Trigonocephaly Patients Research Articles

Orthoptic findings in trigonocephaly patients after completed visual development.

Trigonocephaly is associated with suboptimal visual outcomes in young children. However, the presence of orthoptic abnormalities after completed visual development remains unknown. The purpose of this study is to assess the prevalence of orthoptic abnormalities in trigonocephaly patients, after completed visual development. A retrospective study among non-syndromic trigonocephaly patients aged 8 years and older was conducted at the Dutch Craniofacial center. Ophthalmologic records were reviewed for refractive errors and a history of strabismus and amblyopia. Refractive errors were classified as follows: myopia: spherical equivalent (SE) ≤ -0.50 diopters (D), emmetropia: SE -0.50 D to + 0.50 D, hyperopia: ≥ + 0.50 D, astigmatism: cylinder error ≥ 1.00 D. The history of strabismus and amblyopia was assessed retrospectively. Prevalence and cumulative incidence of these abnormalities in healthy age-matched populations were retrieved from literature. We included 78 trigonocephaly patients with a median (interquartile range) age of 10.0 (9.0-12.0) years. Thirty-four (43.6%) of these patients presented with a refractive error after the age of 8 years. Specific findings in these 78 patients versus controls were hyperopia in 35.9% vs 8.4%; myopia in 6.4% vs 11.4%; astigmatism in 20.5% vs 11.9%; strabismus in 14.1% vs 2.65%; amblyopia in 6.4% vs 3.4%. Trigonocephaly patients have a two-to-threefold higher risk of hyperopia, astigmatism, amblyopia, and strabismus, as compared to healthy populations. We recommend screening and, in case of abnormalities, regular follow-up before completed visual development. In addition, we recommend long-term surveillance of visual functioning by a pediatric ophthalmologist and/or orthoptist.

Part II: Blood Transfusion and Donor Exposure in the Surgical Management of Trigonocephaly Patients: A Protocol From Alder Hey Craniofacial Unit.

Trigonocephaly is a craniofacial malformation caused by premature fusion of the metopic suture. Surgical correction frequently results in the need for blood transfusion. Transfusion complications include transfusion-transmitted infections (TTIs), immune-mediated reactions, and volume overload. Donor exposure (DE) describes the number of blood products from unique donors with increasing DE equating to an increased risk of TTI. We evaluate data on 204 trigonocephaly patients covering 20 years of practice with respect to blood transfusions and DE. This represents the largest series from a single unit to date. A protocol based on our experiences has been devised that summarizes the key interventions we recommend to minimize blood transfusions and DE in craniofacial surgery. Patients operated on between 2000 and 2020 were included. DE and a range of values were calculated including estimated red cell loss (ERCL) and estimated red cell volume transfused (ERCVT). Groups were established by relevant interventions and compared using the Mann-Whitney U test. Mean DE fell from 1.46 at baseline to 0.85 ( P <0.05). Median allogenic transfusion volume fell from 350mL at baseline to 250mL ( P <0.05). Median ERCL fell from 15.05mL/kg at baseline to 12.39mL/kg and median ERCVT fell from 20.85 to 15.98mL/kg. Changes in ERCL and ERCVT did not reach statistical significance. DE can be minimized with the introduction of key interventions such as a restrictive transfusion policy, preoperative iron, cell saver, tranexamic acid, and use of a matchstick burr for osteotomies.

Is endoscope-assisted strip craniectomy the future of metopic suture craniosynostosis treatment? An 11-year experience with 62 patients.

