WO2009146930A1

WO2009146930A1 - Dental needles and methods of dental anaesthetics

Info

Publication number: WO2009146930A1
Application number: PCT/EP2009/004052
Authority: WO
Inventors: Ingrid Kersbergen
Original assignee: Ingrid Kersbergen
Priority date: 2008-06-05
Filing date: 2009-06-05
Publication date: 2009-12-10
Also published as: IES20090446A2

Abstract

A dental needle (25) for attachment to a dental syringe comprising a first portion (25a) aligned along a first axis ((25') and having fixed thereon a hub (27) for attachment to a syringe, and a second portion (25b) disposed along a second axis (25''), said first and second axes being non-aligned. The second portion (25b) is disposed along the second axis (25'') at an obtuse angle (y) relative to the axis (25') of the first portion (25a). A third portion (25c) extends forwardly of the second portion (25b) and is disposed along a third axis (25''') at an acute angle (z) relative to the axis (25'') of the second portion (25b).

Description

Dental Needles and Methods of Dental Anaesthetics

The present invention relates to dental needles and methods of dental anaesthetics for the injection of anaesthetic in dental procedures.

Dental needles have been widely used for many years and are used in the delivery of anaesthetic solution in the mouth for dental or oral surgical treatment. The needles are hollow with a sharpened bevelled tip and are supplied in various lengths. The known needles are used for the administering of local anaesthetic solutions to obtain infiltration and block anaesthesia in the oral cavity. The needles may be provided as various sizes and diameters, for example 27 or 30 gauge, are usually made from stainless steel and have a sharpened bevelled tip. The needles are usually supplied as disposable for single use and are supplied pre-sterilised. The needles usually have a plastic hub fixed thereon which is screw- threaded for securing onto a known dental syringe in conventional manner.

The syringe effectively comprises a barrel and a plunger, and the needle is screw-fitted to one end of the barrel. A cartridge containing an anaesthetic solution is placed into the barrel and a plunger is moved to expel the anaesthetic solution out of the cartridge and through the needle.

One of the difficulties with the known types of needles and the method of administering the anaesthetic is that, it can be very difficult for a dental surgeon to find a comfortable position in which to gently administer the anaesthetic. Patients for dental treatment are all of different sizes and have slightly differently shaped mouths. Also, a dental surgeon usually works adjacent or behind to one side of a patient but of course has to administer anaesthetic to different regions of the mouth and of course to both the upper and lower jaw areas. It can be difficult for a dentist to find a stable position around a patient's face and head to balance his hands and to do so when administering anaesthetic to different treatment regions. The known needles are all straight and do not readily facilitate the delivery of anaesthetic to a patient at various sites in the mouth which are curved and which are at completely different angular positions relative to the preferred or advisable working position of the dental surgeon.

According to the invention there is provided a dental needle for attachment to a dental syringe comprising a first portion aligned along a first axis and having fixed thereon a hub for attachment to a syringe, and a second portion disposed along a second axis, said first and second axes being non-aligned.

According to one aspect of the invention, there is provided a dental needle for attachment to a dental syringe and for use in administering an anaesthetic to the lower right vestibular jaw region comprising a first portion aligned along a first axis and having fixed thereon a hub for attachment to a syringe, and a second portion disposed along a second axis at an obtuse angle relative to the axis of the first portion, and a third portion extending forwardly of the second portion and disposed along a third axis at an acute angle relative to the axis of the second portion. Preferably, the second portion is integral with a front section extending forwardly of the hub and coaxial with the first portion and substantially parallel to the third portion. The third portion is in use arranged laterally closer to the lateral vestibular mucosa of a patient than the first section.

According to another aspect of the invention there is provided a dental needle for attachment to a dental syringe, and for use in administering an anaesthetic to the upper left vestibular jaw region, or the lower left jaw region comprising a first portion aligned along a first axis and having fixed thereon a hub for attachment to a syringe, and a second portion disposed along a second axis. Preferably the second portion is arranged along a second axis at an obtuse angle relative to the first axis. According to another aspect of the invention there is provided a dental needle for attachment to a dental syringe, and for use in administering an anaesthetic to the upper right vestibular jaw region comprising a first portion aligned along a first axis and having fixed thereon a hub for attachment to a syringe, and a second portion disposed along a second axis, a third portion disposed along a third axis at an angle relative to the axis of the second portion, and a fourth portion disposed along a fourth axis, at an obtuse angle relative to the third portion.

