HK1090533B - Dental face bow - Google Patents

Description

Dental face bow

Technical Field

The present invention relates to a face arch suitable for use in dental treatment of edentulous jaws, lesser teeth, and the like.

Background

It is extremely important for denture base treatment or implant treatment of edentulous jaws and lesser teeth, etc., to give the artificial dentures and pontic teeth a desired occlusion. Traditionally, attempts have been made to understand the chewing movement of the lower jaw relative to the upper jaw, often by determining mainly the tissue form of the hard tissue in and around the buccal cavity and its mean value, together with several vertical reference lines and planes. In this case, in the actual treatment, dentists and technicians reconstruct the occlusion of each patient based on this ordinary chewing motion.

The above reconstruction of the occlusion of each patient by dentists and technicians is done by means of experience and intuition of the doctors and technicians, who lack references for the direction and strength of the strong clenching force at the time of actual occlusion, and therefore, it is generally difficult to quantitatively establish the ideal occlusion of each patient, thereby causing problems such as that it takes a considerable time and is subjected to many troubles for forming a denture base satisfactory to the patient.

To improve upon this problem, the present inventors focused their attention on the full force generated by the actual occlusion and determined it precisely, and developed a setting method for simply generating the ideal occlusion available in a short time, so that the complete denture base of each patient can be generated particularly effectively in a short time, and developed an occlusion device for use with a face arch suitable for use in conjunction therewith, which device has been patented (see Japanese patent application 2001-.

When using the newly developed occlusion device as described above, it is possible to establish an almost ideal occlusion in a short time with considerable ease as compared with the conventional method, and thus a good reputation is obtained in terms of practical treatment, but the face bow which is widely used at present is not satisfactory and requires considerable labor for practical use. The present inventors have focused their attention on that the resultant force generated by the maxilla and teeth of a typical human and the jaw closing muscle group connected thereto is applied only to a generally fixed site inside the skull bone, conducted many years of research and conducted many dental treatment cases, and found that the resultant force would be directed from a central point within an angle between the left and right portions of the maxilla to the central point of the anterior sinus canal without any moment of the biting force on both jaws. The object of the present invention is to provide a facebow which is suitable for establishing a desired occlusion on the basis of the principle of these forces and which is excellent in practice.

Disclosure of Invention

In order to solve the above problems, the present invention adopts the following structure. That is, a facebow according to the present invention includes: a base frame having a pair of left and right side frames along both sides of the patient's head and a laterally elongated frame interconnecting the pair of left and right side frames; and a rotating frame (rotation frame) rotatably supported by the base frame in such a direction as to approach or leave the face of the patient in the side frame (side frame). The face bow is characterized in that: a mouthpiece (mouthpiece) to be inserted into a buccal cavity of a patient is installed at left and right centers of a rotating frame, and, for the rotating frame, ear pieces are engaged near left and right ear holes of the patient and a reference point indicating means indicating a bite force concentrating part is installed near a nasal root of the patient, and a small piece (pat member) including a shaft part connected to the base frame and a base provided in an end part of the shaft part is provided at a center between left and right sides of the base frame. The frame must be placed symmetrically on the same plane at three points where the partial and bilateral mandibular angles (mandible angles) are concentrated.

As the above-mentioned mouthpiece, a reference member for measuring a tooth row curve (tooth row curve) of a patient or a bracket structure for fixing and supporting a wax limb (wax limb) installed inside a buccal cavity of a patient is attached. Here, both side portions of the rotating frame are preferably provided with a rotation indicating device which is rotatable with respect to the rotating frame and indicates the installation height of the rotating frame. Also, a nub is applied adjacent between the patient's eyebrows (eyebrow) and supports the base frame. As the small piece, in order not to damage the patient's skin when worn and moved, it is preferable that the small piece includes a pair of freely rotatable spherical members applied to both sides of the nasal ridge near the eyebrow portion of the patient.

