NO20240624A1 - Toothbrush and method of cleaning tooth surfaces - Google Patents

Description

[0001] TOOTHBRUSH AND METHOD OF CLEANING TOOTH SURFACES

[0003] FIELD

[0004] The present invention relates to an improved toothbrush. More specifically, the 5 present invention relates to a toothbrush configured to better reach areas of the mouth which are difficult to reach with a conventional toothbrush and/or interdental cleaning devices.

[0006] BACKGROUND

[0007] 10 It is well known that maintaining proper oral hygiene is essential for overall health, as it prevents dental issues such as cavities and gum disease, to name a few. Toothbrushes are widely used across the world and are an effective tool in maintaining oral hygiene. The conventional toothbrush has undergone various innovations aimed at improving its cleaning efficiency, comfort, and usability. Despite these advancements, 15 there remains a need for further improvements to address persistent challenges in oral hygiene practices.

[0008] Toothbrushes provide a cost-effective treatment device which are portable and can be implemented by the user themselves without specialist knowledge or particular training beyond what is typically and easily learned as a child. More thorough cleaning of 20 teeth, including harder to reach sites, can be performed in dental surgeries by dental practitioners, including for example dentists and hygienists, however this requires physical attendance at a dental surgery and incurs significantly higher costs than home cleaning. Toothbrushes also provide a reusable device which is therefore more sustainable than disposable cleaning devices which are to be thrown away after a single 25 use. It is typically recommended that toothbrushes are replaced every three months, however in normal use the only consumable product related to use of the toothbrush within the three month period is toothpaste.

[0009] Traditional toothbrushes for home/self-cleaning typically feature a handle and a head with a multitude of bristles arranged in various patterns. While these designs have 30 been effective to some extent, they often fail to reach and thoroughly clean all areas of the mouth, particularly palatal and lingual tooth surfaces.

[0010] For the avoidance of doubt, palatal tooth surfaces are tooth surfaces which face the palate (i.e. the roof of the mouth). The term is generally used to refer to the inner surfaces of the upper teeth. Lingual tooth surfaces are tooth surfaces that face the tongue. The term is generally used to refer to the inner surface of the lower teeth but can also refer to the inner surfaces of the upper teeth. Both terms are typically used to refer to the surfaces of the teeth that are oriented towards the centre of the oral cavity, as opposed to the outer surfaces, called the buccal or labial surfaces, that face the cheeks 5 or lips.

[0011] These inward facing tooth surfaces are prone to more residual plaque than the outward facing surfaces of the teeth which are easier to reach and self-evaluate.

[0012] Traditional efforts at educating patients performing oral hygiene includes education around plaque removal. The more visible outward facing surfaces are typically more 10 desirable for the user to keep clean and plaque free since they are the surfaces which are visible to the public. Therefore, the inward facing surfaces often comprise greater plaque than the outward facing surfaces.

[0013] It is well accepted that the desired effect of using a toothbrush is entire plaque removal at all sites on the teeth.

[0014] 15 Innovations such as angled bristles, varying bristle textures, and flexible toothbrush heads have been introduced in recent decades. Angled bristles aim to reach between teeth and along the gum line more effectively, while flexible heads are designed to adapt to the contours of the mouth. However, these designs can still fall short in providing a comprehensive cleaning experience, particularly in ensuring

[0015] 20 adequate plaque removal in hard-to-reach places.

[0016] Conventional toothbrushes typically have a straight head. When cleaning the entire set of teeth some users find conventional toothbrushes difficult to locate properly in the areas to be cleaned. Other users think that the toothbrush has been located properly when in fact suboptimal cleaning is being performed.

[0017] 25 Conventional toothbrushes typically provide a longitudinal head upon which the bristles are mounted. The longitudinal head is effective at traversing the teeth running towards the back of the mouth, but is less effective at cleaning palatal and lingual tooth surfaces, particularly those of the front teeth.