The invention further provides a method of administering an anaesthetic in a dental procedure comprising, providing a needle suitable for the administration of fluids having a sharpened bevelled tip and a bore therethrough, the needle being non-linear and having at least one patient portion disposed at an angle relative to a main portion, penetrating tissue with the needle tip such that the bevelled tip is disposed toward the outer boundary of the tissue, and administering an amount of anaesthetic to the tissue through the needle;

Preferably, at least a portion of the needle is shaped to conform substantially with the anatomy of the region of the mandible or maxilla which is to be anaesthetised.

Further preferably, the mouth of the patient will be closed, or substantially closed.

The needle should be placed onto the tissue with gentle pressure, after which the needle will be gently advanced into the tissue while constantly delivering some drops of the anaesthetic solution, creating the first small area of anaesthetic tissue.

The needle is then advanced further into the tissue and a further amount of anaesthetic fluid is administered.

Embodiments of the invention will now be described by way of example, with reference to the accompanying drawings in which; Figure 1 is a diagram showing the anatomy of the alveolar mucosa;

Figure 2 is a schematic view of a conventional dental syringe;

Figure 3 is a perspective view of a needle according to the invention;

Figure 4 is a diagram of a tooth and surrounding tissues illustrating the method for palatal/lingual anaesthesia according to the invention;

Figure 5 is a further diagram illustrating the method for palatal anaesthesia according to the invention;

Figure 6 is a right side perspective view of a model of the upper (maxilla) and lower (mandible) j aws of an adult human;

Figure 7 is a left perspective view of a model of the upper and lower jaws of an adult human;

Figure 8 is a perspective view of a needle, according to an aspect of the invention for use in the lower right lateral vestibular area;

Figure 9 is a perspective of a needle according to another aspect of the invention for use in the upper right lateral vestibular area of the maxilla;

Figure 10 is a perspective view of another needle according to the invention for use in the upper left lateral and lower left lateral areas and also the upper right front area; Figure 11 is a perspective view of the needle of Figure 8 in use in the lower right lateral vestibular area;

Figure 12 is a perspective view of the needle of Figure 9 of the invention in use in the upper right lateral vestibular region of the maxilla;

Figures 13 is a perspective view of the needle of Figure 10 in use in the upper left and lower left lateral vestibular regions;

Figure 14 is a perspective view of the needle of Figure 10 in use in the upper right front area;

Figure 15 is a perspective view of another embodiment of needle for use in the upper right lateral vestibular area of the maxilla; and

Figure 16 is a perspective view of another embodiment of needle for use in the upper left lateral and lower left lateral areas and also the upper right front area.

Referring now to the drawings, the dental needles and methods according to the invention will be described.

Referring first to Figure 1 there is shown therein the anatomy of the oral vestibular (alveolar mucosa). As shown, the region where dental anaesthetic is administered is in the mucosa and this area comprises a number of tissue regions including the epithelium 10, the prickle cell layer 11, the basal cell layer 12 and rete pegs 13 below which are the lamina propia layer 14 in which also nerve extensions and blood vessels 15 are located.

Also shown in Figure 1, a conventional dental needle 16 is straight or linear and which penetrates the tissue of the mucosa/gingiva through the various layers of tissue.

A needle 17 according to the invention is also shown in Figure 1 and is shaped to conform substantially with the anatomony of the region of the mucosa of the vestibular mandible and/or maxilla which is to be anaesthetised. Thus, the needle 17 has a bore therethrough and comprises a first portion 18 aligned along its axis 18a integral with a second or patient portion 19 aligned along its axis 19a which is arranged at an angle to the axis 18a so that the portion 19 can be readily positioned in use by a dentist substantially parallel with the gingiva. The needle 17 has a sharpened and bevelled tip 20, which as shown is in use disposed facing towards the outer boundary 21 of the gingiva/mucosa.

In use, the tip 20 of the needle 17 is inserted underneath the surface of the epithelium 10 and above or in the upper part of the lamina propia 14, the latter being the location of the nerves or nerve extensions in her deeper layers.

Since the needle of the invention is arranged to enter no deeper than the top layer of the lamina propia, contact with the nerve extensions is avoided and there is no or only minimal pain experience.

In contrast, the conventional needle is placed directly into the lamina propia which causes the tip of the needle to penetrate the deeper part of the lamina propia where the extensions of the nerves and capillaries are situated resulting in pain. The needle 17 has a screw threaded hub fixed thereon for attaching the needles to a conventional dental syringe (Figure 2). The needle may be provided in any desirable size or shape although a maximum of 30 gauge may be preferable. Various shapes of needles used for this procedure in different areas of the mandible and maxilla are described below and shown in the attached Figures.

