CA2487625A1

CA2487625A1 - Toothbrush with contoured head

Info

Publication number: CA2487625A1
Application number: CA002487625A
Authority: CA
Inventors: Michael Shunock
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-11-14
Filing date: 2004-11-12
Publication date: 2005-05-14
Also published as: US20050108842A1

Abstract

A toothbrush is described having a contoured head that is suitable for cleaning teeth with orthodontic brackets. The toothbrush head has a ridge located a direction transverse to the longitudinal axis of the toothbrush. Bristles may be attached to the surface of the contoured head and ridge to extend outwardly therefrom. The bristles target the gingival margin, interproximal areas and the surfaces of the orthodontic bracket base as well as the remaining exposed surfaces of the tooth for cleaning.

Description

4 [0001] The present invention relates to toothbrushes.

7 [0002] To effectively clean teeth, various areas should be targeted to properly remove 8 plaque, debris and bacteria. Orthodontic patients whose teeth have orthodontic brackets attached 9 to them (commonly known as "braces") have cleaning areas where plaque removal is particularly challenging. These areas are the gingival margin which is the area of the tooth along the gum 11 line, the bracket base around the periphery of the orthodontic bracket and the interproximal areas 12 which are the spaces between contiguous teeth.

14 [0003] Human teeth have a curvature to them in two directions. These are the occlusogingival direction which is the up-and-down direction and the mesiodistal direction 16 which is the side-to-side direction. With the attachment of an orthodontic bracket in the case of 17 an orthodontic patient, properly cleaning all the necessary areas becomes quite difficult. It has 18 been proposed by dental practitioners for their patients to use a modified brushing technique to 19 clean teeth and orthodontic brackets using several brush angulations.
21 [0004] Generally a toothbrush includes a substantially planar head with bristles attached to 22 the head and projecting outward. The modified technique proposed by dental practitioners as 23 discussed above is based upon this toothbrush structure. In prior art toothbrushes, the bristles 24 have been created with various profiles with the intention of improving the cleaning efficiency of the toothbrush. The substantially planar shape of the toothbrush head does not properly take into 26 account the occlusogingival and mesiodistal curvatures of the tooth and with this design, a 27 modified brushing technique is needed to clean the areas around an orthodontic bracket.

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1 [0005] Prior art toothbrushes have attempted to alter the shape of the toothbrush's head to 2 achieve improved cleaning coverage. A "V" or "U" shaped head has been used to angle the 3 bristles in such a way as to target both sides of the tooth at the same time. U.S. Patent No.
4 4,137,593 to Porper and U.S. Patent No. 4,131,967 to Northemann are both examples of a toothbrush with a twin-banked, "V" shaped head. This design is intended to reach the inner and 6 outer surfaces of the tooth simultaneously. With the presence of an orthodontic bracket, the 7 bristles targeting the outer surface of the tooth would be impeded and may result in ineffective 8 cleaning. The orientation of the bristles as a result of this design would not be able to effectively 9 clean the mesial and distal wings (the left and right edges) of the orthodontic bracket.
Furthermore, due to the presence of a bracket, the bristles are prevented from reaching the 11 gingival margin or the upper surface of the bracket base. A complete cleaning would require a 12 modified technique and the additional bank of bristles could become awkward. Similarly, U.S.
13 Patent No. 4,625,357 to DeMartino uses a "U" shaped head that is one continuous piece as 14 opposed to a "V" shaped twin-bank design. Again, this design fails to target the mesial and distal wings of an orthodontic bracket and would not be effective in cleaning the gingival margin 16 due to the orientation of the bristles.

18 [0006] U.S. Patent No. 5,230,118 to Chamma teaches a "U" shaped channel on the posterior 19 side of the toothbrush head intended to surround an orthodontic bracket.
Bristles are arranged to target the outwardly facing surface and the top and bottom edges of the bracket base with 21 auxiliary bristles positioned outside of the channel to target the remaining tooth surface and 22 gingival margin. This design as before fails to target the mesial and distal wings of the bracket 23 and furthermore the "U" shaped channel is fixed in size and therefore may not accommodate the 24 various sizes of orthodontic brackets available. There is additionally a risk of inadvertent contact between the toothbrush's "U" shaped channel and the bracket due to the surrounding fit which 26 could cause undesired de-bonding of the bracket from the tooth.

