Valentina Pucciarelli

Facial Evaluation in Holoprosencephaly.

Abstract Holoprosencephaly (HPE) is a malformation of the brain, occurring during the first weeks of pregnancy, that may be associated with several craniofacial alterations and different pathological conditions. The authors describe a 2-year-old girl with lobar HPE, epilepsy, but with a roughly normal face. Despite the macroscopic, clinical appearance, a facial morphometric analysis, performed through a stereophotogrammetric system, showed features that diverge from reference subjects and that are considered typical of HPE. This study highlights how a digital anthropometric facial assessment through stereophotogrammetry can be a useful and noninvasive instrument to investigate the facial features of HPE, especially in the presence of an apparently normal facial aspect. Additionally, it can provide the bases for future insights about the relationship between embryological facial and cerebral development, the time of the occurred defect and, in the end, enrich basic scientific knowledge.

The face of Glut1-DS patients: A 3D craniofacial morphometric analysis

Glut1 deficiency syndrome (Glut1‐DS) is a neurological and metabolic disorder caused by impaired transport of glucose across the blood brain barrier (BBB). Mutations on the SCL2A1 gene encoding the glucose transporter protein in the BBB cause the syndrome, which encompasses epilepsy, movement disorders, and mental delay. Such variability of symptoms presents an obstacle to early diagnosis. The patients seem to share some craniofacial features, and identification and quantification of these could help in prompt diagnosis and clinical management. We performed a three‐dimensional morphometric analysis of the faces of 11 female Glut1‐DS patients using a stereophotogrammetric system. Data were analyzed using both inter‐landmark distances and Principal Component Analysis. Compared with data collected from age‐, sex‐, and ethnicity‐matched control subjects, common and homogenous facial features were identified among patients, which were mainly located in the mandible and the eyes. Glut1‐DS patients had a more anterior chin; their mandibular body was longer but the rami were shorter, with a reduced gonial angle; they had smaller and down‐slanted eyes with a reduced intercanthal distance. This study highlights the importance of morphometric analysis for defining the facial anatomical characteristics of the syndrome better, potentially helping clinicians to diagnose Glut1‐DS. Improved knowledge of the facial anatomy of these patients can provide insights into their facial and cerebral embryological development, perhaps further clarifying the molecular basis of the syndrome. Clin. Anat. 30:644–652, 2017.

3D Craniofacial Morphometric Analysis of Young Subjects with Marfan Syndrome: A Preliminary Report

Marfan syndrome (MFS) is a rare autosomic dominant disease of connective tissues mostly due to mutations in the fibrillin 1 gene. Clinical manifestations of MFS include a variety of signs and symptoms, mainly affecting the heart, blood vessels, bones, joints and eyes, and comprising craniofacial alterations. At present, diagnosis of MFS is largely based on clinical signs and family history. However, it could may be difficult, as its manifestations vary greatly and they are not always present right away. Since a life-threatening complication of MFS is aortic dissection, an early diagnosis of the disorder is essential. We aim to better describe the face of patients with MFS, identifying new quantitative morphological features which could facilitate the early diagnosis of the disease. In the current preliminary study, a group of young subjects with MFS was investigated. Three-dimensional facial images of 3 girls and 8 boys aged 5-15 years were collected by stereophotogrammetry. From the coordinates of 50 anatomical facial landmarks, linear distances and angles were measured; z score values were calculated through the comparison with data obtained from 556 control subjects matched for gender, age, and ethnicity. All subjects with MFS showed a longer face than controls, mainly due to an increased middle third (mean z score = 1.7). They also showed a longer mandibular body (mean z score = 1.4) with a shorter ramus (mean z score = -1.4) and a greater facial divergence (mean z score = 2.2). The assessment of facial features of subjects with MFS pointed out some morphometric characteristics that had never been reported in literature, alongside with other well known alterations, and suggests the usefulness of a three-dimensional quantitative approach for the recognition of facial phenotypic features of the syndrome. Nevertheless, they need to be confirmed extending the study on more patients.

Stereophotogrammetric Evaluation of Labial Symmetry After Surgical Treatment of a Lymphatic Malformation

Abstract Lymphatic malformations (LMs) are rare, nonmalignant masses, frequently involving the head and neck, potentially causing impairment to the surrounding anatomical structures. Major LMs frequently cause facial disfigurement with obvious consequences on self-esteem and social functioning. The attempt to restore symmetry is thus one of the main goals of treatment. In this study, the authors present a not-invasive method to objectively quantify the symmetry of the labial area before and after surgical treatment of a LM, affecting a 16-year-old woman. This was done with sequential three-dimensional stereophotogrammetric imaging and morphometric measurements. The method showed a high reproducibility and supplied quantitative indicators of the local degree of symmetry, helping clinicians in its objective assessment, and facilitating treatment planning and evaluation. A quantitative appraisal of the results can additionally improve patient adherence to a usually multistage therapy.

