A three-dimensional-printed model from ultrasound volumes: a new tool for the prenatal diagnosis of frontonasal dysplasia

In recent years, prenatal screening and diagnosis have been the subject of considerable attention, especially in China (1). Ultrasound imaging plays an indispensable role in prenatal examinations (2). The combination of two-dimensional (2D) and three-dimensional (3D) ultrasound is essential for the diagnosis of fetal body surface abnormalities, especially fetal facial abnormalities (3). Although surface rendering improves diagnosis and facilitates counseling regarding future treatment, several limitations remain. Notably, three-dimensional (3D) ultrasound reconstruction yields only a 3D image, which may be affected by various factors, including fetal position, maternal body habitus, amniotic fluid volume, acoustic shadowing, operator experience, and equipment-related variables. Moreover, parents may struggle to fully grasp the underlying facial abnormality based solely on reconstructed ultrasound images (4).

With advances in science and technology, 3D printing technology is increasingly being applied in medicine (5). 3D-printed medical models are widely used in many clinical fields, such as oral cavity surgery, orthopedics, and vascular surgery; however, their application in the examination of fetal facial deformities remains limited (5). Following developments in 3D printing technology, the costs of printing have decreased rapidly, and various raw materials have become more readily available, enabling its wider use in clinical practice (6).

Traditionally, the acquisition of data for 3D-printed medical models has relied on image datasets sourced from computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound examinations stored in the Digital Imaging and Communications in Medicine (DICOM) format (7). However, acquisition is now much more convenient, as these images can be obtained directly from ultrasound datasets in the form of standard tessellation language (STL) files for printing.

Frontonasal dysplasia is a facial malformation first described by Sedano et al. in 1970 as a constellation of findings involving the face and head (8). Compared with fetal cleft lip or palate, frontonasal dysplasia is rare and more difficult to diagnose prenatally (8). The condition primarily affects the midfacial area and is characterized by defects such as ocular hypertelorism, nasal root widening, median facial clefts (involving the nose, upper lip, or palate), unilateral or bilateral clefting of the alar nasi, and nasal tip hypoplasia (underdevelopment) (8,9).

The combination of 3D ultrasound and 3D printing may facilitate the detection of minor defects and improve the prenatal diagnosis of fetal facial deformities such as frontonasal dysplasia. 3D-printed models can help evaluate the risks of surgery and also enable parents to touch and feel the defects. Thus, 3D printing has emerged as a valuable new tool in the diagnosis and surgical planning of fetal facial abnormalities (10). In addition, 3D-printed models enable a better understanding of the anatomical and surgical aspects of frontonasal dysplasia and other facial deformities (10).

This report describes a 3D-printed model of a fetus with frontonasal dysplasia at 25 weeks of gestation. The model was printed from a surface-rendered sonographic view and used for diagnosis.

Case presentation

A 31-year-old woman, gravida 2, para 1, underwent a mid-trimester ultrasound scan at 25 weeks of gestation at West China Second University Hospital using a Voluson^TM E8 ultrasound system (GE Healthcare, Zipf, Austria) equipped with C4-8-D and 3D RAB6-D abdominal mechanical transducers. During the ultrasound examination, features of facial dysplasia, such as ocular hypertelorism, a median facial cleft involving the nose, bilateral clefting of the alar nasi, and impaired formation of the nasal tip, were detected (Figures 1). Subsequently, 3D ultrasound was used to acquire 3D images (Figure 1D) and was combined with 3D printing to enhance anatomical visualization and diagnose frontonasal dysplasia.

Figure 1 Prenatal ultrasound images of frontonasal dysplasia. Two-dimensional images showing facial dysplasia, including ocular hypertelorism (A, arrow), a median facial cleft involving the nose (B, arrow), bilateral clefting of the alar nasi (C, arrow), and abnormal formation of the nasal tip (C, arrow). (D) Three-dimensional images showing frontonasal dysplasia (arrow).

A highly specialized multidisciplinary team (MDT), comprising an obstetrician, surgeon, sonographer, radiologist, geneticist, and neonatologist, is recommended to optimize fetal and perinatal outcomes in cases of frontonasal dysplasia. The application of 3D printing enables clinicians to diagnose frontonasal dysplasia and discuss further management. In the present case, amniocentesis, genetic testing, and postnatal rhinoplasty were offered to the parents; however, the parents declined these interventions, as they were unable to accept the diagnosis.

