Sichuan University to Transfer Digital Invisible Orthodontic Technology Portfolio to Angelalign for RMB 5 Million

Recently, the Institute of Scientific and Technological Development of Sichuan University released a public notice on the transformation of scientific and technological achievements, proposing to"Clear Aligners"more than ten patents and the right to apply for related patents, intended to be transferred to Wuxi Angelalign Medical Device Technology Co., Ltd. via patent assignment, with a transaction amount of5 million yuan。

The patents transferred in this transaction cover multiple key technologies in the fields of orthodontics and digital healthcare, including clear aligners, invisible brace assemblies, orthodontic assessment systems, inter-elastic push rods, and airway image recognition systems.

Patent Title and Inventor

The relevant patent invention team, withProfessor Zhao Zhiheas the core. Professor Zhao Zhihe graduated from the School of Stomatology, West China University of Medical Sciences, and currently serves as the Director of the Department of Orthodontics at West China Hospital of Stomatology.

This technical team brings together experts and researchers in the fields of stomatology, materials science, and artificial intelligence, including Liu Junqi, Zhu Guanyin, Pei Fang, Lu Wenxin, Cai Jingyi, Li Peilin, and Liao Wen. They have established a full-chain innovation system spanning clinical design, device development, and intelligent assessment, demonstrating systematic R&D capabilities and clinical translation potential in clear aligner orthodontic technology.

Assignee of This Patented TechnologyWuxi Angelalign Medical Device Technology Co., Ltd., is a leading provider of clear aligner solutions in China, specializing in the research and development, manufacturing, and services of digital orthodontic technologies. Leveraging advanced 3D printing, biomechanical simulation, and artificial intelligence technologies, the company has launched multiple generations of clear aligner products, serving numerous dental professionals worldwide, and demonstrating significant market influence and technological integration capabilities in the field of dental medical devices.

This technology cluster centers on digital clear aligner orthodontics, forming a comprehensive innovation system that encompasses intelligent assessment, personalized treatment design, efficient force delivery, and solutions for complex cases.

Specifically, innovations in traction structures (such as external traction components and detachable traction buttons) enable precise force application while maintaining aligner integrity; specialized orthodontic devices (such as asymmetric palatal expanders, interelastic push rods, and protraction auxiliary structures) provide integrated solutions for clinical challenges like skeletal discrepancies and molar intrusion; meanwhile, automated assessment systems and AI-based airway recognition technologies are driving the transformation of diagnosis from experience-dependent to objective data-driven approaches.

Overall, this patent portfolio significantly enhances the precision, predictability, and clinical operational convenience of clear aligner therapy, demonstrating comprehensive technical integration capabilities spanning from digital modeling to biomechanical control.

MalocclusionIt is one of the most common oral diseases in modern society, and its treatment relies on an objective assessment of orthodontic difficulty. Currently, international practice commonly employs assessment systems such as the Orthodontic Treatment Need Index. These assessments require clinicians to perform manual measurements and scoring on plaster casts of dental arches. However, the impression-taking process demands significant clinical expertise, often results in poor patient experience, and may lead to defects in the resulting models.

Manual measurements are time-consuming and highly subjective, with potential discrepancies in assessments among different doctors, leading to insufficient objectivity and making it difficult to establish unified clinical audit standards. Although software-assisted diagnosis and treatment already exist, there is still a lack of fully automated evaluation systems for orthodontic difficulty assessment both domestically and internationally.

Among the various types of malocclusion,Deep OverbiteTreatment ofis a major challenge.

In orthodontic treatment, deep bite correction is primarily achieved by intruding anterior teeth or extruding posterior teeth. In conventional fixed appliance therapy, reverse curve of Spee archwires or auxiliary arches are often fabricated to apply forces for patients with deep overbite and a steep Curve of Spee (which reflects the longitudinal curvature of the dental arch). In clear aligner therapy, this concept is adapted by designing the target occlusion with an anti-Curve of Spee and incorporating overcorrection to intrude the mandibular anterior teeth.

For complex cases, a precision lingual bite ramp is designed on the aligner, i.e., creating raised platforms on the palatal surfaces of the maxillary anterior teeth for the mandibular anterior teeth to occlude against, thereby discluding the posterior teeth and facilitating intrusion. However, the efficacy rate of clear aligners in intruding anterior teethOnly about 50%, posterior tooth extrusion presents an even greater challenge, resulting in suboptimal treatment outcomes for many deep overbite cases and often necessitating multiple restarts, which increases both time and cost. Traditional removable flat plane bite planes used to open the bite are incompatible with full-coverage clear aligners.

