Adjustable multifunctional retractor for microapical surgery

Abstract

This invention discloses an adjustable multifunctional retractor for microsurgical periapical surgery, comprising a handle, a connecting rod, and a working head. The working head is a wide, crescent-shaped retractor with both ends curved inwards to match the natural curvature of the alveolar ridge. A stabilizing wing folds outwards at the center of the working head's tail end, and a serrated occlusal portion at the end of the stabilizing wing. The stabilizing wing is used to insert into a pre-fabricated groove on the alveolar bone surface to form a mechanically interlocking anchorage. This invention, by setting an outwardly folding stabilizing wing in the center of the working head, and combining it with a pre-fabricated groove on the alveolar bone surface to form a mechanically interlocking anchorage, transforms the traditional passive anti-slip mode relying on friction into an active mechanical locking mode. The serrated occlusal portion, after inserting into the bone groove, forms a bidirectional barrier in both lateral and longitudinal directions, effectively preventing neurovascular bundle cutting, compression, or traction damage caused by retractor slippage, significantly improving surgical safety.

Description

Technical Field

[0001] This invention relates to the field of oral and maxillofacial surgical medical device technology, specifically to an adjustable multifunctional retractor for microscopic apical surgery. Background Technology

[0002] Endodontic microsurgery is an important surgical technique for treating refractory periapical lesions, and its success depends heavily on adequate exposure and stability of the surgical field. During the procedure, the gingiva needs to be incised and the mucoperiosteal flap raised to expose the alveolar bone and periapical region, while surgical retractors are the core instruments for achieving soft tissue traction and maintaining an open surgical field.

[0003] Current periapical surgical retractors are mostly made of fixed-shape stainless steel or titanium alloy, mainly consisting of a handle, connecting rod, and working head. Based on the shape of the working head, they can be divided into winged retractors, angular retractors, and clamping retractors. With the development of microsurgical techniques, higher requirements have been placed on retractors: they need to adapt to the anatomical variations of different tooth positions (from anterior teeth to molars), maintain stable operation in confined spaces, and maximize the protection of important anatomical structures such as the inferior alveolar nerve, mental nerve, and greater palatine neurovascular bundle.

[0004] Traditional retractors have fixed angles and shapes, making them unadjustable based on the surgical tooth position (e.g., the vertical angle in the anterior region versus the inclination angle in the molar region). Frequent changes of retractors at different angles are often necessary during surgery, reducing efficiency and increasing the risk of soft tissue trauma. Furthermore, existing retractors primarily prevent slippage by increasing friction with the bone surface through a planar design of the working head's underside or simple serrations. For example, Chinese invention patent CN112353520A discloses a 3D-printed periapical surgical retractor that uses personalized occlusal teeth to conform to the bone surface and increase friction; Chinese utility model patent CN223026193U discloses a gingival retractor for dental surgery that improves fit through a trapezoidal working head and arc-shaped cross-section design. However, these designs all rely on passive frictional resistance for fixation, and the retractors are still prone to anteroposterior or lateral slippage during prolonged surgery or under unexpected external forces. Summary of the Invention

[0005] In view of the technical problems existing in the background art, the present invention provides an adjustable multifunctional retractor for microscopic apical surgery that can effectively stabilize the retractor and improve surgical efficiency.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An adjustable multifunctional retractor for microsurgical periapical surgery includes a handle, a connecting rod, and a working head. The working head is wide and crescent-shaped, with both ends curved inward to match the natural curvature of the alveolar ridge. A stabilizing wing folds outward at the center of the working head's tail end, and a serrated occlusal portion at the end of the stabilizing wing. The stabilizing wing is used to insert into a pre-fabricated groove on the alveolar bone surface to form a mechanically interlocked anchorage. By incorporating the outward-folding stabilizing wing in the center of the working head, and in conjunction with the pre-fabricated groove on the alveolar bone surface to form a mechanically interlocked anchorage, the traditional passive anti-slip mode relying on friction is transformed into an active mechanical locking mode. The serrated occlusal portion, after inserting into the bone groove, forms a bidirectional barrier in both the lateral and longitudinal directions, preventing the retractor from slipping forward, backward, or laterally even under prolonged traction or unexpected external force. This structure is particularly suitable for high-risk areas such as the mandibular molar region (adjacent to the inferior alveolar nerve canal) and the mental foramen region. It can effectively avoid neurovascular bundle cutting, compression or traction damage caused by retractor slippage, and significantly improve surgical safety.

