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Patients with unicoronal synostosis (UCS) or plagiocephaly without synostosis (PWS) have distinctive skull dysmorphologies. Associated mandibular dymorphologies have been suspected but not quantified. This study was performed to test the hypothesis that discrete mandibular dysmorphology exists in both UCS and PWS. All patients at a tertiary referral center at a medical school-affiliated children's hospital with confirmed diagnosis of UCS or PWS with adequate pretreatment CT data were included in the study population, which population was comprised of 20 UCS, 23 PWS, and 8 normal infants. Each patient had a head CT scan using 2-mm slices. 3-D images were created using Analyze, a biomedical imaging program. The mandibles were isolated, and the coordinates of 8 landmarks were sampled from each mandible by a single investigator: a single volume value was measured, and 9 linear distances and 4 angles were calculated. Corresponding measurements from each hemimandible were expressed as ratios of ipsilateral/contralateral side. In UCS, the affected side was defined as the side ipsilateral to the synostosis; In PWS, the affected side was defined as the side ipsilateral to the occipital flattening. The results from both groups were t tested for statistical significance. For UCS, statistically significant (p < .001) findings included: ipsilateral hemimandibular volume 5% smaller than contralateral; affected hemimandibular body length 1.9% shorter; affected gonial angle 2.6% more acute; affected coronoid process tilted anteriorly 2.5%; and distances from condylion and tip of the coronoid process to the chin landmarks 4% shorter on the affected side. For PWS, significant findings included: affected hemimandibular volume 3.8% larger; ramal height 3.5% shorter; mandibular body length 3% longer; and coronoid process tilted anteriorly by 2.3% on the affected side. In the UCS/PWS comparison, findings included: affected hemimandibular volume in UCS 8.7% less; affected gonial angle in UCS 3% more acute; affected mandibular corpus length in UCS 5% shorter; distances from the condylion and the tip of the coronoid process to the chin landmarks 4% shorter on the affected side in UCS. The hypothesized presence of diagnosis specific mandibular dysmorphology in UCS and PWS is confirmed. This analysis forms the baseline for study of the effects of unperturbed growth or therapeutic interventions upon the dentoskeletal dysmorphology of these anomalies.

Unilateral coronal synostosis (UCS) produces overt craniofacial dysmorphology. UCS surgery in infancy aims to release the osseous restriction and normalize the fronto-orbital deformity. The quantitative effect of this surgery on the orbit and its contents is unknown. This study was conducted to quantify the preoperative orbital dysmorphology and its surgical outcome in patients with unilateral coronal synostosis. Twenty-eight UCS patients had preoperative three-dimensional computerized tomographic (CT) scans (at mean age 4.0 months), cranio-orbital reconstructive surgery (at 4.7 months), and postoperative scans (at 18.1 months). The CT data were analyzed using a computer workstation and AnalyzeTM biomedical imaging software. Four measurements were performed on both ipsilateral (same side as synostosis) and contralateral (opposite to synostosis) orbits of each scan: orbital index (OI, 100 x height/width of orbit), orbital cavity volume (OV), ocular globe volume (GV), and ventral globe Index (VGI, 100 x globe volume ventral to the anterior surface of orbital cavity/GV). The data were analyzed for statistical significance using Student's ttest. Preoperatively, the OI was significantly greater on the ipsilateral than on the contralateral side (113.7 vs. 87.3). There was a significant improvement on both sides of the orbit postoperatively, with ipsilateral 99.1 and contralateral 92.1. However, the difference between both sides remained significant. The OV was smaller in the ipsilateral orbits both pre- and postoperatively, with ipse/contralateral ratios of 95.8 and 95.2, respectively. Importantly, the GV was consistently smaller in the ipsilateral orbits preoperatively, with an ipse/contralateral ratio of 93.3. The ratio increased to 97.1 postoperatively, a statistically significant change. In the ipsilateral orbits, the preoperative VGI was significantly greater. The VGI improved postoperatively. These data indicate that UCS affects the development of the osseous orbit as well as its soft-tissue contents. After cranio-orbital surgery, there is diminution of asymmetry of both the bony orbit and its soft-tissue contents. Partial normalization of orbital dysmorphology occurred during the first postoperative year. UCS surgery in infancy does not prevent growth of orbital hard or soft tissues, and it seems to permit normalization of previously impaired growth.

