Squamosal Suture Research Articles

A new Homo erectus molar from Sangiran

Indonesia, and particularly Java island, has been the place of the longest occupation by Homo erectus' species. Since the first Homo erectus found by Eugene Dubois in 1891 in the Trinil site, the discoveries of human remains have been regular, allowing the gathering of the most important concentration of Homo erectus in the world spanning more than 1.7 million years. The new fossil specimen discovered near Sendang Klampok in the Sangiran Dome (Central Java, Indonesia), which represents the left infero-posterior part of a skullcap, supplements the more ancient sample from Sangiran dome. The metrical and morphological features observed on this specimen with in particular the length of the parietomastoid suture, the lower position of the temporal lines which relief is blunt and joining those of the mastoidal crest and lateral part of the transverse occipital torus constituting an extensive formation covering the junction of the temporal, parietal and occipital bones, the protruding mastoid process, external occipital crest well expressed and shape of cerebellar lobes are many characters closer to the Ngandong hominins, clearly different from those of Kabuh (Bapang) and Zhoukoudian Lower Cave specimens.

Consequences of Uteroplacental Insufficiency on Developmental and Intellectual Performances

After completing this article, readers should be able to: 1. Explain why the difference between small for gestational age and intrauterine growth restriction is important for determining time of delivery. 2. Describe the potential developmental consequences of placental insufficiency. 3. Delineate the hypotheses underlying the association between prenatal stress and developmental outcome. Deprivation of supplies is the common pathogenic factor for fetuses experiencing placental insufficiency, even if all do not exhibit hypotrophy at birth or accelerated maturation as a response to stress. Nearly one century ago, placental insufficiency was remarkably described by the French obstetrician Pierre Budin: “They are tiny, puny infants with great vitality. Their movements are untiring and their crying lusty, for their organs are quite capable of performing their allotted functions. These infants will live, for although their weight is inferior … their sojourn in the womb was longer.” (1) Since then, normative growth curves and precise determination of gestational age (GA) have permitted consensual categorization of newborns, the last advance being the identification of an intrauterine growth restriction (IUGR) subgroup among the small-for-gestational age (SGA) group (10th percentile). (2) However, this categorization remains unsatisfactory when dealing with the very preterm group for several reasons, including unknown GA in many cases and inadequacy of the current growth curves in the low range of GA. Why is it so important to make a distinction between SGA and IUGR infants? First, the cause is different: genetic factors explain a large proportion of cases in SGA infants and epigenetic factors are involved in IUGR fetuses. This current conception is elegantly summarized by Fowden: “Normal fetal growth depends on an adequate supply of nutrients and on a strict temporal relationship between tissue accretion and differentiation. During early development, the pattern of intrauterine growth is largely determined by the fetal genome but, as size …

Suboccipital burr holes and craniectomies

The goal of this study was to delimit the external cranial projection of the transverse and sigmoid sinuses, and to establish initial strategic systematized burr hole sites for lateral infratentorial suboccipital approaches based on external cranial landmarks particularly related to the lambdoid, occipitomastoid, and parietomastoid sutures. The external cranial projection of the transverse and sigmoid sinuses was studied through their external outlining obtained with the aid of multiple small perforations made from inside to outside along the inner margins of the sinuses of 50 paired temporoparietooccipital regions in 25 dried adult human skulls. The burr hole placement was studied by evaluating the supratentorial, over-the-sinuses, and infratentorial components of 1-cm-diameter openings made at strategic sites identified in the initial part of the study, which was performed in another 50 paired temporoparietooccipital regions. The asterion and the midpoint of the inion-asterion line were found to be particularly related to the inferior half of the transverse sinus; the transverse and sigmoid sinuses' transition occurs 1 cm anteriorly to the asterion across the parietomastoid suture, and the most superior part of the sigmoid sinus is located anteriorly to the occipitomastoid suture, with its posterior margin crossing this suture posteriorly to the most superior aspect of the mastoid process, which is located at the most superior level of the mastoid notch. Burr holes made at the midpoint of the inion-asterion line, at the asterion, 1 cm anterior to the asterion, just inferiorly to the parietomastoid suture, and over the occipitomastoid suture at the most superior level of the mastoid notch are appropriate to expose the inferior half of the transverse sinus at its midpoint, the inferior half of the transverse sinus at its most lateral aspect, the transverse and sigmoid sinuses' transition, and the posterior margin of the basal aspect of the sigmoid sinus, respectively. These findings allow an estimation of the transverse and sigmoid sinuses' external cranial projection. The asterion and the most posterior part of the parietomastoid suture constitute a suitable initial burr hole site at which to perform an upper or asterional suboccipital craniectomy to expose the superior aspect of the cerebellopontine angle (CPA). The occipitomastoid suture at the most superior aspect of the mastoid notch constitutes an adequate initial burr hole site at which to perform a basal suboccipital craniectomy to expose the lower portion of the CPA. The sites can be used together as initial burr hole sites to perform wide suboccipital exposures, because they already constitute natural infratentorial lateral limits.

