Sybill D. Naidoo

Anthropometric precision and accuracy of digital three-dimensional photogrammetry: comparing the Genex and 3dMD imaging systems with one another and with direct anthropometry.

A variety of commercially available three-dimensional (3D) surface imaging systems are currently in use by craniofacial specialists. Little is known, however, about how measurement data generated from alternative 3D systems compare, specifically in terms of accuracy and precision. The purpose of this study was to compare anthropometric measurements obtained by way of two different digital 3D photogrammetry systems (Genex and 3dMD) as well as direct anthropometry and to evaluate intraobserver precision across these three methods. On a sample of 18 mannequin heads, 12 linear distances were measured twice by each method. A two-factor repeated measures analysis of variance was used to test simultaneously for mean differences in precision across methods. Additional descriptive statistics (e.g., technical error of measurement [TEM]) were used to quantify measurement error magnitude. Statistically significant (P < 0.05) mean differences were observed across methods for nine anthropometric variables; however, the magnitude of these differences was consistently at the submillimeter level. No significant differences were noted for precision. Moreover, the magnitude of imprecision was determined to be very small, with TEM scores well under 1 mm, and intraclass correlation coefficients ranging from 0.98 to 1. Results indicate that overall mean differences across these three methods were small enough to be of little practical importance. In terms of intraobserver precision, all methods fared equally well. This study is the first attempt to simultaneously compare 3D surface imaging systems directly with one another and with traditional anthropometry. Results suggest that craniofacial surface data obtained by way of alternative 3D photogrammetric systems can be combined or compared statistically.

Face shape of unaffected parents with cleft affected offspring: combining three‐dimensional surface imaging and geometric morphometrics

OBJECTIVE Various lines of evidence suggest that face shape may be a predisposing factor for non-syndromic cleft lip with or without cleft palate (CL/P). In the present study, 3D surface imaging and statistical shape analysis were used to evaluate face shape differences between the unaffected (non-cleft) parents of individuals with CL / P and unrelated controls. METHODS Sixteen facial landmarks were collected from 3D captures of 80 unaffected parents and 80 matched controls. Prior to analysis, each unaffected parent was assigned to a subgroup on the basis of prior family history (positive or negative). A geometric morphometric approach was utilized to scale and superimpose the landmark coordinate data (Procrustes analysis), test for omnibus group differences in face shape, and uncover specific modes of shape variation capable of discriminating unaffected parents from controls. RESULTS Significant disparity in face shape was observed between unaffected parents and controls (p < 0.01). Notably, these changes were specific to parents with a positive family history of CL/P. Shape changes associated with CL/P predisposition included marked flattening of the facial profile (midface retrusion), reduced upper facial height, increased lower facial height, and excess interorbital width. Additionally, a sex-specific pattern of parent-control difference was evident in the transverse dimensions of the nasolabial complex. CONCLUSIONS The faces of unaffected parents from multiplex cleft families displayed meaningful shape differences compared with the general population. Quantitative assessment of the facial phenotype in cleft families may enhance efforts to discover the root causes of CL/P.

Helmet Versus Active Repositioning for Plagiocephaly: A Three-Dimensional Analysis

BACKGROUND AND PURPOSE: Orthotic helmets and active repositioning are the most common treatments for deformational plagiocephaly (DP). Existing evidence is not sufficient to objectively inform decisions between these options. A three-dimensional (3D), whole-head asymmetry analysis was used to rigorously compare outcomes of these 2 treatment methods. PATIENTS AND METHODS: Whole-head 3D surface scans of 70 infants with DP were captured before and after treatment by using stereophotogrammetric imaging technology. Helmeted (n = 35) and nonhelmeted/actively repositioned (n = 35) infants were matched for severity of initial deformity. Surfaces were spatially registered to a symmetric template, which was deformed to achieve detailed right-to-left point correspondence for every point on the head surface. A ratiometric asymmetry value was calculated for each point relative to its contralateral counterpart. Maximum and mean asymmetry values were determined. Change in mean and maximum asymmetry with treatment was the basis for group comparison. RESULTS: The helmeted group had a larger reduction than the repositioned group in both maximum (4.0% vs 2.5%; P = .02) and mean asymmetry (0.9% vs 0.5%; P = .02). The greatest difference was localized to the occipital region. CONCLUSIONS: Whole-head 3D asymmetry analysis is capable of rigorously quantifying the relative efficacy of the 2 common treatments of DP. Orthotic helmets provide statistically superior improvement in head symmetry compared with active repositioning immediately after therapy. Additional studies are needed to (1) establish the clinical significance of these quantitative differences in outcome, (2) define what constitutes pathologic head asymmetry, and (3) determine whether superiority of orthotic treatment lasts as the child matures.

