Abstract: Multi-piece, reusable orthodontic appliances that include a support assembly to be bonded to a tooth and a corrective assembly adapted to receive an archwire and direct corrective forces exerted by the archwire to the tooth. The support assembly is releasably engaged with the corrective assembly, such as with coupling portions that disengage responsive to a force applied to the corrective assembly exceeding a predetermined value, such as less than a force sufficient to debond the support assembly from the tooth. In response to such a force, the corrective assembly disengages from the support assembly, rather than the appliance debonding from the tooth. Self-release assemblies for use with a corrective orthodontic bracket, including either a support assembly or a corrective assembly, and an engagement assembly configured to disengage as described above, may allow a conventional set of orthodontic hardware to be retrofitted with a self-release feature.

Abstract: An adjustable dental device for use with a CPAP system in the treatment of sleep apnea and snoring is comprised of an upper bite block, a lower bite block having one or more tongue retainers, means for adjustably connecting the upper bite block to the lower bite block, and means for connecting the dental device to a CPAP system. The adjustable dental device is compatible with a variety of CPAP systems, including systems that utilize nasal inserts and systems that utilize a nasal mask.

Abstract: An adjustable orthodontic bracket comprising: a fixed support base having a circular housing and an inferior surface for attaching to the surface of a tooth; a rotating base, rotary housed inside the circular housing, having a superior surface for receiving a bracket; and locking means for the rotating base, for locking the rotary movement of the base at a specific rotational position, wherein said locking means can be disabled to allow the rotation of the rotating base.

Abstract: An orthodontic article and method of making the orthodontic article, where the orthodontic article includes a fine-grain ceramic bracket and a metal liner secured in an archwire slot of the bracket with a brazing alloy comprising silver, copper, and at least about 1.5% by weight titanium.

Abstract: The invention is an archmatrix. In one embodiment the archmatrix of the invention comprises: an occlusal wire; an apical wire; and a plurality of connecting elements located between the occlusal wire and the apical wire (see, e.g., FIG. 3). The connecting elements serve to connect and maintain the configuration of the occlusal and apical wires. The connecting elements can take the form of interconnecting network or mesh. A complementary set of brackets are used to attach the archmatrix to a patient's teeth. The archmatrix can comprise archwires in addition to the occlusal and apical wires.

Abstract: An orthodontic bracket includes a body contoured to fit a tooth surface and a lumen extending horizontally across the body to engage orthodontic wires. Different embodiments of the orthodontic bracket are disclosed herein.

Abstract: A method for producing an orthodontic bracket is comprised of sintering a molded body of highly-pure alumina fine powder at a temperature of 1,200° C. to 1,300° C. to obtain a sintered body composed of crystals having a relative density of 96% to 99.5% and an average crystal grain size of at most 1 ?m, and thereafter subjecting the sintered body to an HIP treatment at a temperature of 1,200° C. to 1,350° C., under a pressure of at least 50 MPa. Such an orthodontic bracket has high strength and high translucency, can be processed into a complicated shape, similar to that of a metal bracket, and maintains excellent translucency.

Abstract: The invention relates to compositions based on Ce-stabilized ZrO2, and single- and multi-colored blanks made from oxide ceramics, and a process for their preparation, in which oxide ceramic powder is coated with a coloring substance, the coated powders are preferably graded and at least one colored powder is filled into a compression mould, the colored powder or powders are compressed to produce a shaped body, and the compressed shaped body is sintered to produce a blank, and to the use of these blanks for the preparation of dental restorations. The compositions exhibit high fracture toughness and high flexural strength.

Abstract: The method for surface inclusions detection, enhancement of endothelial and osteoblast cells adhesion and proliferation and sterilization of electropolished and magnetoelectropolished Nitinol implantable medical device surfaces uses an aqueous solution of chemical compounds containing halogenous oxyanions as hypochlorite (ClO?) and hypobromite (BrO?) preferentially 6% sodium hypochlorite (NaClO).

Abstract: An orthodontic connector assembly 10 including a plurality of substantially identical connecting members, such as members 12, 14 which include a movable but biased portion 20 which is adapted to selectively and removably receive a pocket portion 44 which is deployed on at least one bracket, such as bracket 40. In an alternative embodiment, the members, such as member 12, 14 each include a ridge, such as ridge 212, which is selectively, removably, and frictionally placed within slot 236.