28 [0007] Alternatively there exists prior art toothbrushes which angle the bristles in a particular 29 manner so as to improve the cleaning efficiency of the toothbrush. U.S.
Patent No. 4,706,322 to TDO-RED #8251129 v. 1 1 Nicolas discloses an orthodontic toothbrush using inclined groups of bristles to specifically target 2 the upper and lower edges as well as the outwardly facing surface of the orthodontic bracket.
3 The outwardly inclined bristles would also target the gingival margin and remaining surface of 4 the tooth. However this design fails to target the mesial and distal wings of the bracket and furthermore would not properly clean the interproximal areas between contiguous teeth with the 6 head arrangement given and subsequently, an auxiliary instrument would be required.

8 [0008] It is therefore an object of the present invention to obviate or mitigate at least one of 9 the above mentioned disadvantages.

12 [0009] In one embodiment, a toothbrush has a head, shank and handle, the head being 13 contoured in both the transverse and longitudinal directions. 'The contoured head has bristles 14 orthogonally attached to its surface so that the orientation and inclination of the bristles is dictated by the contour of the head. These bristles are inclined and oriented to follow the natural 16 curvature of the human tooth, clean the periphery of an orthodontic bracket attached to the tooth 17 and target the gingival margin and interproximal areas.

19 (0010] In one aspect, a toothbrush having an elongated body with a longitudinal axis running lengthwise through the toothbrush is provided. The toothbrush comprises a toothbrush head 21 located towards a lateral end of the elongated body, and a ridge extending upwardly from an 22 undersurface of the head. The ridge is transverse to the longitudinal axis and has a set of bristles 23 projecting outwardly therefrom.

[0011] The toothbrush may include a second ridge extending upwardly from the 26 undersurface transverse to the longitudinal axis. The second ridge may be in spaced relationship 27 with the ridge and have a second set of bristles projecting outwardly therefrom.

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1 [0012] The toothbrush may further include a third ridge extending upwardly from the 2 undersurface transversely of the ridge. The third ridge may be located on one longitudinal side 3 of the longitudinal axis and extend generally along the longitudinal axis.
The third ridge may 4 have a first lateral end located near a lateral end of the ridge located on the one longitudinal side of the longitudinal axis and a second lateral end located near a lateral end of the second ridge 6 located on the one longitudinal side of the longitudinal axis. The third ridge may have a third set 7 of bristles projecting outwardly therefrom.

9 [0013] The toothbrush may further include a fourth ridge extending upwardly from the undersurface transversely of the ridge. The fourth ridge may be located on another longitudinal 11 side of the longitudinal axis and extend generally along the longitudinal axis. The fourth ridge 12 may have a first lateral end located near another lateral end of the ridge located on the another 13 longitudinal side of the longitudinal axis and a second lateral end located near another lateral end 14 of the second ridge located on the another longitudinal side of the longitudinal axis. The fourth ridge may have a fourth set of bristles projecting outwardly therefrom.

17 [0014] The undersurface of the toothbrush may have a fifth set of bristles projecting 18 outwardly therefrom. The ridge, second ridge, third ridge and fourth ridge may be spaced to 19 form a continuous rim around the undersurface. The undersurface may be concave, and may be smoothly curved. Each of the ridge, second ridge, third ridge and fourth ridge may be smoothly 21 curved. The rim may be oval or circular in shape.

23 [0015] The ridge, second ridge, third ridge, fourth ridge and undersurface of the toothbrush 24 may be mounted on a rotatable body for rotating in an angular direction about the rim.
26 [0016] The fifth set of bristles of the toothbrush may project orthogonally from the 27 undersurface.

TDO-RED #8251129 v. 1 1 [0017] In another aspect, a replaceable toothbrush head for attachment to a toothbrush is 2 provided. The toothbrush has a longitudinal axis running lengthwise through the toothbrush, and 3 the toothbrush head comprises a ridge extending upwardly from an undersurface of the head.
4 The ridge is transverse to the longitudinal axis and has a set of bristles projecting outwardly therefrom.

7 [0018] The toothbrush head may further comprise a second ridge extending upwardly from 8 the undersurface transverse to the longitudinal axis. The second ridge may be in spaced 9 relationship with the ridge and have a second set of bristles projecting outwardly thereform.
11 [0019] The toothbrush head may further comprise a third ridge extending upwardly from the 12 undersurface transversely of the ridge. The third ridge may be located on one longitudinal side 13 of the longitudinal axis and extend generally along the longitudinal axis.
The third ridge may 14 have a first lateral end located near a lateral end of the ridge located on the one longitudinal side of the longitudinal axis and a second lateral end located near a lateral end of the second ridge 16 located on the one longitudinal side of the longitudinal axis. The third ridge may have a third set 17 of bristles projecting outwardly therefrom.

