The craniofacial anomalies archive at St. Louis Children's Hospital: 20 years of craniofacial imaging experience

Morphologic Severity of Craniosynostosis: Implications for Speech and Neurodevelopment

BACKGROUND

Single-suture craniosynostosis (SSC) can be associated with neurodevelopmental deficits. We examined the correlation between morphologic severity and incidence of speech-language or psychological concerns.

METHODS

In 62 patients (33 sagittal, 17 metopic, and 12 unicoronal), morphologic severity was determined via preoperative computed tomography (CT). Severity metrics for sagittal, metopic, and unicoronal synostosis were adjusted cephalic index (aCI), interfrontal angle (IFA), and anterior cranial fossa area ratio (ACFR), respectively. Speech-language and psychological concerns were assessed at age ≥4.5 years and defined as recommendation for therapy or monitoring.

RESULTS

Mean assessment age was 5.7 years; 32% had a speech-language concern and 44% had a psychological concern; 44% had neither. Sagittal: Mean aCI of those with a speech-language concern (0.62) and those without (0.62) were equivalent (P = .580), as were mean aCI of those with a psychological concern (0.62) and those without (0.62; P = .572). Metopic: Mean IFA with (117.9) and without (125.2) a speech-language concern were equivalent (P = .326), as were mean IFA with (120.2) and without (123.2) a psychological concern (P = .711). Unicoronal: Mean ACFR with (0.65) and without (0.69) a psychological concern (P = .423) were equivalent. However, mean ACFR with (0.74) and without (0.63) a speech-language concern were not (P = .022*). Bivariate rank correlation showed significant association between morphologic severity and speech-language score only for unicoronal synostosis (ρ = .722; P = .008*).

CONCLUSION

A significant portion of patients with SSC had speech-language or psychological concerns. We found no correlation between morphologic severity and incidence of speech-language or psychological concerns for patients with sagittal or metopic synostosis. Morphological severity did correlate with speech concerns in patients with unicoronal synostosis.

Long-Term Characterization of Cranial Defects After Surgical Correction for Single-Suture Craniosynostosis

INTRODUCTION

Craniosynostosis is typically corrected surgically within the first year of life through cranial vault reconstruction. These procedures often leave open calvarial defects at the time of surgery, which are anticipated to close over time in a large proportion of cases. However, residual calvarial defects may result as long-term sequelae from cranial vault remodeling. When larger defects are present, they may necessitate further reconstruction for closure.Better understanding of the calvarial osseous healing process may help to identify which defects will resolve or shrink to acceptable size and which will require further surgery. Our study aims to assess the long-term changes in defect size after cranial vault reconstruction for craniosynostosis.

METHODS

One-year postoperative and long-term computed tomography scans were retrieved from the craniofacial anomalies archive. Analysis used custom software. All defects above the size of 1 cm were analyzed and tracked for calvarial location, surface area, and circularity. Monte Carlo simulation was performed to model the effect of initial defect size on the rate of defect closure.

RESULTS

We analyzed a total of 74 defects. The mean ± SD initial defect surface area was 3.27 ± 3.40 cm. The mean ± SD final defect surface area was 1.71 ± 2.54 cm. The mean ± SD percent decrease was 55.06% ± 28.99%. There was a significant difference in the percentage decrease of defects in the parietal and frontoparietal locations: 68.4% and 43.7%, respectively (P = 0.001). Monte Carlo simulation results suggest that less than 10% of defects above the size of 9 cm will close to the size of 2.5 cm or less.

CONCLUSIONS

We describe and make available a novel validated method of measuring cranial defects. We find that the large majority of initial defects greater than 9 cm remain at least 1 in in size (2.5 cm) 1 year postoperatively. In addition, there appear to be regional differences in closure rates across the cranium, with frontoparietal defects closing more slowly than those in the parietal region. This information will aid surgeons in the decision-making process regarding cranioplasty after craniosynostosis correction.

