<%server.execute "isdev.asp"%> Trigonocephaly: A simple modified technique Mohammad D, Dhandapani S - J Pediatr Neurosci
home : about us : ahead of print : current issue : archives search instructions : subscriptionLogin 
Users online: 398      Small font sizeDefault font sizeIncrease font size Print this page Email this page

  Table of Contents    
Year : 2014  |  Volume : 9  |  Issue : 2  |  Page : 125-128

Trigonocephaly: A simple modified technique

Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India

Date of Web Publication21-Aug-2014

Correspondence Address:
Sivashanmugam Dhandapani
Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh - 160 012
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/1817-1745.139305

Rights and Permissions



Trigonocephaly is the premature fusion of the metopic suture leading to deformation of anterior calvarium causing keel shaped deformity of forehead. In most cases, surgical correction is for aesthetic and psychosocial reasons. Various techniques have been described. Here we describe a technique, which is simple to perform with good postoperative results. Metopic suture is excised, one side is reconstructed in finger clasping manner to fit in an expanded area, and the other side is transected and simply molded, and all these fixed with nonabsorbable suture. Supraorbital horizontal bar is mobilized on either side anteriorly and fixed with titanium plate and screws.

Keywords: Craniofacial surgery, craniosynostosis, metopic suture, trigonocephaly

How to cite this article:
Mohammad D, Dhandapani S. Trigonocephaly: A simple modified technique. J Pediatr Neurosci 2014;9:125-8

How to cite this URL:
Mohammad D, Dhandapani S. Trigonocephaly: A simple modified technique. J Pediatr Neurosci [serial online] 2014 [cited 2020 Aug 9];9:125-8. Available from: http://www.pediatricneurosciences.com/text.asp?2014/9/2/125/139305

   Introduction Top

Trigonocephaly, coined by Welcker 1862, is an entity characterized by premature fusion of metopic suture. [1] It is a rare form of craniosynostosis, reported in 0.3/1000 live births. [2] Frontal bone grows in the transverse direction, perpendicular to the fused metopic sutures leading to arrested development of frontal area with compensatory expansion of other areas resulting in trigonocephaly. It is characterized by keel shaped deformity of forehead with midline ridge, bilateral fronto temporal constriction with compensatory biparietal expansion, supra orbital and lateral orbital retrusion and hypotelorism. [3],[4],[5],[6]

Surgery is performed predominantly for aesthetic and psychosocial considerations. Various techniques have been described for the surgical treatment of trigonocephaly ranging from simple suturectomy to calvarial bone remodeling, minimally invasive procedures to distraction osteogenesis. [2],[7],[8],[9],[10],[11],[12],[13],[14],[15],[16],[17],[18]

We describe a new surgical technique in which in addition to excision of the metopic suture, the remaining frontal cranial free bone flaps are differently fashioned, and the supraorbital bar is advanced on both sides and fixed.

   Case Report Top

A 3-year-old child presented with a complaint of triangular forehead since birth [Figure 1] and [Figure 2]. There were no other complaints, like features of raised intracranial pressure or another associated deformity of the craniofacial area. Patient was evaluated and diagnosed as a case of nonsyndromic trigonocephaly, Noncontrast computed tomography head was done with three-dimensional reconstruction to rule out another intracranial pathology as well as to study the bony anatomy of the craniofacial area. Then the patient was taken up for surgery.
Figure 1: Preoperative noncontrast computed tomography showing small anterior cranial fossa (ACF) and conical shape of ACF with keel shaped ridge

Click here to view
Figure 2: Photograph showing conical shape fore head with ridge

Click here to view

   Surgical Technique Top

After induction patient is placed supine on a head ring holder in a neutral position with a slight extension. After scrubbing bicoronal skin incision marking done starting from one ear lobule to the other ear lobule and running posterior to the coronal suture in a zig zag fashion and infiltrated with xylocain with adrenalin 0.5%. The incision site was painted with betadine and draping done. The scalp flap was raised until temporal muscles and borders of both orbital rims were visible bilaterally. Periorbita was gently separated from the superior medial and lateral orbital walls. Supraorbital neurovascular bundles released with a fine chisel and then retracted, along with periorbita. Dissection around both orbital rim is done to expose nasofrontal suture medially and both frontozygomatic suture bilaterally. Temporal muscle is dissected and retracted posteriorly to expose the area of pterion and squamous part of the temporal bone. Aggressive use of cautery and dissection is avoided because this will cause temporal muscle atrophy and postoperative temporal hollowing. Bilateral pterional burr hole made, two para saggital burr hole behind the coronal suture and one midline frontal burr hole 2 cm above frontonasal suture is made. With the help of craniotome bone flap is raised. This frontal craniotomy extends behind the coronal suture. Inferior limit of craniotomy is nearly 1.5 cm above the superior orbital rim thus leaving a thick fronto orbital bandeau for remodeling. Frontal bone is separated from dura all around and removed. Superior sagittal sinus is covered with gel foam to prevent air embolism and oozing. Dura is freed from lesser wing of the sphenoid bone laterally and foramen caecum medially. Supraorbital horizontal bar is mobilized on either side anteriorly and fixed with titanium plate and screws.