Purpose: To measure diagnostic performance and preference of two three-dimensional CT reconstruction modalities (voxel-gradient and surface-projection) displayed two ways (conventional and unwrapped) in craniosynostosis confirmed by surgical inspection and histologic analysis of resected sutures., Methods: High-resolution 2-mm contiguous CT sections were obtained and three-dimensional reconstruction images generated for 25 infants and children with skull deformities before surgical treatment of craniosynostosis. Two pediatric radiologists and two neuroradiologists first ranked images by their own preferences for diagnostic use. Then they diagnosed craniosynostosis from images presented in random order and blinded. The standard of reference was inspection during surgery and histologic evaluation of excised sutures. Finally, reviewers repeated their subjective preference tests., Results: The least experienced radiologist had 100% sensitivity for all imaging modalities and specificities ranging from 43% to 83%. The two most experienced radiologists performed nearly identically, with sensitivities of 96% and specificities of 100%. After performing diagnostic tasks using all image types, all radiologists preferred conventional surface projections., Conclusion: Experienced readers can achieve nearly perfect diagnostic performance using the latest three-dimensional CT reconstruction images, making it a contribution to the diagnostic process. Although performance is nearly identical for all modalities, readers strongly prefer conventionally presented surface-projection images.

Rationale and Objectives: Two independent gold standards and diagnoses from three-dimensional computed tomography (CT) images were used to examine the possibility that craniosynostosis is a binary abnormality that potentially may be diagnosed without error., Methods: Surgical reports, histology of excised sutures, and three-dimensional CT images were compared for 25 children undergoing surgical management of craniosynostosis. Surgical reports identified sutures as normal or abnormal. Histology reported suture closure on a 5-point scale. Four radiologists used three-dimensional CT images to diagnose sutures on a 6-point rated response scale., Results: Sutures with histology 0, 1, or 2 were normal on surgical reports, and those with histology 3 or 4 were abnormal. Most readers achieved nearly perfect sensitivity and specificity. Reader confidence was unrelated to degree of pathology., Conclusion: Craniosynostosis appears to be binary in our sample. Surgical reports, pathology results, and three-dimensional CT images read by experienced viewers achieved nearly perfect agreement.

Scaphocephaly is caused by premature sagittal suture closure. It restricts medial-lateral growth of the cranial vault which appears longer and narrower than normal. We examined how this natural malformation affected morphology of the cranial base and face. A prehistoric adult male Hopi with scaphocephaly was compared to 19 normal male Hopi (Old Walpi Series, Field Museum of Natural History, Chicago, IL). Three-dimensional coordinates of 53 landmarks were recorded on the cranial vault, cranial base, and face. Finite element scaling analysis was used to test for significant differences between the scaphocephalic and normal individuals in craniofacial morphology. Finite element scaling results indicated that scaphocephaly has a profound effect on cranial vault morphology. However, morphology of the cranial base and face were only slightly affected and, typically, are within the normal range of variation for the sample. An abnormality in the cranial base is not associated with scaphocephaly in this individual.

Computer-assisted medical imaging technology provides useful tools for the in vivo study of congenital craniofacial deformities. Using these tools, a standardized operation for infants with nonsyndromal unicoronal synostosis has been shown to consistently normalize orbital dimensions and decrease exocranial base angulation. Normalization of endocranial base angulation is less consistent. The plasticity of the infant's cranial base after cranial vault surgery suggests a locus of the primary pathology at a site other than the cranial base.

This article reports a retrospective quantitative (cephalic index) evaluation of the effect that two different operations for treatment of scaphocephaly secondary to sagittal synostosis have on cranial shape. Combining our results with those of others, the trend is clear: if the objective of surgical intervention for isolated nonsyndromal sagittal synostosis is normalization of the calcarial width to length ratio, a more extensive procedure than simple or extended craniectomy is required.