Assessing calvarial vault constriction associated with helmet therapy in deformational plagiocephaly

OBJECTIVE Deformational plagiocephaly and/or brachycephaly (DPB) is a cranial flattening frequently treated in pediatric craniofacial centers. The standard of care for DPB involves patient positioning or helmet therapy. Orthotic therapy successfully reduces cranial asymmetry, but there is concern over whether the orthotics have the potential to restrict cranial growth. Previous research addressing helmet safety was limited by lack of volume measurements and serial data. The purpose of this study was to directly compare head growth data in patients with DPB between those who underwent helmet therapy and those who received repositioning therapy. METHODS This retrospective cohort study analyzed pre- and posttherapy 3D photographs of 57 patients with DPB who had helmet therapy and a control group of 57 patients with DPB who underwent repositioning therapy. The authors determined the change in cranial vault volume and cranial circumference between each patient's photographs using 3D photogrammetry. They also computed a cubic volume calculated by multiplying anterior-posterior diameter, biparietal diameter, and height. Linear regressions were used to quantify effects of age and therapy type on these quantities. RESULTS A comparison of the following variables between the two groups yielded nonsignificant results: age at the beginning (p = 0.861) and end (p = 0.539) of therapy, therapy duration (p = 0.161), and the ratio of males to females (p = 0.689). There was no significant difference between patients who underwent helmeting versus positioning therapy with respect to change in either volume calculation or head circumference z-score (p ≥ 0.545). Pretherapy photograph age was a significant predictor of cranial growth (p ≤ 0.001), but therapy type was not predictive of the change in the study measurements (p ≤ 0.210). CONCLUSIONS The authors found no evidence that helmet therapy was associated with cranial constriction in the study population of patients with DPB. These results strengthen previous research supporting helmet safety and should allow health care providers and families to choose the appropriate therapy without concern for potential negative effects on cranial growth.

Orthodontic treatment of a particular subgroup of children with special health care needs, children with craniofacial anomalies: An analysis of treatment length and clinical outcome

OBJECTIVE

To analyze any differences in the orthodontic treatment between children belonging to a particular subgroup of subjects with special health care needs (SHCN), children with craniofacial anomalies (CFA), and children not diagnosed with SHCN (NO SHCN).

MATERIALS AND METHODS

The study sample consisted of 50 children with SHCN and a confirmed diagnosis of CFA (SHCN/CFA); the control group consisted of 50 NO SHCN children fully matched for age, gender, and type of appliance used. The differences between the two groups were analyzed retrospectively: pre-, posttreatment scores, and score reduction of the Peer Assessment Rating Index (PAR), dental health component (DHC), and aesthetic component (AC) of Orthodontic Treatment Need Index (IOTN), number of appointments, number of simple or complex chair-time appointments, overall treatment time, and age at treatment start and end.

RESULTS

There were no statistically significant differences between the SHCN/CFA and NO SHCN groups for number of appointments, overall treatment time, age at treatment start, and age at treatment end (P  =  .682, .458, .535, and .675, respectively). There were statistically significant differences between groups in PAR, DHC, AC pre- and posttreatment, and number of simple and complex chair-time appointments (P  =  .030 and .000; .020 and .023; .000 and .000; .043; and .037; respectively). The reduction of PAR, DHC, and AC scores was not significantly different between groups (P  =  .060, .765, and .825, respectively).

CONCLUSION

The treatment of children with SHCN, in general, and with CFA, in particular, on the one hand involves a higher rate of using complex chair time appointments and an inferior treatment outcome, by the other side implies an overall treatment time and a reduction of PAR, DHC or AC scores similar to the treatment of children not diagnosed with SHCN.

