπερ” (hyper), which means too much, “τελο” (telo), which means distance, and “οριτισμός” (oritismos) for orbit.

Some use the term telorbitism instead and even hypertelorbitism, which lacks classical and accepted approaches in ancient languages, by mixing terms from Greek and Roman.

It has been a pure contemplative science because no treatment was proposed for these conditions.

First transcranial approach: “Pourquoi pas”

Paul Tessier performed the first radical treatment of a severe case of hypertelorism in 1963 [Figure 1] through a transcranial approach. Paul Tessier said to his colleague Gerard Guiot, a neurosurgeon at Suresnes’ Hospital Foch, to address this condition. “To correct this malformation will require violating the cranial base: are you willing? (At that time, an impassable border).” Guiot answer was: “Pourquoi pas?,” which means “why not.” This later became the International Society of Craniofacial Surgery’s motto.[2] It was the first actual craniofacial procedure since the first Le Fort III for a case of Crouzon’s syndrome, in 1958, was a subcranial procedure.
Figure 1: Tessier’s inaugural cases: preop and long-term results

Click here to view

Diagnosis of hypertelorism

By clinical examination, we can measure the inner canthal distance, the outer canthal distance, and the interpupillary distance and compare the results with Feingold and Bossert[3] standard curves. Standard curves of interorbital distance growth, which is mainly used, come from Gerald and Silverman article: interorbital distance values were obtained from plain frontal radiography, the value measured as the distance between the two lacrimal crests.[4]

A distance over two standard deviations defines hypertelorism. Tessier has given a classification for adults in three levels of severity[5]: grade I (30–34 mm), grade II (35–39 mm), and grade III (>40 mm). A grade III deformity involves gross facial disfigurement and requires surgical intervention.

There is another way to appreciate hypertelorism: because the esthetic imbalance is achieved when the inner canthal distance is the same as the palpebral fissure length, it is straightforward to quote the difference between those two values as the extent of hypertelorism.

One has to differentiate hypertelorism where all of the four orbital walls are moved apart from inner telecanthus with normal skeleton and even the condition where the anterior part of the medial wall, as well as the lacrimal crest and ascending ramus of the maxilla, is moved laterally by a nasal or frontonasal or frontal encephalocele, which is wrongly called “long nose hypertelorism”[6]; when actually in most of these conditions, it is hypotelorism. The encephaloceles may also frequently be associated with hypoplasia of the corpus callosum [see [Figure 2]], and only the inner canthi are dystopic because of the presence of the encephalocele mass. In holoprosencephaly, the other orbital parts are normal or moved medially associated with some degree of holoprosencephaly.
Figure 2: Red lines are for lateral canthus, blue lines are for pupils, and green lines for medial canthus N is normal; a pupils and lateral canthus are normal when the inner canthus is abnormal in a case of blepharophimosis syndrome with telecanthus; b lateral canthus is normal, interpupillary distance narrowed, and inner canthus enlarged and lowered in a case of frontonasal encephalocele with hypotelorism; c true hypertelorism

Click here to view

   Etiology Top

Interorbital Tessier’s rare clefts

Out of the anatomical types of craniofacial defects classified by Paul Tessier as “rare craniofacial clefts,”[7] the interorbital types include hypertelorism[Figure 3]. Those are cleft 14, 13, and 12 [Figure 4]. Most of those cases must be addressed since the nasal and cutaneous anomalies require treatment: hypertelorism is only a part of the problem. Its surgical repair is most of the time simultaneous to the craniofacial osteotomy.
Figure 3: Tessier’s classification (modified)

Click here to view
Figure 4: Examples of interorbital clefts 14, 13, and 12

Click here to view

Other malformations

Hypertelorism is a symptom in a large spectrum of birth defect syndromes; researching the OMIM website would bring you over 800 matches, but none, all of them, needs to be addressed: Jackie Kennedy had hypertelorism [Figure 5] but did not require any treatment!
Figure 5: Jackie Kennedy

Click here to view

Tessier’s grading is[5] therefore interesting but works only for adults.