Endoscopic mini-invasive treatment for sporadic trigonocephaly is becoming a widely accepted surgical treatment. In most centers this treatment is performed in association with postoperative helmeting. The aim of the present study was to review and report the authors' 11-year experience of endoscope-assisted metopic suturectomy for treatment of 62 trigonocephaly patients without helmet use. For this retrospective study, clinical data of 62 consecutive pediatric patients (age 3-8 months) were obtained from the data bank of the "Anna Meyer" Children Hospital. These patients had been diagnosed with trigonocephaly (type II and III) and undergone surgery performed with a mini-invasive endoscopic technique during the period from January 2011 to January 2022. No helmet was used postoperatively in these patients, and they were evaluated through craniometric measurements, pre-/postoperative photographs, and parents' impressions, as well as thorough clinical examinations during follow-up appointments. The mean patient follow-up period was 6 ± 1.3 years. The female/male ratio was 1:2; 52% of the patients presented with type II trigonocephaly and the remaining patients with type III. The mean age at surgery was 153 ± 44 days (5 ± 1.5 months, range 3-8 months). In 92% of the patients the surgical outcome was defined as good to excellent. However, 4 patients presented with an unsatisfactory outcome, including 1 patient with a CSF collection requiring surgical repair 2 months after the first surgery and 1 patient who developed infection of the surgical wound and needed a second surgery. In the latter patient the outcome was evaluated as satisfactory, and no sequelae regarding the infection were encountered during follow-up. According to the authors' experience, endoscopic metopic suturectomy alone, without the use of a helmet, is a valid surgical option for trigonocephaly treatment, and its application can be considered in patients of older age groups (up to 8 months). Thus, in the right patient selection context, this technique represents the treatment of choice.

11. Part II: Blood Transfusion and Donor Exposure in the Surgical Management of Trigonocephaly Patients – A protocol from Alder Hey Craniofacial Unit and Literature Review

Patients undergoing surgical correction of trigonocephaly frequently require blood transfusion. Transfusion complications include transfusion-transmitted infections (TTIs), immune-mediated reactions and volume overload. Donor exposure (DE) describes the number of blood products from unique donors with the risk of a TTI increasing with higher DE.

8. Surgical Correction in 231 Trigonocephaly Patients – The Alder Hey Experience

Isolated metopic synostosis presents with a range of severity, from a palpable ridge as the sole presenting feature to a constellation of features resulting in trigonocephaly. At our unit, patients on the moderate to severe end of the phenotypic spectrum of trigonocephaly are offered fronto-orbital advancement and remodelling (FOAR). We present the largest series of trigonocephaly patients who have undergone surgical correction.

A Diffusion Tensor Imaging Analysis of Frontal Lobe White Matter Microstructure in Trigonocephaly Patients

BackgroundChildren with trigonocephaly are at risk for neurodevelopmental disorders. The aim of this study is to investigate white matter properties of the frontal lobes in young, unoperated patients with metopic synostosis as compared to healthy controls using diffusion tension imaging (DTI). MethodsPreoperative DTI data sets of 46 patients with trigonocephaly with a median age of 0.49 (interquartile range: 0.38) years were compared with 21 controls with a median age of 1.44 (0.98) years. White matter metrics of the tracts in the frontal lobe were calculated using FMRIB Software Library (FSL). The mean value of tract-specific fractional anisotropy (FA) and mean diffusivity (MD) were estimated for each subject and compared to healthy controls. By linear regression, FA and MD values per tract were assessed by trigonocephaly, sex, and age. ResultsThe mean FA and MD values in the frontal lobe tracts of untreated trigonocephaly patients, younger than 3 years, were not significantly different in comparison to controls, where age showed to be a significant associated factor. ConclusionsMicrostructural parameters of white matter tracts of the frontal lobe of patients with trigonocephaly are comparable to those of controls aged 0-3 years.

Cerebral Blood Flow of the Frontal Lobe in Untreated Children with Trigonocephaly versus Healthy Controls: An Arterial Spin Labeling Study.

