CN102988123B - The substitute prosthese that a kind of longitudinal direction of jaw face is fixing - Google Patents

Abstract

The invention discloses a structural design of a substitute prosthesis for longitudinal fixation of the maxillofacial surface. Nail holes for longitudinal fixation of the substitute prosthesis are arranged on the cross section of the prosthesis. The nail holes are equipped with drill sleeves and screws, and the drill sleeve and The nail hole forms a clearance fit, and the drill sleeve forms a clearance fit with the screw. The longitudinally fixed prosthesis changes the traditional extension plate fixation technique, avoids large-area peeling of the periosteum and soft tissue during the fixation process, and reduces the possibility of prosthesis fracture. More importantly, the longitudinal fixation method does not change the main stress-bearing mode of the patient's mandible, and it can also avoid the stress shielding effect of the extension plate on the mandible in the covered area in the transverse fixation, effectively preventing postoperative bone atrophy.

Description

A longitudinally fixed substitute prosthesis for maxillofacial

technical field

The invention belongs to the technical field of substitute prosthesis, and relates to a structural design of a longitudinally fixed substitute prosthesis of the maxillofacial region.

Background technique

The shape of the human mandible varies greatly among individuals. For large bone loss caused by trauma, tumors, and congenital bone defects, the fundamental method is to implant artificial substitutes through surgery. Because the shape of the traditional artificial implant is very different from that of the original bone, which seriously affects the aesthetics of the patient's face and brings great physical and mental pain to the patient, the design and manufacture of substitute prostheses are increasingly attracting people's attention. An important problem faced by surrogate prostheses in practical application is the issue of fixation.

The traditional fixation method of the substitute prosthesis mainly relies on the fitting of the extension plate and the outer surface of the human bone to determine the mutual position, and the substitute prosthesis and the stump of the mandible are reliably fixed together through the screws on the extension plate. In order to ensure accurate positioning and reliable fixation of the substitute prosthesis and the mandibular stump, the extension plate is usually designed with a larger area to increase the contact area between the positioning plate and the outer surface of the mandibular stump and increase the number of fixation screws. However, stress concentration tends to occur at the connection part of the extension plate, which leads to fracture at the connection point; the lateral fixation of the extension plate changes the main force-bearing mode of the mandible, making its force nature change from the initial tensile and compressive stress to shear stress; The stress shielding effect prevents the covered mandibular region from receiving proper mechanical stimulation, resulting in atrophy of the connecting part of the mandible.

Contents of the invention

The problem to be solved by the present invention is to provide a longitudinally fixed substitute prosthesis of the maxillofacial surface, which avoids the possibility of fracture at the junction of the extension plate of the substitute prosthesis and effectively prevents postoperative atrophy of the mandibular joint.

The present invention is achieved through the following technical solutions:

An alternative prosthesis for longitudinal fixation of the maxillofacial region, the cross section of the alternative prosthesis is provided with nail holes for longitudinal fixation of the alternative prosthesis, the nail hole is equipped with a drill sleeve and a drill bit, and the drill sleeve and the nail hole form a clearance fit , The drill sleeve and the drill bit form a clearance fit.

The screw hole is provided with an offset angle, and its offset direction should not deviate from the outer side of the cortical bone or into the mandibular canal, so as to ensure that the screw does not penetrate the cortical bone after fixation.

The section of the fixed part of the surrogate prosthesis matches the osteotomy surface of the broken end of the mandible, and the buccal connection part has a smooth transition of the outer contour of the mandible.

The diameter of the nail hole is 1-3 mm, the length of the nail hole is 3-20 mm, the diameter of the nail hole is 0-0.2 mm larger than the outer diameter of the drill sleeve, the inner diameter of the drill sleeve is 0-0.2 mm larger than the diameter of the drill bit, and the diameter of the drill bit is equal to the small diameter of the screw .

A flange for auxiliary connection and positioning is provided at the contact part between the outside of the substitute prosthesis and the broken end of the mandible.

The protruding length of the flange is 1-10 mm, and the thickness of the flange is 0.5-3 mm.

The cross-sectional shape of the substitute prosthesis is a solid cross-section or a U-shaped groove cross-section.

The solid section of the substitute prosthesis is provided with a positioning boss matching the mandibular canal, the height of the positioning boss is 3-10mm, and the draft angle is 5°-30°.

The thickness of the U-shaped groove substitute prosthesis is 0.5-3mm.

Compared with the prior art, the present invention has the following beneficial technical effects:

In the longitudinally fixed surrogate prosthesis of the maxillofacial surface provided by the present invention, the transverse fixation of the extension plate is changed to the longitudinal fixation, which avoids the possibility of fracture of the joint of the extension plate of the surrogate prosthesis due to stress concentration.