However, existing lingual precision occlusal splints are limited in size and are only suitable for patients with a small overjet (the horizontal distance by which the upper anterior teeth overlap the lower anterior teeth). If the patient has an excessive overjet, the lower anterior teeth may fail to contact the protrusions, potentially forcing the mandible into a retruded position.

Furthermore, this protrusion acts directly on the palatal aspect of the maxillary anterior teeth, potentially compromising aligner coverage and generating adverse forces, which may lead to loss of torque (inclination of the long axis) in the maxillary anterior teeth or occlusal trauma.

Existing clear aligner solutions also have limitations in treating Class II malocclusion caused by mandibular retrusion or hypoplasia, as well as functional crossbite with mandibular deviation due to functional factors. Treatment of mandibular retrusion typically requires mandibular advancement prior to the peak growth period to stimulate development, while correction of crossbite necessitates guiding the mandible back to the midline position.

Currently, clear aligners have been developed to treat mandibular retrusion by incorporating bite ramps, while functional appliances address dental midline deviations through guide planes set at specific angles. However, for patients presenting with both conditions simultaneously, existing appliances cannot provide a simple and effective combined correction.

Furthermore, existing guidance pads require individual customization for each patient, involving complex manufacturing processes, long lead times, and high costs, while also lacking the capability for fine-tuned adjustments during treatment.

In the treatment of skeletal Class III malocclusion, maxillary sagittal deficiency often leads to anterior crossbite and facial concavity. Maxillary protraction therapy promotes maxillary development by applying forward orthopedic forces. Its effects are categorized into skeletal effects (promoting bone growth) and dental effects (merely causing tooth inclination), with skeletal effects being more desirable.

Traditional facemask protraction appliances utilize extraoral anchorage (such as a facebow) or intraoral anchorage (such as tooth- and hard palate-based appliances). With the expanding indications for clear aligner therapy, attempts have been made to employ them for facemask protraction, typically by incorporating transparent protrusions on the aligners to connect with the facebow. However, this approach primarily applies force to the teeth, resulting in limited skeletal effects and suboptimal treatment outcomes; it may even cause undesirable movement of the anchor teeth.

When correcting insufficient dental arch width, expansion therapy is often required, and the need for asymmetric expansion is also common.Traditional activities or fixed expanders use devices such as screw expanders to apply force, deviating them to one side in an attempt to achieve asymmetric effects. However, this method cannot precisely control the difference between both sides, has high requirements for production, and is bulky with a strong foreign body sensation, making it difficult to clean.

Although clear aligners are aesthetically pleasing and comfortable, during arch expansion, the teeth on the left and right sides of the dental arch serve as reciprocal anchorage. Based on the principle of action and reaction, it is difficult to achieve significant asymmetric movement with substantial differences between the two sides. Some techniques have attempted to combine clear aligners with auxiliary devices (such as temporary anchorage devices), but this introduces issues such as trauma and foreign body sensation.

During orthodontic treatment, intermaxillary traction is often required to adjust the occlusal relationship between the upper and lower teeth.In clear aligner systems, elastics are typically suspended by bonding metal buttons to the tooth surface or by incorporating pre-designed traction hooks into the aligners. Bonded buttons reduce aligner coverage, compromise control, and carry a risk of debonding. Conversely, pre-formed traction hooks are prone to generating dislodging forces under load, which can impair the aligner’s fit against the teeth, potentially leading to “off-tracking” and compromising treatment efficacy.

For cases requiring dental traction, the conventional approach involves cutting openings in clear aligners to install traction buttons, which compromises the structural integrity of the aligners and adversely affects their mechanical properties and wearing comfort.

Although some protocols involve bonding traction buttons to the aligners prior to factory shipment, their fixed positions preclude adjustment. In clinical practice, traction sites require personalization; if a clinician wishes to apply traction at alternative locations, they must manually cut openings, which is highly inconvenient. Furthermore, the bonding method itself poses concerns regarding connection reliability.

For the intrusion of over-erupted molars, mini-implants are currently commonly used as anchorage. However, this is an invasive procedure that often causes patient anxiety and carries a risk of mini-implant loosening or failure.

If multiple teeth need to be intruded, the placement of multiple mini-implants may be required. In cases accompanied by tooth inclination, segmental archwires with inferior aesthetics and comfort must also be used. For patients with porcelain crowns in the oral cavity, bonding brackets is challenging and may damage the crowns.

Finally, clear aligners themselves have limitations in achieving complex tooth movements and control.Its material has limited elasticity and undergoes degradation, resulting in weak control over teeth and making it difficult to achieve ideal bodily tooth movement.