[0018] Many users of toothbrushes know and understand that for optimal cleaning the 30 toothbrush must be manipulated into hard-to-reach areas of the teeth, however manipulation of conventional toothbrushes is difficult, not least because of the conventional gripping portion provided by the toothbrush shaft.

[0019] Patent document US2017/156482 discloses a curved toothbrush including a plurality of bundled fine bristles adapted to frictionally brush teeth and gums and a curved body plate adapted to plant the plurality of fine bristles thereinto at uniform intervals, wherein the curved body plate includes a curved underside and a curved top formed curvedly by twisting both ends of the curved body plate in a longitudinal direction thereof, the curved top having obliquely protruding portions formed on both sides thereof 5 in an oblique direction and an obliquely concaved groove formed between the obliquely protruding portions, so that all of users can keep clean and healthy teeth.

[0020] Patent document US152/0730 discloses a toothbrush comprising an approximately rectangular toothbrush head with bristle tufts mounted thereon. The toothbrush head comprises a convex surface upon which the bristle tufts are mounted.

[0021] 10 The invention has for its object to remedy or to reduce at least one of the drawbacks of the prior art, or at least provide a useful alternative to prior art.

[0022] The object is achieved through features, which are specified in the description below and in the claims that follow.

[0024] 15 SUMMARY

[0025] The invention is defined by the independent patent claims. The dependent claims define advantageous embodiments of the invention.

[0026] According to a first aspect of the invention, there is provided a toothbrush for cleaning palatal or lingual tooth surfaces, the toothbrush comprising: an anterior side 20 facing towards the teeth being cleaned in use; a posterior side facing away from the teeth being cleaned in use; a proximal portion for gripping and manipulating the toothbrush in use; a distal portion for at least partially locating in the mouth of the user in use; wherein the proximal portion comprises: an elongate shaft portion; and a first curved shaft portion extending anteriorly and configured to receive a digit in use; and the 25 distal portion comprises: a second curved shaft portion extending posteriorly; and a head connected to or integrally formed with the second curved shaft portion and comprising a plurality of bristles arranged on the anterior side for cleaning the palatal or lingual surfaces of the teeth in use.

[0027] The elongate shaft portion may be straight or substantially straight.

[0028] 30 The head may comprise a base wherein the bristles are mounted or arranged on the base.

[0029] The first curved shaft portion extending anteriorly may form a partial anterior loop.

[0030] The second curved shaft portion extending posteriorly may form a partial posterior loop.

[0031] The second curved shaft portion extending posteriorly may be configured to position the head inside an oral cavity of the user with the anterior side of the head 5 facing the palatal or lingual surfaces of the teeth in use.

[0032] The second curved shaft portion may comprise a shallow curve with a low angle of curvature. The second curved shaft portion may comprise a sharp curve with a high angle of curvature. The second curved shaft portion may comprise both a shallow curve with a low angle of curvature and a sharp curve with a high angle of curvature.

[0033] 10 The sharp curve may comprise an angle of less than 90 degrees.

[0034] The shallow curve may comprise an angle of around 42 degrees where the shallow curve intersects the central axis of the toothbrush.

[0035] The shallow curve may comprise an angle of between 40 and 50 degrees where the shallow curve intersects the central axis of the toothbrush.

[0036] 15 The shallow curve may gradually fall in steepness as the curve progresses from the proximal end of the shallow curve to the distal end of the shallow curve.

[0037] The shallow curve may fall to parallel to the central axis at the distal end of the shallow curve.

[0038] The shallow curve may fall to near to parallel to the central axis at the distal end 20 of the shallow curve.

[0039] The width of the head may be greater than the height of the head.

[0040] The width of the plurality of bristles may be greater than the height of the plurality of bristles.

[0041] According to a second aspect of the invention, there is provided a method of 25 cleaning palatal or lingual tooth surfaces, comprising the steps of:

[0042] i) providing a toothbrush according to the first aspect of the invention;

[0043] ii) gripping the proximal portion and locating a digit in the first curved shaft portion;

[0044] 30 iii) locating the distal portion in an oral cavity with the head facing the palatal or lingual surfaces of the teeth;

[0045] iv) engaging the bristles of the head with a palatal or lingual surface of the teeth; and

[0046] v) moving the toothbrush to clean the palatal or lingual surface of the teeth.