Craniofacial surgery is the standard treatment for children with moderate to severe trigonocephaly. The added value of surgery to release restriction of the frontal lobes is unproven, however. In this study, the authors aim to address the hypothesis that the frontal lobe perfusion is not restricted in trigonocephaly patients by investigating cerebral blood flow. Between 2018 and 2020, trigonocephaly patients for whom a surgical correction was considered underwent magnetic resonance imaging brain studies with arterial spin labeling to measure cerebral perfusion. The mean value of cerebral blood flow in the frontal lobe was calculated for each subject and compared to that of healthy controls. Magnetic resonance imaging scans of 36 trigonocephaly patients (median age, 0.5 years; interquartile range, 0.3; 11 female patients) were included and compared to those of 16 controls (median age, 0.83 years; interquartile range, 0.56; 10 female patients). The mean cerebral blood flow values in the frontal lobe of the trigonocephaly patients (73.0 ml/100 g/min; SE, 2.97 ml/100 g/min) were not significantly different in comparison to control values (70.5 ml/100 g/min; SE, 4.45 ml/100 g/min; p = 0.65). The superior, middle, and inferior gyri of the frontal lobe showed no significant differences either. The authors' findings suggest that the frontal lobes of trigonocephaly patients aged less than 18 months have a normal cerebral blood flow before surgery. In addition to the very low prevalence of papilledema or impaired skull growth previously reported, this finding further supports the authors' hypothesis that craniofacial surgery for trigonocephaly is rarely indicated for signs of raised intracranial pressure or restricted perfusion for patients younger than 18 months. Risk, II.

Using Perfusion Contrast for Spatial Normalization of ASL MRI Images in a Pediatric Craniosynostosis Population.

Spatial normalization is an important step for group image processing and evaluation of mean brain perfusion in anatomical regions using arterial spin labeling (ASL) MRI and is typically performed via high-resolution structural brain scans. However, structural segmentation and/or spatial normalization to standard space is complicated when gray-white matter contrast in structural images is low due to ongoing myelination in newborns and infants. This problem is of particularly clinical relevance for imaging infants with inborn or acquired disorders that impair normal brain development. We investigated whether the ASL MRI perfusion contrast is a viable alternative for spatial normalization, using a pseudo-continuous ASL acquired using a 1.5 T MRI unit (GE Healthcare). Four approaches have been compared: (1) using the structural image contrast, or perfusion contrast with (2) rigid, (3) affine, and (4) nonlinear transformations – in 16 healthy controls [median age 0.83 years, inter-quartile range (IQR) ± 0.56] and 36 trigonocephaly patients (median age 0.50 years, IQR ± 0.30) – a non-syndromic type of craniosynostosis. Performance was compared quantitatively using the real-valued Tanimoto coefficient (TC), visually by three blinded readers, and eventually by the impact on regional cerebral blood flow (CBF) values. For both patients and controls, nonlinear registration using perfusion contrast showed the highest TC, at 17.51 (CI 6.66–49.38) times more likely to have a higher rating and 17.45–18.88 ml/100 g/min higher CBF compared with the standard normalization. Using perfusion-based contrast improved spatial normalization compared with the use of structural images, significantly affected the regional CBF, and may open up new possibilities for future large pediatric ASL brain studies.

Photogrammetric evaluation of corrective surgery for trigonocephaly

The aim of this study was to capture preoperative, postoperative, and follow-up head shapes of male trigonocephaly patients who underwent fronto-orbital remodelling (FOR), using three-dimensional (3D) photography. Fifty-seven male infants with metopic synostosis operated on using standardized FOR during a 5-year period were included. All measurements were compared with those of an age-matched healthy control cohort (n = 253 for early postoperative comparison, n = 43 for the 1-year follow-up comparison) to determine the effect of FOR at 14 days and at 1 year post-surgery. Intracranial volume, frontal angle, nasofrontal angle, interfrontoparietal–interparietal ratio, and inter-orbital distances were measured 1 day preoperatively, 14 days and 1 year postoperatively. Mean age at surgery was 9.7 ± 1.1 months. Prior to surgery, boys with metopic synostosis showed a reduced intracranial volume (−7.0%, P < 0.001), frontal angle (−10.2%, P < 0.001), interfrontoparietal–interparietal ratio (−4.9%, P < 0.01), and orbital distances (−6.5%, P < 0.001) compared to the reference group, but values did not differ significantly from the specific control group after surgery (all P> 0.05). This was consistent by the time of the follow-up examination. Corrective surgery should therefore aim to achieve volume expansion and correction of the deformity. Furthermore, 3D photogrammetry provides a valuable alternative to computed tomography scans in the diagnosis of metopic synostosis, significantly reducing the amount of radiation exposure to the brain.

