Three-dimensional Printing in Reconstructive Oral and Maxillofacial Surgery

Application of 3D-printed teeth models in teaching dentistry students: A scoping review

INTRODUCTION

Both regular teaching of dentistry students and various training schemes for dentists primarily make use of the series teeth models, resin blocks or extracted teeth, whereas the 3D teeth models may well offer an alternative in this respect.

METHODS

PubMed and EMBASE were searched in September 2020. Eligibility of the studies was determined on whether they had made use of the 3D-printed teeth models in both pre- and post-graduate education in dentistry.

RESULTS

The final review embraced 15 studies. There were 659 (89.54%) student participants, and 77 (10.46%) dentists involved in those studies. Five studies addressed the prosthetic and surgical procedures, two-endodontics, one-paediatric dentistry and one-trauma management. The 3D-printed models were also used in the study focused on enhancing the students' manual dexterity, whilst making use of the PhantHome tool.

DISCUSSION

The 3D-printed teeth models developed for teaching purposes are used in various areas of dentistry. Their overall usefulness in acquiring the necessary hands-on skills for clinical work was acknowledged in all the studies under review, regardless of a specific procedure at issue. The 3D models effectively eliminate the hazard of cross-infection. Overall effectiveness of the soft tissue reproduction appears to be their weakest point indicated to date, especially in the surgical models.

CONCLUSIONS

The 3D-printed teeth models provide an alternative to the extracted ones, and the series teeth models in regular teaching practice. Participants of the studies under review thoroughly recommend introducing 3D models into any hands-on practice.

Application of digital positioning guide plates for the surgical extraction of multiple impacted supernumerary teeth: A case report and review of literature

BACKGROUND

An extra tooth in the normal tooth sequence in any region of the dental arch is regarded as a supernumerary tooth (SNT). Due to the large variation in location and morphology, the extraction of impacted SNTs is an extensive and complex procedure with high risks of several complications. This report presents a rare case of seven impacted SNTs in the bilateral upper and lower arch that were successfully extracted with the use of digital positioning guide plates.

CASE SUMMARY

In January 2022, a 21-year-old male was referred to our department with a chief complaint of pain in relation to tooth #36. Clinical examination showed a deep carious lesion with pulpal involvement in tooth #36 and lingual swelling of the bilateral mandibular posterior area. Radiographic examination revealed seven deeply impacted SNTs in the bilateral posterior area and bilateral impacted mandibular third molars. Based on these findings, the patient was diagnosed with bilateral, multiple impacted SNTs and tooth #36 chronic pulpitis. A root canal treatment and an all-ceramic crown restoration for tooth #36 were performed. An individualized digital positioning guide plate was designed by computer-aided design/computer-aided manufacturing technology and cone-beam computed tomography for extraction of the impacted SNTs. During the operation, the digital positioning guide plate allowed rapid positioning and exposure of the SNTs while avoiding adjacent important anatomical structures. At 3-month follow-up, regeneration of bone and soft tissues was visible.

CONCLUSION

The application of digital positioning guide plates is useful for the individualized and minimalized extraction of impacted supernumerary teeth.

New dual-function in situ bone repair scaffolds promote osteogenesis and reduce infection

Background

The treatment of infectious bone defects is a difficult problem to be solved in the clinic. In situ bone defect repair scaffolds with anti-infection and osteogenic abilities can effectively deal with infectious bone defects. In this study, an in situ polycaprolactone (PCL) scaffold containing ampicillin (Amp) and Mg microspheres was prepared by 3D printing technology.

Results

Mg and Amp were evenly distributed in PCL scaffolds and could be released slowly to the surrounding defect sites with the degradation of scaffolds. In vitro experiments demonstrated that the PCL scaffold containing Mg and Amp (PCL@Mg/Amp) demonstrated good cell adhesion and proliferation. The osteogenic genes collagen I (COL-I) and Runx2 were upregulated in cells grown on the PCL@Mg/Amp scaffold. The PCL@Mg/Amp scaffold also demonstrated excellent antibacterial ability against E. coli and S. aureus. In vivo experiments showed that the PCL@Mg/Amp scaffold had the strongest ability to promote tibial defect repair in rats compared with the other groups of scaffolds.