The anterior sylvian point and the suprasylvian operculum

The sylvian fissure or lateral sulcus is the most identifiable feature of the superolateral brain surface and constitutes the main microneurosurgical corridor, given the high frequency of approachable intracranial lesions through this route. The anterior sylvian point (ASyP) divides this fissure in its main anterior and posterior rami and was evaluated in this study for its morphology, exact location, and sulcal and neural relationships to assess its suitability as an initial, visually identifiable landmark for further neuroimaging and intraoperative estimation of its adjoining suprasylvian structures. This study is based on 32 formalin-fixed cerebral hemispheres. The brains were removed from the skulls of 16 cadavers after the introduction of plastic catheters through properly positioned burr holes; the number of specimens for some of the analyzed data differed because of incorrect positioning of catheters or damage to the studied structures caused by the initial steps of the study. The ASyP had a cisternal aspect in 94% of the specimens and was always located inferior to the triangular part of the inferior frontal gyrus, 2.3 6 0.5 cm in front of the inferior rolandic point. The ASyP was located underneath the 1.5-cm-diameter cranial area of the anterior aspect of the squamous suture. Its adjoining structures that compose the suprasylvian operculum have constant basic morphological configurations. The ASyP underlies the anterior aspect of squamous suture just behind the pterion, can be easily recognized, and constitutes a reliable initial sulcal landmark for further estimation of the suprasylvian sulcal and gyral structures. The suprasylvian operculum can be understood as a series of convolutions roughly arranged as a V-shaped convolution, with its vertex constituted by the ASyP, followed by three U-shaped convolutions and one C-shaped convolution.

Neonatal neurological disorders involving the brainstem: neurosonographic approaches through the squamous suture and the foramen magnum

Brainstem damage which often indicates a critical condition is usually underestimated by trans-anterior-fontanel neurosonography (NS) owing to the far-field limitations. Instead, NS alternately scanning through the squamous suture of the temporal bones and the foramen magnum could provide a better visualization of the brainstem structures. The NS characteristics of brainstem lesions caused by various neonatal neurological disorders, such as hypoxic-ischemic encephalopathy (HIE), metabolic encephalopathy, birth trauma and bacterial meningoencephalitis, can be depicted at the acute stage. An echogenic change in the midbrain was found in patients with HIE or metabolic encephalopathy. In addition to the echogenic change, bilateral transtentorial temporal lobe herniation distorting the contour of the midbrain was observed in a patient with group B streptococcus meningoencephalitis, whereas echogenic changes at the level of the pons and/or the medulla oblongata, mainly localized in the dorsal part, could be observed in newborns with severe HIE, maple syrup urine disease or birth trauma. In this pictorial assay, we demonstrate the feasibility of NS imaging in evaluating the entire brainstem structure of critically ill neonates in the near field and illustrate the characteristic features of brainstem involvement in various neonatal neurological disorders along with computed tomography or magnetic resonance imaging correlation.

Head growth and cranial assessment at neurological examination in infancy.

The most dramatic increase in brain volume occurs in the last three months of fetal life and the first two years after birth. Concomitantly, the skull follows the volumetric increase in the cerebral hemispheres mostly by passive adaptation. The relationship between head and brain growth explains why the classical neurological assessment in infancy universally includes measurement of head circumference (HC). However, this crude information derived from HC measurement remains insufficient to qualify brain growth. One way to better document the relation between brain and skull could be to rely on the correlation between HC and body growth parameters, given a general agreement on the definition of proportionate and disproportionate head–body growth. Significant information with respect to the integrity of the underlying cerebral hemispheres can also be provided by systematic palpation of the main cranial sutures. In particular, the distension or overlapping of the squamous sutures which are strategically located at the junction of the cranial vault and the cranial base could be a valid marker of brain growth disorder.

Craniosynostosis and altered patterns of fetal TGF-beta expression induced by intrauterine constraint.