The nasal septum deviation index (NSDI) based on CBCT data

OBJECTIVE To assess whether three-dimensional morphometric parameters could be useful in nasal septal deviation (NSD) diagnosis and, secondarily, whether CBCT could be considered an adequate imaging technique for the proposed task. METHODS We analysed images of 46 subjects who underwent CBCT for reasons not related to this study. Two experienced operators divided all the images into healthy and NSD subjects. Subsequently, the images were segmented using ITK Snap in order to obtain the three-dimensional model of the nasal airways and compute four morphological parameters: septal deviation angle (SDA), percentage of volume difference between right and left side of the nasal airways, nasal airway total volume and a new synthetic septal deviation index (SDI). Principal component analysis (PCA) was used to unveil relationships between each variable and the global nasal airway variability. RESULTS Differences between the groups were found in SDA (p < 0.001), in volume percentage difference (p < 0.05) and in SDI (p < 0.001). PCA showed high correlation between the SDI and the first principal component (0.97, p < 0.001). CONCLUSIONS Among the analysed parameters, SDI seemed to be the most suitable for the quantitative assessment of NSD, and CBCT allowed accurate assessment of airway morphology.

Mirroring Procedures for the Assessment of Asymmetry of Different Anatomical Structures of the Cranium: A Protocol Based on 3D-3D Superimposition

The assessment of asymmetry has always represented one of the most relevant field of research in anatomy, with several applications in reconstructive and aesthetic surgery. This study aims at exposing an innovative protocol for the assessment of asymmetry of cranial structures based on 3D-3D superimposition and mirroring procedures. Five patients who underwent a head CT scan were selected. Three anatomical structures were automatically segmented through ITK-SNAP free software: maxillary sinuses, zygomatic bones and the petrous portion of both temporal bones. The left structure was then reflected automatically into the right image and superimposed over the contralateral one according to the least point-to-point distance on the entire surface. RMS (root mean square) distance was then automatically calculated for each superimposition. In addition, a chromatic map of superimposition was generated, showing the most variable areas between the two sides. Possible statistically significant differences in RMS value according to the three anatomical structures were assessed through one-way ANOVA test (p<0.05). On average, RMS values for maxillary sinuses, zygomatic bones and petrous part of temporal bones were respectively 1.00 mm (SD: 0.27 mm), 0.70 mm (SD: 0.34 mm) and 1.26 mm (SD: 0.17 mm). A significant difference among the symmetry of the three analysed structures was found (p<0.01, ANOVA). A novel approach for the assessment of anatomical asymmetry is suggested, based both on a morphological and a quantitative evaluation of differences between the right and left side skull bones.

Palatal Volume Changes in Unilateral Cleft Lip and Palate Paediatric Patients

Cleft lip and/or palate (CL/P) are the most common craniofacial abnormalities. CL/P therapy involves also orthopedic and surgical treatments. In particular, the orthopedic treatment can help to align the cleft segments and facilitate surgery. Traditionally, facial and palatal structures have been analyzed by 2D methods, omitting information of volume bone defects. A pre-surgical volume estimation can be useful to determine the anatomical boundaries of the alveolar bone defect; subsequently, volume assessments can appreciate the outcome of secondary alveolar bone grafting. In the present study, we developed a 3D stereophotogrammetric technique for volume estimation of the dental arches of children with CL/P. The method was employed to assess the 3D changes occurring in the maxillary arch of unilateral CLP (UCLP) patients with the use of plates before the first year of life. We collected 96 palatal casts of 32 neonatal patients with UCLP. Palatal casts were obtained before orthopedic treatment, before cheiloplasty, and after cheiloplasty. Half patients were treated with an active plate, half with a passive one. Casts were marked with a set of landmarks, digitized using a stereophotogrammetric system, and then analyzed. Volumes of the greater and the minor alveolar segments were separately assessed, and compared with a 3-w repeated measures ANOVA. Method accuracy was assessed using objects of known size, while repeatability was evaluated using Student’s t test and technical error of measurements. Volume estimates were accurate, without systematic errors; random errors were lower than 5% of the total variance. Significant effects of alveolar segment and time were observed (p<0.0001). Instead, no differences were found for the kind of plate. In conclusion, stereophotogrammetric systems can be a valid instrument to estimate palatal volumes of patients with CL/P during treatment, that can be followed up in a safe, rapid and non-invasive way.