The invention is characterized in that: a site of occlusion is formed, and attention is focused on the resultant force of the biting muscles generated during occlusion. That is, as shown in fig. 6, the muscles working at the time of occlusion are the masseter muscle Mm and the temporalis muscle Mt. The forces generated by these muscles are vectors having predetermined directions and numbers, and the resultant forces thereof are slightly different among individual patients according to the study of the present inventors, but as a criterion, as shown in fig. 7 and 8, it has been found that a point (a portion directly above the nasion) within the vicinity of the anterior edge portion of the anterior sinus is directed (will be referred to as "N point").

In fig. 7 in which the side surface of the head is drawn two-dimensionally, reference numerals P, Pa, Pb, and Pc denote the starting point of the masticatory force, the occlusal point of the anterior teeth, the occlusal point of the posterior teeth, and the condylar point, respectively. In the drawing, the resultant force of the biting point Pb applied to the posterior tooth and the biting force applied to the condylar point Pc is a vector having an L direction as shown in the drawing, and the relationship between these forces and their resultant force F from the center between the right and left mandibular angles from the middle point of the left and right mandibular angles is shown in the following equation. The reference symbol "o" indicates the above-mentioned N point.

N₁ Sin θ₁＝N₂ Sin θ₂

N₁ COS θ₂+N₂ COS θ₂＝F

2N₁ COS φ₁·Sin θ₁＝2N₂ COS φ₂·Sin θ₂

2N₁ COS φ₁·COS θ₁+2N₂ COS φ₂·COS φ₂＝F

Further, it has been found that the resultant force at the time of occlusion of all patients does not always point to O (N point), and the point at which the resultant force points at the time of occlusion is gradually close to the P point side in a line L (referred to as "resultant force" or "vector axis") connecting the above-mentioned N point and a point P of the mandibular angle (angle of the lower jaw), which is the aging and absorption of bone due to aging or the like.

Thus, if a circle (actually a ball) is drawn with the point on the resultant line L (the position of which is slightly different in the cases) as the center, each bite point in the ideal bite must lie on the circle. The present invention has been completed on the basis of this knowledge, and an ideal occlusion is obtained by producing a denture base on the basis of the above-described circle for chewing vector balance.

Drawings

Fig. 1 is a perspective view of an example of an occluding device of the present invention, fig. 2 is a side view of the device, fig. 3 is a plan view of the device, fig. 4 is a front view of the device, and fig. 5 is a rear view of the device.

Fig. 6 is a side view of the skull showing the biting muscles, fig. 7 is a two-dimensional side view of the skull showing the resultant force of the biting forces, and fig. 8 is a front and side view of the skull showing the direction of the biting forces.

Fig. 9 is a plan view, fig. 10 is a front view, fig. 11 is a side view and fig. 12 is a perspective view showing how the face bow is used.

Fig. 13 is an explanatory view of a method of holding a wax limb to the facial arch, and fig. 14 is a plan view of a base supporting the facial arch.

Fig. 15 is a perspective view showing a state in which the wax limb has been mounted on the occluding device.

Fig. 16 is a plan view (a) and a perspective view (b) of a tooth unit.

FIG. 17 is a plan view of a denture base.

Fig. 18 is a plan view of the small block, fig. 19 is a front view of the small block, and fig. 20 is a perspective view of the small block.

Detailed Description

The following description is made specifically on the basis of the embodiments of the present invention shown in the drawings. First, an example of an occlusion device suitable for use with a facebow relating to the present invention for producing a denture base is shown in fig. 1 to 5. This articulating device 1 comprises a base part 2 arranged on a plane, a support body 3 provided for standing in the rear end part of the base part 2, and a mandibular support 4 provided in the front end part. The mandible support 4 is mounted on the base 2 such that the longitudinal position thereof, as well as the angle of inclination of the articulator relative to the central axis in longitudinal operation of the shaft 6, is adjustable. Reference numeral "5" in fig. 5 denotes an arch support device for supporting a conventional facebow, which is not required in the case where the facebow of the present invention is used. Here, the face bow relating to the present invention is used as a vector analyzer capable of analyzing the occlusal force.

