|Year : 2022 | Volume
| Issue : 1 | Page : 180-186
Robotics in orthodontics
Rashmi Rukshana, Geetanjali Gandhi
Department of Orthodontics and Dentofacial Orthopaedics, Maharishi Markandeshwar College of Dental Sciences, Mullana, Ambala, Haryana, India
|Date of Submission||22-Apr-2021|
|Date of Decision||19-Oct-2021|
|Date of Acceptance||05-Jan-2022|
|Date of Web Publication||25-Jul-2022|
Dr. Rashmi Rukshana
Department of Orthodontics and Dentofacial Orthopaedics, Maharishi Markandeshwar College of Dental Sciences, Mullana, Ambala, Haryana
Source of Support: None, Conflict of Interest: None
The successful application of robotics in the medical field has paved way to explore their scope in dentistry. Their goal was to increase precision of the present appliances in use. A literature review was performed using electronic searching methods for the applications of robots in dentistry. From the gathered data, this review article was compiled. This article summarizes some of the promising researches done and developed in dentistry with regard to robotics. A brief about what the future research can focus has been put into account.
Keywords: Nanorobots, robots in dentistry, three dimensional (3D) imaging
|How to cite this article:|
Rukshana R, Gandhi G. Robotics in orthodontics. J Datta Meghe Inst Med Sci Univ 2022;17:180-6
| Introduction|| |
The discipline of orthodontics has strived to improve the efficacy of orthodontic appliances through improvement in appliance design. The use of robotic technology in orthodontics is a natural extension of this endeavor to improve the efficiency of clinical and laboratory procedures. The uses of robotics in the field of orthodontics have enabled us to perform complex tasks which require great amount of precision with ease. As new vistas of use of this technology are explored in orthodontics, the clinician will have the luxury of spending more time for diagnosis and treatment planning rather than spending time on cumbersome wire bending and appliance fabrication.
Developments in three-dimensional (3D) imaging and manufacturing processes have made the customization of orthodontic appliances to improve treatment efficiency possible. Advances in technology have yielded patient-specific products such as Insignia® system and Suresmile® that utilize computers to create an interactive treatment plan and then manufacturing a custom-designed appliance.
Further, the latest research in dentistry is on nanorobots. Even though the field of nano robotics is fundamentally different from that of the macro robots due to the differences in scale and material, there are many similarities in design and control techniques that eventually could be projected and applied. It has been hypothetically explained, how nano robots can be used to do preventive, restorative, and curative procedures. The on-going in vitro researches based on nanotechnology so far have given appreciable results, which pave way for future in vivo use. The common uses of nano dental techniques involve many tissue engineering procedures for major tooth repairs. They can also be employed to desensitize tooth, manipulate the tissues and to improve durability of teeth.
| Methodology|| |
A systemic review was carried out by following PRISMA guidelines [Figure 1]. This study was done to give an overview on the all innovations with regard to robotics in orthodontics. Database was collected from MEDLINE, PubMed, and Google Scholar. The timeframe for the literature search was fixated from January 1990 to December 2021.
|Figure 1: Preferred reporting items for systematic reviews and meta-analyses|
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The primary database included a total search result of 116 records, after removing duplication of records 97 were established; out of which 42 articles met our study criteria and were included for the review. Based on the derived content, the exclusive use of the keyword search “Robotics in Orthodontics” has been described below in detail.
| Applications of Robots in Dentistry|| |
In dentistry, robots have been developed and introduced since 1900s by a remarkable number of researchers for various purposes. Some of the highlighted applications which have been put into practice over the century have been discussed below:
Archwire bending systems
In 1900s, bending arch system was developed as the first computer-aided device for automatic bending of individual arch wires. It can be utilized with all edgewise brackets on lingual or buccal side, despite their slot sizes.,, As technology advanced, the need to update oneself to newer versions kept the practice flowing. Dr. Rohit Sachdeva, an orthodontist, who was the first to patent Copper − Nickel titanium archwires, utilized computed tomography (CT) scans, which was an emerging technology in dentistry and developed sure smile technology in 1998. This system utilized high-end technologies coupled with the orthodontist's conventional skill sets for diagnosis and treatment planning. It helped the practitioner deliver a truly customized care in a patient-centered practice, by paying attention to wire bending instead of the bracket to achieve ideal results., The system consisted of an intraoral scanning device, cone-beam CT scans, special alloy arch wires, and precisely bent archwires using robots.
