As part of my final year of medical school at Monash University, Australia, I spent time in the health plastics and reconstructive surgery department of Monash Health. One of the operations that I saw was the primary closure of a cleft palate—palatoplasty. Cleft palate requires surgical management and is usually a two step process: closure of the soft palate takes place when the patient is between 6 and 12 months of age, and closure of the hard palate is done when the patient is around 18 months old. During discussions with surgeons who deal with cleft palate and university staff who teach anatomy, Paul McMenamin, professor of anatomy at Monash University, and I developed an idea to produce three dimensional (3D) prints of the children with cleft palate, which could be used as a teaching tool for students and to educate the families of patients about the procedure. We thought that the models could also be used during the planning of operations and in the development of new, conservative managements for cleft palate.

The first step towards making the 3D cleft palate models entailed finding the appropriate imaging data. A combination of computed tomography and magnetic resonance imaging (MRI) scans can produce an accurate representation of hard and soft tissues. I searched Monash Health’s imaging database for individuals with cleft palate pathology but could not find any computed tomography head scans in children younger than 18 months. From a select number of MRI head scans, two were of high enough quality and resolution to allow the creation of a 3D print model. In collaboration with the 3D modelling staff of the Centre for Human Anatomy Education at Monash University, I set about the process of creating 3D models from imaging data. The software I used allowed me to view each slice of an MRI scan in axial, coronal, and sagittal planes and segment out regions or tissues of interest.

To create a virtual 3D model I selected on screen the exact parts of the scan I wanted to be converted into three dimensions as a “mask.” Multiple masks can be created to signify different anatomical regions, using different colours to view the regions separately. The chosen masks become 3D models on screen (fig 1). ¹ In this instance, I created a simple virtual model of two parts: one part showed the lower jaw with tongue and another showed the rest of the head.

Fig 1 Three dimensional model on a computer screen

When I was satisfied with the 3D version of the model on the computer screen, I exported it as a file which can be coloured using specialist software—this makes the printout look more realistic. Modifications to the model can be made at this stage. Changes might include localised smoothing, surface elevation, and depression, as well as more advanced model sculpting. Even with a simple model the colouring process can take many hours to complete. When the final edits were complete, I sent the file to a 3D printer.

Fig 2 Three dimensional models immediately after printing

The 3D printer I used to print this model (fig 2) uses a powder based material as its printing base. ² The printer resolution is very high (0.1 mm), and the model was about 16 cm high, which meant it took about 12 hours to print. The completed models (figs 3 and 4) were made from one year old patients and show variations of soft and hard palate deformities. ^{3 4}

Fig 3 Model showing anteriorly located hard palate deformity

Fig 4 Model showing posteriorly located soft palate deformity

A limitation of creating models for cleft palate is that it is often diagnosed without the use of clinical imaging. This makes it challenging to draw on a dataset that is of good enough quality to create 3D prints. However, as 3D printing technology develops and new materials are incorporated into the process—for example, biosynthetic material—it presents an opportunity to share teaching aids bespoke to certain conditions for medical students and trainee surgeons at a relatively low cost.[1]

Peter Lioufas, final year medical student

¹Monash University, Australia

Correspondence to: palio3@student.monash.edu

I thank Christopher Bennett, head of the Cleft and Facial Anomalies Unit, Monash Health; Paul McMenamin, professor of anatomy and director of the Centre for Human Anatomy Education, Monash University; and Michelle Quayle, research assistant at the Centre for Human Anatomy Education, Monash University, for their help in the creation of these models.

Competing interests: None declared.

Provenance and peer review: Commissioned; not externally peer reviewed.

Cite this as: Student BMJ 2015;23:h2686