The supporting body 3 includes a pair of left and right frames arranged in parallel with a gap, and a rotating member (moving rear supporting body) 7 is supported in the gap portion of the supporting body 3 so as to rotate it by a shaft 10. A handle 10a corresponding to the temporomandibular shaft 10 is provided to be fixed to the left and right sides of the rotation member 7, respectively, and engaged with the long hole 8 provided laterally in the support body 3 in a movable manner in the length direction. A portion which is brought into engagement with the ear portion of the facebow is attachable to the end portion of the above-mentioned handle 10 a. The bolt 11 is a longitudinal position adjusting structure that determines the longitudinal position of the shaft 10, and is provided in the left and right sides of the supporting body 3 and elastically urges the shaft 10 by springs provided in the long holes 8, respectively. The upper portion of the above-mentioned rotating member 7 is curved in the forward direction, and the lower portion is provided with a supporting post 7 b. The backward movement of the post of the rotation member 7 is restricted by the shaft 15, and the rotation of the rotation member 7 is held to be restricted by the shaft, so that the rotation of the rotation member in the vertical direction is held within a predetermined angle.

Wherein a spring provided in a long hole 16 in the length direction in the support body 3 always presses/biases the shaft 15 backward. Shafts 15 are provided in the left and right portions with which the direction of the rotating member can be adjusted. The upper front side of the rotating member 7 is coupled to a model (cast) of an upper jaw, so that a rotating force works in a counterclockwise direction of fig. 11 depending on the weight of the model, but its rotation is restricted by the shaft 15 and the vertical inclination angle is maintained at a predetermined angle. On the other hand, a rod 25 is inserted into the rotation member 7 in the vertical direction. The rod 25 is a double structure including an outer cylinder 26 and an inner shaft 27, the inner shaft 27 being supported to be vertically adjustable in position and rotatable about an axis, and being vertically rotatably connected thereto to an arm 30 by a shaft 31. Reference numeral "28" denotes a spiral knob which fixes the outer cylinder 26 and the inner shaft 27.

The arm 31 is length-adjustable and its free end is provided with a circular arc shaped peg (snap curve) 35. When the spikes 35 are attached to an arm of the occluding device, each of the above spikes 35 accompanies the arm within a predetermined length, which is designed to fit a radius of the arc. In which a number of sets with arms (and pegs 35) of different lengths are preferably prepared, ready for appropriate exchange according to the patient's posture or age.

The forwardly protruding front end portion of the above-mentioned rotation member 7 is provided with an upper jaw supporting part 40. Wherein magnets 45 for attracting and fixing a model (model) in which a steel member is embedded are attached to the lower plane of the upper jaw support part and the upper plane of the lower jaw support 4.

Next, an embodiment of the facebow of the present invention shown in fig. 9 to 12 will be specifically described. The facebow 100 includes a base frame 101 made of a material having some degree of rigidity and strength, such as metal, plastic, etc. The base frame 101 includes a pair of left and right lateral brackets 102 and 102 provided on left and right sides of the head of a patient, respectively, and a lateral bracket 103 interconnecting the left and right lateral brackets, and is formed substantially like a square support. The lateral support is used as a side plane vector axis representing the direction of the force at the time of occlusion in a lateral view.

As for the base frame 101, shafts 106 and 106 are rotatably connected to a rotating frame 105 shaped substantially as a square support body. The lateral support 105a of the revolving frame 105 is provided with a movable bracket 107 along the lateral support, to which a locking nut 108 is connected. This bracket 107 and the lock nut 108 enable to set the swivel frame 105 in any angular position with respect to the base frame 101. That is, the bracket 107 is moved and the contact point to the bracket 115 to be described later is changed, thereby setting the angle of the rotating frame 105.