Clinically, a thin coat made of aluminum oxide or an articulating spot spray was applied to the teeth for easy visualization while using the intraoral scanner. All conventional radiographs and CT scans were uploaded into the system along with the intraorally scanned images. However, the introduction of i-CAT 3D scans had enabled the clinician to visualize both crown and root movement and also aided in treatment planning [Figure 2].
|Figure 2: Virtual teeth with anatomically correct roots from i-CAT 3D scan|
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Initially, bracket positions were determined by default settings, chosen from a digital library that contained most common bracket types and prescriptions. The arch wire geometry was automatically calculated in 3D for the bracket positions on the target arch. In the final phase of digital treatment planning, individual teeth were viewed close up using zoom function and the position of each tooth was further refined by changing bracket position, arch wire geometry, or a combination of the two. In short, it gave a degree of control, which was not possible with manual wire bending. After the geometry of the digital arch wire has been finished, the orthodontist selects the appropriate cross-section, material, and force output from the computer menu. The result was an electronic prescription of the arch wire design and customized bracket positions on the image of the original malocclusion. This treatment plan is sent over a secure computer network to the SureSmile Precision Appliance Center for fabrication of arch wires and precision bracket trays.
The orthodontist receives the arch wires and trays for indirect bonding. These trays were fabricated with a Biostar vacuum former over solid models generated by stereolithography from the OraScan images.
SureSmile can be used to manage errors at any stage during the treatment cycle. If re-bonding is necessary, the clinician can use the initial indirect bonding tray, order a new tray, or fabricate a tray from the solid model (with printed brackets) provided by the Appliance Center. The orthodontist can also replace a bracket by direct bonding and verify its position with the digital bracket template. New OraScans can be used for designing finishing wires and fixed 3–3 lingual retainers before debonding. In 2009, Dr. Randall Moles had stated that his average treatment time was 13.1 months which was comparatively lesser than those cases he has treated using traditional orthodontics.
As days progressed, the need for better esthetic options were on demand by the adult patients especially, which led to the spike in lingual orthodontics. Conventionally, bending of the lingual archwire requires a specialized skills training. Despite occupying increased chairside time, one still cannot ensure the accuracy of appliances. Therefore, a novel robotic system was developed for automatic and accurate preparation.
In 2011, Alfredo Gilbert introduced Lingual Arch wire Manufacturing and Design Aid (LAMBDA) to design and bend arch wires more precisely and also at a rapid pace. This robot is intended to be used in office, thereby eliminating both external laboratory fees and the delay in waiting for wires to be shipped. However, the disadvantage was that only 1st-order bends could be manufactured. Fabrication of other dimension bends required Hiro bonding system.
LAMDA utilizes Gantry robots which have the ability to move the device at the end of a robotic arm in multiple planes of space (end effector). LAMDA robot works only on the x and y axes, it is relatively simple, compact, and inexpensive to manufacture. This robot consists of a heater [Figure 3] that can elevate the tempertaure of a NiTi archwire without losing its property to transform reversibly between the martensitic and austenitic phases, making it possible to bend the wire.,
Simultaneously, SureSmile Qt was introduced exclusively for customization and manufacture of archwires for lingual orthodontic treatment. In order to reduce patient's discomfort, with no comprise to esthetics, lingual braces in the upper arch combined with ceramic brackets for the lower arch was considered as an alternative.
In 2012, LAMBDA 2 was developed with 12 motors instead of four unlike its previous counterpart to make compensation bends between canine and premolars [Figure 4].
Followed by LAMBDA, in 2013, a group of Chinese engineers introduced Cartesian type of wire bending using the curve control method. This comprised of an end effector that automatically replaced the pincer as and when required. A series of changes in arch wire robots were brought to market with minor improvements year after year, a few of them being motion planning robots, robots to improve pin point wire bending, spring back action of rectangular arch wires and trajectory projection for archwire bending.,,,
In 2018, the spring back mechanism model was introduced to avoid slip warping phenomenon; which was a common occurrence during the bending of arch wires. Moving forward, fully customized archwires and brackets using computer-aided design computer-aided manufacturing (CAD/CAM) appliances were fabricated by robots. Retrospectives studies were done and comparisons were made regarding efficiency of these with their conventional counterparts. All results showed improved effectiveness of the former.,
Apart from manufacture of customized archwires, robots were introduced for appliance fabrication. In 1995, Sassani and Roberts introduced an automated appliance fabrication process. This system consists of a machine vision, a robotic manipulator (a computer-controlled platform and gantry), and process planning and collision avoidance software.