All procedures in this study were performed in accordance with the ethical standards of the Ethics Committee of the West China Second University Hospital and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient for the publication of this article and accompanying images. A copy of the written consent form is available for review by the editorial office of this journal.

Acquisition of surface-rendered sonographic views and 3D printing

First, an anterior coronal view was acquired using 2D sonography to visualize the fetal nose, followed by a mid-sagittal view to assess the middle portion of the fetal face. The diagnosis of frontonasal dysplasia was established according to the diagnostic standards. This phenotype is defined as the presence of two or more of the following manifestations: ocular hypertelorism, widening of the nasal root, median facial cleft involving the nose, upper lip, or palate, unilateral or bilateral clefting of the nasal alar, nasal tip hypoplasia, anterior cranium bifidum occultum, and a V-shaped frontal hairline extending over the bifid cranium region (8,9).

Subsequently, to complete the screening protocol, a surface-rendered coronal view of the fetal face was generated using 3D ultrasound with a Voluson^TM E8 ultrasound system equipped with a 3D RAB6-D mechanical abdominal transducer. Multiplanar reconstructions across the three standard anatomical planes were then analyzed. The raw data were imported from the Voluson^TM E8 ultrasound system to the Voluson^TM E10 ultrasound system, where the STL files were subsequently exported and prepared for 3D printing.

In this case, 3D printing was performed using an A-9 3D printer (Shenzhen Jgmaker Technology Co., Ltd., Shenzhen, China), a rapid prototyping system based on a fused deposition modelling technique. Acrylonitrile-butadiene-styrene (ABS) was used as the raw material to generate printed models with good definition. The 3D models were created layer by layer with a layer thickness of 0.1 mm. Figure 2A shows a screenshot of the STL file displayed using the A-9 3D printing software before 3D printing. The ABS model weighed approximately 42 g, cost 1 dollar, and took 7 hours to print using a fine-quality setting with a lightweight filling modality at the School of Aeronautics and Astronautics (Figure 2B).

Figure 2 3D printing screenshot and ABS model of frontonasal dysplasia. (A) Screenshot from the A-9 3D printing software showing the standard tessellation language file before 3D printing. (B) A 3D-printed plastic haptic model created layer by layer with a thickness of 0.1 mm. 3D, three-dimensional; ABS, acrylonitrile-butadiene-styrene. The arrows show the abnormal nose of frontonasal dysplasia in model.

The 3D model of frontonasal dysplasia enabled the surgeon to evaluate the surgical approach and predict the prognosis. It also helped the parents to better understand the deformity.

Discussion

In this article, we reported the first case of frontonasal dysplasia diagnosed and surgically evaluated using a 3D-printed model. According to previous reports, frontonasal dysplasia is difficult to diagnose in utero and is often not diagnosed until birth (9). However, with improvements in probe resolution, facial dysplasia may be diagnosed in early- or mid-pregnancy (8). 2D and 3D ultrasound are increasingly being used for the diagnosis of infant deformities, particularly fetal facial dysplasia (3,4). In this study, 3D ultrasound was combined with 3D printing to provide a more accurate and stereoscopic display to diagnose frontonasal dysplasia.

3D-printed models of fetal malformations have been applied to a range of anatomical structures, including body surfaces, bones, and internal soft tissues, as demonstrated in cases involving outer ear, limb, facial, brain, cardiac, and conjoined twin abnormalities (4,7,10). By presenting fetal facial manifestations of these diseases to parents through 3D-printed models and clinical explanations, parents can develop a deeper understanding of the diagnosis and treatment options through visual and tactile interaction. Therefore, this approach may serve as a valuable tool in the diagnosis and management of facial developmental abnormalities. Future studies collecting survey responses from patients and providers on their experience with this tool may provide valuable insights into its clinical utility.

Previously, ultrasound systems did not support the direct export of STL files, which are required for the creation of 3D-printed models (5,7). However, current fetal ultrasound systems can generate STL files. In addition, if the ultrasound system does not allow the exporting of STL files, DICOM files can easily be exported and converted into STL files for 3D printing (7). The combination of ultrasound and 3D printing is convenient, cost-effective, radiation-free, and rapid, avoiding the need for CT or MRI (7).

With the help of 3D-printed models, highly specialized and dedicated MDTs can achieve the timely diagnosis of rare diseases, such as frontonasal dysplasia, thus potentially improving fetal and perinatal outcomes. 3D-printed models also enable the parents of the fetus to touch and feel the defect through tactile interaction (11). In addition, 3D-printed models are at 1:1 scale, enabling accurate measurements (11). Further, 3D-printed models aid in clinical teaching, as they are more vivid and concrete, and also more convenient for long-term storage than traditional biological specimens (11).