The connection member 110 for fixing the mouth is fixed to the center of the lateral bracket 105b of the rotating frame 105. A reference member 112 (mouth) of a tooth row curved body (tooth row curve) is connected to the connecting member 110 with a fixing structure such as a bolt. By this tooth row flexure datum 112, it is meant that the datum is selectively attached with many different shapes and sizes.

Here, the rotating frame 105 is attached to a position adjusted for the patient with screws screwed to a plurality of screw holes 115a, … … provided in the brackets 115 and 115 fixed to the base frame 101. Further, rotating frame height indicating devices 117 and 117 rotatable with respect to the rotating frame 105 are attached to both sides of the rotating frame 105. The end portion of this indicating means 117 is provided with an indicating pin 118. By connecting the rotating frame 105 to the base frame so that the trajectory of the above-mentioned indicator pin 118 will remain within a predetermined range, i.e. between the auricular foramen of the temporal part of the patient's head and the condyles, when the indicating means 117 is rotated, the corresponding tooth row curve can be measured. Reference numeral "119" denotes a holding member that fixes the pointing device 117 to the rotating frame 105. If the indication pin 118 of any size is out of a predetermined range, the pointer 0 of the reference point indicating means 131 is placed on the axis (center line) of the sagittal and fine-tuned, and then the identification of the size of the indication pin 118 indicating a predetermined range becomes possible.

A bracket 130 is fixed on the center of the lateral support 103 of the base frame 101. Connected to this bracket 130 are: a fiducial point indicator 131 for correctly mounting the base frame 101 on the patient's head and adjustable in protrusion length and a small block 132 applied near and supporting the base frame 101 between the patient's brow and vertically adjustable in position. A plate-shaped small block contacting the skin of a patient can be moderately bent according to the fact that the small block is in contact with the skin of the patient when it is mounted on the face of the patient, and thus a small block made of a rotating ball structure shown in the drawings is preferably used as the small block member 132. At least the small block 132, a plate-shaped base 134 is provided at the distal end portion of the shaft portion 133 attached to the base frame 101, and a pair of left and right support shafts 138 are attached to the base 134 so as to intersect (substantially perpendicular to) the shaft portion 133. A pair of left and right turning spherical structures 136 and 136 are rotatably supported by the respective support shafts. Wherein the base 132 is preferably connected to the shaft portion 133 by a pin 137 so as to be rotatable.

The above-mentioned reference point indicating means 131 is used to indicate a position (N position) where the resultant force when the patient bites intersects the surface of the patient's frontal bone, since it is found that this biting force concentration portion is generated for the middle point of the base frame between the angles of the left and right lower jaws and that this portion is located near the upper portion of the nasion of the human head where the base frame is installed, thereby indicating that the middle point between the patient's left and right eyebrows will actually function.

Further, the lateral brackets 102 and 102 in both sides of the basic frame are connected to the earpiece supports 135, respectively, which protrude in a direction perpendicular to the lateral brackets. The earpiece support 135 is adjustable in its protruding length, and its end portion is connected to an earpiece 140 extending in the direction perpendicular to the support 135. The earpiece 140 is a piece having a smooth end portion and wherein the frame 101 is capable of being supported on the head of a patient by insertion into an ear canal of the patient.

The facebow 100 is mounted to the patient's head with the nubs 132 and ears 140 described above, but this mounted state will be one in which the lateral supports 102 of the base frame 101 overlap the projected line viewed from the side of the bite force vector axis. That is, the connection is made on the patient such that the planes defined by the two lateral supports 102 and 102 overlap the direction of the resultant force. In this state, the rotating frame 105 is connected to the base frame 101 and the rotating frame 105 is rotated, so that the mouthpiece connected to the rotating frame 105 can be inserted into the buccal cavity of the patient, and the patient's teeth can be checked with the reference member held in the mouth of the patient, which can be held fixed to the face bow 100 by the rotating frame, or the wax limb. The angle of the rotating frame 105 fixing/holding the wax limb to the base frame 102 is determined so that an optimal bite situation can be reproduced.