Recent work has demonstrated that fusion of the calvarial sutures is mediated by locally elaborated soluble growth factors, including the transforming growth factor-betas (TGF-betas), leading some to speculate that external biomechanical forces play little role in suture development. Clinical evidence has long suggested, however, that fetal head constraint may play a critical role in the pathogenesis of many cases of nonsyndromic craniosynostosis. The purpose of these experiments was to test the hypothesis that intrauterine constraint leads to an alteration in normal patterns of TGF-beta expression and that these alterations are associated with craniosynostosis. Fetal constraint was induced by allowing C57Bl/6 murine fetuses to grow for 2.5 days beyond the normal 20-day gestation by performing uterine cerclage on the eighteenth day. Cranial suture morphology was examined in hematoxylin and eosin-stained sections and in cleared whole-mount specimens, double stained with alizarin red S and Alcian blue. Expression patterns of TGF-beta1 and TGF-beta3 were examined by immunohistochemical techniques. Gross and microscopic examination of the cranial sutures of 17 constrained fetuses revealed changes that ranged from narrowing to complete osseous obliteration of the coronal and squamosal sutures. All sutures of 14 nonconstrained control pups remained patent. Fetal head constraint was associated with increased TGF-beta1 immunoreactivity within the new bone and the underlying dura when compared with nonconstrained age-matched controls. TGF-beta3 immunoreactivity was associated with the dura underlying patent, nonconstrained sutures, whereas constraint-induced synostosis was characterized by down-regulation of dural TGF-beta3 expression. These experiments confirm the ability of intrauterine constraint to induce premature fusion of the cranial sutures and provide evidence that intrauterine head constraint induces the expression of osteogenic growth factors in fetal calvarial bone and the underlying dura.

Minor neurological signs and developmental performance in high risk children at preschool age.

The aim of this study was to establish correlations between minor neurological findings and developmental performance. A cohort of 72 preschool children was studied (38 females, 34 males; mean age 3 years 8 months, SD 1 year 2 months, range 2 to 5 years) who were considered to be at high risk due to placental insufficiency. The cohort was divided into four categories of neurological status: (1) minimal cerebral palsy (MCP) with independent walking before age 2 years; (2) Amiel-Tison triad (ATT) including imbalance of passive axial tone, phasic stretch reflex in triceps surae, and cranial signs, particularly on the squamous suture; (3) intermediate with one or two of the three ATT signs; and (4) absence of neurological findings. Six subscales of the Griffiths Mental Developmental Scales assessing locomotion, eye-hand coordination, interpersonal skills, language, performance, and practical reasoning were administered. Significant differences were found according to neurological status in three specific domains of development: coordination (F=2.84, p=0.04), language (F=3.65, p=0.02), and practical reasoning (F=3.62, p=0.02). In addition, significant differences were also found in language (L) and practical reasoning (R) performances according to the side of the abnormal stretch reflex: bilateral stretches (L=87.8; R=75.3) or an isolated right stretch (L=95.3; R=83.6) are more strongly associated with impaired developmental performances than an isolated left stretch (L=101.3; R=88.2) with F=2.94; p=0.04 for language and F=3.00, p=0.04 for practical reasoning. We concluded that a short neurological examination, easily performed by pediatricians and family practitioners, can identify permanent markers of minor brain damage occurring before, during, or soon after birth and so anticipate consequences.

Minor neurological signs and developmental performance in high risk children at preschool age

The aim of this study was to establish correlations between minor neurological findings and developmental performance. A cohort of 72 preschool children was studied (38 females, 34 males; mean age 3 years 8 months, SD 1 year 2 months, range 2 to 5 years) who were considered to be at high risk due to placental insufficiency. The cohort was divided into four categories of neurological status: (1) minimal cerebral palsy (MCP) with independent walking before age 2 years; (2) Amiel‐Tison triad (ATT) including imbalance of passive axial tone, phasic stretch reflex in triceps surae, and cranial signs, particularly on the squamous suture; (3) intermediate with one or two of the three ATT signs; and (4) absence of neurological findings. Six subscales of the Griffiths Mental Developmental Scales assessing locomotion, eye‐hand coordination, interpersonal skills, language, performance, and practical reasoning were administered. Significant differences were found according to neurological status in three specific domains of development: coordination (F=2.84,p=0.04), language (F=3.65,p=0.02), and practical reasoning (F=3.62, p=0.02). In addition, significant differences were also found in language (L) and practical reasoning (R) performances according to the side of the abnormal stretch reflex: bilateral stretches (L=87.8; R=75.3) or an isolated right stretch (L=95.3; R=83.6) are more strongly associated with impaired developmental performances than an isolated left stretch (L=101.3; R=88.2) with F=2.94;p=0.04 for language and F=3.00,p=0.04 for practical reasoning. We concluded that a short neurological examination, easily performed by pediatricians and family practitioners, can identify permanent markers of minor brain damage occurring before, during, or soon after birth and so anticipate consequences.