Especially when traction is required, the traditional method of creating precision-cut windows in aligners for elastic attachment compromises the integrity of the aligner. Moreover, the traction force is typically applied to the crown region, which tends to cause tipping movement rather than bodily movement of the teeth.

Furthermore, screening for upper airway obstruction is crucial in the diagnosis of malocclusion in children, as it can lead to a series of oral health issues such as mouth breathing. Clinically, diagnosis is primarily conducted by analyzing lateral cephalometric radiographs, on which physicians must manually trace and measure specific landmarks.

This process relies entirely on physicians’ experience, is highly subjective, and varies among doctors in their interpretation of grayscale boundaries in images, easily leading to diagnostic bias. Given the current strain on medical resources, there is an urgent need to develop automated and objective analytical methods and systems.

Against the backdrop of these clinical pain points having long plagued the development of clear aligner therapy, this patent cluster provides systematic solutions to these challenges through a series of foundational and systematic technological innovations. The following section will elaborate in detail on how these technologies collectively build the core advantages of the next-generation clear aligner system from multiple dimensions, including mechanical design, digital intelligence, and clinical operation.

This patent cluster systematically enhances the overall performance of clear aligner technology in terms of precision, efficiency, and comfort through a series of closely integrated innovative designs.Its core strengths are reflected in targeted breakthroughs and intelligent upgrades addressing key clinical challenges.

To address the clinical challenge of difficult bite opening in the treatment of deep overbite, this cluster innovatively proposesRemovable clear flat plane bite plate.The device is not bonded integrally with the clear aligner; instead, it wraps around the buccal aspect of the premolar region of the conventional appliance like a “jacket” via its bilateral retention zones.

This overlay design achieves perfect compatibility with full-coverage clear aligners and allows for easy removal and insertion. Its core feature is the flat bite plane area, which is aThree-Sided Enclosed Hollow Three-Dimensional Structure, when the patient occludes, the lower anterior teeth contact this area first, thereby discluding the posterior teeth and eliminating interfering occlusal forces, which effectively facilitates intrusion of the anterior teeth and extrusion of the posterior teeth.

Compared with traditional hard resin flat bite plates or size-limited lingual bite ramps, this hollow cellular structure provides sufficient supporting hardness while maintaining a degree of elasticity, significantly enhancing wearing comfort and reducing the risk of inducing temporomandibular joint disorders (TMD), making it particularly suitable for complex cases with excessive overjet.

In scenarios requiring the application of intermaxillary traction forces, the traction button assembly provided by the cluster resolves the challenge of compromising the integrity and positional stability of the aligner. This assembly consists of a separate mounting component and a traction component connected via a snap-fit mechanism.

During clinical procedures, the physician only needs to use medical forceps to create a small hole at any desired location on the appliance, insert the attachment component from the inner side, and then snap the traction component into place from the outer side. The entire process requires no adhesive or significant alteration of the appliance structure, enabling fully personalized positioning of the traction anchor points while ensuring a secure and reliable connection. This approach not only preserves the mechanical properties of the appliance but also significantly enhances the convenience and flexibility of clinical operations.

To establish a more objective and efficient starting point for orthodontic treatment, the consortium has developed a fully automated system for assessing orthodontic difficulty. This system fundamentally transforms the traditional model that relies on plaster models and manual measurements by clinicians.

Its core process is:After acquiring high-resolution 3D scan data of the patient's teeth, the data volume is first optimized and simplified through algorithms to preserve key geometric features; subsequently, deep learning networks are employed to automatically identify and segment each tooth and the gingival region.

Finally, based on these precise digital models, the system automatically calculates multiple orthodontic discrepancy indices (DI metrics), including tooth crowding, overjet and overbite relationships, and occlusal relationships. This fully digitalized process eliminates errors associated with manual impression-taking and subjective measurement biases, providing an objective, reproducible, and quantitative basis for treatment planning and the allocation of medical resources.

For the correction of skeletal deformities, Cluster has designed clear aligner devices capable of enhancing skeletal effects.For example, in the treatment of maxillary hypoplasia (commonly presenting as an anterior crossbite), traditional clear aligners rely primarily on teeth for anchorage during protraction, resulting in limited skeletal effects.

This solution integrates an “invisible palatal plate” that conforms to the patient’s palatal morphology, built directly into the clear aligner system.This palatal appliance can be fabricated from multiple layers of polymeric materials and reinforced with resin filling, thereby more effectively transmitting orthopedic protraction forces to the maxilla to promote skeletal changes rather than merely tipping the teeth. Meanwhile, the abutment structure designed on the appliance allows for flexible installation and adjustment of the traction hook angle, enabling precise control of the direction of traction force according to treatment needs, unrestricted by the angulation of the tooth surfaces.