Intracranial Volume Not Correlated With Severity in Trigonocephaly.

Objectives:Severity of trigonocephaly varies and potentially affects intracranial volume (ICV) and intracranial pressure (ICP). The aim of this study is to measure ICV in trigonocephaly patients and compare it to normative data and correlate ICV with the severity of the skull deformity according to UCSQ (Utrecht Cranial Shape Quantifier).Design:Retrospective study.Setting:Primary craniofacial center.Patients, Participants:Nineteen preoperative patients with nonsyndromic trigonocephaly (age ≤12 months).Intervention:Intracranial volume was measured on preoperative computed tomography (CT) scans by manual segmentation (OsiriX Fondation). Utrecht Cranial Shape Quantifier was used to quantify the severity of the skull deformity. When present, papilledema as sign of elevated ICP was noted.Main Outcome Measures(s):Measured ICV was compared to Lichtenberg normative cranial volume growth curves, and Pearson correlation coefficient was used to correlate UCSQ with the ICV.Results:Mean age at CT scan was 6 months (2-11). Mean measured ICV was 842 mL (579-1124). Thirteen of h19 patients (11/15 boys and 2/4 girls) had an ICV between ±2 SD curves of Lichtenberg, 2 of 19 (1/15 boys and 1/4 girls) had an ICV less than −2 SD and 4 of 19 (3/15 boys and 1/4 girls) had an ICV greater than +2 SD. Mean UCSQ severity of trigonocephaly was 2.40 (−622.65 to 1279.75). Correlation between severity and ICV was negligible (r = −0.11). No papilledema was reported.Conclusions:Measured ICV was within normal ranges for trigonocephaly patients, in both mild and severe cases. No correlation was found between severity of trigonocephaly and ICV.

New method for quantification of the relative severity and (a)symmetry of isolated metopic synostosis

Trigonocephaly is the result of premature fusion of the metopic suture and its severity can vary widely. However, there is no gold standard for quantification of the severity. This study was performed to quantify severity using the Utrecht Cranial Shape Quantifier (UCSQ) and to assess forehead symmetry. Nineteen preoperative non-syndromic trigonocephaly patients (age ≤1 year) were included for the analysis of severity and symmetry. Severity according to the UCSQ was based on the following combined variables: forehead width and relative skull elongation. The UCSQ was compared to the most established quantification methods. A high correlation was found between the UCSQ and visual score (r=0.71). Moderate to negligible correlation was found between the UCSQ and frontal angle, binocular distance, inter-ocular distance, and frontal stenosis. Additionally, correlation between the visual score and these established quantification methods was negligible. Assessment of the frontal peak (a)symmetry (ratio of right to left triangle area in the curve) showed a mean right versus left triangle area ratio of 1.4 (range 0.9–2.4). The results suggest that the UCSQ is appropriate for the quantification of severity based on the high correlation with clinical judgement. Furthermore, a larger triangle area right than left was unexpectedly found, indicating forehead asymmetry.

Craniometric Measurements and Surgical Outcomes in Trigonocephaly Patients Who Underwent Surgical Treatment.

ObjectiveThe aim of this study was to discuss the results of craniometric measurements and surgical treatments in patients operated for isolated trigonocephaly (TC) in light of the current literature.MethodsA total of 18 cases who underwent surgery for isolated TC were included in the study. Age, gender, family history, follow-up time, complications, duration of surgery, surgical blood loss, and amount of blood replacement in these patients were recorded. Craniometric measurements such as metopic angle (MA), cephalic index (CI), interparietal distance (IPD), intercoronal distance (ICD), and their ratio to each other were evaluated according to pre-and postoperative parameters. Photographs of the patients were taken before and after the operation. The Whitaker classification and Kampf "aesthetic outcome staging" were used in the evaluations.ResultsThe mean MA values after the operation increased to reach above 147 degrees in all cases. The average CI did not change. ICD measurement averages increased significantly. The average IPD/ICD ratio decreased due to the increase in ICD and the enlargement of the anterior fossa after the operation. According to the Whitaker classification and Kampf “aesthetic outcome staging” scale, 17 of our cases were at stage I, rated as perfect, and one was at stage II, rated as good.ConclusionSurgery performed at the appropriate time for TC yields cosmetically satisfactory results. Since potential neurological and cognitive morbidities occur mostly in school-age patients, long-term follow-up of the cases is required. Performing craniometric measurements enables patients to be evaluated with objective and measurable numerical data.