Isolated sagittal craniosynostosis: definition, classification, and surgical indications

Sagittal craniosynostosis (SC) remains the most common type of synostosis, accounting for about a half of all forms. It would result from a mesenchymal disorder involving the intramembranous ossification of the sagittal suture and leading to its early fusion. No specific data on the etiologic factors are currently available. The premature ossification of the sagittal suture can result in three main types of SC, according to the different segment prevalently involved: anterior, posterior, and complete SC. The diagnosis is easily obtained by clinical examination. However, a radiological work up (3D CT scan) may be necessary to rule out hidden venous or cranial anomalies possibly associated with most severe cases, or for the surgical planning. The most common indication for surgery is the improvement of the cosmetic appearance of the skull, since a cranial deformation may have a significant psychological impact on affected subjects. To relieve from raised intracranial pressure is a further indication to surgery. Although an increased intracranial pressure can be demonstrated in a minority of affected children at diagnosis, indeed, it can present later (usually after the second/third year of life) with chronic symptoms. The role of surgery in the preservation of cognitive functions in scaphocephalic patients does not seem to be relevant, since minor anomalies of the cerebral development associated with SC would occur independently from the cranial shape. On the other hand, the surgical correction may show a protective effect on some visual skills, like the ability to fix and follow, and the fixation shift.

Validity and reliability of craniofacial anthropometric measurement of 3D digital photogrammetric images

BACKGROUND

Direct anthropometry performed during a patient examination is the standard technique for quantifying craniofacial dysmorphology, as well as for surgical planning and outcome assessment. Several new technologies have been designed to computerize anthropometric measurements, including three-dimensional (3D) digital photogrammetry. These digital systems have the advantage of acquiring patient craniofacial surface images quickly and noninvasively. Before morphometry using digital photogrammetry can be applied in clinical and research practice, it must be assessed against direct anthropometry.

OBJECTIVE

To evaluate the validity and reliability of facial anthropometric linear distances imaged by 3D digital photogrammetry with respect to direct anthropometry. DESIGN, SETTING, PARTICIPANTS, MEASURES: Standard craniofacial distances were directly measured twice on 20 normal adult volunteers. Craniofacial surfaces were also imaged using the 3dMDface digital photogrammetry system, and distances were digitally measured twice for each subject. Validity measures of accuracy and bias (for direct versus digital measurements) and reproducibility measures of precision and test-retest reliability (for repeated sets of digital measurements) were computed.

RESULTS

Seventeen of the 18 direct measurements correlated highly with digital values (mean r = 0.88). The correlation for one measurement (upper prolabial width) was not statistically significant. The overall precision of all 17 digital measurements was less than 1 mm, and the reliability was high (mean r = 0.91).

CONCLUSIONS

Craniofacial anthropometry using the 3dMDface System is valid and reliable. Digital measurements of upper prolabial width may require direct marking, prior to imaging, to improve landmark identification.

Neuroimaging of the child with developmental delay

Developmental delay (DD) affects approximately 1% to 3% of all children in the United States. This diagnosis significantly impedes quality of life and full participation in the life of the family, school, and community. In this setting, the clinician's ability to detect, diagnose, and possibly treat the cause for DD in a timely manner depends on a multimodality approach to neuroimaging and a robust understanding of the various imaging algorithms aimed at determining the etiology of disease, structural and/or anatomic defects, functional activity, metabolic profiles, and genetic characteristics. Taken separately and in combination, these features are effectively depicted and analyzed using an array of brain imaging modalities: ultrasound, computed tomography, nuclear medicine, magnetic resonance (MR) spectroscopy, and a growing mix of sophisticated MR imaging (MRI) techniques, including diffusion-weighted imaging, diffusion tensor imaging, perfusion MRI, and functional MRI. Thus, equipped with these advanced imaging capabilities, pediatric neurologists and neuroradiologists are now positioned to diagnose with greater accuracy and speed; this, in turn, results in more effective treatment plans and improved patient outcomes as measured by progress in reaching developmental milestones and in ameliorating secondary conditions such as seizures, poor motor control, incontinence, and impulsivity. The purpose of this article is to present the numerous causes of pediatric DD, describe their respective neuroimaging findings, discuss various neuroimaging approaches for elucidating etiology, and offer specific guidelines for optimizing imaging results in the setting of multimodality imaging capabilities.