This approach still has two primary limitations. First, fetal movement and maternal respiration may interfere with 3D image acquisition. Second, acoustic shadowing at object edges may prevent the capture of sufficient detail to reconstruct the complete surface of the target object. To enable subsequent 3D printing, the acquisition of appropriately rendered, high-resolution 3D surface images should be prioritized.

In conclusion, the combination of 3D printing and 3D ultrasound represents a promising new tool for the diagnosis and surgical planning of fetal facial abnormalities. Haptic 3D models provide a convenient and practical approach for MDTs to assess conditions, plan surgeries, and predict prognoses. They also provide parents with better prenatal information to support their decision-making. Finally, 3D-printed models are also important for clinical teaching and education, particularly for rare diseases.

Acknowledgments

We thank Junpeng Xue, professor at the School of Aeronautics and Astronautics, Sichuan University for his help in creating the 3D-printed model.

Footnote

Funding: This work was supported by Sichuan Medical Science and Technology Innovation Research Institute Fund (grand No. 2025ZHCSC008).

Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-2026-0871/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the Ethics Committee of the West China Second University Hospital and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient for publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Liao Y, Wen H, Ouyang S, Yuan Y, Bi J, Guan Y, Fu Q, Yang X, Guo W, Huang Y, Zeng Q, Qin Y, Xiang H, Li S. Routine first-trimester ultrasound screening using a standardized anatomical protocol. Am J Obstet Gynecol 2021;224:396.e1-396.e15. [Crossref] [PubMed]
2. Edwards L, Hui L. First and second trimester screening for fetal structural anomalies. Semin Fetal Neonatal Med 2018;23:102-11. [Crossref] [PubMed]
3. Vimercati A, Chincoli A, de Gennaro AC. DʼAddario V, Cicinelli E. 2D and 3D Ultrasonographic Evaluation of Fetal Midface Hypoplasia in Two Cases with 3-M Syndrome. Geburtshilfe Frauenheilkd 2016;76:814-8. [Crossref] [PubMed]
4. Sondern K, Kreitz K, Hammer K, Möllers M, Oelmeier de Murcia K, Köster HA, Braun J, Klockenbusch W, Schmitz R. 3D Ultrasound Evaluation of the Fetal Outer Ear: Novel Biometry Ratio and Comparison of Different Surface Display Modes. Fetal Diagn Ther 2019;46:200-6. [Crossref] [PubMed]
5. Squelch A. 3D printing and medical imaging. J Med Radiat Sci 2018;65:171-2. [Crossref] [PubMed]
6. Nicot R, Hurteloup E, Joachim S, et al. Using low-cost 3D-printed models of prenatal ultrasonography for visually-impaired expectant persons. Patient Educ Couns 2021;104:2146-51. [Crossref] [PubMed]
7. Tutschek B. 3D prints from ultrasound volumes. Ultrasound Obstet Gynecol 2018;52:691-8. [Crossref] [PubMed]
8. Lourenço C, Godinho C, Marinho M, Melo M, Nogueira R, Valente F. Prenatal diagnosis of isolated frontonasal dysplasia: A case report. J Clin Ultrasound 2021;49:145-8. [Crossref] [PubMed]
9. Lehalle D, Altunoglu U, Bruel AL, Arnaud E, Blanchet P, Choi JW, Désir J, Kiliç E, Lederer D, Pinson L, Thauvin-Robinet C, Singer A, Thevenon J, Callier P, Kayserili H, Faivre L. Clinical delineation of a subtype of frontonasal dysplasia with creased nasal ridge and upper limb anomalies: Report of six unrelated patients. Am J Med Genet A 2017;173:3136-42. [Crossref] [PubMed]
10. Liang J, Ma Q, Zhao X, Pan G, Zhang G, Zhu B, Xue Y, Li D, Lu B. Feasibility Analysis of 3D Printing With Prenatal Ultrasound for the Diagnosis of Fetal Abnormalities. J Ultrasound Med 2022;41:1385-96. [Crossref] [PubMed]
11. Nicot R, Couly G, Ferri J, Levaillant JM. Three-dimensional printed haptic model from a prenatal surface-rendered oropalatal sonographic view: a new tool in the surgical planning of cleft lip/palate. Int J Oral Maxillofac Surg 2018;47:44-7. [Crossref] [PubMed]