Age-Related Morphological Changes in Squamous and Parietomastoid Sutures of Human Cranium

Age-related morphological changes in the inner and outer surfaces of the squamous and parietomastoid sutures were examined in 65 skulls (35 male, 30 female) obtained from Japanese subjects 5–90 years of age at the time of death. Dimensions were measured in both the horizontal and sagittal planes. Wavelength analysis was done by three-dimensional construction. Irregularities were evaluated by calculating fractal dimensions. The outer squamous suture showed no significant age-related changes in size, but wavelength increased because of the development of bony interdigitations with aging. The posterior part of the outer squamous suture showed significant age-related increases in both wavelength (p < 0.01, R² = 0.164) and fractal dimension (p < 0.01, R² = 0.101) in males. The parietomastoid suture showed significant age-related changes in size (p < 0.05), but not in wavelength or fractal dimension. These distinct morphological changes found on both the inner and outer surfaces of the squamous and parietomastoid sutures suggest that the age-related morphological characteristics of these sutures are affected by extrinsic mechanical forces.

ヒト頭蓋における鱗状縫合のレ線的および組織学的研究 特に前頭断面での型分類について

ヒト頭蓋における鱗状縫合のレ線的および組織学的研究 特に前頭断面での型分類について

Development of plagiocephaly in rabbits with unicoronal synostosis.

Human unicoronal synostosis results in plagiocephaly of the cranial vault due to predictable compensatory growth patterns of the contralateral coronal, sagittal, and ipsilateral squamosal sutures. The present study describes the development of plagiocephaly and tests compensatory growth predictions in a naturally occurring rabbit model of uncorrected unicoronal synostosis. Cranial vault and sutural growth data were collected from serial x-ray films in 70 normal rabbits and 19 rabbits with congenital unicoronal synostosis from 1.5 to 18 weeks of age. One-way analysis of variance results revealed that rabbits with unicoronal synostosis had significant (p < 0.05) growth inhibition at both coronal sutures and the contralateral frontonasal suture and a significantly wider (p < 0.05) cranial vault compared to controls. Paired Student's t-tests between affected and unaffected sides of the vault in rabbits with synostosis revealed significant (p < 0.05) asymmetry, with ipsilateral coronal sutures growing less than contralateral ones. Gross qualitative examination of the adult brains revealed severe asymmetry and anteroposterior reduction on the ipsilateral side. These results demonstrate that this congenital rabbit model effectively simulates human cranial vault growth predictions from unicoronal synostosis and produces a plagiocephalic morphology.

Dynamic cranioplasty for brachycephaly.

In craniofacial surgery, the most common techniques for treatment of brachycephaly have been either to let the forehead float on the brain or to fix it in an advanced position. Since neither of these techniques renders acceptable results with enough consistency, we have developed a different way of addressing the problem. In principle, the design of the operation is to restrict upward and transverse growth of the cranium but to allow anterior and posterior expansion. This is accomplished by producing transverse tension across the skull and letting it expand anteriorly by means of a superiorly hinged fronto-orbital flap and posteriorly by an inferiorly based occipital flap. To prevent upward expansion at the squamosal sutures when still open, these junctions are bridged with miniplates. This surgical technique has brought definite improvement to the results even in some Apert syndrome children. During a 2-year period, we have treated 14 infants with this technique and followed 10 of them with roentgencephalometry, 3 for more than 1 year, and 4 for more than 6 months. The diagnoses were the following: nonsyndromal bicoronal synostosis (4), Apert (7), bicoronal synostosis with midline cleft, Saethre-Chotzen, and Antley-Bixler (1 each). The mean age of surgery was 6.6 months (range 3 to 16 months). There were no major complications.