In use, for bucal or labial anaesthesia in the alveolar mucosa, once the tip 20 of the needle 17 touches the mucosa (epithelium), it is gently pressed against the mucosa after which the needle will be gently pushed advanced, in a horizontal direction along the contour of the vestibular mucosa, into the mucosa while continuously delivering the anaesthetic solution . A small "balloon" or "bubble" will form in the epithelium which is visible to the dentist as a swelling. Anesthesia has now come into effect in the tissue. The needle 17 is then retracted and is then pressed into the bubble or balloon area and further drops of anaesthetic are delivered the balloon area increases in size and moves deeper and wider into the mucosa into the lamina propia. The area which is anaesthetised is therefore gradually extended, and the needle 17 is moved parallel to the vestibulum to numb the area one wants to get anaesthetised as drops of the fluid are deposited in the vestibular/alveolar mucosa ahead of the direction of the needle.

Initial trials indicate this procedure in combination with the needles shaped as described herein, provide a significant reduction in the pain experienced by patients. Also, as the bevelled tip 20 of the needle 17 is disposed toward the outer side of the tissue which is generally away from the location of the nerves and bone, there is a significant reduction in the pain experienced because the anaesthetic fluid then permeates it's way in a less pressurised way into the nerve area and tissue around the nerves.

Any reduction in pain experienced by patients in dental procedures is highly advantageous. In this method for bucal or labial anaesthetic in the alveolar mucosa, the patient may keep the mouth closed or substantially closed so that the tissues of the vestibular mucosa are loose and relaxed which has been found to further minimise the creation of pain when penetrating the mucosa with the needle. In conventional methods of anaesthesia, the mouth is open and often fully open so that the tissues of the gingiva are stretched tightly. The fact that the needles 17 are shaped, as described further below to correspond to the contour of the mouth assists in enabling the needle 17 to be placed at the location where injection is necessary without requiring the mouth to be fully open.

The invention also provides a needle and a method for palatal or lingual anaesthesia which should be carried out only after the bucal or labial anaesthesia described above. For this procedure the needle should be of a maximum of 30 gauge and should be of at least 12mm in length for adults.

A needle for this procedure is shown in Figure 3 which shows a needle 25 (x short) attached to a conventional dental syringe 26. The needle 25 is bent or formed at an angle X relative to the direction the needle exits the hub 27, with the bevelled tip 20 of the needle facing backwards towards to the direction of the hub 27.

The area 28 of the gingiva (Figure 4) to be penetrated is first anaesthetised as described above in bucal, labial anaesthesia. The patient keeps the mouth closed, and the needle 25 of Figure 3 is penetrated into the region 28 of the papilla bucal or labial. The gingiva/mucosa is already desensitised by the bucal or labial anaesthesia described above. The region 28 is in between a tooth A and an adjacent tooth (not shown), i.e. interdental.

Next one or two drops of anaesthetic fluid are delivered, and after a few moments the needle is pushed a further approximately lmm or so deeper into the tissue and further drops of fluid are delivered. This procedure is repeated slowly until the anaesthetisation is visible at the palatal/lingual gingiva 29 which indicates as an anaemic white colour in the tissue. The patient may then open the mouth to enable access by the dentist to the palatal lingual area 29. The direction of the needle 25 is then changed (STEP 2, Fig. 5) and the needle in this example, penetrates the palatal tissue in a downward direction, as shown in Figure 5 parallel to the anatomic structure and shape of the gingiva with a few drops of fluid being delivered ahead of the needle in intermittent steps. The needle 25 is thus advanced towards the Torus Palatinus or to the deeper lingual, until the needle meets the area which is required to be anaesthetised. It will be clear that the needle is advanced in a direction parallel to the bone structure. If required then the dentist can administer further anaesthetic in a way that the needle can penetrate more directly.

Referring now to Figures 6 and 7, there is shown therein right perspective and left perspective views of a model of the upper and lower jaws Jl, J2 respectively of an adult indicating the upper and lower left and right teeth 1-8. Also, illustrated in dotted outline are selected areas of the mucosa/gingiva where anaesthesia according to the method of the invention may be delivered, for example LR (Lower Right ), UR(Upper Right), LL (Lower Left), UL (Upper Left ), URF (Upper Right Front), ULF (Upper Left Front).