Abstract: Systems and methods are disclosed for intra-oral delivery of drugs.

Abstract: The low profile orthodontic appliance generally has a height between and generally not including 0.0190 and 0.020 inches and having a depth less than 0.026 inches, with a preferred embodiment being a height of 0.0195 inches and a depth of 0.025 inches. The slot is preferably rectangular in cross-sectional shape thus having equal length short sides and preferably equal length long sides, the long sides having straight, uninterrupted walls. The orthodontic appliance may be in the form of a bracket or tube, each for receiving a 0.019×0.025 inch archwire and each shaped for one or more upper or lower permanent teeth. The appliances may be universal, thus being of a same size on all applicable teeth or may be a bi-dimensional setup, which uses conventional 0.018 or 0.022 inch slotted brackets in combination with the slotted bracket having a height between and not including 0.0190 and 0.020 inches.

Abstract: Convertible orthodontic brackets (100) with a selectively removable labial web (112) are formed by machining. A circular pilot hole is formed so as to extend mesially-distally through the body of the orthodontic bracket (100). One or more shaping broaches are then pushed or pulled through the pilot hole so as to form a desired rectangularly-shaped arch wire hole (106) within the orthodontic bracket body (104). The area surrounding the labial web cover (112) is also machined to form first and second connecting web regions (114, 116) of reduced cross-sectional thickness on either side of the labial web cover (112). Manufacture by machining allows stronger more dense metals to be employed compared to manufacturing by metal injection molding.

Abstract: An orthodontic bracket is comprised of a translucent ceramic containing at least 99.5 wt % of alumina, and having an absorption/scattering coefficient of at most 2.8 mm?1 for visible light at a wavelength of 550 nm and a bending strength of, at least 700 MPa. This bracket is obtained, for example, by sintering a molded body of highly-pure alumina fine powder at a temperature of from 1,200° C. to 1,300° C. to obtain a sintered body composed of crystals having a relative density of from 96% to 99.5% and an average crystal grain size of at most 1 ?m, and thereafter subjecting the sintered body to an HIP treatment at a temperature of from 1,200° C. to 1,350° C. and under a pressure of at least 50 MPa. Such an orthodontic bracket has high strength and high translucency, can be processed into a complicated shape, similar to that of a metal bracket, and maintains excellent translucency.

Abstract: A coated medical implant, such as a coated dental component, is provided, the coated medical implant including a substrate surface formed of a material comprising available hydroxyl groups and a silicon oxide coating layer chemisorbed on the substrate surface. A method for the preparation of such coated implants is also provided, the method involving application of the silicon oxide coating layer to the substrate surface by chemical vapor deposition. A dental structure is also provided, which includes a first dental component having a substrate surface formed of a material comprising available hydroxyl groups; a silicon oxide coating layer chemisorbed on the substrate surface; a silane coupling agent overlying and covalently attached to the silicon oxide layer; a dental cement overlying and coupled to the silane coupling agent; and a second dental component having a surface bonded to the dental cement.

Abstract: A customized orthodontic bracket system is provided. The system can include a bracket having a customized bracket bonding pad for bonding the bracket to a tooth of a patient and a bracket slot adapted to receive a customized archwire. The customized archwire is adapted to be positioned in the bracket slot to form a precise bracket slot-archwire interface. The bracket slot and the archwire when positioned in the bracket slot can be positioned substantially adjacent the tooth surface to reduce induced vertical error in tooth positioning. The bracket slot can be configured to have a bracket slot width substantially matching a cross-section of the archwire to reduce torque rotation around an axis of the archwire when positioned therein to further enhance end-of-treatment tooth positioning and reduce overall treatment time.

Abstract: An orthodontic connector assembly 10 including a plurality of substantially identical connecting members, such as members 12, 14 which include a movable but biased portion 20 which is adapted to selectively and removably receive a pocket portion 44 which is deployed on at least one bracket, such as bracket 40. In an alternative embodiment, the members, such as member 12, 14 each include a ridge, such as ridge 212, which is selectively, removably, and frictionally placed within slot 236.