Conclusions

This kind of dual-function in situ bone repair scaffold with anti-infection and osteogenic abilities has good application prospects in the field of treating infectious bone defects.

Engineered 3D-Printed Polyvinyl Alcohol Scaffolds Incorporating β-Tricalcium Phosphate and Icariin Induce Bone Regeneration in Rat Skull Defect Model

The skull defects are challenging to self-heal, and autologous bone graft repair has numerous drawbacks. The scaffolds for the rapid and effective repair of skull defects have become an important research topic. In this study, polyvinyl alcohol (PVA)/β-tricalcium phosphate(β-TCP) composite scaffolds containing icariin (ICA) were prepared through direct-ink three-dimensional (3D) printing technology. β-TCP in the composite scaffold had osteoconductive capability, and the ICA molecule had osteoinductive capacity. The β-TCP and ICA components in the composite scaffold can enhance the capability to repair skull defects. We show that ICA exhibited a slow-release behaviour within 80 days. This behaviour helped the scaffold to continuously stimulate the formation of new bone. The results of in vitro cell compatibility experiments showed that the addition of ICA molecules contributed to the adhesion and proliferation of MC-3T3-E1 cells. The level of alkaline phosphatase secretion demonstrated that the slow release of ICA can promote the osteogenic differentiation of MC-3T3-E1 cells. The introduction of ICA molecules accelerated the in situ bone regeneration in in vivo. It is concluded that the 3D-printed PVA scaffold with β-TCP and ICA has a wide range of potential applications in the field of skull defect treatment.

A randomized controlled trial: evaluation of efficiency and safety of a novel surgical guide in the extraction of deeply impacted supernumerary teeth in the anterior maxilla

Background

Preoperative X-ray and cone-beam computed tomography (CBCT) are helpful for locating supernumerary teeth, but the images cannot be transferred to the operation. To design a novel surgical guide plate for intraoperative navigation, we transfer the patient's oral CBCT and gypsum model scan data to a computer for analysis. In our study, we evaluate the efficiency and safety of a novel surgical guide plate for the extraction of deeply impacted supernumerary teeth (DIMSNT) in the anterior maxilla.

Methods

Forty patients treated at the Department of School & Hospital of Stomatology, Wenzhou Medical University from March 2019 to December 2020 with DIMSNT (type II/III according to Liu et al.) in the anterior maxilla were randomly divided into 2 groups (20 patients for each group) for the extraction. For group I, a novel surgical guide was selected using CBCT and gypsum model scan. In contrast, for group II who underwent freehand surgery, only the CBCT data was used. The evaluation of operation time, complications, satisfaction score, and the number of cases that underwent extraction immediately after removing the bone were performed to assess the efficiency and safety of this novel surgical plate.

Results

All patients completed the surgery successfully. The guides for group I had a good application effect. Group I's operation time (23.35±5.39 min) was shorter than group II (29.60±9.76 min) (P=0.0194). The average pain degree of group I (1.8±1.08) was significantly less than group II (2.82±1.68) (P<0.05). The average swelling score of group I (34) was significantly less than group II (44.7). Patient satisfaction was significantly higher in group I (8.95±1.05) than in group II (7.90±1.51) (P=0.0152).

Conclusions

The novel surgical guide assisted with DIMSNT extraction have been effective in improving the quality of the surgery, patient satisfaction, and reduce its difficulty and duration. We can construct a surgical guide plate to guide the incision and osteotomy in DIMSNT surgery through the data analysis of DIMSNT on computer, which has a broad application prospect for clinical use.

Trial registration

Chinese Clinical Trial Registry ChiCTR2100054523.

The effect of 3D-printed plastic teeth on scores in a tooth morphology course in a Chinese university

BACKGROUND

The tooth morphology course is an important basic dental course. However, it is difficult to fully reflect the three-dimensional (3D) morphological characteristics of tooth structure in two-dimensional pictures in traditional textbooks. The aim of this study was to assess the effect of 3D-printed plastic model teeth in the teaching of tooth morphology.

