Guided by the advancement of scanning devices, computer-aided design and manufacturing (CAD/CAM) technology, digital manufacturing and treatment planning is becoming increasingly popular in orthodontics. Meanwhile, more and more dental CAD software solutions have found their way into the market, enabling the digital creation of a variety of appliances for patient care. Until now, mostly adult patients have benefitted from this progress, whereas infant care has largely been left untouched by digitalization. Infants undergoing orthodontic treatment often suffer from a variety of craniofacial disorders that sometimes affect the upper airway. Treatment traditionally requires impression procedures using alginate or silicone, which carry a risk of aspiration or ingestion [
1]. As intraoral scanning is capable of accurately registering the upper jaw of neonates and infants, it allows clinicians to switch to a fully digital production of appliances [
2,
3]. As the scanning procedure is less invasive and can be interrupted at any time, the advantages are obvious. In Part I of this technical note, an easy-to-implement, linear digital workflow for manufacturing simple stimulation plates was presented, where the appliance is created using the Individual Impression Tray module of the Dental Designer (3Shape, Copenhagen, DK) software. Besides stimulation plates, this workflow can also be applied to create palatal plates for patients with cleft lip and palate (CLP) [
4]. The next step in the development goes towards more complex appliances, where more than one software solution is required to replace the conventional workflow. This is the case in patients suffering from Robin Sequence (RS), where the Tübingen Palatal Plate (TPP) is used for early treatment as an alternative to surgical methods. RS is characterized by mandibular retrognathia and micrognathia, glossoptosis and upper airway obstruction (UAO); 80–90% of affected patients also have a U-shaped cleft palate. For treatment, a team of neonatologists, orthodontists and maxillo-craniofacial surgeons at our hospital developed the TPP, which consists of a palatal base plate and a velar extension (spur) of individual length that ends just above the epiglottis. Its purpose is to shift the base of the tongue forward, thereby opening the airway in a minimally invasive [
5]. It has been shown in numerous studies to improve respiration, oxygen saturation and swallowing function and also aids in early palate closure which has a positive impact on hearing ability of RS patients [
6,
7]. In addition to opening the upper airway, TPP therapy induces mandibular growth which might make surgical advancement treatments redundant [
8]. After birth, the aim is to start treatment within 48 h. Upon admission, a sleep study (polysomnogram) is performed, to evaluate the severity of obstruction. The results of this study in combination with an intraoral and extraoral orthodontic examination indicates, whether a TPP or a stimulation plate following the Castillo Morales concept will be chosen for treatment. Independently, the intraoral scan (IOS), which is performed upon admission, will be the basis for digitally creating the appliance.
In order to fit the TPP to the patient’s anatomy, a prototype is manufactured after impression taking. The TPP prototype, which contains a standardized spur, is then introduced under endoscopic supervision. If necessary, the spur is adjusted (material is removed or added) until the optimum length, width and angle are found. For the definitive TPP, a threaded wire is incorporated into the spur to increase stability and extraoral retention elements are attached to the base. Finally, the definitive TPP is inserted under endoscopic control to verify that the changes made had the desired effect. In some cases, two or more adjustment cycles have to be performed until the appliance perfectly fits the patient’s anatomy [
9].
In part II of this technical note, a complete digital workflow to produce functional TPP prototypes solely based on an intraoral scan is presented. This enables creating two or more prototypes with different spur-configurations at minimum time expenditure, thus speeding up the fitting procedure and reducing the burden on the patient. Despite the evolution of dental CAD software, there is no established digital workflow yet for TPP manufacturing. Switching to a digital design protocol can be seen as the next step in further advancing TPP therapy and making the process more reproducible and available to a wider range of clinicians. Above and beyond any therapeutic long-term benefits, which still have to be quantified, replacing the conventional impression by intraoral scanning is an immediate benefit for the patient. To visualize the digital workflow, we present it here along a patient case.