This patent application refers to a mechanical equipment that, when used in conjunction with a device to determine the position of the superior arcade of the patient, based on landmarks on the skull of the same, allows accurate reproduction of the position of the dental arches, represented by plaster models and simulation of mandibular movements. These models are connected to the equipment, through a unique positioning mechanical system, eliminating the use of plaster to fix the same.
The invention, now required, includes features of the equipment currently called “articulator” and “face-bow” and adds new features in an unprecedented and innovative way.
The set of the equipment presented in this patent application is light weighted, and for its simplicity, its cost may be lower than any of the equipment with equivalent functionality on the market.
The total process time can be reduced by up to 50%, depending on the ease of handling. Its guide system makes the reproduction of mandibular movements very accurate, avoiding errors in diagnosis and treatment.
In this way, we eliminate the barriers that make the current equipment being less used, obtaining relevant gains in time and cost and greater flexibility in scope and possibilities of study and planning dental treatment.
There are, in the current state of the art, various appliances and equipments used in dental treatment within the same scope of the present invention.
We can cite, for example, U.S. Pat. No. 7,048,539 which refers to an anatomical protractor bow, with the aim to take the correct position of the arcade of the patient in relation to the skull base to the articulator, using the anatomical points of reference.
U.S. Pat. No. 6,109,917 refers to a dental device that determines a specific aesthetic reference plane for mounting the patient's teeth. The device includes a face-bow, a relational set nose, a level gauge and a bite fork.
U.S. Pat. No. 5,632,619 refers to a face-bow for receiving and transferring an arcade model to an articulator, in the correct spatial orientation on the skull of a patient and the axis of temporomandibular joint. The face-bow transfer element has a curved face to engage the patient and a guide column pivoted to the transferring element, to support an adjustable bite fork. The transfer element has an elongated groove centering guide and the column has an adjustable projection, which is perpendicular to the column guide to fit the slot centering.
U.S. Pat. No. 5,090,901 refers to a support with a vertical column, to hold a face-bow, a bite fork with moldable material to obtain the impressions of the cusps of the teeth of the patient, elements plug headset to be positioned in to the patient's ears, and an indicator of fit the lips. The face-bow can be removed from the support and adapted to an articulator.
The patent application BR 8502218-7 refers to a device with three-dimensional adjustment system for quick fixing of plaster models on a dental articulator that already exists on the market.
The first researchers who noticed the importance of knowledge of the dynamic of TMJ (temporomandibular joint) and mandibular movements in occlusion, understood the need to create a device that could simulate the TMJs function, position the plaster models and reproduce the mandibular movements on a satisfactory occlusion.
The articulator is a mechanical instrument that represents the temporomandibular joint, and superior and inferior maxillary arcades, represented by plaster models. The articulator records the inter-maxillary relations and the mandibular activity is reproduced by the movement of the upper arm.
The articulator is one of the most important instruments used by the dentist, when treating their patients, being used with three primary goals:
The articulator may be: Non-adjustable, Semi-Fully-adjustable or fully-adjustable.
The Non-adjustable articulators, called “hinges” are considered the simplest instruments, allowing only the opening movement and arbitrary closure, preventing, for example, the eccentric mandibular movements. The occlusion limitations of the equipment requires, from the professional, to spend considerable time adjusting the prosthetics elements of treatment installed in the patient, until they are free from interferences. Another limitation is the impossibility of using the face-bow for any of these instruments. This type of articulator is responsible for many problems related to prosthetic occlusal interferences, which result in injury to the patient's stomatognathic system.
The Semi-adjustable articulators are designed to replicate some mandibular movements, supporting the diagnosis, treatment planning and the manufacturing of various components of treatment, allowing, usually, three types of adjustment: inter-condylar distance, condylar trajectory and Bennet angle.
Several studies and authors have demonstrated that the semi-adjustable articulators, when used correctly, are very useful in daily practice, reducing the time of many clinical procedures as a result of good planning. Standard angles can also be useful in reducing the whole time procedure.
The Fully-adjustable articulator, which provides more precision in reproduction of mandibular movements, have more complex systems, and are indicated for cases of great specificity. Its technical difficulty of handling and high cost of equipment causes them to be less used.
The face-bow is an instrument used to record the spatial position of the patient's superior dental arch in relation to the skull and to transfer this registration to the articulator.
For the correct use of the set composed of articulator and face-bow, the following steps must be observed:
The complexity of current equipment creates a barrier to its use by dentists in their daily clinic. The process requires the handling of plaster for positioning the models (with the inaccuracies and difficulties of hardening time and the impossibility of changing the position) and it is uncomfortable to the patient. It requires a great assembly time, since the use of face-bow, filling casts, and mounting to the articulator until its use for treatment planning. The total time of the process may reach approximately 4 hours, generating a high cost to patients and dental professionals.