[0008] The technical solution of the present invention is further defined as follows: the stabilizing wing is connected to the working head body by an elastic hinge, and the stabilizing wing is adaptively fine-tuned within a range of ±5° to ensure that the stabilizing wing is always inserted into the groove in an attitude perpendicular to the alveolar bone surface.

[0009] Furthermore, the working head has a width of 35mm to 45mm and a bending radius of 3mm to 5mm for both ends that curve inward.

[0010] Furthermore, the stabilizing wing is folded upwards perpendicular to the main body plane of the working head, and the width of the stabilizing wing is 4mm to 6mm, and the height is 2.5mm to 3.5mm.

[0011] Furthermore, the tooth shape of the serrated biting part is triangular or trapezoidal, the tooth tip angle is 25° to 45°, and the tooth spacing is 0.8mm to 1.2mm.

[0012] Furthermore, the soft tissue protection wings of the working head are symmetrically distributed on both sides of the stabilizing wing. The width of the soft tissue protection wings on both sides is 15mm to 20mm, and the surface is polished or coated with a medical soft rubber layer.

[0013] Furthermore, an angle adjustment mechanism is provided between the connecting rod and the handle to adjust and lock the angle between the working head and the handle. The angle adjustment mechanism includes a worm gear transmission assembly or a gear transmission assembly, and the angle of the working head can be adjusted steplessly or in multiple positions by rotating the adjustment knob.

[0014] Furthermore, the angle adjustment mechanism has an adjustment range of 30° to 90°, and it is equipped with a mechanical self-locking structure to provide holding force at the set angle to prevent accidental angle rebound. Multi-position angle adjustment from 30° to 90° is achieved through a worm gear or gear transmission mechanism. The surgeon can adjust the hook angle in real time with one hand during surgery according to different anatomical access requirements for anterior teeth, premolars, or molar regions, adapting to different tooth exposure requirements without changing instruments. Simultaneously, the bone anchoring structure allows the stabilizing wing to remain perpendicular to the bone surface and maintain its anchored state during angle adjustment, ensuring the hook will not dislodge when the traction direction is changed. This synergistic design significantly reduces the number of instrument changes during surgery, shortens surgical time, and avoids multiple traumas to soft tissues caused by repeated hook placement.

[0015] Furthermore, the working head and the connecting rod are detachably modularly connected, and the working head includes at least one of standard type, narrow type or deep type to adapt to the surgical needs of different tooth position areas.

[0016] Furthermore, the handle is made of medical-grade titanium alloy and features a thick-walled hollow structure with an outer diameter of 12mm to 18mm and a wall thickness of 2mm to 3mm. This thick-walled hollow structure (2-3mm thick) reduces the overall weight by 30%-40% compared to traditional solid stainless steel hooks while maintaining structural strength, significantly reducing the static load on the surgeon's wrist, forearm, and neck muscles during prolonged microsurgical procedures. The handle surface is covered with medical-grade TPU soft rubber and features a grid-like anti-slip texture, increasing the grip area and coefficient of friction. This provides stable grip even in environments wet with blood or irrigation fluid, effectively preventing accidental movement due to instrument slippage. This design helps prevent occupational musculoskeletal diseases such as carpal tunnel syndrome and tenosynovitis, ensuring the surgeon's long-term occupational health.

[0017] The beneficial effects of this invention are as follows: This invention provides an adjustable multifunctional retractor for microsurgical root apical surgery, which combines adjustability, mechanical anchoring stability, and soft tissue protection. The sufficiently wide retractor head can lift the entire flap at once, fully exposing the field of vision and improving surgical efficiency. The inwardly curved design at both ends allows the working head to fit closely to the bone surface, making traction gentler and effectively protecting soft tissue. Inserting the serrated occlusal part into the groove can effectively stabilize the retractor while maintaining minimally invasiveness, preventing damage to important facial nerves and blood vessels due to retractor head slippage during surgery. The angle of the hook can be adjusted in real time via a knob and gear structure to adapt to different surgical tooth positions or anatomical locations, avoiding frequent instrument changes during surgery and improving operational efficiency. Attached Figure Description

[0018] Figure 1 A schematic diagram of an adjustable multifunctional retractor for microsurgical apical surgery provided by the present invention;

[0019] Figure 2 Detailed structural diagram of an adjustable multifunctional retractor for microscopic apical surgery provided by the present invention;

[0020] Figure 3 A schematic diagram of an adjustable multifunctional retractor angle adjustment mechanism for microsurgical apical surgery provided by the present invention;

[0021] Figure 4 This invention provides an adjustable multifunctional retractor for microscopic apical surgery, showing its usage state after angle adjustment.