In terms of mechanical application, the cluster proposes a disruptive "thrust" concept.Traditional intermaxillary elastics generate tensile forces, which may cause side effects such as tooth extrusion. The intermaxillary elastic push rod invented by this consortium connects the upper and lower orthodontic appliances via retention rings at both ends; upon placement, the rod undergoes bending deformation, converting its elastic restoring force into a continuous pushing force.

This force can be resolved into horizontal and vertical components: the horizontal component adjusts the anteroposterior relationship between the maxillary and mandibular teeth, while the vertical component acts as an additional intrusive force, helping to seat the aligner more tightly onto the teeth, enhance retention, and prevent dislodgement. This is particularly suitable for cases requiring simultaneous retraction and intrusion of teeth.

To address the complex need for asymmetric arch expansion, the cluster provides a precise biomechanical control solution.Conventional palatal expanders struggle to precisely control differential expansion amounts between the left and right sides. This approach disrupts mechanical equilibrium by attaching specialized winged support structures to the main body of the clear aligner: on the side requiring greater expansion, a "buccal-shielding wing" extending to the buccal mucosal fold is added to isolate inward pressure from the buccinator muscle, thereby facilitating outward tooth movement on that side; on the side with minimal expansion or requiring retention, a "lingual wing" extending to the mandibular lingual aspect is employed, utilizing the entire maxillomandibular complex as strong anchorage to counteract the reactive forces generated on the expansion side.

The expansion amount is precisely designed for each tooth and manufactured integrally through 3D printing technology, enabling efficient and controlled unilateral or asymmetric expansion while avoiding unnecessary tooth tipping.

For complex malocclusions involving both mandibular retrognathia and functional mandibular deviation (chin asymmetry), Cluster has developed a modular and adjustable orthodontic system.The system comprises a base with precision grooves, multiple sets of adjustment shims of varying specifications, and a rotatable adjustment shaft. The inclined surfaces of each set of shims have specific slopes, corresponding to different degrees of mandibular protrusion or lateral adjustment.

Clinicians can select the appropriately numbered adjustment pads based on the treatment plan and precisely set the vector (i.e., direction and magnitude) of the “mandibular advancement jump” by rotating the adjustment shaft to a preset angle. This design enables a single system to flexibly address cases of isolated mandibular retrusion, isolated jaw deviation, or a combination of both, while allowing fine-tuning during treatment in response to patient feedback, thereby achieving a high degree of personalization and controllability. The accompanying specialized fabrication device further facilitates the rapid and precise production of these adjustment pads, enhancing clinical efficiency.

In the field of computer-aided diagnosis, clusters have achieved automated screening for upper airway obstruction by leveraging artificial intelligence technology.This system, based on a deep learning model, can automatically identify the upper airway region in lateral cephalometric X-rays and determine whether pathological obstructions such as adenoid hypertrophy are present.

It first performs image preprocessing and grayscale normalization, then automatically extracts features and classifies them through a deep convolutional neural network. This replaces the traditional method that relies entirely on doctors’ visual assessment and manual measurements, making the diagnostic process more objective, faster, and highly reproducible. It facilitates early detection and intervention in children for mouth breathing and malocclusion caused by airway problems.

For cases requiring intrusion of over-eroded molars, the cluster provides a non-invasive solution, avoiding the trauma, anxiety, and risk of detachment associated with mini-implant placement.The treatment plan incorporates “intrusion slots” penetrating the occlusal surface of the molars requiring intrusion, along with traction hooks designed on the labial and lingual margins of these teeth, oriented toward the gingiva.

By simply looping a medical-grade elastic band in a figure-eight pattern around the two traction hooks and across the intrusion slot, patients can generate the force required for molar intrusion. Integrated into the aligner as a single unit, this device is aesthetically pleasing and easy to clean. Patients can replace the elastic bands daily on their own to maintain consistent and stable orthodontic forces, achieving efficient, comfortable, and patient-friendly molar intrusion.

Finally, at the most fundamental level of clear aligner mechanical design, ClearCorrect has optimized the mode of action of traction forces.Traditional methods often involve cutting openings in braces to attach elastics, which compromises structural integrity and typically applies traction forces to the crown portion of the teeth, easily leading to tipping movement.

This protocol involves directly designing and manufacturing the “traction attachments” on the outer surface of the aligner, typically near the height of contour (the most prominent point) of the tooth. This design not only preserves the integrity of the aligner but, more importantly, by positioning the force application point closer to the tooth’s “center of resistance” (the theoretical pivot point around which a tooth rotates when subjected to force), it facilitates more ideal bodily movement, minimizes unnecessary tipping, and thereby enhances both movement efficiency and treatment outcomes.