Relation of early neuromotor and cranial signs with neuropsychological outcome at 4 years

The persistence and predictive value at 3–5 years of age of three signs detected within the first 18 months of life were investigated: phasic stretch reflex in one or both gastrocnemius muscles, imbalance in passive axial tone with an excess of dorsal extension, and a ridge on the squamous sutures. Phasic stretch reflex and at least one of the other signs were found in 14 children during repeated assessments within the first 18 months. The progress of these children was compared with that of 14 matched controls who had repeatedly normal neurological assessments during the first 18 months in the same clinic in Paris. At the age 3–5 years all the children were then assessed blindly by the second author from a pediatric neurological viewpoint and by two psychologists and two psychomotor therapists as well. The parents of the affected children reported significantly more problems in motor/praxis skills, language development and attention. Abnormal neurological signs were also significantly more frequent than in the controls. Suboptimal cognition did not reach significance. The neurological inclusion criteria were still present at 3–5 years old in 86% (vs. respectively 100% and 93% during the first 18 months of life) of this small group of children, while the cranial suture sign was still present in only 28% (vs. 64%). Findings of these three signs during the first 18 months of life may help in predicting long-term neurobehavioral or long-term neuropsychological problems.

Surface and Superficial Surgical Anatomy of the Posterolateral Cranial Base: Significance for Surgical Planning and Approach

We have performed an anatomic study, 15 using fixed cadaveric preparations, with the goal of identifying surface landmarks that will reliably locate the underlying transverse and sigmoid sinus complex. Simple morphometric relationships were first determined on both sides of each specimen to yield 30 sides measured. The following relationships were determined: 1) zygoma root-asterion, 2) asterion-mastoid tip, 3) zygoma root-suprameatal spine (Henle's spine), 4) asterion-suprameatal spine, 5) mastoid tip-suprameatal spine. The relationship of the asterion to the transverse-sigmoid junction was determined by bone removal. Also, the distances from the asterion to the sigmoid sinus-superior petrosal sinus junction and the superior margin of the transverse sinus were studied. Surface and marks were found to have definitive relationships to underlying anatomic substrates in all specimens studied. The critical relationships that were concluded from this study can be described in terms of two easily identified lines between bony surface structures. A line drawn from the zygoma root to the inion, i.e., the superior nuchal line, reliably located the rostrocaudal level of the transverse sinus in all specimens. Although the asterion did not consistently fall on this line, the transverse-sigmoid junction could reliably be placed at the anteroposterior level of the asterion. Further, a line drawn from the squamosal-parietomastoid suture junction to the mastoid tip reliably defined the axis of the sigmoid sinus through the mastoid. We also found that the junction of the squamosal and parietomastoid sutures lay over the anterior border of the upper curve of the sigmoid sinus. The anterior portion of the supramastoid crest correlated with the level of the middle fossa. These surface relationships all have significance for posterolateral approaches to the cranial base. Since performing this study, these relationships have been found reliable for operative planning in our clinical cases.

Growth of the Cranial Vault in Rabbits with Congenital Coronal Suture Synostosis

Craniofacial growth data from craniosynostotic children have shown that suture immobilization results in predictable restrictions of cranial vault growth in a direction perpendicular to the affected suture and compensatory growth at sutures perpendicular to the affected one. This study tests these predictions by using rabbits with nonsyndromic congenital coronal suture synostosis. Data were collected from 96 rabbits divided into three groups: 42 unaffected litter mate controls, 33 partially synostosed rabbits, and 21 completely synostosed rabbits. Markers were placed bilaterally on either side of the vault sutures at 1.5 weeks of age. Serial radiographs were taken at 1.5, 6, 12, and 18 weeks of age for assessment of growth at the vault sutures and of various cranial landmarks. Results revealed that completely synostosed animals had significantly (p < .05) shorter cranial vaults, reduced growth at the coronal suture, and increased growth at the sagittal, frontal, and squamosal sutures compared with unaffected rabbits. Results also showed that the calvarial growth observed in this craniosynostotic rabbit model closely reflects predicted compensatory patterns seen in human clinical populations and that this rabbit model is valuable for understanding the pathogeneses and craniofacial growth patterns of humans with premature cranial suture synostosis.

Growth of the cranial vault in rabbits with congenital coronal suture synostosis.