[0048] BRIEF DESCRIPTION OF THE DRAWINGS

[0049] 5 An embodiment of the invention will now be described with reference to the following drawings, in which:

[0050] Figure 1 shows a toothbrush according to the invention;

[0051] Figure 2 shows the toothbrush of Figure 1 in an alternative view;

[0052] Figure 3 shows the toothbrush of Figure 1 in a side view;

[0053] 10 Figure 4 shows the toothbrush of Figure 1 in an alternative view;

[0054] Figure 5 shows the toothbrush of Figure 1 being held by a user;

[0055] Figure 6 shows the toothbrush of Figure 1 in use to clean the inner surface of the upper teeth of a user; and

[0056] Figure 7 shows the toothbrush of Figure 1 in use to clean the inner surface of the 15 lower teeth of a user.

[0057] For clarity reasons, some elements may in some of the figures be without reference numerals. A person skilled in the art will understand that the figures are just principal drawings. The relative proportions of individual elements may also be distorted.

[0059] 20 DETAILED DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 shows a front view of a toothbrush 100. Figures 2, 3 and 4 show alternative views of the toothbrush 100. The toothbrush 100 is for cleaning palatal or lingual tooth surfaces. As explained previously, palatal tooth surfaces are tooth surfaces which face the palate while lingual tooth surfaces are tooth surfaces that face the 25 tongue. Both “palatal” and “lingual” are typically used to refer to the surfaces of the teeth that are oriented towards the centre of the oral cavity, as opposed to the outer surfaces that face the cheeks or lips.

[0061] Still referring to Figures 1 to 4, the toothbrush 100 comprises an anterior side 100A facing towards the teeth (not shown in Figure 1) being cleaned in use and a 30 posterior side 100B facing away from the teeth being cleaned in use.

[0062] The toothbrush 100 comprises a proximal portion 200 and a distal portion 300. The proximal portion 200 is for gripping and manipulating the toothbrush in use. That is to say, a user will typically pick up the toothbrush by the proximal portion 200 and move the toothbrush to an oral cavity where palatal or lingual tooth surfaces are to be cleaned.

[0063] It will be understood that the user of the toothbrush 100 described herein may clean their own teeth using the toothbrush 100. Alternatively, the user may clean another person’s teeth using the toothbrush 100. Teeth may be cleaned in a professional setting such as in a dentist’s or hygienist’s surgery, wherein the dentist or hygienist uses the 5 toothbrush 100 to clean a patient’s teeth.

[0064] It will also be understood that the terms “tooth” and "teeth” are to be interpreted broadly, in that they are intended to cover dental prosthetics as well as natural teeth. In this connection, dental prosthetics is intended to refer to artificial devices used to replace missing teeth or support existing teeth, damaged or not damaged, or other structures in 10 the mouth. In this connection, the terms “tooth” and “teeth” are intended to cover dental implants, crowns, bridges, dentures etc.

[0065] The user may wrap their fingers 402, 403, 404, 405 around an elongate shaft portion 210 and position their thumb 401 in a first curved shaft portion 220, as shown in Figure 5. As shown in Figure 6, the user may in some cases wrap their fifth, fourth and 15 third fingers 405, 404, 403 around an elongate shaft portion 210 and position their thumb 401 in a first curved shaft portion 220 and their second finger on the alternate side 221 of the first curved shaft portion 220.

[0066] In the preferred example described herein, the elongate shaft portion 210 is straight. In alternative examples, the elongate shaft portion 210 may be substantially 20 straight or curved.

[0067] In some examples, for example as shown in Figure 7, the user may position some fingers 403, 404, 405 on and/or around the elongate shaft portion 210 and position one or more fingers 402 in the first curved shaft portion 220. The thumb 401 may naturally rest on the alternate side 221 of the first curved shaft portion 220 as shown in Figure 7.