[0022] As shown in the figure: 1. Handle; 2. Connecting rod; 3. Working head; 4. Stabilizing wing; 5. Serrated engagement part. Detailed Implementation

[0023] Example 1: An adjustable multifunctional retractor for microsurgical apical surgery, comprising a handle 1, a connecting rod 2, and a working head 3, as shown in the schematic diagram and detailed structural diagram. Figure 1 and Figure 2 As shown.

[0024] The working head 3 is a wide crescent shape, 40mm wide and 2mm thick, and is integrally molded from medical-grade titanium alloy (TC4). Both ends of the working head 3 are curved inward with a bending radius of 4mm to form a fitting edge that matches the natural curvature of the alveolar ridge.

[0025] The working head 3 is divided into a central anchoring area and two soft tissue protection wings along its width. The central anchoring area has outwardly folded stabilizing wings 4, and the surfaces of the two soft tissue protection wings are polished or coated with a medical soft adhesive layer. The stabilizing wings 4 are 5mm wide and 3mm high, extending outward at a 90° angle perpendicular to the working head body. The stabilizing wings 4 are connected to the working head 3 body by a flexible hinge, allowing the stabilizing wings 4 to adaptively fine-tune within a range of ±5° to ensure that when the angle adjustment mechanism adjusts the angle, the stabilizing wings 4 always remain perpendicular to the alveolar bone surface and inserted into the groove.

[0026] The stabilizing wing 4 has a serrated engagement portion 5 at its end. The teeth are triangular or trapezoidal, with a tooth tip angle of 25° to 45° and a tooth spacing of 0.8mm to 1.2mm, totaling 5-7 teeth. The stabilizing wing 4 is used to insert into a pre-made groove on the alveolar bone surface to form a mechanical interlocking anchor. It adopts the mechanical interlocking anchoring principle, whereby the outwardly folded serrated wing inserts into the pre-made bone groove to form a lateral mechanical barrier, fundamentally eliminating the possibility of slippage.

[0027] The stabilizing wing 4 is connected to the main body of the working head 3 by an elastic hinge, and the stabilizing wing 4 can be adaptively fine-tuned within a range of ±5°.

[0028] The working head 3 has a width of 35mm to 45mm, and the bending radius of its inwardly curved ends is 3mm to 5mm. The stabilizing wing 4 is folded upward perpendicular to the main body plane of the working head 3, and has a width of 4mm to 6mm and a height of 2.5mm to 3.5mm. The serrated engagement part 5 has triangular or trapezoidal teeth with a tooth tip angle of 25° to 45° and a tooth spacing of 0.8mm to 1.2mm.

[0029] The soft tissue protection wings of the working head 3 are symmetrically distributed on both sides of the stabilizing wing 4. The width of the soft tissue protection wings on both sides is 15mm to 20mm, and the surface is polished or coated with a medical soft rubber layer. The stabilizing wings are used to insert into the pre-made grooves on the alveolar bone surface to form a mechanical interlocking anchorage to prevent the hook from slipping during the operation.

[0030] An angle adjustment mechanism is provided between the connecting rod 2 and the handle part 1 to adjust and lock the included angle between the working head 3 and the handle part 1. The angle adjustment mechanism includes a worm gear transmission assembly or a gear transmission assembly. A schematic diagram of the angle adjustment mechanism that adjusts the angle through the gear transmission assembly is shown below. Figure 3 As shown, the angle of the working head can be adjusted steplessly or in multiple positions by rotating the adjustment knob. The adjustment angle range of the angle adjustment mechanism is 30° to 90°, and the working state after angle adjustment is shown in the figure. Figure 4 As shown, the angle adjustment mechanism is equipped with a mechanical self-locking structure to provide holding force at the set angle to prevent accidental angle rebound.

[0031] The working head 3 and the connecting rod 2 are detachably modularly connected. The working head 3 includes at least one of a standard type, a narrow type, or a deep type to adapt to the surgical needs of different tooth positions. In this embodiment, the width of the working head is 35mm to 45mm, and the bending radius of the inward arc at both ends is 3mm to 5mm.

[0032] The handle part 1 is made of medical-grade titanium alloy and has a thick-walled hollow structure with an outer diameter of 12mm to 18mm and a wall thickness of 2mm to 3mm. The internal hollow cavity accounts for approximately 44% of the volume, and the overall weight is 35% lighter than that of a solid stainless steel hook. The surface of the handle part is covered with a medical-grade TPU soft rubber layer, and the surface of the soft rubber layer has a grid-like or striped anti-slip texture.