Endoscopically assisted versus open repair of sagittal craniosynostosis: the St. Louis Children's Hospital experience

OBJECT This study investigated the differences in effectiveness and morbidity between endoscopically assisted wide-vertex strip craniectomy with barrel-stave osteotomies and postoperative helmet therapy versus open calvarial vault reconstruction without helmet therapy for sagittal craniosynostosis. METHODS Between 2003 and 2010, the authors prospectively observed 89 children less than 12 months old who were surgically treated for a diagnosis of isolated sagittal synostosis. The endoscopic procedure was offered starting in 2006. The data associated with length of stay, blood loss, transfusion rates, operating times, and cephalic indices were reviewed. RESULTS There were 47 endoscopically treated patients with a mean age at surgery of 3.6 months and 42 patients with open-vault reconstruction whose mean age at surgery was 6.8 months. The mean follow-up time was 13 months for endoscopic versus 25 months for open procedures. The mean operating time for the endoscopic procedure was 88 minutes, versus 179 minutes for the open surgery. The mean blood loss was 29 ml for endoscopic versus 218 ml for open procedures. Three endoscopically treated cases (6.4%) underwent transfusion, whereas all patients with open procedures underwent transfusion, with a mean of 1.6 transfusions per patient. The mean length of stay was 1.2 days for endoscopic and 3.9 days for open procedures. Of endoscopically treated patients completing helmet therapy, the mean duration for helmet therapy was 8.7 months. The mean pre- and postoperative cephalic indices for endoscopic procedures were 68% and 76% at 13 months postoperatively, versus 68% and 77% at 25 months postoperatively for open surgery. CONCLUSIONS Endoscopically assisted strip craniectomy offers a safe and effective treatment for sagittal craniosynostosis that is comparable in outcome to calvarial vault reconstruction, with no increase in morbidity and a shorter length of stay.

A comparison of costs associated with endoscope-assisted craniectomy versus open cranial vault repair for infants with sagittal synostosis

OBJECT The surgical management of infants with sagittal synostosis has traditionally relied on open cranial vault remodeling (CVR) techniques; however, minimally invasive technologies, including endoscope-assisted craniectomy (EAC) repair followed by helmet therapy (HT, EAC+HT), is increasingly used to treat various forms of craniosynostosis during the 1st year of life. In this study the authors determined the costs associated with EAC+HT in comparison with those for CVR. METHODS The authors performed a retrospective case-control analysis of 21 children who had undergone CVR and 21 who had undergone EAC+HT. Eligibility criteria included an age less than 1 year and at least 1 year of clinical follow-up data. Financial and clinical records were reviewed for data related to length of hospital stay and transfusion rates as well as costs associated with physician, hospital, and outpatient clinic visits. RESULTS The average age of patients who underwent CVR was 6.8 months compared with 3.1 months for those who underwent EAC+HT. Patients who underwent EAC+HT most often required the use of 2 helmets (76.5%), infrequently required a third helmet (13.3%), and averaged 1.8 clinic visits in the first 90 days after surgery. Endoscope-assisted craniectomy plus HT was associated with shorter hospital stays (mean 1.10 vs 4.67 days for CVR, p < 0.0001), a decreased rate of blood transfusions (9.5% vs 100% for CVR, p < 0.0001), and a decreased operative time (81.1 vs 165.8 minutes for CVR, p < 0.0001). The overall cost of EAC+HT, accounting for hospital charges, professional and helmet fees, and clinic visits, was also lower than that of CVR (

Assessing long-term outcomes of open and endoscopic sagittal synostosis reconstruction using three-dimensional photography.

37,255.99 vs

Are endoscopic and open treatments of metopic synostosis equivalent in treating trigonocephaly and hypotelorism

56,990.46, respectively, p < 0.0001). CONCLUSIONS Endoscope-assisted craniectomy plus HT is a less costly surgical option for patients than CVR. In addition, EAC+HT was associated with a lower utilization of perioperative resources. Theses findings suggest that EAC+HT for infants with sagittal synostosis may be a cost-effective first-line surgical option.