The configuration of the neurocranium has long been used as a diagnostic tool in assessing infants with abnormal head shape. In the case of craniosynostosis, a characteristic shape is caused by a constraint placed on growth of the neurocranium by prematurely closed sutures and secondary accommodation to that constraint. This investigation is a preliminary test of our hypotheses of growth of the cranial base under these constraints. Three dimensional landmark coordinate data were collected from pre-, peri-, and postoperative CT scans of eleven patients from The Cleft Palate and Craniofacial Deformities Institute, St. Louis, MO. These data were used in two sets of analytical comparisons. Comparisons of preoperative and perioperative morphology were taken to represent preoperative growth, while comparisons of perioperative to postoperative CT scans represent postoperative growth. Finite-element scaling analysis (FESA) and Euclidean distance matrix analysis (EDMA) were used to make these comparisons. Our results show that in cases involving premature closure of the metopic, sagittal, and bilateral coronary sutures, predictions about growth of the cranial base made prior to analysis prove correct. In these forms of craniosynostosis there are characteristic and consistent changes in the cranial base in both pre- and postoperative growth. Preoperative and postoperative growth in patients diagnosed with unicoronal synostosis show a greater degree of individual variability and do not follow a predictable pattern.

Three-dimensional surface images from CT scans have been used to study the pre- and postoperative anatomy of patients with craniosynostosis: the sutural pattern per se, the morphology of the calvaria, the morphology of the endo- and exocranial bases, the morphology of the orbits and the position of the globes, and the morphology of the mandible. This technology assists diagnosis, treatment planning, and longitudinal follow-up.

Three-dimensional osseous surface images from CT scans have been used to study the endo- and exocranial bases of 87 patients with a variety of craniosynostoses. Patients were studied prior to cranial surgery in infancy, perioperatively, and 1 year postoperatively. The dysmorphology of the endocranial base is diagnostically specific for synostosis of the metopic, sagittal, unicoronal, and bicoronal sutures. Cranio-orbital surgery in infancy for nonsyndromal solitary and bicoronal synostosis seems to induce normalization of endocranial symmetry in the first postoperative year. This normalization occurs to a lesser degree in patients with multiple synostoses. These findings suggest that the cranial base dysmorphology of craniosynostosis is a secondary manifestation of an undefined primary disorder. Furthermore, persistent postoperative dysmorphology may reflect abnormal neural rather than osseous growth.

High resolution, thin slice computerized tomography (CT) scans with paraxial and three-dimensional surface reconstructions were utilized to document the endocranial, exocranial, and orbital anatomy of non-syndromal unicoronal synostosis (UCS). Eighteen patients with UCS were evaluated qualitatively and quantitatively. Of these, 10 were studied both preoperatively and 1 year postoperatively. The endocranial base in UCS is characterized by a 9 degree angulation toward the synostosis of the anterior cranial base with respect to the posterior cranial base. The exocranial base has a 7 degree angulation toward the synostosis between the midpalatal suture and the posterior cranial base. The locus of angulation appears to be posterior to the anterior clinoids endocranially, and between the maxillopalatopterygoid articulations and the mandibular condyle exocranially. The orbital rim height is greater ipsilateral to the synostosis than contralaterally. The analysis documents the normalizing effect of one of two different surgical procedures upon orbital height. Application of computer assisted medical imaging to the study of UCS has allowed in vivo quantitation of cranial base and orbital dysmorphology for both preoperative assessment and postoperative evaluation.

The authors used the diagnosis of craniosynostosis to compare subjective evaluation of image quality with objective diagnostic utility. They studied in detail the responses of one observer, who read plain radiographs, computed tomographic (CT) scans, and three-dimensional reconstructions of CT scans (obtained with three different methods) for 82 patients with this diagnosis. The observer rated image quality and certainty in diagnosis made from each image. Subjective and objective performances were found to be strongly linked. High-quality images served as the basis for more accurate diagnoses than low-quality images. The increase in diagnostic performance results primarily from increased specificity, a fact that suggests that specificity and the concomitant diagnosis of normalcy are the focus of attention when image quality is evaluated.

Three-dimensional computed tomography (CT) has an important role in determining the presence and extent of congenital and acquired craniofacial deformities. The authors compared the sensitivity and specificity of three-dimensional CT in the detection and characterization of craniosynostosis with that of planar CT and skull radiography. Eighty-two patients with isolated and syndromal synostoses were imaged with CT and three-dimensional CT, and 42 with skull radiography. Three-dimensional CT scan processing was performed by shaded-surface reconstruction, volumetric, and depth-coded methods. Two trained observers read each scan series in a blinded fashion. Diagnostic utility of the images was determined with receiver operating characteristic analysis. The observers ranked three-dimensional shaded images higher than the other types, with three-dimensional volumetric images second and three-dimensional surface images ranked third. Results of this study demonstrate that three-dimensional shaded-surface reconstruction from CT scans is superior to conventional plain radiographs and CT scans in diagnosing craniosynostosis.