METHODS

Twenty-two undergraduate students who matriculated at the School of Stomatology, the Fourth Medical University, in 2014 and 23 who matriculated in 2016 participated in the study. Each student who matriculated in 2016 was given a full set of fourteen standard 3D-printed plastic model teeth for use during the learning process, and an anonymous questionnaire was used to evaluate the usefulness of the 3D-printed plastic model teeth from the perspective of the students.

RESULTS

There was no significant difference between the two groups in the scores of the theoretical examination or the total score. However, for the score of the sculpted gypsum teeth, the students who used the 3D-printed plastic model teeth in their studies scored significantly higher (P = 0.002). More than 90% of the students thought that the 3D-printed plastic model teeth were of great help or were very helpful for mastering the anatomy of teeth and for carving the gypsum teeth.

CONCLUSION

Standard 3D-printed plastic teeth can effectively assist students in learning tooth morphology by transforming two-dimensional pictures and descriptions in the textbook into a 3D conformation, effectively promoting students' learning and mastery of tooth morphology and structure. Additionally, the results suggest that 3D-printed plastic model teeth are of great help to the students in mastering and improving their carving skills.

Application of a surgical guide in the extraction of impacted mesiodentes: a randomized controlled trial

OBJECTIVE

To explore and evaluate the application of a surgical guide in the extraction of impacted mesiodentes.

MATERIALS AND METHODS

Patients with impacted mesiodentes approachable from the labial side of the maxilla were randomly divided into three groups. The surgical guide for group I was made using cone beam computed tomography (CBCT) and dental cast, whereas the surgical guide for group II was only made using CBCT data. Group I and group II were first evaluated to determine whether guide use could accurately locate the cementoenamel junction (CEJ) of the mesiodentes, and the impacted mesiodentes were extracted with the help of the surgical guide. Group III underwent an operation without a guide. For all patients, the preoperative design time, tooth searching time, operation time, complications, and costs were measured.

RESULTS

The guides for group I and group II could locate the CEJ of the mesiodentes accurately, with good application effect during the operation. Group I and group II required additional preoperative design time compared with group III. However, the tooth searching time and operation time in groups I and II were significantly reduced compared with those in group III. Group I and group II showed no intraoperative complications, and two cases in group III showed imprecision during localization. The overall cost for group III was higher than that of group I or group II. But group I and group II required extra visits and costs.

CONCLUSIONS

Despite some limitations, the surgical guide assisted with mesiodentes extraction and can improve the quality of the operation quality as well as reducing its economic burden, difficulty, and duration. Through proper design, we can create a high-quality surgical guide using only CBCT data.

CLINICAL RELEVANCE

The surgical guide can be used as an important assistive tool in alveolar surgery.

3D printing in pharmaceuticals: An emerging technology full of challenges

Although in its infancy, when compared with the other sectors, year 2005 marked the rapid evolution of 3 Dimensional printing (3DP) technologies in pharma sector with a huge potential in the dosage form designing and personalisation of the medication. 3DP is an innovative and highly promising way for the instant manufacturing in contrast with the tailored made conventional manufacturing. Various 3DP technologies are categorized into the various areas on the basis of the type of material used, deposition techniques and the solidification/fusion techniques. 3DP technologies have multiple pharmaceutical applications including formulation of the precise and unique dosage forms, medical research, personalization of medicine, tissues engineering and surgical application. In the present article, we have accentuated the comparative merits and demerits of various 3DP technologies used in the pharmaceutical sector. An insight in to the challenges, apropos availability and the choice of the excipients, as well as the printer, regulatory and safety concern of the product is provided.

[Application of digital positioning guide plate in extraction of impacted supernumerary teeth]

OBJECTIVE

To explore the application of digital positioning guide plate in extraction of impacted supernumerary teeth and evaluate its clinical efficacy.