Abstract: The invention relates to a method for producing an orthodontic component (1) formed by a polycrystalline ceramic structure, wherein the powder that is used is formed into a green body and subsequently sintered in a temperature range having a lower limit of more than 1900° C., in particular 2100° C., and an upper limit of 2500° C., in particular 2400° C., preferably 2200° C., over a duration having a lower limit of 3 hours, in particular 5 hours, preferably 7 hours, up to an upper limit of 24 hours, in particular 15 hours, preferably 10 hours. Subsequently, the sintered component (1) is cooled down to room temperature, wherein the material is formed in a thickness of 0.5 mm having inline translucency with a lower limit of 70%, in particular 85%, and an upper limit of 100%.

Abstract: The invention concerns a mounting arrangement for mounting an orthodontic bracket on a tooth. The mounting arrangement comprises an orthodontic bracket and a mounting aid, wherein the mounting aid can be detachably connected to the orthodontic bracket with positive engagement by pushing it onto the bracket in such a way that long sides of the side pieces of the mounting aid engage in guide grooves of the bracket.

Abstract: Hardenable and hardened dental compositions, and articles including such hardenable and hardened compositions, are provided. The hardenable dental compositions include a thermally labile component including one or more thermally labile groups. Upon heating, the hardened compositions are useful, for example, for reducing the bond strength of orthodontic appliances adhered to tooth structures with the hardened compositions.

Abstract: Because fracture toughness and translucency of translucent colored alumina sintered body of the past were low, the alumina sintered body was not suitable for uses such as dental materials, which require high toughness. The present invention relates to providing a translucent colored alumina sintered body that contains transition metal oxides, and with which the fracture toughness is 4.5 MPa·m0.5 or more and the maximum value of total forward transmittance (sample thickness 1 mm) to a wavelength of 300-800 nm is 60% or more. The present invention relates to obtaining a sintered body, at least 20% of which contains anisotropic grains with a long axis length of 10 ?m or greater and an aspect ratio of 1.

Abstract: The invention relates to a bracket for fixing to the exterior face of a tooth, the bracket having a base, which lies against the tooth and in which a trapezoid shape slot is configured to receive a wire bow. The base of the slot runs essentially perpendicularly in the oral cavity with elevated surface, thus retaining the wire bow, which exerts forces and torques in an essentially horizontal direction, in an optimum position in the slot. The unique form of the inventive brackets has a dimple concave female surface and a channel for attachments to passes through which would allow the female to receive a convex male surface extension from the attachments and form a locking mechanism between concave female surface and the attachment convex male extension when attachment is used during the Orthodontic treatment. This unique model of locking mechanism has created a new inventive platform in Orthodontics for interchangeable attachments.

Abstract: An improved orthodontic tensioning device having an elastomeric resilient body portion and first and second connectors which are securely attached to the elastomeric resilient body portion and have elements for connecting with a connecting structure. The orthodontic tensioning device preferably is applied by the orthodontist thus eliminating any dependency on the patient to faithfully wear his elastics. This provides control by the dental professional, and generally may improve results by reducing or eliminating tendencies of those who fail to replace or use elastics.

Abstract: Method for producing a customized orthodontic device having an arch wire and a plurality of elements which each include a bracket provided with a groove for inserting the arch wire, each bracket being placed on an intermediate component which is itself placed on a base placed on a face of a tooth. The method making provision for the brackets, intermediate components and bases to be digitally designed in a customized manner after having formed a representation in the corrected position of the arch and faces of the teeth, wherein: a model arch wire is positioned relative to the faces of the teeth on the representation, the geometry of the modal arch wire being homothetic with that of the treatment arch wire; the elements are digitally designed so as to give them a shape which corresponds to the space which would separate the tooth and the curved member when the tooth had assumed its corrected position and the arch wire had returned to its initial shape.

Abstract: A method of producing a customized orthodontic appliance (1), including brackets (12) fixed to teeth (13) of a dental arch of a patient and an orthodontic archwire (11). Each bracket (12) is fixed to a surface of a tooth (13) of the dental arch by a bracket bonding pad (121) of the bracket, and the orthodontic archwire (11) is fixed to the brackets in a housing (123) of a bracket body (122) of each bracket. The bracket is produced with a blank (50) having at least two volumes (51, 52), one volume representative of an envelope volume of a bracket bounding pad and an envelope volume of a bracket body.

Abstract: A method for deriving shape information of a person's skull and dentition, comprising the steps of: taking an impression of the person's dentition, taking a first scan of the person's head, while the person is wearing the impression, taking a second scan of the impression alone, combining the scans, deriving the shape information from the combined scans. Advantageously the method further comprises the step of taking a third scan of the person's head alone without the impression.