Frontal reconstruction is made by excising the metopic suture and fashioning the residual two pieces as shown in [Figure 3] and [Figure 4]. On one side it was simply transected and molded and on the other side, it was fashioned in finger clasping shape. The reconstruction in finger clasping manner covers expanded area without significant bony defect. Moreover, space between the parts of the bone will be filled by the growth of bone. Also, there is widening of anterior cranial fossa in the transverse direction. These pieces of calvarium were fixed with nonabsorbable suture as shown in [Figure 3] and [Figure 4]. After hemostasis suturing of bilateral temporalis muscles was done. Scalp flap sutured in layers. Intraoperative total blood loss is 200 ml, 100 ml blood transfusion was given intraoperatively, and patient was discharged after 4 days with good cosmetic result [Figure 5] and [Figure 6], improving further over 1 year.
Figure 3: Intraoperative photograph showing the manner in which bone has been cut

Click here to view
Figure 4: Intraoperative photograph showing the manner in which bone has been cut from frontal side

Click here to view
Figure 5: Postoperative photograph showing improved contour of fore head

Click here to view
Figure 6: Postoperative noncontrast computed tomography head with three-dimensional reconstruction showing increased volume of anterior cranial fossa as well as improved contour of fore head

Click here to view

   Discussion Top

Trigonocephaly is a post-neurulation defect causing premature fusion of the metopic suture usually occurring before birth. [19],[20] Normally it fuses at 1 year of age or may remain patent up to the age of 2 years. [19] Reason for premature fusion of the metopic suture may be one or combination of following-Intrauterine compression; from the subjacent dura mater supplying osteoinductive growth factors and cellular elements to the suture mesenchyme; exposure to high level of thyroxine resulting from maternal, juvenile, or neonatal hyperthyroidism; deficient brain growth; primary abnormality of mesenchyme; rickets; hypercalcemia; and or gene mutation. [21],[22],[23],[24],[25],[26],[27],[28]

Trigonocephaly is a rare form of craniosynostosis with an incidence of about 7/2500 live births, and accounts for 7-23% of the largest series. More common in males, accounting for 65-85% cases. [3],[29] Spectrum of disease ranges from mild to very severe degree deformity. In severe forms, brain growth is largely restricted between the frontal bones in the coronal plane, with obvious secondary cranial vault deformities. [4],[30],[31],[32] Characteristic keel shaped forehead can be seen, with bifrontal retrusion, bifronto temporal narrowing, and compensatory biparietal expansion. Hypotelorism develops due to restricted forward and lateral expansion of the anterior skull base and changes in the orbital shape and volume, with or without epicanthal folds. [4],[17],[33]

Various techniques have been described for the correction of deformity at the various stages of operation. Range is from simple suturectomy to calvarial bone remodeling. Distraction osteogenesis which is based on Elizarovs principle is also tested. [2],[7],[8],[9],[10],[11],[12],[13],[14],[15],[16],[17],[18]

Correction of trigonocephaly requires mainly work at two levels one is at the level of frontal bandeau and another is at the level of calvarial part of the frontal bone. [22] Supraorbital bar is usually advanced and fixed with titanium plates and screws. Green stick fractures are made at lateral orbital walls to correct the bitemporal constriction and to normalize contour. In the calvarial part of the frontal bone, multiple fingers like osteotomy done toward its center so that it can expand in the lateral direction to provide space for growing brain, this maneuver creates the round shape of head. [2],[34],[35] There are multiple ways of doing osteotomy of the frontal bone like zig zag, finger like fashion. We had excised metopic suture, and the residual two halves were refashioned. One-half is cut in a step ladder manner in the anteroposterior direction, and the other half is remodeled in finger clasping shape to fill the gap of the metopic suture, as shown in [Figure 3] and [Figure 4]. As the growth of bone occurs perpendicular to the suture line and in case of metopic suture fusion which lies in the anteroposterior direction the growth will be restricted in the transverse direction and doing surgery in such a manner that is cutting the bone in step ladder pattern with suturectomy of the metopic suture and creating a space between bone fragments, we can give a space for the growth of the bone in the transverse direction and this direction is most physiological for the frontal bone growth. Hence, we believe that this may result in better cosmetic appearance.