In summary, this patent cluster is not a mere aggregation of isolated technologies, but rather a collaborative innovation system that spans intelligent diagnostic assessment, personalized device design, precise biomechanical control, and efficient therapeutic implementation.

By deeply integrating digital design and manufacturing, intelligent algorithms, biomechanical principles, and clinical needs, it significantly expands the technological boundaries of clear aligner therapy, enabling more reliable and comfortable management of various clinical challenges, including skeletal malocclusions and complex tooth movements. This represents the advanced development direction in the field of digital orthodontic treatment.

In response to clinical needs that remain unmet—such as the efficiency of tooth movement, control of skeletal effects, and intelligent diagnosis and treatment—leading enterprises and research institutions both in China and abroad are actively laying out their next-generation technology pipelines.

Align Technology, the parent company of InvisalignCore Achievements in This Related FieldInvisalign Mandibular Advancement System(equipped with bite blocks), this is the company’s first clear aligner product integrating solid bite blocks, specifically designed to simultaneously correct Class II skeletal and dental malocclusions. It targets growing patients aged 10 to 16 years in the late mixed dentition or early permanent dentition stages.

The system’s solid bite blocks are fabricated using laser welding technology to provide structural rigidity and durability, enabling an earlier onset of the mandibular advancement (MA) phase through vertical opening of the bite. This system is suitable for patients with Class II deep overbite or Class II Division 2 malocclusion; only a subset of crossbite cases may still require pre-MA treatment. Additionally, the system is manufactured from patented SmartTrack™ material, which offers improved comfort and compliance compared to the previous single-layer material (EX30), and allows for the placement of attachments on teeth beneath the bite blocks to facilitate leveling or other tooth movements.

From a development perspective, this mandibular advancement system was first launched in the U.S. market in April 2025 and has recently been commercially released in the Philippines. It has since expanded further to markets including Australia, New Zealand, Japan, Hong Kong (China), Malaysia, Singapore, India, South Korea, China, Thailand, and Vietnam. The product is now officially available to Invisalign-certified doctors in these regions and, together with the Invisalign® Palatal Expander system and Invisalign First™, forms Align Technology’s portfolio of treatment solutions for growing patients.

AngelalignRelevant achievements addressing clinical needs such as maxillary transverse deficiency, Class II high-angle malocclusion, crossbite, and deep overbite in children have been successfully implemented:

Among these, the A10 palatal expansion solution establishes a tiered treatment pathway for mild-to-moderate cases. Mild-to-moderate cases can be managed with Angel Aligners to guide dental arch development and correct narrow dental arches, while severe cases are treated with the self-developed, high-rigidity “Angel Palatal Expander.” This device enhances expansion efficacy and efficiency through innovative palatal structural design, thereby shortening the treatment duration.

angelActivator HG Angel Headgear-Type ActivatorIntegrating the principles of traditional headgear activators with clear aligner systems to achieve daytime alignment of the dental arch and nighttime orthopedic mandibular advancement and facial profile control. This approach specifically targets Class II high-angle malocclusion, a challenging case in early orthodontic treatment, enhancing both treatment efficiency and patient compliance while balancing function and aesthetics.

The Angel Crossbite Correction Guide features a unique winged guide design that creates an occlusal interaction structure, eliminating the need for traditional solid bite plate bonding. It leverages the patient’s own occlusal force to assist in tooth intrusion and torque control, and can be used in conjunction with intermaxillary elastics or mini-implant traction. This system adapts to various treatment strategies to efficiently and controllably correct crossbites.

Angel Curved Guide PlateIt is optimized in terms of structure and mechanical force transmission, adapting to the movement trajectory of the lower anterior teeth through bionic curved surface design. It precisely guides the intrusion of anterior teeth and improves torque control, while simultaneously achieving natural posterior occlusal separation. This effectively overcomes the limitations of traditional flat bite planes and inclined bite planes, providing a solution for deep overbite.

These technologies were officially unveiled at the 11th A-TECH Conference and, as evidenced by subsequent market developments, have entered the clinical application phase. Also launched concurrently were the new-generation intelligent orthodontic platform iOrtho 2025 and the first self-developed intraoral scanner, AngelScanner A8, further enhancing the digital orthodontics ecosystem.

From an industry trend perspective, the field of clear aligner therapy is undergoing a profound expansion from simple tooth alignment to the correction of complex skeletal malocclusions. Future competition will increasingly center on integrated innovation capabilities that combine material mechanics, AI-driven diagnosis and treatment, and specialized vertical solutions.