[0068] 25 Said another way, the user may position their thumb 401 on the anterior side 100A while wrapping their third, fourth and fifth 403, 404, 405 around the elongate shaft portion 210 from the posterior side 100B and position their second finger 402 in the first curved shaft portion 220.

[0069] The thumb 401 and fingers 402, 403, 404, 405 of the user are described herein 30 with reference to their usual medical numbering. That is to say, the thumb is referred to as the first finger 401, with the index finger being referred to as the second finger 402, the middle finger being referred to as the third finger 403, the ring finger being referred to as the fourth finger 404 and the smallest finger being referred to as the fifth finger As will be understood by a person skilled in the art, the first curved shaft portion 220 is configured to receive a finger 402, 403, 404, 405 or a thumb 401, or in some cases the user may locate multiple fingers 402, 403, 404, 405 into the first curved shaft portion 220, for example the user may located the second 402 and third 403 fingers into 5 the first curved shaft portion 220 when holding the toothbrush 100 in the position shown in Figure 7. In some cases, the user may locate a finger 402, 403, 404, 405 and a thumb 401 or multiple fingers 402, 403, 404, 405 and a thumb 401 into the first curved shaft portion 220.

[0070] To concisely refer to fingers and/or thumbs of a user, the generic term “digits” is 10 used herein to cover fingers and/or thumbs, i.e. a finger is a digit and a thumb is a digit.

[0071] Referring to Figures 6 and 7, it can be seen that the distal portion 300 is for at least partially locating in the mouth of the user in use.

[0072] Like conventional toothbrushes, the toothbrush 100 is inserted into the mouth, manipulated and moved by the user from outside of the mouth. The toothbrush 100 is 15 preferably slightly rotated to perform a cleaning action. The amount the distal portion 300 is inserted into the mouth depends on the size of the user’s mouth and the location of the teeth to be cleaned, as will be easily understood by a person skilled in the art.

[0073] Referring to Figures 1 to 7, the distal portion 300 comprises a second curved shaft portion 310 extending posteriorly and a head 320 integrally formed with the second 20 curved shaft portion 310. In alternative examples not shown herein, the head 320 may be a separate component which is attached to the second curved shaft portion 310 rather than being integrally formed therewith. The head 320 comprises a base 321 and a plurality of bristles 322 arranged on the anterior side 100A for cleaning the palatal or lingual surfaces of the teeth in use.

[0074] 25 It will be understood that in some examples the first 220 and/or second 310 curved shaft portions may comprise one or more straight or substantially straight regions in addition to curved regions. In some examples, the straight or substantially straight regions may be located between the curved regions forming the curved shaft portions, or may be located at one end or another end of the curved regions.

[0075] 30 That is to say, the first 220 and second 310 curved shaft portions do not require the entire portion to be curved at all locations along the length of the respective curved shaft portion. For example, the first curved shaft portion 220 and/or the second curved shaft portion 310 may have one or more small straight portions. As explained above, the head 320 is connected to the second curved shaft portion 310 and may in some cases be connected to a substantially straight portion of the second curved shaft portion 310. In such cases, the second curved shaft portion 310 may, for example, include a continuously curved region towards the proximal end of the toothbrush 100 and include a short straight shaft at the distal end of the second curved shaft portion 310. In such 5 cases, the second curved shaft portion 310 may be seen to include both the curved region and the non-curved region, wherein the non-curved region may connect to the head 320.

[0076] As can be best seen in the side view shown in Figure 3, the first curved shaft portion 220 extends anteriorly and forms a partial anterior loop. That is to say, from the 10 proximal end of the first curved shaft portion 220 to the distal end of the first curved shaft portion 220, the first curved shaft portion 220 comprises a curve which extends at or near the centre of the curve towards the anterior side 110A. That is to say, as can be seen most clearly in Figure 3, the curve extends firstly outwards towards the anterior side 110A and then back towards the posterior side 110B, thereby creating a first curved 15 shaft portion 220 extending anteriorly. It can clearly be seen in Figure 3 that in the presently described example, the first curved shaft portion 220 extends anteriorly with the curve returning to in line with the central axis Y of the elongate shaft 210. However, it will be understood that in alternative examples not shown herein in the interest of brevity, the first curved shaft portion 220 may extend anteriorly and not return fully to the 20 central axis Y. In such cases, the first curved shaft portion 220 will have formed a partial anterior loop although the anterior loop did not return fully to the central axis Y.