Among those syndromes, craniofrontonasal dysplasia syndrome (CFNS) [Figure 6] is almost addressed at any time it is diagnosed because it combines with craniosynostosis frequently; asymmetric (plagiocephaly) requires early treatment. Craniofrontonasal syndrome is an X-linked developmental disorder that shows paradoxically greater severity in heterozygous females than in hemizygous males.[8] CFNS is caused by a mutation in the EFNB1 gene (300035) on chromosome Xq13.[9]
Figure 6: Craniofrontonasal syndrome, a mother and her daughter

Click here to view

In four cases of Opitz syndrome with the involvement of cleft lip, the conditions require surgical correction for their hypertelorism. Features of the Opitz GBBB syndrome include hypertelorism or telecanthus, laryngotracheoesophageal cleft, clefts of lip, palate, and genitourinary defects, especially hypospadias in males and splayed labia majora in females.

Nonsyndromic association of bilateral cleft lip and palate and hypertelorism requiring surgical correction could be encountered. It happened twice in our experience.

Surgical evolution

The first radical procedure designed by Paul Tessier[10] has been the so-called “box osteotomy” because it moves as a whole the four orbital walls as a square box. It is still popular and widely popular among craniofacial surgeons in the same original form.

In this original design [Figure 7], you can see that the olfactory nerves are to be sacrificed and the lateral mass of the ethmoid and the nasal septum, so several proposals have been made to save the olfactory groove and olfaction [Figure 8], in particular by Converse.[11] But the next dramatic evolution: moving the two halves of the face was done shortly after. This move was made with some hesitation primarily because of the difficulty to choose a name for the principle of the procedure. Hugo Obwegeser was the first to perform a facial bipartition in July 1969 that he published in 1978[12] in a case of facial duplication (cleft 14 in Tessier’s classification). The second author who published about this procedure was Jacques Van der Meulen, 1979,[14] he named it “medial faciotomy” [Figure 9]b. In 1985 during the first International congress of the ISCFS in La Napoule, France,[14] the complete bipartition concept was formulated by Paul Tessier (proceedings: pages 217–45).
Figure 7: Box osteotomy, original Tessier’s design

Click here to view
Figure 8: Converse modification to preserve olfaction

Click here to view
Figure 9: Facial bipartition history: (A) Obwegeser’s “unique Antonio case” and (B) Van der Meulen’s “medial faciotomy”

Click here to view

Subcranial procedures

There is little room left for subcranial procedures in hypertelorism surgery for three reasons:

  • Most of the conditions associated with hypertelorism include intracranial anomalies, which must be addressed.

  • Without moving the orbital roof, the procedures fail to correct the efficacy of Tessier’s grade III hypertelorism.

  • With increasing experience of craniofacial teams, transcranial procedures.

  • This is our opinion as well as Converse’s[11]: “In traumatic telecanthus (and in other forms of pseudohypertelorism), the deformity is usually entirely subcranial, involving the facial bones below the level of the anterior cranial fossa. In moderate hypertelorism, a subcranial operation may achieve a compromise improvement.”

       Discussion Top

    Our personal opinions have been based on experience acquired during the planning, realization, and follow-up reduction of 36 hypertelorism conditions through 38 years’ experience in 1982 [Table 1].
    Table 1: Etiology repartition for operated hypertelorisms and surgical technics

    Click here to view

    Box osteotomy versus facial bipartition

    The choice of a surgical strategy is enlightened by a plus and minus table.