Part 1: Surgical Correction in 231 Trigonocephaly Patients - The Alder Hey Experience.

Isolated metopic synostosis presents with a range of severity, from a palpable ridge as the sole presenting feature to a constellation of features resulting in trigonocephaly. At our unit, patients on the moderate to severe end of the phenotypic spectrum of trigonocephaly are offered fronto-orbital advancement and remodeling. The authors present our series of trigonocephaly patients who have undergone surgical correction. From January 2000 to January 2020, the authors operated on 231 patients with trigonocephaly. The average age at surgery was 18 months, with an average follow-up of 77.4 months. Seventy-nine percent of patients had no comorbidity. Ten percent of patients sustained a dural tear with no long-term consequences. The total early complication rate was 12.1%. The most common early complications were wound infection and wound dehiscence at 7.4% and 3.9% respectively. The total reoperation rate was 6.5%. The introduction of infection prevention and control measures over the 2 decades at our unit reduced the reoperation rate to 1.1%. The most common late complication was temporal recession in 20.8% of patients, none of whom required aesthetic correction. The recurrence rate of a metopic ridge was 2.3% with no patients requiring further surgery. None of our patients required calvarial remodeling for raised intracranial pressure after the primary fronto-orbital advancement and remodeling. There were no life-threatening complications or mortalities in our cohort. The authors present recommendations which include an infection control care bundle, cessation of surgical drains, and practice adjustments to reduce risks of infection and risk of requiring further calvarial remodelling for raised intracranial pressure.

Combining deep learning with 3D stereophotogrammetry for craniosynostosis diagnosis

Craniosynostosis is a condition in which cranial sutures fuse prematurely, causing problems in normal brain and skull growth in infants. To limit the extent of cosmetic and functional problems, swift diagnosis is needed. The goal of this study is to investigate if a deep learning algorithm is capable of correctly classifying the head shape of infants as either healthy controls, or as one of the following three craniosynostosis subtypes; scaphocephaly, trigonocephaly or anterior plagiocephaly. In order to acquire cranial shape data, 3D stereophotographs were made during routine pre-operative appointments of scaphocephaly (n = 76), trigonocephaly (n = 40) and anterior plagiocephaly (n = 27) patients. 3D Stereophotographs of healthy infants (n = 53) were made between the age of 3–6 months. The cranial shape data was sampled and a deep learning network was used to classify the cranial shape data as either: healthy control, scaphocephaly patient, trigonocephaly patient or anterior plagiocephaly patient. For the training and testing of the deep learning network, a stratified tenfold cross validation was used. During testing 195 out of 196 3D stereophotographs (99.5%) were correctly classified. This study shows that trained deep learning algorithms, based on 3D stereophotographs, can discriminate between craniosynostosis subtypes and healthy controls with high accuracy.