Further, the prosthesis of the longitudinal fixation of the maxillofacial provided by the present invention utilizes the nail holes and the drill sleeve provided on the prosthesis to realize the guiding function when the mandible is drilled in the longitudinal direction, so as to ensure that the screw does not deviate after being nailed into the cortical bone. On the surface of the mandible or deviated into the medullary cavity of the mandible.

The prosthesis of the longitudinal fixation of the maxillofacial surface provided by the present invention adopts the method of positioning the lingual surface of the mandible, avoiding the influence of extension plates and transverse fixation screws on the smoothness of the buccal side of the mandible after surgery, and ensuring the smoothness of the mandible after surgery. The beauty of the face.

The longitudinally fixed substitute prosthesis of the maxillofacial surface provided by the present invention is designed with a flange on the cross-section of the substitute prosthesis, which is used for assisting positioning when connecting the mandible and the prosthesis cross-section.

The prosthesis for the longitudinal fixation of the maxillofacial surface provided by the present invention avoids large-area stripping of the periosteum and soft tissue in the process of transverse fixation, and does not change the main force-bearing mode of the mandible at the connecting part, and avoids the extension plate in the transverse fixation method The stress shielding function of the mandible in the area covered by it can effectively prevent the atrophy of the mandible after operation.

Description of drawings

Figures 1-1 to 1-2 are structural schematic diagrams of the longitudinal fixation of the substitute prosthesis and the broken end of the mandible;

Figures 2-1 to 2-2 are structural schematic diagrams of the position and offset angle of the lingual positioning flange of the substitute prosthesis and the reserved nail holes in the fixed part;

Fig. 3 is a schematic diagram of the installation of the drill sleeve during the fixation process of the substitute prosthesis;

Fig. 4 is a partial cross-sectional view of the assembly of the drill sleeve and the prosthesis during the fixation process of the prosthesis.

Among them, 1 is the broken end of the bone; 2 is the substitute prosthesis, 3 is the drill bit, and 4 is the drill sleeve.

Detailed ways

The present invention will be further described in detail below in conjunction with specific embodiments, which are explanations of the present invention rather than limitations.

See Fig. 1-1～1-2, a kind of surrogate prosthesis for longitudinal fixation of maxillofacial region, the cross-section of the surrogate prosthesis is provided with nail holes for longitudinal fixation of the surrogate prosthesis, and the nail holes are equipped with drill sleeves and The drill bit, the drill sleeve and the nail hole form a clearance fit, and the drill sleeve and the drill bit form a clearance fit.

In this way, screws can be penetrated through the mandibular section and nailed into the cortical bone through the reserved nail holes on the prosthesis section and the outer surface to complete the longitudinal fixation of the prosthesis and the stump of the mandible.

Figure 1-1 is a prosthesis with a solid structure, and Figure 1-2 is a prosthesis with a U-shaped groove structure. The more the number of nail holes reserved on the substitute prosthesis, the smaller the angle of deviation to the medial cancellous bone, and the more the titanium nails penetrate the mandibular stump cortical bone, the more secure the fixation. However, too many reserved nail holes will reduce the strength of the connection part of the substitute prosthesis, and too small offset angle will increase the difficulty of the doctor's drilling operation in clinical operations, or even make drilling impossible. Therefore, on the premise of ensuring stable fixation, the number of reserved nail holes should be reduced as much as possible and the offset angle should be increased.

Specifically, the surrogate prosthesis is designed to have a solid section or a U-shaped groove section, and the solid section of the surrogate prosthesis is also provided with a positioning boss that matches the mandibular canal (see Figure 1-1), The height of the positioning boss is 3-10mm, and the draft angle is 5°-30°; the thickness of the U-groove prosthesis should be between 0.5-3mm (see Figure 1-2), and the cross-section of the substitute prosthesis is broken from the mandible. Matching the osteotomy surface at the end, the buccal junction has a smooth transition to the outer contour of the mandible.

A nail hole with a diameter of 1-3mm is reserved on the outer contour surface of the prosthesis. The nail hole is designed individually to ensure that its direction does not deviate from the outer side of the cortical bone or into the mandibular canal, so that the fixed screw does not deviate. cortical bone. Specifically, the length of the nail hole is 3-20 mm, the nail hole is equipped with a drill sleeve and a drill bit, the drill sleeve and the nail hole form a clearance fit, the diameter of the nail hole is 0-0.2 mm larger than the outer diameter of the drill sleeve, and the drill sleeve and the drill bit form a clearance fit , The inner diameter of the drill sleeve is 0-0.2mm larger than the diameter of the drill bit, and the diameter of the drill bit is equal to the small diameter of the screw.

Furthermore, a flange is designed at the contact part between the lingual side of the substitute prosthesis and the broken end of the mandible for auxiliary connection and positioning. The protruding length of the flange is 1-10 mm. The thickness of the edge is 0.5 ~ 3mm.