[0077] Still referring to Figure 3, the second curved shaft portion 310 extends posteriorly and forms a partial posterior loop. That is to say, from the proximal end of the second curved shaft portion 310 to the distal end of the second curved shaft portion 310, the 25 second curved shaft portion 310 comprises a curve which extends towards the posterior side 110B. The second curved shaft portion 310 extends outwards towards the posterior side 110B without returning back towards the anterior side, thereby creating a second curved shaft portion 310 extending posteriorly.

[0078] It can clearly be seen in Figure 3 that in the presently described example, the 30 second curved shaft portion 310 extends posteriorly with the curve not returning to in line with the central axis Y of the elongate shaft 210. However, it will be understood that in alternative examples not shown herein in the interest of brevity, the second curved shaft portion 310 may extend posteriorly and return fully to the central axis Y. In any either case, i.e. fully returning to in line with the central Y axis or not returning to in line with the central Y axis, the second curved shaft portion 310 will have formed a partial posterior loop. As explained previously, in some examples, a region of the second curved shaft portion 310 towards the distal end may comprise a short straight region where the head 320 is mounted or integrally formed with the second curved shaft portion 5 310. As previously explained, such short straight or substantially straight sections may be considered to be part of the second curved shaft portion 310. In this regard, the head 320 is mounted to the second curved shaft portion 310 or is integrally formed with the second curved shaft portion 310. Said another way, the second curved shaft portion 310 must feature at least one curved region, however it may also comprise straight or 10 substantially straight region(s) in addition.

[0079] Referring briefly to Figures 6 and 7, it can be seen that the second curved shaft portion 310 is configured position the head 320 inside an oral cavity of the user with the anterior side 100A of the head 320 facing the palatal or lingual surfaces of the teeth in use.

[0080] 15 Referring to Figure 4, it can be seen that in the presently described example, the second curved shaft portion 310 comprises a shallow curve 311 with a low angle of curvature and a sharp curve 312 with a high angle of curvature. It can be seen in Figure 6 that the shallow curve 311 allows the hand of the user to be located in a free space in front of the mouth while the sharp curve 312 locates the head 320 at the required 20 position on palatal/lingual surface of the teeth. In this connection, the shallow curve 311 allows the head 320 to be brought into the mouth in use, over a relatively large portion of the total length of the toothbrush. At the same time, the head 320 must be aligned such that it is facing the palatal/lingual surface of the teeth, therefore the sharp curve 312 provides said required orientation.

[0081] 25 The shown combination of the shallow curve 311 and sharp curve 312 allows the head 320 to be brought into the desired position without requiring the toothbrush to be held in an unnatural or awkward position for cleaning the teeth. For example, if the second curved shaft portion 310 is provided as a single uniform curve, rather than a shallow curve 311 followed by a sharp curve 312, the toothbrush 100 may need to be 30 held with the hand of the user closer to the mouth, i.e. the hand further towards a horizontal position, otherwise the curve may hit off of the bottom teeth (Figure 6). The close positioning of the hand to the mouth or in the mouth may make brushing less effective. Furthermore, it is highly desirable to keep the hands away from the mouth during brushing to achieve the most sanitary conditions.

[0082] In some examples, the sharp curve 312 may be at a sharp angle 312’ of less than 90 degrees relative to the central Y-axis. As can be seen in Figure 6, when the toothbrush 100 is in use, a sharp curve 312 sharp angle 312’ of less than 90 degrees, relative to the central Y-axis, will help to easily locate the bristles 322 of the toothbrush 5 100 at the palatal/lingual surface of the teeth.