Treatment of metopic synostosis is multidisciplinary, plastic and reconstructive surgeon, neurosurgeon, pediatrician and ophthalmologist are necessary. Timing of surgery is controversial. Aim is best long-term cosmetic results and minimal risk. While patients are usually operated at around 1 year of age, patients in few other series were operated at the age of 3-9 months. [30],[36],[37]

   Conclusion Top

This technique seems to be a simple and cost-effective technique for correction of trigonocephaly with good results. The finger clasping reconstruction provides better molding with expanded coverage. The avoidance of miniplates and screws for the calvarial reconstruction brings down the cost of surgery while allowing for natural molding.

   References Top

1.Welcker H. Untersuchungenüber Wachstum und Bau des Menschlichen Schädels (Investigation over growth and formation of the human skull). Leipzig: Engelmann; 1862.  Back to cited text no. 1
2.Fearon JA, Kolar JC, Munro IR. Trigonocephaly-associated hypotelorism: Is treatment necessary? Plast Reconstr Surg 1996;97:503-9.  Back to cited text no. 2
3.Aryan HE, Jandial R, Ozgur BM, Hughes SA, Meltzer HS, Park MS, et al. Surgical correction of metopic synostosis. Childs Nerv Syst 2005;21:392-8.  Back to cited text no. 3
4.Havlik RJ, Azurin DJ, Bartlett SP, Whitaker LA. Analysis and treatment of severe trigonocephaly. Plast Reconstr Surg 1999;103:381-90.  Back to cited text no. 4
5.Selber J, Reid RR, Gershman B, Sonnad SS, Sutton LN, Whitaker LA, et al. Evolution of operative techniques for the treatment of single-suture metopic synostosis. Ann Plast Surg 2007;59:6-13.  Back to cited text no. 5
6.Warschausky S, Angobaldo J, Kewman D, Buchman S, Muraszko KM, Azengart A. Early development of infants with untreated metopic craniosynostosis. Plast Reconstr Surg 2005;115:1518-23.  Back to cited text no. 6
7.Albin RE, Hendee RW Jr, O′Donnell RS, Majure JA. Trigonocephaly: Refinements in reconstruction. Experience with 33 patients. Plast Reconstr Surg 1985;76:202-11.  Back to cited text no. 7
8.Barone CM, Jimenez DF. Endoscopic approach to coronal craniosynostosis. Clin Plast Surg 2004;31:415-22.  Back to cited text no. 8
9.Delashaw JB, Persing JA, Park TS, Jane JA. Surgical approaches for the correction of metopic synostosis. Neurosurgery 1986;19:228-34.  Back to cited text no. 9
10.Jimenez DF, Barone CM. Endoscopic craniectomy for early surgical correction of sagittal craniosynostosis. J Neurosurg 1998;88:77-81.  Back to cited text no. 10
11.Jimenez DF, Barone CM, McGee ME, Cartwright CC, Baker CL. Endoscopy-assisted wide-vertex craniectomy, barrel stave osteotomies, and postoperative helmet molding therapy in the management of sagittal suture craniosynostosis. J Neurosurg 2004;100:407-17.  Back to cited text no. 11
12.Kovács AF, Sauer SN, Stefenelli U, Klein C. Growth of the orbit after frontoorbital advancement using nonrigid suture vs rigid plate fixation technique. J Pediatr Surg 2008;43:2075-81.  Back to cited text no. 12
13.Marchac D. Radical forehead remodeling for craniostenosis. Plast Reconstr Surg 1978;61:823-35.  Back to cited text no. 13
14.Marsh JL, Schwartz HG. The surgical correction of coronal and metopic craniosynostoses. J Neurosurg 1983;59:245-51.  Back to cited text no. 14
15.Matson DD. Surgical treatment of congenital anomalies of the coronal and metopic sutures. Technical note. J Neurosurg 1960;17:413-5.  Back to cited text no. 15
16.Murad GJ, Clayman M, Seagle MB, White S, Perkins LA, Pincus DW. Endoscopic-assisted repair of craniosynostosis. Neurosurg Focus 2005;19:E6.  Back to cited text no. 16
17.Sadove AM, Kalsbeck JE, Eppley BL, Javed T. Modifications in the surgical correction of trigonocephaly. Plast Reconstr Surg 1990;85:853-8.  Back to cited text no. 17
18.Yano H, Tanaka K, Sueyoshi O, Takahashi K, Hirata R, Hirano A. Cranial vault distraction: Its illusionary effect and limitation. Plast Reconstr Surg 2006;117:193-200.  Back to cited text no. 18
19.Hayward R, Jones B, Evans R. Functional outcome after surgery for trigonocephaly. Plast Reconstr Surg 1999;104:582-3.  Back to cited text no. 19