Another common problem is the inaccuracy of motion reproduction, because the upper branch must be handled by the professionals and can easily slide over the platforms guides, or even be detached from the inferior branch which could interfere in the final movement.
Additionally, the current devices are heavy weighted and with average purchase price very high.
We understand that a large proportion of dental professionals do not use these equipments because of those barriers, decreasing the quality of study and treatment.
In order to solve the disadvantages of the current prior art equipment as currently called “articulator” and “face-bow”, the present invention has the following features:
The patent application covers the functions of the equipments currently called “articulator” and “face-bow”, adding new functionality in an unprecedented and innovative way.
The set of equipment presented is light weighted, and for its simplicity, its cost may be lower than any of the equipment with equivalent functionality on the market.
The total lead time can be reduced by up to 50% related of the ease handling and does not wasting time to wait plaster harden.
In this way, we eliminate the barriers that make the current equipment, being less used, obtaining relevant gains in time and cost and greater flexibility in scope and possibilities of study and planning dental treatment.
According to
The support structure (1) comprises a cover (10), supported by two lateral structures (13), which in turn are supported across the lower base (12). The whole set of the lower base (12) comprises means for moving the inferior arcade which will be explained in details later.
This support structure (1) has all its surfaces opened, facilitating the visualization during the manipulation of the arm. The cover (10) has a prismatic quadrangular format with a hollow structure and it is fixed in the supporting structure(1), through a hinge with removable pins (14), placed in the rear, which allows its opening or closing movements, or the removal of the cover (10), by removing the pins of it. A notch (15) is located in the front of the cover (10) for receiving the horizontal rod (5) of the protractor (4). The spin button (16) for locking the vertical movement of the superior positioning/repositioning set (2) is located in the right lateral surface. A latch (11) is disposed on the right side of the cover (10) to allow the locking of it on the same support structure (1).
The base (12), has a prismatic quadrangular format, and is connected to the upper portion of the support structure (1), through its lateral structures (13). There is a fillister (40) in front of the base (12) of the support structure (1) through which the arm movement (9) is positioned.
As seen in detail in
In these tilting sets (17, 17a), shown in detail in
In the front of the base (12) there is the mechanism for the lateral-frontal movement (80) of the inferior arcade (
As shown in
The set for lateral-frontal motion (80) also has two side plates (86) in the form of a quarter circle. These plates have an indentation (87) that accompanies the circular edge and ends at the front of the plate in the form of two flaps (88) with threaded holes and, following the indentation, there are markings corresponding to the angles between 0-90 degrees. These flaps (88) slides through protruding tabs (89) arranged in front of the base (12), and has its sliding motion controlled by screws (89a) (
On the side plates (86), also slide plate guides (91) through the indentations (87), around the axis located at the apex of the side plates (86). A connection platform (99) provides the union between the plate guides (82.91).
Such disposal of the guide plates (91), sliding on the side plates (86), allows the lateral angular displacement of the arm movement (9).
The arm movement (9) has its structure in a “T” shaped form. The longer part is combined with a screw (23) with a head shaped as a knurled knob (18). In the body of the longest part, is a square hole (21) to receive the rod (27) of the positioning/repositioning set (2a), which is attached by tightening the screw (23). On the other side, stands a pin (51) with a ball on its end that is intended to be coupled in the guide plates (82, 91). At the perpendicular direction of the “T” shaped structure, there are protruding pins (46), with balls at their ends, to be embedded in the recesses (62, 63). The pin (51) rests on a spring (100) to allow a small displacement of the inferior arcade by pressing the arm movement (9).
It is observed in
The connector base of the plaster model is semi-oval shaped plate (3) with a rectangular cavity (31) with metal cladding and the dimensions needed to fit the magnet (30) system positioning. On its other face(the surface is composed of slots.
The protractor assembly (4) to the reference position comprises a flexible arch (4a) with rubber tips (32) at its ends and at its center stands one block (33) of rectangular shape which has a slot in the front side and under it, a nosepiece (34), consisting of an element in soft material with the anatomical shape to the human nose.
The horizontal rod (5) consists of a hollow prismatic bar, with a locking element (6) running through it. The horizontal rod (5) has scale markings engraved into their faces all along its surface.
The locking element (6) slides into the hollow interior of the horizontal rod (5). It has a prismatic shape with a threaded hole in its side in the horizontal plane. In the vertical plane has a square hole, to collect the positioning/repositioning set of the arc (7) which rod is locked by a screw.
The positioning/repositioning set of the arc (7) is similar to the superior and inferior positioning/repositioning set to the models (2, 2a). It consists of a set of two balls (24), encapsulated in a vertical cylindrical enclosure (25) which embraces the two spheres (24), exposing half of one in its upper portion and the other one on its lower portion, allowing them to slip freely without loosening. This receptacle has a slit (semi-open) that by a locking device (26) prevents the rotation of the spheres (24).