[0083] In some examples, the shallow curve 311 may be at a shallow angle 311’ of around 42 degrees relative to the central Y-axis at the point where the shallow curve 311 intersects the central Y-axis. In some examples, the shallow curve 311 may be at a shallow angle 311’ of between 40 and 50 degrees relative to the central Y-axis at the 10 point where the shallow curve 311 intersects the Y-axis.

[0084] As can be seen in Figure 4 and 5, the shallow curve 311 gradually falls in steepness as the curve progresses from the proximal end of the shallow curve 311 to the distal end of the shallow curve 311.

[0085] As shown in the Figures, the shallow curve may fall to parallel to the central Y-15 axis or near to parallel to the central Y-axis at the distal end of the shallow curve 311.

[0086] Referring again to Figure 4, it can be seen that the width of the head 320 is greater than the height of the head 320, such that the head 320 can efficiently clean along the palatal/lingual surface of the teeth.- In the presently described example the width of the head 320 is around 2cm. In alternative examples not shown herein, the 20 width of the head 320 may be greater than or less than 2cm. It will be easily understood that when considering the inner surfaces of the teeth to be cleaned, the surface extends along a wide area – i.e. the teeth extend a relatively short height but a wide area, therefore the provision of a wide, rather than tall, toothbrush head 320 provides an improved arrangement for providing cleaning of this particular area of the teeth.

[0087] 25 The provided arrangement of a wide toothbrush head 320 may allow that a large area may be cleaned with very little movement and/or rotation of the toothbrush.

[0088] It can be seen clearly in Figure 4 that the bristles in the described example are located evenly across the head 320 which, as mentioned above, is wider than it is tall. Therefore, in the presently described example, the bristles are provided in a

[0089] 30 corresponding pattern wherein they are wider than they are tall. It will be understood that in alternative examples, the bristles may be arranged to be secured or mounted in the base 321 at an angle such that the formation of the bristles 322, at the opposite end of the bristles 321 from the mounting end, will be collectively wider than they are collectively tall.

[0090] Although the method of use of the described toothbrush has already been described through the description of the features of the toothbrush, Figures 6 and 7 are again briefly referred to in a further explanation of a method of use.

[0091] To provide cleaning of material, a non-limiting example being plaque, from the 5 inner surface of the teeth, a toothbrush as provided in Figures 1 to 7 may be provided. If it is desired to clean the inward facing surfaces of the upper teeth, the user may arrange their thumb 401 into the first curved shaft portion 220 as shown in Figure 6. The user may grip the elongate shaft portion 210 with the remaining fingers 402, 403, 404, 405 and locate the distal portion 300 in an oral cavity with the head 320 facing the inner 10 surfaces of the upper teeth. The user can then engage the bristles 322 of the head 320 with the inner surface of the teeth such that the bristles 322 can remove plaque or other undesirable material from the inner surface of the teeth. To remove such material, the toothbrush 100 can be moved such that the bristles 322 perform a cleaning action on the inner surface of the teeth.

[0092] 15 If it is desired to clean the inward facing surfaces of the lower teeth, the user may arrange their second finger 402 into the first curved shaft portion 220 as shown in Figure 7. The user may grip the elongate shaft portion 210 with the remaining fingers 402, 403, 404, 405 and may locate the thumb 401 on the elongate shaft portion 210 or on the alternate side of the first curved shaft portion 220 as previously described. The user can 20 then locate the distal portion 300 in an oral cavity with the head 320 facing the inner surfaces of the lower teeth. The user can then engage the bristles 322 of the head 320 with the inner surface of the teeth such that the bristles 322 can remove plaque or other undesirable material from the inner surface of the teeth. To remove such material, the toothbrush 100 can be moved such that the bristles 322 perform a cleaning action on the 25 inner surface of the teeth.

[0093] In the above described example, the total length of the toothbrush is 18cm. It will be understood that in alternative examples, a longer or shorter total length may be provided.

[0094] Referring again to Figure 4, the toothbrush head 320 can be seen most clearly.