The craniofacial phenotype of the Crouzon mouse: analysis of a model for syndromic craniosynostosis using three-dimensional MicroCT

OBJECTIVE

To characterize the craniofacial phenotype of a mouse model for Crouzon syndrome by a quantitative analysis of skull morphology in mutant and wild-type mice and to compare the findings with skull features observed in humans with Crouzon syndrome.

METHODS

MicroCT scans and skeletal preparations were obtained on previously described Fgfr2(C342Y/+) Crouzon mutant mice and wild-type mice at 6 weeks of age. Three-dimensional coordinate data from biologically relevant landmarks on the skulls were collected. Euclidean Distance Matrix Analysis was used to quantify and compare skull shapes using these landmark data.

RESULTS

Obliteration of bilateral coronal sutures was observed in 80% of skulls, and complete synostosis of the sagittal suture was observed in 70%. In contrast, fewer than 40% of lambdoid sutures were found to be fully fused. In each of the 10 Fgfr2(C342Y/+) mutant mice analyzed, the presphenoid-basisphenoid synchondrosis was fused. Skull height and width were increased in mutant mice, whereas skull length was decreased. Interorbital distance was also increased in Fgfr2(C342Y/+) mice as compared with wild-type littermates. Upper-jaw length was shorter in the Fgfr2(C342Y/+) mutant skulls, as was mandibular length.

CONCLUSION

Skulls of Fgfr2(C342Y/+) mice differ from normal littermates in a comparable manner with differences between the skulls of humans with Crouzon syndrome and those of unaffected individuals. These findings were consistent across several regions of anatomic interest. Further investigation into the molecular mechanisms underlying the anomalies seen in the Crouzon mouse model is currently under way.

A model for the pharmacological treatment of crouzon syndrome

OBJECTIVE

Crouzon syndrome is caused by mutations in fibroblast growth factor receptor 2 (FGFR2) leading to constitutive activation of receptors in the absence of ligand binding. The syndrome is characterized by premature fusion of the cranial sutures that leads to abnormal cranium shape, restricted brain growth, and increased intracranial pressure. Surgical remodeling of the cranial vault is currently used to treat affected infants. The purpose of this study was to develop a pharmacological strategy using tyrosine kinase inhibition as a novel treatment for craniosynostotic syndromes caused by constitutive FGFR activation.

METHODS

Characterization of cranial suture fusion in Fgfr2 mutant mice, which carry the most common Crouzon mutation, was performed using micro-computed tomographic analysis from embryogenesis through maturation. Whole calvarial cultures from wild-type and Fgfr2 mice were established and cultured for 2 weeks in the presence of dimethyl sulfoxide control or PD173074, an FGFR tyrosine kinase inhibitor. Paraffin sections were prepared to show suture morphology and calcium deposition.

RESULTS

In untreated Fgfr2 cultures, the coronal suture fused bilaterally with loss of overlap between the frontal bone and parietal bone. Calvaria treated with PD173074 (2 micromol/L) showed patency of the coronal suture and were without evidence of any synostosis.

CONCLUSION

We report the successful use of PD173074 to prevent in vitro suture fusion in a model for Crouzon syndrome. Further studies are underway to develop an in vivo treatment protocol as a novel therapeutic modality for FGFR associated craniosynostotic syndromes.

Long-Term Osseous Morphologic Outcome of Surgically Treated Unilateral Coronal Craniosynostosis

BACKGROUND

Unilateral coronal craniosynostosis has characteristic osseous dysmorphology that persists into adulthood if untreated. Knowledge of the long-term in vivo osseous morphologic outcome of surgically treated unilateral coronal craniosynostosis patients is limited. The purpose of this study was to define the osseous morphology of adolescent patients who underwent surgery for unilateral coronal craniosynostosis in infancy, compared with both their 1-year postoperative morphology and the morphology of other individuals with untreated unilateral coronal craniosynostosis.