    Our personal choice is, whenever feasible, a facial bipartition [Table 2].
    Table 2: Box osteotomy technic versus craniofacial bipartition: the plus and the minus

    Click here to view

    How I prefer to do it

    Surgical planning

    Careful analysis and measurements are necessary to establish precise preoperative planning. In the beginning, we just had a clinical examination, plain radiography, and conventional tomography, but the availability of high-definition computerized tomographic scanner (CT scan) with a spatial resolution over 1 mm (slices) and the development of Dicom reading software with three-dimensional reconstruction (3D) capacities running on personal computers have made possible not only comprehensive and accurate analysis of each case but also very precise surgical simulation where measurement can be used peroperatively on the patient. We use software Osirix or Horos running under Mac OS on Apple computer.

    Because, in severe craniofacial malformation, there is not a classical craniometric landmark left untouched, we use the vestibular orientation,[15] a technique used for research in comparative craniology since long time,[16] which uses as referential plane the plane of both lateral semicircular canals that matches the horizontal plane under normal gravity and could be compared to the CT of normal age-matching patients.

    The process of vestibular orientation requires some steps[17]:

  • Obtain a CT scan with a good spatial resolution (slice thickness under 1 mm) including the whole craniofacial skeleton.

  • Get the native Dicom files from the radiologist (native, not postprocessed!).

  • With your Dicom reader software, open the series and create a new series vestibular oriented with the multiplanar rendering tool.

  • The new series is opened, on the slice corresponding to the vestibular plane dots. Regions of interest are drawn as landmarks for the front, back, left, and right.

  • The 3D view is oriented and then exported with the drawn lines, which will be used as a ruler in the next step, as a JPEG file.

  • The .jpeg file is opened with the software Adobe Photoshop, resized to the ruler to fit a 1/1 scale such as you could do any direct measurement on the image, which will be exact in vivo patient’s value.

  • On the processed picture, you could draw and move the pieces of bone as you like and get the accurate values of any move [Figure 10]. We evaluate the amount of narrowing at the inner canthus level as the difference between inner canthal distance and the length of palpebral fissure when normal.
    Figure 10: Three stages of preop simulation on scaled 1/1 picture of 3D oriented CT scanner

    Click here to view

    My surgical choices

    Considering the plus and minus, I prefer facial bipartition over box osteotomy, even when the anterior occlusal plane seems correct and there is a “keel-shaped deformity” described by Van der Meulen.[13] Most of those patients have anterior overcrowding and a posterior endoclusion, so the postoperative incisive diastasis will give room for the overcrowding, and even without orthodontic treatment in children it corrects itself.

    Even when the occlusion is good if the preoperative planning demonstrates skeletal feasibility, I prefer to do a bipartition and to do orthodontic correction afterward.

    Specific technical points

    The intermediate frontal bar

    Paul Tessier like other workers[18] [Figure 11] keeps an intact bar of frontal bone between the bifrontal bone flap raised for intracranial approach and the facial skeleton. The purpose is to keep a solid ground floor to secure the facial skeleton by the end of the surgery. We do not do that for two reasons: first, it narrows the approach to the operative field, which grows the difficulties during an operation that is not that simple. Second, we do not need it because the simple wire construct between both halves of the face gives very stable results (see infra). It is just in instances of craniofrontonasal dysplasia when a forward frontofacial advancement is required that we design a tongue in groove thank to a frontal arch bar but we totally free it, and it does not stay in the way during the process.
    Figure 11: (A) Tessier’s design for bipartition after Figure 13 in “Facial bipartition: a concept more than a procedure.” In Craniofacial Surgery: Proceedings of the First International Congress of The International Society of Cranio-Maxillo-Facial Surgery President: Paul Tessier Cannes-La Napoule, 1985. (B) Author’s design; a is an adjustment ostectomy to fit the new orbital position and a way to lock its position. B is the axis of the movement which is a rotation