Fig. 12 shows a state in which the facebow 100 is mounted on the head of the patient in a lying state. This face bow is partially slightly different from the face bow shown in fig. 9 to 11, but the basic structure is the same. Fig. 12 shows a state in which the reference member 112 is inserted into the buccal cavity and the dental curve of the patient is investigated. A rotating frame is arranged relative to the base frame to which the wax limb securing/retaining structure (numbered 145 in figure 13) having a steep end portion in place of the reference piece 112 and the wax limb 200 held in the mouth of the patient are secured.

Next, a method of producing a denture base for a patient using the occluding device 1 and the face bow 100 will be briefly described below.

First, a substrate is produced by known methods. The method of producing the substrate is: the impression agent is first placed on a predetermined tray and the shape of the upper and lower teeth and gums of a patient is taken for impression. From this impression, plaster of paris is flowed into and made into a plaster of paris model. On this plaster of paris model, a resin base is made and wax is used to create the approximate upper and lower wax limbs (alveolar ridges or wax ridges).

This wax limb (wax ridge) 200 is inserted into the buccal cavity of the patient and allowed to actually bite into it, determining the central position of the upper and lower jaws. In a state in which the wax limb is held in the mouth, the upper and lower wax limbs (wax ridges) are brought together with each other. In this state, the affinity is adjusted by buccal mucosa or outlook (outlook), etc., to attach the wax ridges to the face bow 100. As for this connection, on the front surface of the wax ridge 200 provided inside the buccal cavity of the patient, the wax limb fixing/holding means (bite fork) is pressed, the steep end portion is inserted into the wax limb and fixed, and, for bite transfer, the angle to the lateral support 102 is kept constant by the lock nut 108 for the fixing bracket 107.

Next, the facebow 100 is removed from the patient and the facebow is retained by a facebow base 150 as shown in FIG. 14. Since this facebow 150 is provided with the concave portions 151 and 151 engaged with the lower end portions of the lateral brackets 102 of the base frame 101, these concave portions 151 are engaged with the lower portions of the lateral brackets 102 and 102, so that the facebow 100 can be supported in an upright state. The substrate is placed on a horizontal surface such as a table plane, and the lateral support 102 representing the lateral vector axis is supported in a vertical position.

As for mounting the face bow 100 to the articulator 1, the articulator 1 is placed between the lateral brackets 102 and 102 of the above-mentioned vertically supported face bow 100, with the wax limbs for the upper jaw supported by the face bow 100 being brought close to the upper jaw support section 40 of the articulator. In this case, the rod 25 representing the vector axis of the articulator 1 is vertical, and therefore corresponds to and is well suited to the reference point indication structure 131 (vector axis position) shown in the facebow of the lateral support 102 supporting the basic frame vertically on a vertical line. The plaster of paris is flowed into the upper side of the wax limb and solidified to produce a plaster of paris model. Fig. 15 shows a state in which the plaster model is attached to the engaging device 1. The occluding device 1 shown in fig. 15 is a device designed to fit a facebow 100 of the present invention and is shaped somewhat differently than the devices described above, but the basic structure is the same as the devices described above, with like reference numerals designating corresponding parts.

On the other hand, since the distance between the position where the incised edge of the central incisor of the patient's mandible contacts the underside of the central incisor of the maxilla and the N position (the maximum radius of curvature of the patient) has been determined by the facebow, according to this distance, a curve is drawn in the wax limb (wax ridge) which will be combined by the upper and lower jaws fitted in the bite device by the spikes 35 of the distal part of the above-mentioned arms. At this time, the shaft portion 25 of the support arm 30 is rotated about its shaft center, and the arm 30 is supported so as to be rotated about the shaft 31 as a center, thereby causing it to be rotated about the shaft 31 as a center and being able to draw a three-dimensional circle on the wax ridge. The position of the shaft 31 supporting the arm corresponds to the N position, and the circle drawn represents the occlusal curve (occlusal curve) of a patient. The arm 30 is three-dimensionally pivotally connected to the shaft portion 250 with an adjustable joint.