Abstract: In the conventional alumina sintered bodies, a sintered body having high flexural strength, high toughness and high translucency in combination is not obtained, and a translucent alumina sintered body suitable for a dental material requiring both strength and sensuousness was not obtained. A translucent alumina sintered body having fracture toughness of 4.5 MPa·m0.5 or more, flexural strength of 350 MPa or more, and all light transmittance (sample thickness: 1 mm) to a visible light having a wavelength of 600 nm, of 60% or more is provided. The sintered body wherein sintered crystal grains are slender plate-like and/or columnar shape having an average aspect ratio of 1.5 or more and an average long axis length of 15 ?m or less is preferred.

Abstract: A subject of the invention relates to providing a powder for a translucent zirconia sintered body which is necessary for the production of a zirconia sintered body having a high sintered-body density and high strength and giving an excellent sense of translucency, without conducting any special sintering, such as HIP sintering. The invention relates to a technique for obtaining, through normal-pressure sintering, a translucent zirconia sintered body characterized by comprising zirconia which contains 2-4 mol % yttria as a stabilizer and has an alumina content of 0.2 wt % or lower, and by having a relative density of 99.8% or higher and a total light transmittance, as measured at a thickness of 1.0 mm, of 35% or higher. It is preferred that a powder containing 0-0.2 wt % alumina with a particle diameter of 0.01-0.5 ?m, having a BET specific surface area of 5-16 m2/g and an average particle diameter of 0.3-0.7 ?m, and having a rate of sintering shrinkage in normal-pressure sintering (??/?T; g/cm3·° C.) of 0.

Abstract: A dental oral appliance to reduce or eliminate snoring or obstructive sleep apnea and to open the airway for a sleeping patient. The appliance covers the inside (lingual) of the upper or lower teeth and has an open palate. Retention for the appliance is provided by an occlusal coverge of the upper or lower teeth. A raised incisor ramp that extends from the incisal tip of the incisors toward the lingual, or posterior ramps, separate the posterior teeth to open the airway. A transpalatal bar, which extends from the inside (lingual) of the right molars to the inside of the left molars, inhibits the upward and backward movement of the tongue. An anterior tongue restrainer which is attached to the transpalatal bar at one end and the front of the appliance at the other end, aids in inhibiting and restraining the upward and backward movement of the tongue.

Abstract: The invention relates to orthodontic or dental appliances with a substrate, at least certain regions of which are provided with a coating containing titanium dioxide and/or titanium nitride, as well as a coating formulation and a method of applying the coating formulation to the orthodontic or dental appliances.

Abstract: Multi-piece, reusable orthodontic appliances that include a support assembly to be bonded to a tooth and a corrective assembly adapted to receive an archwire and direct corrective forces exerted by the archwire to the tooth. The support assembly is releasably engaged with the corrective assembly, such as with coupling portions that disengage responsive to a force applied to the corrective assembly exceeding a predetermined value, such as less than a force sufficient to debond the support assembly from the tooth. In response to such a force, the corrective assembly disengages from the support assembly, rather than the appliance debonding from the tooth. Self-release assemblies for use with a corrective orthodontic bracket, including either a support assembly or a corrective assembly, and an engagement assembly configured to disengage as described above, may allow a conventional set of orthodontic hardware to be retrofitted with a self-release feature.

Abstract: An oral functional appliance for adjusting functions of oral muscle organs includes a base and a body. The base is connected to a tooth surface, and the body is provided with at least one protrusion at a surface thereof.

Abstract: The present invention relates to an anchoring device for regulating teeth and/or jaw, having an anchoring element (1) comprising a shank (2) for arranging in a jaw bone or a tooth, and a head (3), whereon a cap (10) for arranging at least one jaw orthopedic and/or dental aid is releasably disposed, wherein the cap is constructed, in at least two parts, of a fastening element (12) for releasably fastening the cap in the head, and a mounting element (11) for mounting at least one jaw orthopedic and/or dental aid, and wherein the mounting element is freely displaceable relative to the fastening element in at least one degree of freedom of motion at least within certain limits.