Clinical and aesthetic outcome analysis of a case series of trigonocephaly patients after early fronto-orbital advancement

The timing of operation for trigonocephaly is recommended before the age of 1 year. To evaluate the outcome of a consecutive series operated in a single centre, the current study was performed. The study cohort comprised a retrospective single-centre series of 20 patients with trigonocephaly operated before the age of 12 months. Intra- and postoperative clinical data, as well as aesthetic outcome measured by two-dimensional asymmetry index (2D AI) and correction of the curvature on lateral and pictures from above were evaluated. Furthermore, to evaluate postoperative aesthetic outcome, a new classification (Grades I–IV) was proposed. The mean age of the cohort was 7.9 months. 2D AI changed from 0.049 pre- to 0.03 postoperatively (P=0.165). The correction of the curvature in lateral pictures yielded a significant change on postoperative pictures (P=0.002) as well as on pictures from above. Using the proposed classification, 16/20 (80%) patients had a postoperative outcome of Grade I, 4/20 (20%) Grade II. In patients operated before the age of 12 months an excellent (Grade I, AI <0.03) or good aesthetic (Grade II, adequate parents’ or surgeon’s opinion) result could be reached in all patients.

S8A-07 SESSION 8A: METOPIC SYNOSTOSIS TRIGONOCEPHALY, A SHIFT IN INDICATION FOR SURGERY

Introduction: Patients with metopic synostosis have a very small chance to develop raised intracranial pressure. In addition, there is no conclusive evidence yet that a surgical correction of trigonocephaly will improve neurocognitive outcome. Only for the most severe presentations of trigonocephaly, there is clear gain in aesthetic outcome. Therefore, the indication for surgery for metopic synostosis at our center shifted towards correction of only the severe clinical presentations in the past three years. The objective is to study the differences between the operated and non-operated group of trigonocephaly patients at our center. Methods: All patients referred to our center for trigonocephaly in the past three years were evaluated. In this presentation, physical parameters on which the operation indication was based are analysed, using photographs, CT and fundoscopy. Furthermore, the results of both the operated and non-operated trigonocephaly patients on the Bayley Scales of Infant and Toddler Development (a developmental test including a Cognitive, Language, and Motor Scale), taken around the age of two years, will be presented. Results: 218 patients were initially referred to our center for trigonocephaly in the period 2016–2018. Further follow-up after the first visit was not indicated in 128 patients (very mild presentation/ metopic ridge). Of the remaining 90 patients, at the first visit, 39 patients had an indication for follow-up without surgery (fundoscopy/ head circumference), and 26 patients got the indication for a fronto-orbital advancement, which they all received. Twenty-five patients had a reassessment at the age of 9 months; a natural improvement occurred in 20 patients, 3 patients were operated and 2 patients had an operation indication but surgery was refused by the parents. The most important clinical parameter for indication for surgery was the relation between the lateral parts of the forehead and the lateral orbital rims from bird eyes view. Fifteen patients of the operated group and 15 patients of the non-operated group received the developmental test. Conclusion: Natural improvement was observed, which advocates reassessment in a selected group. Short-term neurocognitive evaluation can be indicative for the future, but further longitudinal follow-up is necessary to determine whether there is a neurocognitive indication for operation or whether it is just an aesthetic procedure. This knowledge is important, in order to better involve parents in the shared decision making process of this possible high risk procedure.

Statistical shape analyses of trigonocephaly patients

Surgery is the first treatment option for patients with metopic craniosynostosis. Fronto-orbital advancement is the preferred method for correction of isolated trigonocephaly, but it is hard to understand whether surgery has been successful mainly in an early period. We aim to investigate the shape differences in the head shapes of trigonocephaly patients compared between preoperative and postoperative term. Cranial shape data were collected from the two-dimensional digital images. The Generalized Procrustes analysis was used to obtain mean shapes of the preoperative and postoperative term. The shape deformation of the frontal calvarium from preoperative to the postoperative term was evaluated using the thin-plate spline (TPS) method. There was significant cranial shape difference between preoperative and postoperative term. The high-level deformations for preoperative to postoperative term determined seen in TPS graphic. Highest deformation was observed at the bifrontal dimension especially at nasion and posterior edge of the forehead. In this study, we showed that the shape difference and structural deformation of the calvarium were correlated with the metopic craniosynostosis. The present study also shows that preoperative and postoperative head shapes of patients with trigonocephaly can be compared using the landmark-based geometrical morphometric method by taking into consideration the topographic distribution.