Here, the skull of the patient is different from person to person, and the ideal occlusion is obtained by appropriately adjusting the length of the arm 30 in the occluding device 1, the shape and size of the nails 35 (it is convenient to prepare a variety of nails in advance and exchange them appropriately), the longitudinal position and vertical inclination angle of the rotating member 7, the longitudinal position of the mandibular support member 4, the longitudinal position of the maxillary support member 40, and the like.

The upper and lower wax ridges are accurately vertically separated along the drawn occlusal curve. Thereafter, the artificial denture is attached to the upper and lower wax ridges along the circle. In particular, the thread of the artificial denture on the maxillary side is placed on the wax ridge of the mandible and temporarily fixed. On the other hand, wax ridges of the upper jaw were washed with hot water to expose the resin matrix. The gap between the tooth row and the resin is temporarily fixed with a resin on the engaging device 1. Thus, only the upper jaw is removed from the occluding device, after which the resin is flowed into the gap and the rows of teeth as a unit.

Secondly, the tooth row of the lower jaw is fixed, which, as far as this is fixed, only has to be arranged and fixed in correspondence with the upper jaw described above. The procedure is generally similar to that described above for the maxilla. Thus, a denture base in which the base and the denture row (dental row) are integrated is obtained. The denture base is subjected to the necessary finishing, such as polishing, etc., to form a product.

Incidentally, if the face bow of the present invention is used, it is not necessary to take a specification photograph of a temporal region of a patient's head, but in some cases, a head specification photograph may be taken and used as a reference. Further, as a simpler method, instead of using the head specification photograph, upper, lower, left and right artificial dentures are temporarily fixed in central incisor portions of upper and lower alveolar ridges (wax ridges) transferred from the inside of a buccal cavity of a patient, and the patient is accurately bitten, and the height and angle of the artificial dentures are adjusted to the most appropriate state for the patient. When the ideal occlusion is obtained, the occlusal curve can be obtained that is appropriate for the patient through the sum of the contact points of these several artificial dentures and the two temporomandibular anterior flanges.

That is, on the basis of the jaw model transferred from the inside of the buccal cavity of the patient, the base portion of the denture base to be mounted to the jaw of the patient is produced, and a plurality of artificial dentures appropriate for the patient are fixed to an aesthetic position in the anterior tooth portion of the maxillary ridge made on the above-mentioned base portion inside the buccal cavity of the patient, thereby determining the inherent radius of curvature on the basis of these plurality of artificial dentures. Also, the denture row is fixed/integrated in accordance with the size of a circle on the ridge structure drawn by these radii of curvature, so that a desired denture base can be obtained. For measuring the circle and determining the radius of curvature, the arms and the nails of the snap device 1 can be used.

Second, in the method of producing the above-described denture base, a large number of artificial dentures must be attached to the wax ridge along the occlusal curve, and thus complicated work and skill requiring a considerable time are indispensable.

If this work is simplified, the production of the denture base becomes considerably simple, and the production cycle can be shortened to a large extent. An improved production method which can achieve this simplification will be described below.

In this modified method, a portion for a denture base (tooth row unit) 70, which is disposed along a different occlusal curve (occlusal surface curve) and fixed to a ridge structure of the base portion, is produced in advance. Fig. 13 illustrates a tooth row unit 70 that is for this portion of the denture base, in which dentures T, … … are fixed on the ridge structure P along the occlusal curve. The occlusal surface curve for the alignment of the dentures of the tooth row unit 70 is different according to the age and posture of the patient, and the dentures themselves have many types, so that the patient can select the optimum one, and the type of the tooth row unit is preferably as many as possible. However, the number of types is increased too much, stock will be increased, management is troublesome, etc., which is not economical, and therefore the number should preferably be as small as possible within a range that can accommodate variations in occlusion of a patient. The type of tooth row unit as a part for denture base is preferably about several tens of types at present, and actually, about 30 to 50 types will be appropriate.