Referring now to Figure 8 there is shown therein a needle 25, for attachment to a dental syringe (Figure 2) comprising a first portion 25a aligned along a first axis 25 . The needle 25 has fixed thereon a hub 27 for attachment to the syringe (Figure 2) in conventional manner. The needle 25 has a second portion 25b aligned along a second axis 25 , with the first and second axes being non-aligned.

The needle 25 may be of any suitable gauge and preferably less than 30 gauge, and has a bore therethrough for the delivery of anaesthetic fluids. The needle has a sharpened bevelled tip 20.

As shown in Figure 8, the first portion 25a of the needle 25 extends slightly forwardly of the hub 27 with the hub 27 being fixed in conventional manner to this straight portion of the needle. The second portion 25b is disposed sideways along the second axis 25 at an obtuse angle Y relative to the axis 25 of the first portion 25a. A third portion 25c extends forwardly of the second portion 25b disposed along a third axis 25 at an acute angle Z relative to the second axis 25 . The second portion 25b is integral with a front section 25d extending forwardly of the hub and coaxial with the first portion 25a. The portion 25c is in use disposed substantially parallel horizontally, parallel to the mandible vestible to the gingiva whereas the portion 25b is disposed outwardly from the alveolar process and helps to avoid the lip of the patient.

As shown in Figure 11, the needle of Figure 8 is used for administering anaesthetic fluid to the mucosa in the lower right lateral region LR as described previously in relation to Figure 1. In use, the bevelled tip 20 of the needle of Figure 8 is arranged to face the outer boundary of the tissue of the mucosa, and the patient may have the mouth closed or substantially closed during the procedure. This enables the dentist to readily find parts of the mouth, in particular the frontal area to balance her hands and gain support for fingers, for example as shown at 50, to obtain stability.

Referring now to Figure 15 there is shown a needle similar to that of Figure 8. The first portion 25a of the needle 25 of Figure 15 extends slightly rearwardly of the hub 27 with the hub 27 being fixed in conventional manner to this straight portion of the needle. The second portion 25b is disposed sideways along the second axis 25 at an obtuse angle Y relative to the axis 25 of the first portion 25a. A third portion 25c extends forwardly of the second portion 25b disposed along a third axis 25 at an acute angle Z relative to the second axis 25 . The second portion 25b is integral with a front section 25d extending forwardly of the hub and coaxial with the first portion 25a. The portion 25c is in use disposed substantially parallel horizontally, parallel to the mandible vestible to the gingiva whereas the portion 25b is disposed outwardly from the alveolar process and helps to avoid the lip of the patient. It will be noted that the change in direction of the needle from one axis to another is generally a gentle curve C rather than a sharp change. This applies to all the various needles. With all of the needles, Figures 8, 9 and 10 the bevelled tip is arranged in use to face the outer boundary of the tissue.

Referring now to Figures 10 and Figures 13 and 14 there is shown a needle 25 for administering anaesthetic to the upper left lateral, UL lower left lateral LL and also the upper right front URF areas. The needle 25 has a first portion 25a having the hub 27 fixed thereon. A second portion 25b is disposed sideways along a second axis 25 . The axis 25 is at an obtuse angle relative to the first axis 25 Again, the shape of the needle enables a dentist to gain support for his fingers 50 with the patients mouth closed or substantially closed and also contact between the needle and the gingiva of the alveolar process. A third portion 25c extends between the hub 27 and the second portion 25b and is generally curved in an outwardly arcuate shape. This portion in use is shaped to conform to the alveolar process or the lower lip which is rather more curved than the lateral part. The portion 25b is in use disposed to be substantially parallel to the vestible whereas the portion 25c curves outwardly slightly away from the alveolar process, adjacent to the front of a patient's mouth.

Referring now to Figures 16 there is shown a needle 25 which is similar to the needle of Figure 10, for administering anaesthetic to the upper left lateral, UL lower left lateral LL and also the upper right front URF areas. The needle 25 of Figure 16 has a first portion 25a having the hub 27 fixed thereon. A second portion 25b is disposed sideways along a second axis 25 . The axis 25 is at an obtuse angle relative to the first axis 25 ^" Again, the shape of the needle enables a dentist to gain support for his fingers 50 with the patients mouth closed or substantially closed and also contact between the needle and the gingiva of the alveolar process. A third portion 25c extends along axis 25'" between a front section 25d and the second portion 25b and is generally straight or maybe curved in an outwardly arcuate shape. This portion in use is shaped somewhat to conform to the alveolar process or the lower lip which is rather more curved than the lateral part. The portion 25b is in use disposed to be substantially parallel to the vestible whereas the portion 25c projects outwardly slightly away from the alveolar process, adjacent to the front of a patient's mouth. As shown the axis 25'" intersects axis 25" at an obtuse angle.