19 [0020] The toothbrush head may further comprise a fourth ridge extending upwardly from the undersurface transversely of the ridge. The fourth ridge may be located on another 21 longitudinal side of the longitudinal axis and extending generally along the longitudinal axis.
22 The fourth ridge may have a first lateral end located near another lateral end of the ridge located 23 on the another longitudinal side of the longitudinal axis and a second lateral end located near 24 another lateral end of the second ridge located on the another longitudinal side of the longitudinal axis. The fourth ridge may have a fourth set of bristles projecting outwardly 26 therefrom.

28 [0021] The undersurface of the toothbrush head may include a fifth set of bristles projecting 29 outwardly therefrom. The ridge, second ridge, third ridge and fourth ridge may be spaced to TDO-RED #8251129 v. I

1 form a continuous rim around the undersurface. The undersurface may concave, and the rim 2 may be cicular in shape.

4 [0022] The ridge, second ridge, third ridge, fourth ridge and undersurface of the toothbrush head may be mounted on a rotatable body for rotating in an angular direction about the rim.

8 [0023] These and other features of the preferred embodiments of the invention will become 9 more apparent in the following detailed description in which reference is made to the appended drawings wherein:
11 [0024] Figure 1 is an oblique view of a toothbrush relating to an embodiment;
12 [0025] Figure 2 is a view of the toothbrush of Figure 1 from one side;
13 [0026] Figure 3 is a sectional view of the toothbrush of Figure 2 along line A-A;
14 [0027] Figure 4 is a sectional view of the toothbrush of Figure 2 along line B-B;
[0028] Figure 5 is a partial front view of a human mouth with a tooth including an 16 orthodontic bracket;
17 [0029] Figure 6 is a partial oblique view of a human mouth showing the curvature of the 18 tooth of Figure 5 without the orthodontic bracket;
19 [0030] Figure 7 is a side view of the orthodontic bracket attached to the tooth of Figure 5 during cleaning;
21 [0031] Figure 8 is a top view of the attached orthodontic bracket of Figure 7 during cleaning;
22 [0032] Figure 9 is an oblique view of an electric toothbrush with contoured cup-head relating 23 to another embodiment;
24 [0033] Figure 10 is a top view of the electric toothbrush of Figure 9 with a contoured cup-head;
26 [0034] Figure 11 is a sectional view of the toothbrush of Figure 10 along line C-C.

TDO-RED #8251129 v. 1 2 [0035] In the preferred embodiment, a manual toothbrush 10, as shown in Figures 1 and 2, 3 includes a shank 14, a handle 16 and a head 12. Head 12 is contoured in both the longitudinal 4 and the transverse directions to define a concave undersurface 18. The plurality of bristles 19 project from the undersurface 18 which in their orientation and inclination define a concavity 6 generally complementary to the recess 18.

8 [0036] The curvature of the head 12 can best be seen in reference to both Figure 3 and Figure 9 4. The head 12 has a "C" shaped transverse and longitudinal curvature having a uniform thickness with the undersurface 18 terminating at an upstanding smoothly curved rim 20 that 11 extends about the periphery of the undersurface 18 and forms a perimeter for a cavity formed 12 within head 12 by undersurface 18. When head 12 is viewed from the top (see Figure 2), surface 13 18 may also be seen as a top surface of a cavity formed within head 12 by rim 20 upwardly 14 extending around the perimeter of surface 18. For consistency, surface 18 will be referred to as "undersurface" 18 throughout this description.

17 [0037] Rim 20 may be seen to have different sections or ridges extending upwardly from the 18 undersurface 18, such as transverse ridges 20a and 20b, longitudinal ridges 20c and 20d.
19 Transverse and longitudinal is in relation to a longitudinal axis 55, such axis 55 generally extending lengthwise along the elongated body, including handle 16 and shank 14, of toothbrush 21 10. As ridges 20a, 20b, 20c and 20d may be curved, "transverse" refers to a direction that 22 crosses longitudinal axis 55, and "longitudinal" refers to a direction that does not cross axis 55.