When the substitute prosthesis is used, close the substitute prosthesis to the broken end of the mandible, position it according to the inner surface of the flange and the outer surface of the broken end of the mandible, and use the reserved nail holes and drill sleeves to place titanium nails to complete the replacement. Fixation of prosthesis and mandibular stump.

See Figures 2-1 to 2-2, where Figure 2-1 is a prosthesis with a solid structure, and Figure 2-2 is a prosthesis with a U-shaped groove structure. Apply the contralateral data or the mathematical properties of the lateral inferior arc of the mandible to design the structure of the substitute prosthesis in the case of bone defect or deformity. The shape of the prosthesis matches the end, and a nail hole is reserved in its fixed part. A flange for auxiliary connection and positioning is designed on the lingual side of the prosthesis. The solid section prosthesis can also be designed with a positioning boss on its cross section.

During the operation, sagittal mandibular osteotomy was completed according to the pre-set osteotomy position, and then the sagittal section of the substitute prosthesis was fitted to the osteotomy surface of the stump of the mandible, and the inner surface of the lingual flange of the substitute prosthesis was Fit the outer surface of the lingual side of the broken end of the mandible to complete the spatial positioning of the substitute prosthesis.

When using a solid-section substitute prosthesis, the positioning boss on the cross-section of the prosthesis can be embedded into the mandibular canal for further positioning. The height of the positioning boss embedded in the mandibular canal is 3-10mm, The mold angle is 5°～30°, and the specific parameters are selected according to the specific situation.

After the positioning is completed, put the designed drill sleeve into the reserved nail hole of the prosthesis, drill a hole in the broken end of the mandible with a drill bit, then remove the drill sleeve, and manually screw in the screws for fixation to complete the integration of the prosthesis. Longitudinal fixation of stump bones.

Specifically, Fig. 3 is a schematic diagram of the installation of the drill sleeve during the fixation process of the substitute prosthesis, and Fig. 4 is a partial sectional view of the assembly of the drill sleeve and the prosthesis during the fixation process of the substitute prosthesis, wherein the drill sleeve and the nail hole form a clearance fit, and the diameter of the nail hole is 0~0.2mm larger than the outer diameter of the drill sleeve, the drill sleeve and the drill bit form a clearance fit, the inner diameter of the drill sleeve is 0~0.2mm larger than the drill bit diameter, and the drill bit diameter is equal to the small diameter of the screw.

The above-mentioned prosthesis for longitudinal fixation of the maxillofacial region avoids the large area of periosteum and soft tissue stripping in the process of transverse fixation, and does not change the main force-bearing mode of the connecting part of the mandible, avoiding the impact of the extension plate in the transverse fixation method The stress shielding function of the mandible in the covered area can effectively prevent the atrophy of the mandible after operation.

Claims (4)

1. the substitute prosthese that the longitudinal direction in a jaw face is fixing, it is characterized in that, the section of substitute prosthese is provided with the longitudinally fixing nail of substitute prosthese, and nail is equipped with drill bushing and drill bit, drill bushing and nail form matched in clearance, and drill bushing and drill bit form matched in clearance; Also comprise the screw matched with nail, drill bushing; Be provided with the auxiliary flange being connected and locating with mandibular bone broken ends of fractured bone contact site outside substitute prosthese;

The section of the standing part of substitute prosthese and the osteotomy surface of the mandibular bone broken ends of fractured bone match, and cheek side connecting portion has the mandibular bone outline seamlessly transitted;

The section of the standing part of described substitute prosthese and the osteotomy surface of the mandibular bone tongue side broken ends of fractured bone match;

Nail is provided with angle of eccentricity, and its biased direction does not deflect away from outside cortical bone or partially enters in mandibular bone pipe, thus ensures that the screw after fixing does not penetrate cortical bone;

Described nail diameter is 1 ~ 3mm, and nail length is 3 ~ 20mm, nail diameter 0 ~ 0.2mm larger than drill bushing external diameter, and drill bushing internal diameter 0 ~ 0.2mm larger than bit diameter, bit diameter equals the path of fixing screw.

2. the substitute prosthese that the longitudinal direction in jaw face as claimed in claim 1 is fixing, it is characterized in that, the protrusion height of described flange is 1 ~ 10mm, and the thickness of flange is 0.5 ~ 3mm.

3. the substitute prosthese that the longitudinal direction in jaw face as claimed in claim 1 is fixing, it is characterized in that, the cross sectional shape of substitute prosthese is solid section or U-type groove cross section.

4. the substitute prosthese that the longitudinal direction in jaw face as claimed in claim 3 is fixing, it is characterized in that, the solid section of substitute prosthese is provided with the sagittal sectional matched with the mandibular bone tongue side broken ends of fractured bone;

The thickness of U-type groove substitute prosthese is 0.5 ~ 3mm.