METHODS

From March to August, 2019, 30 patients with labial impacted supernumerary teeth treated in the Department of Oral and Maxillofacial Surgery, Stomatological Hospital, Southern Medical University were enrolled in this study. Fifteen of the patients were treated with digital positioning guide plate to remove the impacted supernumerary teeth (test group). According to the CBCT data and the dentition model of the patients, the positioning guide plate was positioned by avoiding the important anatomical structure with the tooth-bone surface as the support to design the soft tissue incision line and bone tissue exposure range. The other 15 patients who were treated without the use of the guide plate for operation served as the control group. The design time, tooth searching time, operation time and complications were compared between the two groups.

RESULTS

The positioning guide plate was well attached during the operation and allowed quick location of the supernumerary teeth while helping to expose the supernumerary teeth and avoid the damage of the adjacent important anatomical structures. The pre-operative design time was 50 ± 5 min in the test group and 0 min in the control group. The average time of tooth finding in the test group was 5±2 min, as compared with 10±3 min in the control group (t=15.40, P &lt; 0.01); the average time of operation was significantly shorter in the test group than in the control group (25±4 min vs 45±6 min; t=35.50, P &lt; 0.01). No intraoperative complications occurred in the test group, and slight deviation occurred in one case in the control group.

CONCLUSIONS

The application of digital positioning guide plate in extraction of embedded supernumerary teeth can significantly shorten the time of tooth finding, reduce the difficulty of operation, and improve the quality of operation.

Personalized Three-Dimensional Printing and Echoguided Procedure Facilitate Single Device Closure for Multiple Atrial Septal Defects

Background

To evaluate the feasibility of using a single device to close multiple atrial septal defects (ASDs) under the guidance of transthoracic echocardiography (TTE) and with the aid of three-dimensional (3D) printing models.

Methods

Sixty-two patients with multiple ASDs were retrospectively analyzed. Thirty of these patients underwent TTE-guided closure (3D printing and TTE group) after a simulation of occlusion in 3D printing models. The remaining 32 patients underwent ASD closure under fluoroscopic guidance (conventional group). Closure status was assessed immediately and at 6 months after device closure.

Results

Successful transcatheter closure with a single device was achieved in 26 patients in the 3D printing and TTE group and 27 patients in the conventional group. Gender, age [18.8 ± 15.9 (3–51) years in the 3D printing and TTE group; 14.0 ± 11.6 (3–50) years in the conventional group], mean maximum distance between defects, prevalence of 3 atrial defects and large defect distance (defined as distance ≥7 mm), and occluder size used were similarly distributed between groups. However, the 3D printing and TTE group had lower frequency of occluder replacement (3.8% vs 59.3%, p < 0.0001), prevalence of mild residual shunts (defined as <5 mm) immediately (19.2% vs 44.4%, p < 0.05) and at 6 months (7.7% vs 29.6%, p < 0.05) after the procedure, and cost (32960.8 ± 2018.7 CNY vs 41019.9 ± 13758.2 CNY, p < 0.01).

Conclusion

The combination of the 3D printing technology and ultrasound-guided interventional procedure provides a reliable new therapeutic approach for multiple ASDs, especially for challenging cases with large defect distance.

Radiographic Assessment of Nasopalatine Canal Using Cone Beam Computed Tomography

PURPOSE

To assess the morphology of nasopalatine canal and to determine the variation of this canal in correlations to age and gender in Iraqi sample using cone beam computed tomography (CBCT).

MATERIALS AND METHODS

A total of 200 requested CBCT images for nasopalatine canal evaluation before dental implantology at the anterior maxillary region. The morphology of canals was classified into 3 groups in coronal cross-sections. The effects of age and gender were also measured.

RESULTS

The study comprised 100 males and 100 females with mean age of 30.64 ± 9.46 years. Most of the cases showed Y-shape configuration type III 43.5% followed by type I single canal 35.5%, and type II with 2 parallel canals 21%, CONCLUSION:: Due to the wide variation in the morphology of nasopalatine canals, it is highly recommended to perform CBCT evaluation to the anterior maxilla before dental implantology in order to prevent any damage to the neurovascular bundle.