Abstract: A connection device for a surgical operation of straightening irregular teeth is provided, which is used to connect a connection wire which connects brackets which are attached to respective teeth with a tension member which is connected with an anchor, to thereby reinforce intensity of the connection device and control height of the connection device, and to thus smoothen bodily movement of teeth. The connection device includes: a wire connection member in which a wire connection groove is formed horizontally lengthwise so that a connection wire is inserted into the wire connection groove; a hook connection member at the center of one end of which one end of the wire connection member is vertically fixed and in which a hook connection groove is formed vertically lengthwise; and a hook member at the lower end of which a fixing rod is formed in various lengths so as to be inserted into and fixed to the hook connection groove of the hook connection member, and at the upper end of which a hook is formed.

Abstract: An orthodontic bracket is provided. The bracket includes a rear wall coming to rest on a buccal or lingual tooth surface; and two guide surfaces running at right angles to one another, for guiding an archwire with a rectangular cross section, wherein the two guide surfaces are arranged distanced to the rear wall. A first gingival web runs below the first guide surface and at least one second occlusal web runs above the first guide surface, with a second passage being left free between the first web and the rear wall, and a first passage being left free between the second web and the rear wall.

Abstract: An orthodontic device and an orthodontic method that can prevent an orthodontic treatment from being eccentrically performed while aligning straightly tooth. The orthodontic device includes teeth-attachment unit attached to an orthodontic tooth object; and hook member provided in the teeth-attachment unit and having a connection part of traction unit for orthodontic treatment that is located in the vicinity of a center of resistance (CR) of a tooth. In addition, the orthodontic device includes teeth-attachment unit; and hook member provided in the teeth-attachment unit and having a connection part of traction unit for orthodontic treatment that is located in the vicinity of at least gingiva. Since the teeth-attachment unit of a bracket or a button is substantially horizontal to a traction line of the traction unit, it is possible to perform the orthodontic treatment effectively without eccentric phenomenon in which the tooth and a dental root are tilted.

Abstract: A system to manufacture orthodontic appliances, program product, and associated methods are provided. An embodiment of a system can include a virtual orthodontic appliance design computer having orthodontic appliance design program product provided to design a virtual dimensional representation of an orthodontic appliance including bracket bodies and bracket pads, and a mold apparatus positioned to form each bracket body and bracket pad. The system also includes a data processing computer including computer-aided manufacturing program product provided to derive electrical discharge device control instructions including a virtual dimensional representation of a bracket slot in the bracket, and an electrical discharge machining apparatus. The electrical discharge machining apparatus can include a controller including control program product to derive a control signal carrying the electrical discharge device control instructions and an electrical discharge device.

Abstract: A ceramic orthodontic bracket assembly for attaching an arch wire to a tooth of the invention includes a bracket body made of a first transparent or translucent ceramic which consists essentially of a monocrystalline alumina. The bracket body has a mesial-distal channel formed therein, and a generally rectangular liner made of a second transparent or translucent ceramic is disposed in the channel. The liner has occlusal and gingival side walls forming an archwire slot therebetween. Means such as brazing or adhesive are provided for bonding the liner in the channel in which it is configured to closely fit.

Abstract: A ceramic bracket has mesial and distal sections that are initially spaced apart from each other by an elongated channel. The bracket is debonded from a patient's tooth at the conclusion of treatment by pivoting one or both of the mesial and distal sections in an arc about a reference axis extending in a direction generally parallel to the channel. The bracket includes a recess that extends across a base of the bracket in generally parallel relationship to the channel. The base of the bracket has an aspect ratio that is less than about 0.95 and enables the bracket to be debonded with less force than might otherwise be necessary.

Abstract: This invention discloses a method of bonding FDA approved pigmented polymeric film forming coatings onto the surface of metallic orthodontic tools and appliances. In the preferred embodiment, stainless steel orthodontic brackets are coated with a functionalized coating that bonds to the metal surface and reacts with the molecules present at the surface as well as functional groups present in the coating formulation. In the present invention, the pigmented coating can be any polymeric material with epoxy, phenolic, carboxylic acid, urethane, or acrylic functionality able to form a continuous film upon curing.

Abstract: An orthodontic connector assembly (10) including a plurality of substantially identical connecting members, such as members (12), (14) which include a movable but biased portion (20) which is adapted to selectively and removably receive a pocket portion (44) which is deployed on at least one bracket, such as bracket (40).