A statistical model of head asymmetry in infants with deformational plagiocephaly

AbstractSagittal synostosis has been successfully managed with numerous surgical techniques. Nevertheless, few data on long-term outcomes exist to justify use of one surgical technique over another. In this study, we compared children with surgically corrected sagittal synostosis to their age-matched control subjects to assess the longevity of their corrections. Furthermore, the outcomes of open repairs were compared with endoscopic repairs.Following institutional review board approval, three-dimensional photographs of patients who underwent surgical reconstruction for nonsyndromic sagittal synostosis were analyzed to determine biparietal and anterior-posterior diameter, circumference, cephalic index, cranial vault volume, cranial height, and forehead inclination. Thirteen patients who had undergone open repair, including 6 total cranial vault and 7 modified-pi reconstructions, and 6 patients who had undergone endoscopic strip craniectomy with barrel-stave osteotomies and postoperative helmeting were compared with nonsynostotic age-matched control subjects. Mean follow-up was 97.5 months after open and 48.9 months after endoscopic repair. Student t tests were used for analysis. In the second arm of this study, 33 patients who had undergone endoscopic repair were compared with the 13 patients who had undergone open repair; mean follow-up was 24.8 months after endoscopic repair. Linear regression models were used to adjust for age and sex.After comparing three-dimensional photographs of children who were more than 3 years postoperative from surgical correction for sagittal synostosis with their age-matched control subjects, no statistically significant differences were found in any of the measured parameters. In addition, no differences were detected between open reconstruction versus endoscopic repair, suggesting equivalence in final results for both procedures.

Comparison of Traditional versus Normative Cephalic Index in Patients with Sagittal Synostosis: Measure of Scaphocephaly and Postoperative Outcome.

BackgroundPatients with metopic craniosynostosis are traditionally treated with fronto-orbital advancement to correct hypotelorism and trigonocephaly. Alternatively, endoscopic-assisted treatment comprises narrow ostectomy of the fused suture followed by postoperative helmet therapy. Here we compare the preoperative and 1-year postoperative results in open versus endoscopic repairs. MethodsWe reviewed preoperative and 1-year postoperative three-dimensional reconstructed computed tomography scans of patients treated for nonsyndromic metopic craniosynostosis by either open (n = 15) or endoscopic (n = 13) technique. Hypotelorism was assessed by interzygomaticofrontal distance and intercanthal distance. Trigonocephaly was assessed by 2 independent angles: first, an axial-plane two-dimensional angle between zygomaticofrontal suture bilaterally and the glabella (ZFR-G-ZFL); second, an interfrontal angle (IFA) between the most anterior point from a reconstructed midsagittal plane and supraorbital notch bilaterally. Age-matched scans of unaffected patients (n = 28) served as controls for each postoperative scan. ResultsPatients with open repair (9.5 ± 1.8 months) were older at time of surgery than patients with endoscopic repairs (3.3 ± 0.4 months) (P = 0.004). Male-to-female ratios were equivalent at roughly 7:3 in both groups. Preoperatively, the endoscopic group had worse hypotelorism and ZFR-G-ZFL than the open group (P ⩽ 0.04). After accounting for preoperative differences, all of the postoperative measurements (ie, interzygomaticofrontal distance, intercanthal distance, ZFR-G-ZFL angle, IFA) of the 2 groups were statistically equivalent (P ≥ 0.135). Trigonocephaly was significantly improved after repair in both the open (8 degrees [ZFR-G-ZFL] and 18 degrees [IFA]) and endoscopic (13 degrees [ZFR-G-ZFL] and 16 degrees [IFA]) groups (P < 0.001). Postoperative measures in both groups were equivalent to controls (0.12 < P < 0.89). Intrarater reliability ranged from 0.93 to 0.99 for all measurements. ConclusionOur retrospective series shows that endoscopic and open repairs of metopic craniosynostosis are equivalent in improving hypotelorism and trigonocephaly at 1-year follow-up. Additional studies are necessary to better define minor differences in morphology, which may result from the different techniques.

Cranial Base and Posterior Cranial Vault Asymmetry After Open and Endoscopic Repair of Isolated Lambdoid Craniosynostosis.

Deformational plagiocephaly is a term describing cranial asymmetry and deformation commonly seen in infants. The purpose of this work was to develop a methodology for assessment and modelling of head asymmetry. The clinical population consisted of 38 infants for whom 3-dimensional surface scans of the head had been obtained both before and after their helmet orthotic treatment. Non-rigid registration of a symmetric template to each of the scans provided detailed point correspondence between scans. A new asymmetry measure was defined and was used in order to quantify and localize the asymmetry of each infants head, and again employed to estimate the improvement of asymmetry after the helmet therapy. A statistical model of head asymmetry was developed (PCA). The main modes of variation were in good agreement with clinical observations, and the model provided an excellent and instructive quantitative description of the asymmetry present in the dataset.