One of the balls (24) has a fixture like a rod with a threaded tip (27), which passes through the locking element (6). On one surface of the rod there is a marking, like a ruler for position reference. The other ball is fixed to a small rod that serves as a mechanism of union between it and a rectangular magnet (30).
The rod with a bite fork (8) is a rectangular stem with one end in a shape of a rectangular cavity (31) with the necessary dimensions for the coupling with the magnet (30) of the rod of positioning/repositioning set. At the other end of the stem there is an element in the shape of a dental arch on which the impression material, like wax or similar is set.
Functionality
This equipment is designed to reproduce the relationship between the superior and inferior dental arches, and the axis that crosses through the temporomandibular joints, which are responsible for all chewing and swallowing movements and phonation. The horizontal plane crossing the base cover (10) and the hinges with removable pins (14) of the equipment corresponds to a reference plane called the Frankfurt plane.
To initiate the process, the impression material is placed in the fork and is pressed against the superior teeth of the patient, obtaining this way, the marks of the cusps that will be used as reference to position the plaster model. The fork is held in position in the mouth while the spatial positioning system is coupled to it at its end.
The arc of the protractor (4) is then positioned in the patient, so that its edges with the rubber tips (32) touch the face in the region correspondent to the location of the TMJs.
The alignment of both ends is determined by a third point located in the anterior region of the face, just above the onset of nasal prominence where is upheld the support of the nose (34) present in the frontal region of arc (4).
At this time, the mechanism of the spatial position must be locked, by rotating the screw (26) of the receptacle (25) of the balls (24) and by locking the screw of the vertical rod (6), thereby determining a static position of superior arcade just to the reference plane, allowing the transfer of this position to the equipment.
The horizontal rod (5) of the protractor, that was embedded in the arc (4a) is detached and transferred to the device being inserted into a slot (15) provided for that purpose.
The plaster model of the superior arcade, which already contains the base connector (3), must be rested on the corresponding marks obtained in the impression material of the fork. The magnet (30) must be seated in the cradle connector (3) and the position of the vertical rod (27) and the system of spheres (24) are held and locked by means of corresponding screws (16, 26).
After the model is positioned, the horizontal rod (5) of the protractor (4) can be removed, allowing the positioning of the inferior model.
The wax plate which contains the marks of the patient bite (clinical step performed before the start of this whole procedure) is set to the superior arcade mounted in the equipment and the inferior model is now fit to it.
The inferior model, which already contains the base connector (3), is attached to the magnet (30) of bottom positioning system, adjusting the position of the vertical rod (27) and the system of spheres (24). Locking is accomplished by tightening the corresponding screws (18, 26).
The opening and closing movement of the arcades is played by opening the cover (10), which is allowed by the hinge pin (14).
The adjustment of the tilting sets (17, 17a) and the angulations of the central guide of the lateral-frontal motion set is made by relating the superior and inferior models to another wax plate, now with the record of the patient's bite in situations of mandibular protrusion. Under this condition the protruding pins (46) and the anterior guide pin (51) make the plates (60, 61) with recesses (62, 63) and the central guide (81) to be inclined forward.
These positions are locked by tightening the screws (45, 85).
The protrusion movement can now be played by making the arm movement (9) walk on the plates (60, 61) with recesses (62, 63) and the central guide (81) well adjusted.
The adjustment of the inclination of the side plates (86) and the plate guides (91) is done individually, first to the right side and then to the left.
To do so, a wax plate, with the marks reproducing the cusps of the superior and inferior teeth during the closure of the mandible under the most extremely lateral position is set to the superior model. Then, the inferior model is guided to the marks in the bottom of the wax plate by sliding arm movement (9). The ball of the pin (51) that is partially retained within the guide plate (91), leads the right movement of this plate and determines the lateral inclination of the plate (86). This movement is locked by tightening the screw (89), that is connected to side plate (86), threaded through the holes of the front flap (88).
To adjust the left side, the same sequence of procedures is repeated, by using the wax bite plate corresponding to this side.
After the final positions of the sets of tilting (17, 17a) and the set of lateral-frontal movement (80) are determined, it is possible to accurately reproduce protrusion and lateral mandibular movements by sliding the arm movement (9) on the plates (60,61) with recesses (62, 63) and the side guides plates (91) and Central plate(82);
To start the movement is necessary to make slight pressure on the spring (100) pin (51), on the anterior region of arm movement (9), allowing the spheres on the ends of protruding pins (46) to rotate about their own centers, promoting a slight detachment from the arcades, freeing the movement.
Number | Date | Country | Kind |
---|---|---|---|
PI0904212-1 | Oct 2009 | BR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/IB2010/053391 | 7/26/2010 | WO | 00 | 8/3/2012 |