20.Dhandapani S, Mehta VS, Sharma BS. "Horseshoe cord terminus" sans filum around a bone spur: A rare composite of faulty gastrulation with agenesis of secondary neurulation: Case report. J Neurosurg Pediatr. 2013;12:411-3.  Back to cited text no. 20
21.Cohen MM Jr, MacLean RE, editors. Craniosynostosis: Diagnosis, Evaluation, and Management. 2 nd ed. New York: Oxford University Press; 2000.  Back to cited text no. 21
22.Drake DB, Persing JA, Berman DE, Ogle RC. Calvarial deformity regeneration following subtotal craniectomy for craniosynostosis: A case report and theoretical implications. J Craniofac Surg 1993;4:85-9.  Back to cited text no. 22
23.Hirano A, Akita S, Fujii T. Craniofacial deformities associated with juvenile hyperthyroidism. Cleft Palate Craniofac J 1995;32:328-33.  Back to cited text no. 23
24.Leonard CO, Ralston C, Carey JC, Morales L. Craniosynostosis and facial dysmorphism due to maternal Graves disease. Clin Res 1987;35:225A (Abstract).  Back to cited text no. 24
25.Manzanares MC, Goret-Nicaise M, Dhem A. Metopic sutural closure in the human skull. J Anat 1988;161:203-15.  Back to cited text no. 25
26.Shuper A, Merlob P, Grunebaum M, Reisner SH. The incidence of isolated craniosynostosis in the newborn infant. Am J Dis Child 1985;139:85-6.  Back to cited text no. 26
27.van der Meulen JJ, Nazir PR, Mathijssen IM, van Adrichem LN, Ongkosuwito E, Stolk-Liefferink SA, et al. Bitemporal depressions after cranioplasty for trigonocephaly: A long-term evaluation of (supra) orbital growth in 92 patients. J Craniofac Surg 2008;19:72-9.  Back to cited text no. 27
28.Zakarija M, McKenzie JM, Hoffman WH. Prediction and therapy of intrauterine and late-onset neonatal hyperthyroidism. J Clin Endocrinol Metab 1986;62:368-71.  Back to cited text no. 28
29.Lajeunie E, Le Merrer M, Arnaud E, Marchac D, Renier D. Trigonocephaly: Isolated, associated and syndromic forms. Genetic study in a series of 278 patients. Arch Pediatr 1998;5:873-9.  Back to cited text no. 29
30.Collmann H, Sörensen N, Krauss J. Consensus: Trigonocephaly. Childs Nerv Syst 1996;12:664-8.  Back to cited text no. 30
31.Hinojosa J, Esparza J, Muñoz MJ, Salván R, Romance A, Alén JF, et al. Surgical treatment of trigonocephalies and associated hypoteleorbitism. Neurocirugia (Astur) 2002;13:437-45.  Back to cited text no. 31
32.Shimoji T, Shimabukuro S, Sugama S, Ochiai Y. Mild trigonocephaly with clinical symptoms: Analysis of surgical results in 65 patients. Childs Nerv Syst 2002;18:215-24.  Back to cited text no. 32
33.Eppley BL, Sadove AM. Surgical correction of metopic suture synostosis. Clin Plast Surg 1994;21:555-62.  Back to cited text no. 33
34.Oh DY, Byeon JH. Right angled Z-osteotomy in total cranial vault remodeling in sagittal synostosis. J Korean Soc Plast Reconstr Surg 2002;29:348-51.  Back to cited text no. 34
35.Smartt JM Jr, Karmacharya J, Gannon FH, Ong G, Jackson O, Bartlett SP, et al. Repair of the immature and mature craniofacial skeleton with a carbonated calcium phosphate cement: Assessment of biocompatibility, osteoconductivity, and remodeling capacity. Plast Reconstr Surg 2005;115:1642-50.  Back to cited text no. 35
36.Di Rocco C, Velardi F, Ferrario A, Marchese E. Metopic synostosis: in favour of a "simplified" surgical treatment. Childs Nerv Syst 1996;12:654-63.  Back to cited text no. 36
37.Ferreira MP, Collares MV, Ferreira NP, Kraemer JL, Pereira Filho Ade A, Pereira Filho Gde A. Early surgical treatment of nonsyndromic craniosynostosis. Surg Neurol 2006;65 Suppl 1:S1:22-1:26.  Back to cited text no. 37


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]


Print this article  Email this article
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Article in PDF (2,270 KB)
    Citation Manager
    Access Statistics
    Reader Comments
    Email Alert *
    Add to My List *
* Registration required (free)  

   Case Report
   Surgical Technique
    Article Figures

 Article Access Statistics
    PDF Downloaded140    
    Comments [Add]    

Recommend this journal