    Click here to view

    The olfactory groove

    Tessier pronounced the radical resection of the interorbital area, which includes the septum, the olfactory grooves, and a part of the lateral masses of the ethmoid as all to one method [Figure 7]. Converse[11] on the other hand proposed a modification in the osteotomy drawing, which respects the olfactory grooves [Figure 8] considering that anosmia is a serious sequel that must be avoided. We share this opinion, and we perform the osteotomy in the orbital roof [Figure 12] as an oblique cut from the lateral orbital wall to the foramen cecum. This design has two advantages: the olfactory grooves are left intact, and the medial translation is accompanied by a forward move, which gives back the intracranial room lost by the transverse narrowing.
    Figure 12: In our personal design, the oblique cut allows the combination of a forward motion with the narrowing which compensates for the loss of volume for the brain

    Click here to view

    The medial orbital wall

    Since the orbital roof osteotomy reaches quite anteriorly to its medial end and that the osteotomy to the medial orbital wall runs in a straight line from this point to the inferoposterior orbital corner before the pterygomaxillary disjunction (fracture), about half of the medial orbital wall does not move medially. We fix this problem very easily by doing an ethmoidal blowout fracture, crushing inward the lamina papyracea with a spatula [Figure 13].
    Figure 13: a (colored in red) is the part of the medial orbital wall to be crushed in

    Click here to view

    The intermaxillary disjunction

    When there is no existing alveolomaxillary cleft (which is present in craniofacial cleft and some hypertelorism associated with cleft lip and palate), a medial alveolomaxillary osteotomy must be done. We used to disinsert the gingiva from the dental neck and alveolar bone from canine to canine on both vestibular and lingual walls and then tunnel the palatal fibro mucosa down to the posterior nasal spine. The bone is cut with a straight bone chisel.

    There is no need either for bone resection or bone graft as advocated by Paul Tessier,[18] and we do not do any construct or peridental ligature since the interfacial wires keep strongly both halves including alveolus bone. We just reinsert with peridental stitches in the gingiva by the end of the process. It results in a wide interincisival diastasis, which will be soon corrected by itself in growing patients and sometimes would need some orthodontic help [Figure 14].
    Figure 14: Inter-incisive space: a before bipartition, b diastasis immediately after bipartition, c spontaneous correction after 1 year

    Click here to view

    The zygomatic bone osteotomy

    Tessier, as well as Converse, advises the malar bone cut through the body and secure the move with a bone graft, we prefer more simply do the cut posteriorly on the zygomatic arch and we do not use to make a graft except in conditions where primary malar hypoplasia requires an augmentation. We have never observed a gap of soft tissues in front of the bony defect, not even a single dimple.

    The osteosynthesis devices

    Because most of the surgeries are done in infants, there is a general agreement that not metallic plating should be done in growing subjects because of the risk of intracranial migration.[19] Resorbable plating has been advocated but they are expensive and they induce huge local inflammatory reactions; in the meantime, steel wire ligature is very effective and at the same time very cheap. The single stabilization of the two halves with one or two 0.4-mm stainless steel wires has always been sufficient to stabilize the interorbital narrowing. Additionally, we always perform a transnasal canthopexy, which reinforces the inter-midfacial osteosynthesis. And as an end, the wire ligatures between the frontal bone flap and the moving part of the skeleton finish a perfect stabilization.

    This is only in cases of craniofrontonasal dysplasia (CFND) when the associated craniosynostosis requires advancement that we use a tongue in groove intermediate frontal bar to stabilize the advancement. For Apert syndrome, we do a midfacial distraction through a transfacial pin located at the end of the hypertelorism correction.

    The grafts

    Use grafts have two logics:

  • First: filling the bone defects to accelerate the healing and consolidation. For that purpose, because in most cases, the correction is done during childhood, when the periosteum, periorbit, and dura mater have been carefully respected, there is no need for bone graft because bone healing from the periosteum and assimilate is very effective in children. Filling the defects with bone is only necessary for adults and in revisions when the tissues have been seriously damaged during the first procedure.

  • Second: stabilization; Paul Tessier used to perform craniofacial surgery when neither miniplating osteosynthesis nor distraction procedure exists so he was very fond of carpenter like tongue in groove, osteotomy “self contensif” design that he used to lock with bone grafts, it is the reason why he advocates so strongly bone grafts.