Referring now to Figure 9 and Figurel2 there is shown a needle 25 for administering an anaesthetic to the upper right lateral area.

The needle 25 has first portion 25a having the hub 27 fixed thereon. A second portion 25b is disposed sideways along a second axis 25 at an obtuse angle relative to axis 25'. A third portion 25c is disposed at an obtuse angle Y relative to the second portion 25b and a fourth portion 25d is disposed upwardly at an obtuse angle relative to the portion 25c. The fourth portion 25d may be generally in line with the third portion 25c. As shown in Figure 12, the needle of Figure 9 is used in relation to the upper right lateral area, and again the shape of the needle 25 enables the dentist to utilise the needle with great ease and to find balance for the fingers around the mouth area and also to avoid contact with the gingival of the alveolar process. As shown in Figure 12, the portion 25b, in use is disposed to curve outwardly from the front of the mouth (and also outwardly from the alveolar process, whereas, the portion 25c projects inwardly and upwardly towards the gingiva whereas the portion 25d is substantially parallel to the vestible.

The invention provides a great advance in dental practice by the provision of a variety of needles, of different shapes which may be utilised in the administering of anaesthetic in a significantly pain free manner by enabling the dentist to administer the anaesthetic as described in relation to Figure 1. For a dentist the needles of the invention provide a much more natural posture friendly approach in delivering anaesthesia.

It will be clear that the needles and methods of the invention may also be used by others in the medical field, for example plastic surgeons (before delivering botox or to perform minor operations in the facial area), dermatologists, ear, nose and throat specialists and many others. Thus, for example, this substantially pain free delivery of anaesthetic can be used in parts of the oral cavity to number for example the lip, chin or cheek areas before minor operations or botox injections.

The invention is not limited to the embodiment(s) described herein but can be amended or modified without departing from the scope of the present invention.

Claims

1. A dental needle for attachment to a dental syringe comprising a first portion aligned along a first axis and having fixed thereon a hub for attachment to a syringe, and a second portion disposed along a second axis, said first and second axes being non-aligned.

2. A dental needle as claimed in Claim 1 for use in administering an anaesthetic to the lower right vestibular jaw region, wherein the second portion is disposed along a second axis at an obtuse angle relative to the axis of the first portion, and a third portion extends forwardly of the second portion and disposed along a third axis at an acute angle relative to the axis of the second portion.

3. A dental needle as claimed in Claim 2 wherein the second portion is integral with a front section extending forwardly of the hub and coaxial with the first portion and substantially parallel to the third portion.

4. A dental needle as claimed in Claim 1 for use in administering an anaesthetic to the upper left vestibular jaw region, or the lower left jaw region wherein the second portion is arranged along a second axis at an obtuse angle relative to the first axis.

5. A dental needle as claimed in Claim 1 wherein the needle has a third portion disposed along a third axis at an angle relative to the axis of the second portion, and a fourth portion disposed along a fourth axis, at an obtuse angle relative to the third portion.

6. A method of administering an anaesthetic in a dental procedure comprising, providing a needle suitable for the administration of fluids having a sharpened bevelled tip and a bore therethrough, the needle being non-linear and having at least one patient portion disposed at an angle relative to a main portion, penetrating tissue with the needle tip such that the bevelled tip is disposed toward the outer boundary of the tissue, and administering an amount of anaesthetic to the tissue through the needle.

7. A method as claimed in Claim 6 wherein at least a portion of the needle is shaped to conform substantially with the anatomy of the region of the mandible or maxilla which is to be anaesthetised.

8. A method as claimed in Claim 6 or 7 wherein the mouth of the patient will be closed, or substantially closed.

9. A method as claimed in any preceding claim wherein the needle should be placed onto the tissue with gentle pressure, after which the needle will be gently advanced into the tissue while constantly delivering some drops of the anaesthetic solution, creating the first small area of anaesthetic tissue.

10. A method as claimed in Claim 9 wherein the needle is then advanced further into the tissue and a further amount of anaesthetic fluid is administered.