[0033] In this embodiment, a pre-made groove is cut at a predetermined location on the alveolar bone surface using a high-speed diamond bur (1.6mm in diameter) before surgery. The groove is 5mm wide, 3mm deep, and its length matches the length of the stabilizing wing (approximately 8-10mm). During surgery, the retractor head is placed against the bone surface, allowing the serrated stabilizing wing to insert into the pre-made groove, forming a mechanical interlocking anchor to prevent the retractor from slipping forward, backward, or laterally during traction. This application transforms the passive anti-slip mechanism of the bone groove and the serrated wing, which relies on friction, into an active mechanical locking mechanism. In surgery in the mandibular molar region (adjacent to the inferior alveolar nerve canal), the retractor slippage rate is reduced to 0%, significantly reducing the risk of iatrogenic nerve injury. Simultaneously, it integrates adjustable angle (adaptability), wide crescent shape (exposure efficiency), and bone anchoring (safety), achieving a unified "exposure-protection-comfort" triple goal.

[0034] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this application are indicated by the claims. It should be understood that this application is not limited to the precise structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. An adjustable multifunctional retractor for microsurgical apical surgery, comprising a handle (1), a connecting rod (2), and a working head (3), characterized in that, The working head (3) is a wide crescent shape with its two ends curved inward to match the natural curvature of the alveolar bone ridge; the middle of the tail end of the working head (3) is provided with an outward folding stabilizing wing (4), and the end of the stabilizing wing (4) is provided with a serrated biting part (5). The stabilizing wing (4) is used to insert into a pre-made groove on the surface of the alveolar bone to form a mechanical interlocking anchor.

2. The adjustable multifunctional retractor for microsurgical apical surgery according to claim 1, characterized in that, The stabilizing wing (4) is connected to the main body of the working head (3) by an elastic hinge, and the stabilizing wing (4) can be adaptively fine-tuned within a range of ±5°.

3. The adjustable multifunctional retractor for microsurgical apical surgery according to claim 1, characterized in that, The working head (3) has a width of 35mm to 45mm and a bending radius of 3mm to 5mm at both ends that are curved inward.

4. The adjustable multifunctional retractor for microsurgical apical surgery according to claim 1, characterized in that, The stabilizing wing (4) is folded upward perpendicular to the main body plane of the working head (3). The width of the stabilizing wing (4) is 4mm to 6mm and the height is 2.5mm to 3.5mm.

5. The adjustable multifunctional retractor for microsurgical apical surgery according to claim 1, characterized in that, The tooth shape of the serrated biting part (5) is triangular or trapezoidal, the tooth tip angle is 25° to 45°, and the tooth spacing is 0.8mm to 1.2mm.

6. The adjustable multifunctional retractor for microsurgical apical surgery according to claim 1, characterized in that, The soft tissue protection wings of the working head (3) are symmetrically distributed on both sides of the stabilizing wing (4). The width of the soft tissue protection wings on both sides is 15mm to 20mm, and the surface is polished or coated with a medical soft rubber layer.

7. The adjustable multifunctional retractor for microsurgical apical surgery according to claim 1, characterized in that, An angle adjustment mechanism is provided between the connecting rod (2) and the handle (1) to adjust and lock the included angle between the working head (3) and the handle (1). The angle adjustment mechanism includes a worm gear transmission assembly or a gear transmission assembly, and the angle of the working head can be adjusted steplessly or in multiple positions by rotating the adjustment knob.

8. The adjustable multifunctional retractor for microsurgical apical surgery according to claim 7, characterized in that, The angle adjustment mechanism has an adjustment angle range of 30° to 90°, and the angle adjustment mechanism is equipped with a mechanical self-locking structure to provide holding force at the set angle to prevent accidental angle rebound.

9. The adjustable multifunctional retractor for microsurgical apical surgery according to claim 1, characterized in that, The working head (3) and the connecting rod (2) are detachable modular connections. The working head (3) includes at least one of standard type, narrow type or deep type to adapt to the surgical needs of different tooth position areas.

10. The adjustable multifunctional retractor for microsurgical apical surgery according to claim 1, characterized in that, The handle is made of medical-grade titanium alloy and has a thick-walled hollow structure with an outer diameter of 12mm to 18mm and a wall thickness of 2mm to 3mm.

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