  • In my opinion, as pleaded supra, the perfect stabilization of osteotomies does not require more than steel wire osteosynthesis, and in childhood, the capacity for bone healing is so strong that there is no room left for bone grafts under those indications.

    The only good reasons to do bone graft are to repair some bone defects such as encephalocele acquired (secondary surgery) or primary hypoplasia of any part of the skeleton.

    So, bone grafting is not a part of the hypertelorism treatment but an adjunct in complex craniofacial malformation.

    The skin resection

    Tessier, who to date is the first in most of the cases, uses to say definitively that the skin excess in the midline must be resected; it is obvious with craniofacial cleft when the skin is involved, but when looking at some conspicuous scar, all of the craniofacial surgeons had asked themselves if this could be avoided.

    Some article came because youngsters always believe that they are better than their elderly.[20] I have done the same mistake, and the third time I dared to avoid the excess skin resection in one cleft 14 and two CFND syndromes. The result was bad with untreatable epicanthal folds, and by the end, I always had to do a skin revision with a final midline scar (with an exception for craniofacial dysplasia syndromes where the hypertelorism is light or at the worst mild, and that the bipartition is just an opportunity when frontofacial advancement is done to improve the result and correct the orbital slanting. In these conditions obviously, there is neither need for splinting the skin nor to do a K stitch…).

       Conclusions Top

    As advocated by Paul Tessier, surgically addressing hypertelorism is a part of a wider project. Hypertelorism by itself is not a disease but a part of a syndrome. The correction of those deformities needs the combination of not only the hypertelorism correction but other anomalies such as clefts, encephalocele, bone defect, microphthalmia, maxillary and mandibular dysplasia, and malformation. Thanks to the tremendous progress of computing science, we have now precise medical imaging: CT scan and magnetic resonance imaging (MRI) as well as software for 3D analysis, which allow precise analysis and preoperative surgical planning.

    But even with these tools, it is a very complex treatment for a very rare disease. Those operations should not be the feat of one surgeon even for the best one.

    Those patients require the multidisciplinary care given all along their growth period up to adulthood by specific teams including neurosurgeons, plastic surgeons, maxilla facial surgeons trained for enough time in the acknowledged departments of craniofacial surgery with a sufficient caseload to stay at the best level.

    Financial support and sponsorship


    Conflicts of interest

    There are no conflicts of interest.