24 [0038] A ridge may simply be a section of rim 20. For the embodiment, ridges 20a to 20d are arranged to be continuous to form rim 20, with each ridge being a section of rim 20. It will 26 be appreciated that in other embodiments, ridges 20a to 20d need not be continuous and may be 27 spaced apart with lateral ends of a ridge located near a lateral end of another ridge, or that a 28 toothbrush head will only have ridges 20a or 20b in combination with one or more other ridges.

TDO-RED #8251129 v. l 1 [0039] A set of the bristles 19e are attached to extend outwardly from the undersurface 18 of 2 the head 12, and sets of bristles 19a to 19d project outwardly, or radially in case of a generally 3 smoothly curved ridge, from each of ridge 20a to 20d of the rim 20. In a preferred embodiment, 4 the set of bristles 19e extends substantially orthogonally from undersurface 18. This arrangement allows the transverse and longitudinal curvature of the head 12 to determine the 6 inclination of the bristles in the transverse plane. It is appreciated that the views given in Figure 7 3 and Figure 4 are exaggerated to illustrate the effect that the curvature of the toothbrush head 12 8 imposes on the brush profile. It may also be appreciated that the number of bristles shown in 9 either view does not represent the actual number of bristles that would be used. The bristles are intentionally enlarged and exaggerated to illustrate the bristle arrangement and overall brush 11 profile.

13 [0040] A partial view of a human mouth 24 is shown in Figure 5. A tooth 25 within the 14 mouth 24 has fixed to it, an orthodontic bracket 27. The orthodontic bracket 27 includes a front face 42 and a base which is more specifically defined by a gingival surface 26, a incisal or 16 occlusal surface 32, a distal surface 30 and a mesial surface 28. The mesial surface 28 and the 17 distal surface 30 are defined as such assuming in the preferred embodiment that the toothbrush 18 10 will travel across the mouth 24 from left to right (right to left on the page) as operated by a 19 human which is right-handed. It is appreciated that the mesial surface 28 and distal surface 30 may be defined in the opposite sense in the case that the toothbrush 10 is travelling from right to 21 left across the mouth.

23 [0041] The important areas to be cleaned around an orthodontic bracket 27 include the four 24 surfaces defined by the bracket base 26, 28, 30 and 32, the front face 42, the gingival margin 36 and the interproximal areas 34. The difficulty in targeting the important areas to be cleaned with 26 a prior art toothbrush is increased due to the natural curvature of the human tooth 25. As can 27 been seen more clearly in Figure 6, the tooth 25 has curvature in both the occlusogingival 28 direction 38 and the mesiodistal direction 40. The benefit of both the transverse and longitudinal 29 curvature of the undersurface 18 of toothbrush head 12 is that the bristles 19 will follow the TDO-RED #8251129 v. I

1 natural curvatures of the tooth 25 while targeting the areas around the orthodontic bracket 27, the 2 gingival margin 36 and the interproximal areas 34. The concavity of the bristles is provided by 3 the curvature of the undersurface 18 by the substantially orthogonal attachment of the individual 4 bristles to the curved toothbrush head 12.
6 [0042] To illustrate the operation of the toothbrush 10, reference is now made to Figure 7. In 7 Figure 7, it is evident that the curvature of the toothbrush head 12 is beneficial in allowing the 8 bristles 19 to follow the occlusogingival direction 38 of the tooth. It can also be seen that the 9 orthogonally attached bristles positioned on undersurface 18 and rim 20 are effective at targeting the gingival surface 26 and the incisal/occlusal surface 32 of the bracket base as well as the 11 gingival margin 36 and the exposed lower surface 41 of the tooth 25. The bristles 19 attached 12 along the innermost surface of the undersurface 18 create a substantially flat profile and it is 13 evident that this bank of bristles 19 is effective in cleaning the front surface 42 of the orthodontic 14 bracket 27.
16 [0043] To further illustrate the operation of the toothbrush 10, reference is now made to 17 Figure 8. Figure 8 shows a top view of the toothbrush 10 while cleaning around an orthodontic 18 bracket 27. It is evident from this view that the longitudinal curvature of the brush head 12 is 19 beneficial in allowing the longitudinal brush profile to follow the mesiodistal curvature 40 of the tooth 25. The bristles 19 orthogonally attached to the fore and after limits of the longitudinal 21 head 12 are effectively angled towards the mesial surface 28 and the distal surface 30 of the 22 bracket base as well as the interproximal areas 34 and remaining exposed marginal surfaces 43 23 of the tooth 25. It can also be seen in this view that the substantially flat bank of bristles located 24 on the innermost surface of the longitudinal curvature 22 is effective in targeting the front surface 42 of the orthodontic bracket 27.