METHODS

Three populations of unilateral coronal craniosynostosis were studied: group 1, patients with surgical treatment of unilateral coronal craniosynostosis in infancy who had reached dentoskeletal maturity, ranging in age from 13.5 to 32.7 years (n= 9); group 2, individuals with untreated unilateral coronal craniosynostosis, ranging in age from 1.1 to 21 years (n= 11); and group 3, a subset of group 1 patients 1 year after surgical correction of unilateral coronal craniosynostosis, ranging in age from 1.2 to 2.6 years (n= 6). Data from high-resolution, thin-slice computed tomographic scans of the head were analyzed. Thirty-five reproducible osseous landmarks were recorded as three-dimensional coordinates using ETDIPS imaging software. Nonmidline landmarks were designated as either ipsilateral or contralateral to the synostosis. One researcher performed all landmarking with high intrarater reliability (average error, <2 mm). Data from the three groups were analyzed for asymmetry using Euclidean distance matrix analysis techniques.

RESULTS

Euclidean distance matrix analysis asymmetry analysis demonstrated more statistically significant ipsilateral-contralateral asymmetric pairs in group 1 (68 of 135) than in group 3 (25 of 135), but fewer statistically significant ipsilateral-contralateral asymmetric pairs than in group 2 (93 of 135).

CONCLUSIONS

Surgical treatment of unilateral coronal craniosynostosis in infancy results in a less asymmetric craniofacial skeleton in adolescence than nontreatment. However, patients who have been followed to dentoskeletal maturity have a greater degree of asymmetry than those evaluated at 1 year postoperatively. These results support the conclusion that with time there is a partial reversion to the untreated phenotype.

Anthropometric proportion indices in the craniofacial regions of 73 patients with forms of isolated coronal synostosis

The study group consisted of 73 North American patients (29 males and 44 females), aged between 0-5 months and 20 years, 26 with right, 33 with left, and 14 with bicoronal synostosis. Basic proportion indices were established in 5 craniofacial regions (cranial, facial, orbital, nasal, oral) calculated from 2 projective measurements [cranial: eu-eu, g-op; facial: n-gn, zy-zy; orbital: en-en, ex-ex; nasal: al-al, n-sn; oral: sn-sto, ch-ch (eu, eurion; g, glabella; op, opisthocranion; n, nasion; gn, gnathion; zy, zygion; en, endocanthion; ex, exocanthion; al, alare; sn, subnasale; sto, stomion; ch, chelion)] taken from the patients by the first author before surgery. These data were then compared with the anthropometric norms established for North American whites (Farkas LG. Anthropometry of the Head and Face. 2nd ed. Raven Press; 1994). In males, the total percentage of normal, subnormal, and supernormal proportion indices was smaller than in females in all 3 groups of patients. Generally, the difference in percentage between normal proportions was the smallest (13.1%) and the supernormal one the greatest (68%). In males, the oral measurements showed the highest frequency of normal proportions (100%) in all 3 patient groups, and the cephalic index the lowest (60%-66.7%). Among the abnormal proportions, the supernormal ones were found more often, especially in the cranial region of females with bilateral coronal synostosis (66.7%). Subnormal proportion indices were rare: none were seen in the facial region of males. A subnormal cephalic index (eu-eu/g-op) was not present in either sex in right and bicoronal synostosis and was observed in only 2 males with left coronal synostosis (13.3%). The study showed that the influence of synostosis gradually decreased from the top to the bottom of the face, with the oral region showing no abnormalities.

Correction of Sagittal Synostosis Using Foreshortening and Lateral Expansion of the Cranium Activated by Gravity: Surgical Technique and Postoperative Evolution

BACKGROUND

The authors present a technique for correction of sagittal synostosis addressing the transverse constriction and providing foreshortening of the skull without the use of hardware. The design of the osteotomies combined with strict postoperative supine positioning allows foreshortening of the skull, with concomitant expansion.