       References Top

    Greig DM Hypertelorism. A hitherto undifferentiated congenital cranio-facial deformity. Edinb Med J 1924;XXXI:560-93.  Back to cited text no. 1
    Tessier P A foreword in the form of a warning. In: Craniofacial Surgery: Proceedings of the First International Congress of the International Society of Cranio-Maxillo-Facial Surgery President: Paul Tessier Cannes-La Napoule, 1985. Berlin, Heidelberg: Springer; 1987. pp. XXIX-XXXVI.  Back to cited text no. 2
    Feingold M, Bossert WH Normal values for selected physical parameters: An aid to syndrome delineation. Birth Defects Orig Artic Ser 1974;10:1-16.  Back to cited text no. 3
    Gerald BE, Silverman FN Normal and abnormal interorbital distances, with special reference to mongolism. Am J Roentgenol Radium Ther Nucl Med 1965;95:154-61.  Back to cited text no. 4
    Tessier P Orbital hypertelorism. I. Successive surgical attempts. Material and methods. Causes and mechanisms. Scand J Plast Reconstr Surg 1972;6:135-55.  Back to cited text no. 5
    Jackson IT, Tanner NSB, Hide TAH Frontonasal encephalocele—“Long nose hypertelorism.” Ann Plast Surg 1983;11: 490-500.  Back to cited text no. 6
    Tessier P Anatomical classification of facial, cranio-facial and latero-facial J Maxillof Surg 1976;4:69-92.  Back to cited text no. 7
    Richieri-Costa A, Guion-Almeida ML The syndrome of frontonasal dysplasia, callosal agenesis, basal encephalocele, and eye anomalies—Phenotypic and aetiological considerations. Int J Med Sci 2004;1:34-42.  Back to cited text no. 8
    Twigg SR, Kan R, Babbs C, Bochukova EG, Robertson SP, Wall SA, et al. Mutations of ephrin-B1 (EFNB1), a marker of tissue boundary formation, cause craniofrontonasal syndrome. Proc Natl Acad Sci U S A 2004;101:8652-7.  Back to cited text no. 9
    Tessier P, Guiot G, Derome P Orbital hypertelorism. II. Definite treatment of orbital hypertelorism (OR.H.) By craniofacial or by extracranial osteotomies. Scand J Plast Reconstr Surg 1973;7:39-58.  Back to cited text no. 10
    Converse JM, Ransohoff J, Mathews ES, Smith B, Molenaar A Ocular hypertelorism and pseudohypertelorism advances in surgical treatment. Plast Reconstr Surg 1970;45:1-13.  Back to cited text no. 11
    Obwegeser HL, Weber G, Freihofer HP, Sailer HF Facial duplication—The unique case of Antonio. J Maxillofac Surg 1978;6:179-98.  Back to cited text no. 12
    van der Meulen JC Medial faciotomy. Br J Plast Surg 1979;32:339-42.  Back to cited text no. 13
    Marchac D Craniofacial surgery. Proceedings of the First International Congress of the International Society of Cranio-Maxillo-Facial Surgery President: Paul Tessier Cannes-La Napoule, 1985, Berlin, Heidelberg: Springer Berlin Heidelberg; 1987. 526p.  Back to cited text no. 14
    Vinchon M, Pellerin P, Pertuzon B, Fénart R, Dhellemmes P Vestibular orientation for craniofacial surgery: application to the management of unicoronal synostosis. Childs Nerv Syst 2007;23:1403-9.  Back to cited text no. 15
    Delattre A, Fenart R La méthode vestibulaire: appliquée à l’étude du crâne Son champ d’applications. Z Für Morphol Anthropol 1958;49:90-114.  Back to cited text no. 16
    Pellerin P, Vinchon M, Dhellemmes P, Guerreschi P Crouzon syndrome: Posterior fossa volume studies in vestibular orientation. Childs Nerv Syst 2021;37:3105-11.  Back to cited text no. 17
    Tessier P Facial bipartition: A concept more than a procedure. In: Marchac D, editor. Craniofacial Surgery: Proceedings of the First International Congress of the International Society of Cranio-Maxillo-Facial Surgery President: Paul Tessier Cannes-La Napoule, 1985. Berlin, Heidelberg: Springer Berlin Heidelberg; 1987. pp. 217-45.  Back to cited text no. 18
    Ayyala HS, Hoppe IC, Rathmann AM, Ciminello FS Intracranial migration of hardware 16 years following craniosynostosis repair. Eplasty 2018;18:e2.  Back to cited text no. 19
    Urrego AF, Garri JI, O’Hara CM, Kawamoto HK Jr, Bradley JP The K stitch for hypertelorbitism: Improved soft tissue correction with glabellar width reduction. J Craniofac Surg 2005;16:855-9.  Back to cited text no. 20


      [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11], [Figure 12], [Figure 13], [Figure 14]

      [Table 1], [Table 2]


    Print this article  Email this article
        Similar in PUBMED
       Search Pubmed for
       Search in Google Scholar for
     Related articles
        Article in PDF (8,263 KB)
        Citation Manager
        Access Statistics
        Reader Comments
        Email Alert *
        Add to My List *
    * Registration required (free)  

        Article Figures
        Article Tables

     Article Access Statistics
        PDF Downloaded155    
        Comments [Add]    

    Recommend this journal