Craniofacial growth data from craniosynostotic children have shown that suture immobilization results in predictable restrictions of cranial vault growth in a direction perpendicular to the affected suture and compensatory growth at sutures perpendicular to the affected one. This study tests these predictions by using rabbits with nonsyndromic congenital coronal suture synostosis. Data were collected from 96 rabbits divided into three groups: 42 unaffected litter mate controls, 33 partially synostosed rabbits, and 21 completely synostosed rabbits. Markers were placed bilaterally on either side of the vault sutures at 1.5 weeks of age. Serial radiographs were taken at 1.5, 6, 12, and 18 weeks of age for assessment of growth at the vault sutures and of various cranial landmarks. Results revealed that completely synostosed animals had significantly (p < .05) shorter cranial vaults, reduced growth at the coronal suture, and increased growth at the sagittal, frontal, and squamosal sutures compared with unaffected rabbits. Results also showed that the calvarial growth observed in this craniosynostotic rabbit model closely reflects predicted compensatory patterns seen in human clinical populations and that this rabbit model is valuable for understanding the pathogeneses and craniofacial growth patterns of humans with premature cranial suture synostosis.

Relationship of squamosal suture to asterion on external skull surfaces versus endocasts of pongids: Implications for Hadar early hominid AL 162‐28

The relationship between the squamosal suture and asterion was quantified in 15 hemispheres of eight chimpanzee endocasts that were aligned in the conventional lateral view (i.e., with frontal pole [FP]-occipital pole [OP] horizontal). Using a three-dimensional digitizer, x, y, and z coordinates were collected for the highest and lowest points of the squamosal suture, and the most rostral point of the suture approximate to the coronal suture. Our results were compared to a similar study of the squamosal suture on the external surfaces of chimpanzee skulls that were oriented in the Frankfurt horizontal (Holloway and Shapiro, 1992). The relationship between the squamosal suture and asterion differs markedly between the outsides of skulls and endocasts. Whereas the squamosal suture is very rarely below asterion on the external skull, we found that most of the squamosal suture is located inferior to asterion on endocasts. We also found that the squamosal suture courses approximately 2.0 mm lower on the right side than the left. (An asymmetry of the same magnitude was reported for the external skull but, curiously, in the opposite direction.) It may be that a lowered right squamosal endosuture on chimpanzee endocasts is associated with earlier closure on that side. The discrepancy in results for the external skull versus endocast is partially attributable to orienting chimpanzee skulls in the Frankfurt horizontal, which usually results in the endocasts being tilted so that FP is above OP, i.e., FP-OP is not parallel with the Frankfurt horizontal. Falk's (1985) orientation of the early hominid endocast from Hadar (AL 162-28) is consistent with data determined from endocasts of chimpanzees.

Asterion region synostosis.

Posterior plagiocephaly historically has been associated with synostosis of the lambdoid suture. The incidence, diagnosis, and modes of treatment for stenosis of the lambdoid suture remain controversial. Commonly, the lambdoid suture is found to be open both on radiographic examination and at the time of surgery. The study reports on nine patients who presented with unilateral posterior plagiocephaly and who were found to have open lambdoid sutures, but a stenosed region of the asterion. The area of involvement included the distal-most lambdoid suture, the parietomastoid, occipitomastoid, and proximal squamosal sutures. Positional molding or torticollis was ruled out in all patients. All the patients showed progressive involvement of the skull base, including anterior shifts of the ipsilateral ear, compensatory ipsilateral frontal bossing and malar protrusion. Stenosis of the asterion was diagnosed with three-dimensional computed tomography scans, corroborated at the time of surgery and confirmed histologically. Surgical correction involved resection of the affected asterion and reconstruction using a bandeau-technique, barrel staves of the occipital bone and bone graft transposition. This approach provided excellent esthetic results in all patients.

Asterion Region Synostosis

Posterior plagiocephaly historically has been associated with synostosis of the lambdoid suture. The incidence, diagnosis, and modes of treatment for stenosis of the lambdoid suture remain controversial. Commonly, the lambdoid suture is found to be open both on radiographic examination and at the time of surgery. The study reports on nine patients who presented with unilateral posterior plagiocephaly and who were found to have open lambdoid sutures, but a stenosed region of the asterion. The area of involvement included the distal-most lambdoid suture, the parietomastoid, occipitomastoid, and proximal squamosal sutures. Positional molding or torticollis was ruled out in all patients. All the patients showed progressive involvement of the skull base, including anterior shifts of the ipsilateral ear, compensatory ipsilateral frontal bossing and malar protrusion. Stenosis of the asterion was diagnosed with three-dimensional computed tomography scans, corroborated at the time of surgery and confirmed histologically. Surgical correction involved resection of the affected asterion and reconstruction using a bandeau-technique, barrel staves of the occipital bone and bone graft transposition. This approach provided excellent esthetic results in all patients.