In the above-described existing section for the denture base (tooth row unit), the optimum one is selected in consideration of the preference of the patient. The selected tooth row unit is attached to a base 80 (shown by a chain line in fig. 13) produced on the basis of the model taken out of the cheek cavity of the patient. In this case, a tooth row unit having a curve adapted to the occlusal curve of the patient selected from the above-mentioned plurality of tooth row units is disposed on a straight line intersecting the curve, the curve passing through a point in the central portion of the condyle to a point closer to the auditory meatus and 2 to 3 mm away therefrom, on a three-dimensional X-ray diagram of the temporal region of the head of the patient on an intrinsic dental arch plane determined inside the buccal cavity of the patient, and the tooth row unit is further fixed on the above-mentioned base portion. The specific fixing procedure is as follows. First, the models with wax ridges vertically divided along the occlusal curve are installed in the above-described occluding device 1, and the upper tooth row unit 70 is installed so as to fit the lower teeth thereof.

Next, wax of the wax ridge of the upper jaw is removed and only the upper plastic base 80 is installed aside, and a high quality resin for immediate polymerization of the teeth is flowed between the plastic base provided in the lower jaw side and the tooth row unit 70 to be polymerized. Thus, a denture base 90 in which the plastic base and the denture row are integrated as shown in the drawings is obtained.

According to this simplified method of preparing the denture base, the operation of implanting the denture on the base 80 produced according to the shape of the inside of the buccal cavity of the patient is not required, and thus the denture base can be produced extremely efficiently. Further, the prepared tooth row is a tooth row with artificial dentures implanted along the occlusion curve in consideration of the occlusion force vector of the patient, so that a substantially ideal occlusion is obtained.

As is apparent from the above description, the use of the facebow relating to the present invention makes it possible to produce extremely efficiently the denture base which produces the best bite believed to be available for each patient. In the above description, the denture base made of resin is mainly described, but it is needless to say that the denture base made of metal can be produced by the same principle.

Industrial applicability

As is apparent from the above description, the use of the facebow relating to the present invention makes it possible to extremely efficiently produce denture bases that produce the best bite believed to be available for each patient. In the above description, the denture base made of resin is mainly described, but it is needless to say that the denture base made of metal can be produced by the same principle.

Claims (6)

1. A dental facebow comprising: a base frame having a pair of left and right side brackets along both sides of the patient's head and a lateral bracket elongated in the left-right direction to interconnect the pair of left and right side brackets; and a rotating frame rotatably supported by the base frame in such a direction as to approach or leave the face of the patient in the side frames;

the method is characterized in that: a mouthpiece to be inserted into a buccal cavity of a patient is installed at left and right centers of the rotating frame, and, for the base frame, the ear pieces are engaged near left and right ear holes of the patient, and a reference point indicating means indicating a bite-force concentrating part is installed near a nasal root of the patient,

wherein a small block member is provided at the center between the left and right of the base frame, the small block member including a shaft portion connected to the base frame and a base provided in an end portion of the shaft portion.

2. A dental facebow according to claim 1 wherein: the mouthpiece is a reference piece that measures the profile of the patient's natural tooth row.

3. A dental facebow according to claim 1 wherein: the mouthpiece is a mounting structure that holds/supports the wax limb mounted inside the buccal cavity of the patient.

4. A dental facebow according to any of claims 1 to 3, wherein; both side portions of the rotating frame are provided with a rotation indicating device which is rotatable with respect to the rotating frame and indicates the installation height of the rotating frame.

5. A dental facebow according to any of claims 1 to 3, wherein; the nub is applied adjacent to and supports a base frame between two brow portions of a patient.

6. A dental facebow according to claim 5, wherein: the base includes a pair of left and right spherical members which are applied to both sides of a nasal ridge in the vicinity of both brow portions of a patient and rotatably supported by a pair of support shafts attached to the base, respectively, in directions intersecting the shaft portions.