The machine vision system [Figure 5], consisting of a laser, rotating mirrors, charge coupled device camera, and image frame grabber, is used to map the surface of the dental cast to generate a 3D computer model. The acrylic deposition and curing system, incorporating a peristaltic pump and an ultraviolet lamp, is used to apply and cure the acrylic on the surface of the dental cast.
In 2008, Lauren and McIntyre created a new computer-assisted method for fabrication of occlusal splints. The splint to be fabricated is designed and saved as a 3D file and imported into the POWERMILL CAM software. The cast to be splinted is roofed with acrylic and mounted over a vertical Haas High speed machine, followed by splint manufacturing. A variety of carbide ball ends measuring different diameters are utilized to produce smooth surface and precise cuts. The product obtained has an accuracy of <10 μm hence the splint does not require finishing.
In 2019, Zhou et al. and team developed a software for an orthodontic robot, based on Blender's secondary technology. It can simulate orthodontic movements and also customize brackets designs for specific malocclusions.
By far, the most happening advancement in orthodontics is the introduction of clear aligners. Initially, in 1945 American orthodontist Harold Kesling developed a removable appliance made of rubber for the correction of malocclusion. These were called as tooth positioners and were used in conjunction with metal braces. However, it was Stanford Students-Zia Chishti and Kesley Wirth, who introduced clear aligners and launched them under the trade name Invisalign in 1997. These are a set of clear, custom made plastic removable trays which can correct malocclusions to some extent and give pleasing results.
Clinical procedure involves accurate impression taking, followed by scanning of the poured casts to obtain a virtual 3D model. This model is studied and the required corrections to treat the particular malocclusion are uploaded by the orthodontist using the software. Once the instructions have been input into the software, a set of aligners which must be worn throughout the duration of treatment are auto printed [Figure 6] and supplied by the manufacturing company. Some of the aligner manufacturing companies other than Invisalign are: Clearpath aligners, Inman aligners, Nuvola and Fantasmino system.,
In 2011, Jack Keith had invented a robotic system for easier manufacture of Aligners. The system included control of a variety of standard mechanical equipment along with laser cutter to trim excess aligner material. The system additionally comprised of CAD software through which the user can compose and create specific features required for aligner therapy.
Robotics for clinical training
Apart from the above-mentioned laboratory procedures, robots have also been utilized in-house for clinical training of dental trainees in certain universities. Although in early years, dental clinical training was carried out on volunteer patients. At present, a functional cephalic region with a complete-teeth set called “Phantoms,” which are different from patients have been used. The purpose of introducing Robotics in dental training was to improve student patient communication skills and to emphasis more on practical guidance rather than a theoretical approach.,
Showa University in Japan designed a realistic robot (Showa Hanoka) to simulate patient gestures and responses, allowing dental students to experience the feel of working on a real patient. It consists of a silicone skin and mouth lining which increases the realistic feel and prevents water from getting into the machinery. It can blink, roll its eyes, sneeze, shake its head, cough, move its tongue, produce gag reflex and even get tired if the mouth is kept open for a prolonged time.
Hiroshi Ishiguro, director of Intelligent robotics Laboratory, Osaka university of Japan introduced Geminoid DK in 2011, which mimics facial expressions and head motions. They have been equipped with advanced motion-capture technology hence can be remotely controlled.,
Around November of the same year, Japan's Kokoro company introduced Simroid, a next-generation dental patient simulator. They were developed to provide emotional feedback to dentists in training. However, the eye-catching feature is the artificial intelligence technology, which makes them react with more lifelike responses. Sensors in and around the mouth allow it to feel simulated pain and discomfort. Speech recognition properties allow it to respond and react to questions or commands. At the end of procedures, the robot has the facility to rate and evaluate the treatment.
Based on techno-psychological distraction techniques, the presence of humanoid robot decreased anxiety during dental appointments in children. Hence, utilization of these humanoid robots during pediatric appointments was insisted. Apart from anxiety management, another such effective response seen among patients of similar age group was the introduction of ROBOTUTOR-An exclusive dental robot to explain the Bass brushing technique to the patient was devised to save chair side time for every clinician. Literature quotes that this is the most attractive methods so far to explain brushing technique.