Perinatal complications in patients with unisutural craniosynostosis: An international multicentre retrospective cohort study

PurposeCraniosynostosis may lead to hampered fetal head molding and birth complications. To study the interaction between single suture craniosynostosis and delivery complications, an international, multicentre, retrospective cohort study was performed. Materials and methodsAll infants born between 2006 and 2012 in the Netherlands and Sweden with sagittal or metopic suture synostosis were included. All births were included as a reference population. The primary outcome measure was rate of medically assisted labor. The secondary outcomes included method of conception, term of birth and fetal position. ResultsWe included 152 trigonocephaly patients, 272 scaphocephaly patients and 1.954.141 controls. A higher rate of assisted reproductive technology (ART) was found in patients with trigonocephaly (13%) and scaphocephaly (7%) compared to controls (3%, p < 0.001). Scaphocephaly resulted in more postterm births (8% vs 4%, p < 0.001). Trigonocephaly patients showed more preterm births (11% vs 6%, p < 0.001), breech position was more frequent (10% vs 4%, p = 0.003) and labor was more often induced. Rate of assisted delivery, including cesarean section, was significantly higher in both patient groups. ConclusionsScaphocephaly leads to more postterm births and an increased rate of cesarean sections. Trigonocephaly is related to ART, and in addition higher rates of breech position and cesarean section are found. Prenatal detection of single suture craniosynostosis could improve perinatal care.

Prenatal ultrasound parameters in single-suture craniosynostosis

Introduction: Although single-suture craniosynostosis is diagnosed sporadically during pregnancy, timely referral is critical for its treatment. Additionally, craniosynostosis leads to increased maternofetal trauma during birth. In the Netherlands, 95% of pregnant women receive a standard ultrasound at around 20 weeks of gestation, potentially an ideal setting for detecting craniosynostosis prenatally. To enhance the prenatal detection of the metopic and the sagittal suture synostosis, we wished to identify new screening parameters.Materials and methods: We retrospectively analyzed data of the 20-week anomaly scan in trigonocephaly patients (n = 41), scaphocephaly patients (n = 41), and matched controls (n = 82). We measured six different cranial dimensions, including head circumference, biparietal diameter, and occipito-frontal diameter, defining the cephalic index as the ratio between biparietal and occipito-frontal diameter.Results: Prenatal biometric measurements did not differ significantly between trigonocephaly patients and controls. Although significantly lower in scaphocephaly patients (0.76 versus 0.79; p = .000), the cephalic index by itself is not appropriate for screening at 20 weeks of gestation. Longitudinal analysis suggests that a deflection in BPD curve is found in scaphocephaly patients, starting at 20 weeks of gestation.Conclusions: Prenatal biometric measurements do not differ significantly between trigonocephaly patients and controls. The CI is lower in scaphocephaly patients. A deflection in BPD curve should be followed by 3 D imaging of the cranial sutures.

A new method for three-dimensional evaluation of the cranial shape and the automatic identification of craniosynostosis using 3D stereophotogrammetry

Craniosynostosis is a congenital defect which can result in abnormal cranial morphology. Three dimensional (3D) stereophotogrammetry is potentially an ideal technique for the evaluation of cranial morphology and diagnosis of craniosynostosis because it is fast and harmless. This study presents a new method for objective characterization of the morphological abnormalities of scaphocephaly and trigonocephaly patients using 3D photographs of patients and healthy controls. Sixty 3D photographs of healthy controls in the age range of 3–6 months were superimposed and scaled. Principal component analysis (PCA) was applied to find the mean cranial shape and the cranial shape variation in this normal population. 3D photographs of 20 scaphocephaly and 20 trigonocephaly patients were analysed by this PCA model to test whether cranial deformities of scaphocephaly and trigonocephaly patients could be objectively identified. PCA was used to find the mean cranial shape and the cranial shape variation in the normal population. The PCA model was able to significantly distinguish scaphocephaly and trigonocephaly patients from the normal population. 3D stereophotogrammetry in combination with the presented method can be used to objectively identify and classify the cranial shape of healthy newborns, scaphocephaly and trigonocephaly patients.