METHODS

Twenty-two patients were operated on using the foreshortening and lateral expansion activated by gravity technique. Postoperative follow-up included clinical evaluation and three-dimensional computed tomographic scanning at 4 to 6 weeks, 1 year, and yearly afterward. These scans were analyzed using three-dimensional surface analysis software, according to a protocol the authors describe in this article.

RESULTS

The cephalic index improved from 66.4 preoperatively to 74.5 at 1 year postoperatively (normal, 72 to 87). Transverse growth continued to be the dominant vector of growth up to 1 year (until ossification-bridging of the vertex craniectomy). Beyond 1 year, the main area of transverse growth was overlying the temporal suture, producing a distinctive temporal bossing in patients. The parietal areas showed mini-mal growth afterward. Growth was mainly occipital between 1 and 3 years of age, and frontal afterward, up to 5 years of age. A low frontal bossing also occurred in some of our patients and resolved spontaneously.

CONCLUSIONS

The authors have described a technique for correction of scaphocephaly that avoids the use of hardware, with acceptable operative times and transfusion needs. Postoperative improvement in shape is satisfactory. Analysis of the three-dimensional scans of these patients shows abnormal skull growth patterns up to 5 years of age.

[Rapid prototyping in planning reconstructive surgery of the head and neck. Review and evaluation of indications in clinical use]

PURPOSE

The aim was to define the indications for use of rapid prototyping models based on data of patients treated with this technique.

PATIENTS AND METHODS

Since 1987 our department has been developing methods of rapid prototyping in surgery planning. During the study, first the statistical and reproducible anatomical precision of rapid prototyping models was determined on pig skull measurements depending on CT parameters and method of rapid prototyping.

RESULTS

Measurements on stereolithography models and on selective laser sintered models confirmed an accuracy of +/-0.88 mm or 2.7% (maximum deviation: -3.0 mm to +3.2 mm) independently from CT parameters or method of rapid prototyping, respectively. With the same precision of models multilayer helical CT with a higher rate is the preferable method of data acquisition compared to conventional helical CT. From 1990 to 2002 in atotal of 122 patients, 127 rapid prototyping models were manufactured: in 112 patients stereolithography models, in 2 patients an additional stereolithography model, in 2 patients an additional selective laser sinter model, in 1 patient an additional milled model, and in 10 patients just a selective laser sinter model.

CONCLUSION

Reconstructive surgery, distraction osteogenesis including midface distraction, and dental implantology are proven to be the major indications for rapid prototyping as confirmed in a review of the literature. Surgery planning on rapid prototyping models should only be used in individual cases due to radiation dose and high costs. Routine use of this technique only seems to be indicated in skull reconstruction and distraction osteogenesis.

Craniofacial imaging informatics and technology development

PURPOSE

'Craniofacial imaging informatics' refers to image and related scientific data from the dentomaxillofacial complex, and application of 'informatics techniques' (derived from disciplines such as applied mathematics, computer science and statistics) to understand and organize the information associated with the data.

METHOD

Major trends in information technology determine the progress made in craniofacial imaging and informatics. These trends include industry consolidation, disruptive technologies, Moore's law, electronic atlases and on-line databases. Each of these trends is explained and documented, relative to their influence on craniofacial imaging.

RESULTS

Craniofacial imaging is influenced by major trends that affect all medical imaging and related informatics applications. The introduction of cone beam craniofacial computed tomography scanners is an example of a disruptive technology entering the field. An important opportunity lies in the integration of biologic knowledge repositories with craniofacial images.

CONCLUSION

The progress of craniofacial imaging will continue subject to limitations imposed by the underlying technologies, especially imaging informatics. Disruptive technologies will play a major role in the evolution of this field.