SOFT-TISSUE FACIAL ASYMMETRY BEFORE AND AFTER ORTHOGNATHIC SURGERY: APPLICATION OF A NEW 3D PROTOCOL

Introduction: Skeletal Class III patients often present a major facial asymmetry. In the current investigation, a quantitative method to assess 3D facial asymmetry was applied to an orthognathic surgery patient to quantify possible postsurgical modifications. Methodology: Soft-tissue facial scans of a 20-year-old man with skeletal Class III, candidate to orthognathic surgery, were collected in the pre-surgery stage and 6, 12, 24 months post-surgery with a stereophotogrammetric system. Soft tissue asymmetry was calculated in the facial thirds according to a published protocol (J Craniomaxillofac Surg 2017;45(1):76-81), and the relevant time-related modifications described. The results were also compared to normal values from a group of 23 control subjects (10 men, 13 women, mean age 26) by using z-scores. Results: The longitudinal analysis of the soft-tissue facial asymmetry showed a marked difference in the analysed time points: orthognathic surgery did reduce facial symmetry in the present patient. The comparison between the patient and the control subjects by using z-scores highlighted a clear difference in all-time points: the patient with facial dysmorphia had a higher degree of asymmetry than healthy subjects. Conclusion: The measurements of soft-tissue facial asymmetry using 3D optical digitisers can provide clinically useful information. The graphical representation of results can help in the patient’s understanding of the treatment phases, thus increasing compliance.

ARE DENTAL MEASUREMENTS TAKEN ON PLASTER CASTS COMPARABLE TO THOSE TAKEN FROM CBCT IMAGES AND LASER SCANNED SURFACES

Introduction: Intraoral scanning techniques, laser scans and cone-beam computed tomography (CBCT) are becoming widely diffused in dental practice. These instruments can replace dental plaster casts with digital models; recent investigations have found that measurements taken on digital models do not differ clinically from those obtained on CBCT scans and physical models, but only intra-examiner reliability has been assessed. In the current study we tested both intraand inter-examiner variations, together with intertechniques reliability. Methodology: Data from six adult subjects were retrospectively obtained. Twelve dental distances were measured on dental plaster casts using a digital calliper; on digital 3D CBCT images using inVivoDental software (Anatomage, San Jose, CA); and on laser scanned surfaces using Mirror Vectra Software (Canfield Scientific, Fairfield, NJ). Two different operators performed all measurements twice. Bland-Altman analysis, Kruskal-Wallis and Wilcoxon tests were used for comparisons. Results: The intraand inter-operator biases range was 0-0.34 mm. The reproducibility range was 72-99%. The three different techniques gave very similar measurements, with biases between ±0.1 mm. Reproducibility ranged between 90 and 100%; the best reproducibility coefficients were found between plaster and digital casts, and only three differences were larger than 0.5 mm. Calliper measurements slightly overestimated digital casts values. Only the mesiodistal distance of tooth 24 (p=0.002) was significantly different among techniques. Conclusion: Measurements on digital dental models and CBCT reconstructions of the dental arches seem clinically reliable as direct calliper measurements. The interand intra-operator reliabilities were acceptable, some more care may be needed for CBCT measurements.

3D-3D facial superimposition between monozygotic twins: A novel morphological approach to the assessment of differences due to environmental factors

Distinction of one twin with respect to the other, based on external appearance, is challenging; nevertheless, facial morphology may provide individualizing features that may help distinguish twin siblings. This study aims at exposing an innovative method for the facial assessment in monozygotic twins for personal identification, based on the registration and comparison of 3D models of faces. Ten couples of monozygotic twins aged between 25 and 69 years were acquired twice by a stereophotogrammetric system (VECTRA-3D® M3: Canfield Scientific, Inc., Fairfield, NJ); the 3D reconstruction of each person was then registered and superimposed onto the model belonging to the same person (self-matches), the corresponding sibling (twin-matches) and to unrelated participants from the other couples (miss-matches); RMS (root mean square) point-to-point distances were automatically calculated for all the 220 superimpositions. One-way ANOVA was used to evaluate the differences among miss-matches, twin-matches and self-matches (p < .05). RMS values for self-matches, twin-matches and miss-matches were respectively 1.0 mm (SD: 0.3 mm), 1.9 mm (0.5 mm) and 3.4 mm (0.70 mm). Statistically significant differences were found among the three groups (p < .01). Comparing RMS values in the three groups, mean facial variability in twin siblings was 55.9% of that assessed between unrelated persons and about twice higher than that observed between models belonging to the same individual. The present study proposed an innovative method for the facial assessment of twin siblings, based on 3D surface analysis, which may provide additional information concerning the relation between genes and environment.