27 [0044] In another embodiment of the present invention, an electric toothbrush 44 is shown in 28 Figures 9 and 10. The electric toothbrush 44 primarily consists of a head 46, a shank 48 and a 29 handle 50. The handle 50 contains the required battery powered components (not shown) to TDO-RED #8251129 v. 1 1 circularly rotate the head 46 at a suitable speed. The handle 50 additionally may include a switch 2 52 to put the electric toothbrush 44 in an "ON" or "OFF" position. Since the head 46 has a 3 circular profile as seen from above, the top portion of the head 46 is symmetrically concave to 4 form a "cup" shaped contour or cavity. The circular, symmetrical shape is preferred to facilitate a circular rotation of the toothbrush head 46. Similar to head 12 described earlier, head 46 can 6 be seen to have a rim 56 that frames the perimeter of an undersurface 57 of head 46. There 7 exists a plurality of bristles attached to the "cup" shaped contour head 46 extending outwardly 8 from undersurface 57 and rim 56 to define a brush profile 54. This brush profile 54 is three 9 dimensional due to the "cup" shape defined by the upper portion of the head 46. In a preferred embodiment, the plurality of bristles are substantially orthogonal to the surface from which they 11 project.

13 [0045] For the embodiment, rim 56 may also be divided into sections, or ridges 56a, 56b, 56c 14 and 56d that may be described in relation to a longitudinal axis 58 of toothbrush 44. As head 46 is circular, each of ridges 56a-56d is a quadrant of the circumference of a circle. As shown in 16 Figure 10 when head 46 is not in motion, ridges 56a and 56b are transverse relative to axis 58 as 17 they cross the longitudinal axis 58, and ridges 56c and 56d are longitudinal relative to axis 58 as 18 they do not cross axis 58. It will be appreciated that in other embodiments ridges 56a to 56d may 19 not continuous and have a lateral end of one ridge located near a lateral end of another ridge, or that in other embodiments ridges 56a to 56d may not be curved, or that rim 56 may not contain 21 the full complement of four ridges.

23 [0046] Reference is now made to Figure 11 showing a cross-sectional view of line C-C of 24 Figure 10. Similar to the manual toothbrush 10, the bristles of the electric toothbrush 44 are dictated by the curvature of the head 46, effectively targeting the exposed areas of the tooth 25, 26 the gingival margin 36, the interproximal areas 34 and the surfaces of the base 26, 28, 30 and 32 27 of an orthodontic bracket 27 as mentioned in reference to the manual toothbrush 10. It is 28 understood that the angled nature of the bristles will target areas similar to that of the manual 29 toothbrush 10. The electric toothbrush 44 is beneficial in that it will rotate around the base of the TDO-RED #8251129 v. I

1 orthodontic bracket 27 at a suitable speed and can clean the areas targeted by the bristles at an 2 increased rate. The circular "cup" shaped head 46 will surround the orthodontic bracket 27 and 3 the bristles located on the outer surface of the curved head 46 will target the remaining desired 4 areas similar to that accomplished by the manual toothbrush 10.
6 [0047] In further embodiments, it is understood that the "C" shape defining the curvature of 7 the head 12 may be modified to suit teeth 25 which do not have orthodontic brackets 27 attached 8 thereto. A modification of the bristle length and a flattening of the "C"
shape would allow the 9 head 12 to clean the entire outer surface of the tooth 25. This would allow the brush profile 18 to follow the occlusogingival curvature 38 and mesiodistal curvature 40 of the tooth 25 while 11 continuing to clean the gingival margin 36 and the interproximal areas 34.
In still further 12 embodiments, it will be appreciated that toothbrush heads 12 or 46 may be detachable from 13 toothbrush 10 or 44, respectively, to facilitate replacement of heads 12 or 46 as bristles are worn 14 out.
16 [0048] Although the invention has been described with reference to certain specific 17 embodiments, various modifications thereof will be apparent to those skilled in the art without 18 departing from the spirit and scope of the invention as outlined in the claims appended hereto.