[0095] 30 In the presently described example, the entire toothbrush head 320 has a curvature which is registered with the curvature of the inner surface of human teeth.

[0096] That is to say, in the presently described example a convex toothbrush head 320 is provided.

[0097] Referring now to Figure 6 which shows the toothbrush 100 located against the teeth in use, it can be seen the central bristles are configured to clean the front teeth, and the laterally mounted bristles are, due to the aforementioned curvature, configured to reach the teeth beside the front teeth. Said another way, when the toothbrush is located in the mouth of a user in use, as in Figure 6, the curvature of the head 320 5 follows the curvature of the teeth such that the bristles 322 reach the teeth to the left and right of the centre of the head 320. By providing the curvature of the head 320 registered with the curvature of the human teeth, the bristles located at the lateral positions on the head 320 do not apply excessive pressure on the teeth and gums in these areas, as could potentially be the case if no curve were provided.

[0098] 10 As previously explained, the bristles 322 in the presently described example are mounted on the base 321. Provision of the base 321 for mounting the bristles 322 may provide manufacturability, particularly in mass production. However, although not shown in the described examples, some alternative examples may be provided with the bristles mounted directly into the second curved shaft portion 310.

[0099] 15 It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of 20 elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

Claims (1)

1. CLAIMS

1. A toothbrush (100) for cleaning palatal or lingual tooth surfaces, the toothbrush (100) comprising:

an anterior side (100A) facing towards the teeth being cleaned in use; 5 a posterior side (100B) facing away from the teeth being cleaned in use;

a proximal portion (200) for gripping and manipulating the toothbrush in use;

a distal portion (300) for at least partially locating in the mouth of the user in use;

10 wherein the proximal portion (200) comprises:

an elongate shaft portion (210); and

a first curved shaft portion (220) extending anteriorly and configured to receive a digit (401) in use; and

the distal portion (300) comprises:

15 a second curved shaft portion (310) extending posteriorly; and

a head (320) connected to or integrally formed with the second curved shaft portion (310) and comprising a plurality of bristles (322) arranged on the anterior side for cleaning the palatal or lingual surfaces of the teeth in use.

20 2. The toothbrush (100) according to claim 1, wherein the elongate shaft portion (210) is straight or substantially straight.

3. The toothbrush (100) according to claim 1 or 2, wherein the first curved shaft portion (220) extending anteriorly forms a partial anterior loop.

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4. The toothbrush (100) according to any preceding claim, wherein the second curved shaft portion (310) extending posteriorly forms a partial posterior loop.

5. The toothbrush (100) according to any preceding claim, wherein the second 30 curved shaft portion (310) extending posteriorly is configured to position the head (320) inside an oral cavity of the user with the anterior side (100A) of the head facing the palatal or lingual surfaces of the teeth in use.

6. The toothbrush (100) according to any preceding claim, wherein the second curved shaft portion (310) comprises a shallow curve (311) with a low angle of curvature and a sharp curve (312) with a high angle of curvature.

5 7. The toothbrush (100) according to claim 6, wherein the sharp curve (312)

comprises an angle of less than 90 degrees with respect to the central axis (Y) of the toothbrush (100).

8. The toothbrush (100) according to any preceding claim, wherein the width of the 10 head (320) is greater than the height of the head (320).

9. The toothbrush (100) according to any preceding claim, wherein the width of the plurality of bristles (322) is greater than the height of the plurality of bristles (322).

15 10. A method of cleaning palatal or lingual tooth surfaces, comprising the steps of:

vi) providing a toothbrush (100) according to any of claims 1 to 9; vii) gripping the proximal portion (200) and locating a digit (401) in the first curved shaft portion (220);

viii) locating the distal portion (300) in an oral cavity with the head 20 (320) facing the palatal or lingual surfaces of the teeth;

ix) engaging the bristles (322) of the head (320) with a palatal or lingual surface of the teeth; and

x) moving the toothbrush (100) to clean the palatal or lingual surface of the teeth.

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