Robotics for diagnosis and treatment planning
A study by Ma et al. in 2020 suggests using of patch-based neural network for automatic marking of landmarks is a CT image after 3D construction, thereby giving an optimistic potential of reducing workload of a surgeon. The results of the study prove that an accuracy of 5.785 mm can be achieved.
To treat patients suffering from the remotely controlled mandible positioner (RCMP) device was introduced for 45 min in obstructive sleep apnea (OSA) diagnosed patients; to calculate the effective target protrusive patient. The purpose of RCMP was to analyze and identify suitable candidates for treatment of OSA using oral appliances. Thereby, this study gave hope for a better life for people battling OSA.,,
Nanotechnology in orthodontics
DENTIFROBOTS-these are devised to be placed sub-occlusal through the use of mouthwash or toothpaste. They usually target supra and sub gingival surfaces and metabolize the trapped organic matter thereby preventing calculus formation. Studies also show indirect prevention of white spot lesions.
Nanorobotics will allow painless tooth movements and rapid tissue repair through nano tissue engineering. This ultimately leads to an accelerated tooth movement. Other uses are as follows:
- To reduce friction between bracket surface and the archwire using nano-coatings
- Nanoparticles such as nitrogen doped-titanium-oxide, fluorapatite, chitosan act as antimicrobial agents. Furthermore, certain materials are being experimented to prevent mini-implant infections
- Nanocomposites for superior orthodontic bonding
- Calcim nanophosphate crystals are being used as Enamel re-mineralizing agent
- Smart bracket with integrated sensor system used for 3D force and moment measurement.
- Ultrasound device for orthodontics-these are nanofabricated devices that transmit mechanical energy into biological tissues as an acoustic pressure wave. One such device is low–intensity pulsed ultra sound [Figure 7], this has been reported to enhance bone growth into titanium porous-coated implants and bone healing after fracture and after mandibular distraction osteogenesis and has also stimulated mandibular cartilaginous growth
- Bio Microelectromechanical systems (MEMS) [Figure 8] abbreviated as biomedical MEMS introduced in 2016 have been in research to improve tooth movement. Previously, the device had a set of nano-scaled electrical systems however, recently a new proposal stating the use of microfabricated biocatalytic fuel (in layman terms described as enzyme batteries) to produce electricity for alveolar tooth movements has sparked an interest in orthodontic field.
|Figure 7: (a) LIPUS device; (b) Prototype of intraoral LIPUS device24. LIPUS: Low–intensity pulsed ultra sound|
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|Figure 8: A schematic diagram of an oral biocatalytic fuel cell. In this system, the following reaction generating electricity for enhancing orthodontic tooth movement occurs: Glucose O2-gluconolactone H2O/H2O2|
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| Future of Roboticts in Dentistry|| |
For progress of robotics in our field, following research aspects should be done in the future.
Reliability, accuracy, and flexibility are requirements of a robot in orthodontics; however, the workspace is limited by the oral cavity. Hence, a structural design which might fulfil all requirements should be developed for day-to-day use.
Sensor and control technique
For orthodontics arch wire bending robot, the future goal is to work on the spring-back properties of wire and their bending algorithm.
Human-computer interaction technology
For facilitating motion control of robot in orthodontics, a friendly human-computer interaction software should be designed to provide humanization input and feedback for the operators., For arch wire bending, future research should focus on 3D virtual display of customized orthodontic arch wire on the screen, a virtual observation and the position's interactive modification of different loop.
Robotics could offer improved accuracy, predictability, safety, quality of care, and speed of treatment in the field of dentistry. The orthodontic treatment which uses a robot or a machine to bend arch wires for the fixed orthodontic appliances will have a much better prognosis with a remarkable less treatment time compared to the conventional method.
The drawback of using robots in daily practice lies in the feasibility of adapting these technologies in teaching and clinical practice. Hence, the cost effectiveness along with the true benefit over conventional therapy must be vigilantly researched for betterment. The future must focus on the development of robotic structures which decreases the self-interference of the bending machine due to their large size.
| Conclusion|| |
Orthodontics is a rapidly growing field, especially in today's world where esthetics, comfort, and the need to speed up the treatment procedure play a vital role. Hence, robotics has great potential in the near future in becoming a day-to-day phenomenon. Although surgical robots have been in experimental use since the early 1920s; however, the lack of precision keeps them at bay, nevertheless with the introduction of renowned Artificial Intelligence in orthodontics could revolutionize everything.
This paper summarizes some of the application of all forms of robotic use in orthodontics in a systemic manner.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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