Abstract: An oral mucous membrane protector for orthodontic appliances formed of a protective element or member arranged on the distal end of the archwire that projects from the molar tube, covering or enveloping the archwire and fixing it to the molar tube by means of an elastic ring joined to the protective element. The protective element may be reinforced on the bottom thereof so as to prevent tearing or perforation.

Abstract: The present invention relates to an orthodontic implement removably attached to a lip protector adapted to cover an orthodontic appliance for correction of irregular alignment of teeth having orthodontic brackets attached on the faces of teeth and orthodontic wires and ligature wires adapted to apply an orthodontic force to the teeth by their elastic forces, so as to reduce the likelihood of the occurrence of the harmful stimulus applied to the interior of lips, wherein the orthodontic implement includes an orthodontic tube removably attached to the lip protector so as to transmit an orthodontic force applied from the pushing force applied from the lips to the teeth and having locking protrusions formed at the upper and lower end portions of an opening formed on the rear side thereof, such that the pushing force applied from the lips or tongue is transmitted to the teeth, thereby accelerating the orthodontic force.

Abstract: Self-ligating orthodontic brackets with archwire retainers formed of materials exhibiting shape memory. Each bracket which includes a base from which extends two spaced and opposing pairs of tie wings each pair of which define an archwire guide slot therebetween. The retainers include at least one flange to retain an archwire within the archwire guide slot but which is yieldable to permit insertion and/or removal of the archwire relative to the archwire guide slots. Portions of the brackets and/or retainer may be coated to reduce friction between the archwire and the bracket and to promote aesthetics and overall bracket appearance.

Abstract: Low profile self-ligating orthodontic brackets and methods of using such orthodontic brackets. The bracket includes a bracket body, a latching member, and a hinge pin pivotally coupling a hinged end of the latching member with the bracket body. The hinge pin, which is made of a resilient material, is configured to flex so that a portion of the latching member can be engaged with a recess defined in the bracket body to couple the non-hinged end of the latching member with the bracket body.

Abstract: There is disclosed an assembly comprising: a brace for correcting the position of teeth and/or molars, and an ornamental element. The assembly comprises an ornamental element which is provided with means for engagement with the brace. The engaging means are provided with one or more toothings configured to be detachably clamped to the brace, in particular to the part of the brace that is present between adjacent teeth.

Abstract: The presently disclosed and claimed invention is directed to anti-microbial orthodontic apparatus and anti-microbial orthodontic compositions comprising an effective amount of a selenium compound, kits containing same, and methods of producing and using said anti-microbial orthodontic apparatus and anti-microbial orthodontic compositions.

Abstract: The invention relates to the use of a sintered body obtained by subjecting a primary sintered body having a relative density of 95% or higher produced from a fine yttria-containing zirconia powder to HIP sintering at a temperature of 1,200-1,600° C. and a pressure of 50 MPa or higher. This sintered body is either a sintered body which has a total light transmittance, as measured at a thickness of 0.5 mm, of 43% or higher and a three-point bending strength of 1,700 MPa or higher or a zirconia sintered body which has a total light transmittance, as measured at a thickness of 1 mm, of 40% or higher and a three-point bending strength of 500 MPa or higher and which combines high strength and total light transmission.

Abstract: Force magnitudes and/or directions may be determined objectively using orthodontic brackets having an elastomeric member which allows one portion of the bracket to be resiliently moveable relative to at least on other portion of the bracket. In a preferred embodiment, the brackets include a lower base member, an upper bracket member, and an elastomeric layer interposed between the lower base and upper bracket members. The orthodontic bracket is advantageously employed as part of a system whereby the orthodontic bracket includes a force indicator which distorts in response to relative movement between the at least one and other portions of the bracket to provide an indication of force applied to the bracket. An optical detector may be provided to optically detect the indicator and issue an output signal indicative of the relative resilient movement between the lower base and upper bracket members.

Abstract: A bell-mouthed active wing bracket includes an immovable wing (11) combined with a bracket holder (1) and a movable wing (2) pivotally disposed on the bracket holder (1) by sliding. A “-” shape groove is formed between the immovable wing (11) and the movable wing (2). The space of the groove is adjustable. The interface plane of the “-” shape groove and the immovable wing (11) or the interface plane of the “-” shape groove and the movable wing (2) are declining. The two interface plane which are formed by the “-” shape groove intersecting with the immovable wing (11) and the movable wing (2) are declining, in order to form a bell-mouth, the top end of which is big and the bottom end of which is small.