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Claims

1. A toothbrush having an elongated body with a longitudinal axis running lengthwise through the toothbrush, said toothbrush comprising:
a toothbrush head located towards a lateral end of said elongated body; and a ridge extending upwardly from an undersurface of said head, the ridge being transverse to said longitudinal axis and having a set of bristles projecting outwardly therefrom.

2. The toothbrush of claim 1, further comprising a second ridge extending upwardly from said undersurface transverse to said longitudinal axis, said second ridge being in spaced relationship with said ridge and having a second set of bristles projecting outwardly therefrom.

3. The toothbrush of claim 2, further comprising a third ridge extending upwardly from said undersurface transversely of said ridge, said third ridge located on one longitudinal side of said longitudinal axis and extending generally along said longitudinal axis, said third ridge having a first lateral end located near a lateral end of said ridge located on said one longitudinal side of said longitudinal axis and a second lateral end located near a lateral end of said second ridge located on said one longitudinal side of said longitudinal axis, said third ridge having a third set of bristles projecting outwardly therefrom.

4. The toothbrush of claim 3, further comprising a fourth ridge extending upwardly from said undersurface transversely of said ridge, said fourth ridge located on another longitudinal side of said longitudinal axis and extending generally along said longitudinal axis, said fourth ridge having a first lateral end located near another lateral end of said ridge located on said another longitudinal side of said longitudinal axis and a second lateral end located near another lateral end of said second ridge located on said another longitudinal side of said longitudinal axis, said fourth ridge having a fourth set of bristles projecting outwardly therefrom.

5. The toothbrush of claim 4, wherein said undersurface has a fifth set of bristles projecting outwardly therefrom.

6. The toothbrush of claim 5, wherein said ridge, second ridge, third ridge and fourth ridge are spaced to form a continuous rim around said undersurface.

7. The toothbrush of claim 6, wherein said undersurface is concave.

8. The toothbrush of claim 7, wherein said undersurface is smoothly curved.

9. The toothbrush of claim 8, wherein each of said ridge, second ridge, third ridge and fourth ridge are smoothly curved.

10. The toothbrush of claim 9, wherein said rim is oval in shape.

11. The toothbrush of claim 9, wherein said rim is circular in shape.

12. The toothbrush of claim 11, wherein said ridge, second ridge, third ridge, fourth ridge and undersurface are mounted on a rotatable body for rotating in an angular direction about said rim.

13. The toothbrush of claim 12, wherein said fifth set of bristles project orthogonally from said undersurface.

14. A replaceable toothbrush head for attachment to a toothbrush, said toothbrush having a longitudinal axis running lengthwise through the toothbrush, said toothbrush head comprising:
a ridge extending upwardly from an undersurface of said head, said ridge being transverse to said longitudinal axis and having a set of bristles projecting outwardly therefrom.

15. The toothbrush head of claim 14, further comprising a second ridge extending upwardly from said undersurface transverse to said longitudinal axis, said second ridge being in spaced relationship with said ridge and having a second set of bristles projecting outwardly thereform.

16. The toothbrush head of claim 14, further comprising a third ridge extending upwardly from said undersurface transversely of said ridge, said third ridge located on one longitudinal side of said longitudinal axis and extending generally along said longitudinal axis, said third ridge having a first lateral end located near a lateral end of said ridge located on said one longitudinal side of said longitudinal axis and a second lateral end located near a lateral end of said second ridge located on said one longitudinal side of said longitudinal axis, said third ridge having a third set of bristles projecting outwardly therefrom.

17. The toothbrush head of claim 16, further comprising a fourth ridge extending upwardly from said undersurface transversely of said ridge, said fourth ridge located on another longitudinal side of said longitudinal axis and extending generally along said longitudinal axis, said fourth ridge having a first lateral end located near another lateral end of said ridge located on said another longitudinal side of said longitudinal axis and a second lateral end located near another lateral end of said second ridge located on said another longitudinal side of said longitudinal axis, said fourth ridge having a fourth set of bristles projecting outwardly therefrom.

18. The toothbrush head of claim 17, wherein:
said undersurface has a fifth set of bristles projecting outwardly therefrom;
said ridge, second ridge, third ridge and fourth ridge are spaced to form a continuous rim around said undersurface; and said undersurface is concave.

19. The toothbrush head of claim 19, wherein said rim is cicular in shape.

20. The toothbrush head of claim 19, wherein said ridge, second ridge, third ridge, fourth ridge and undersurface are mounted on a rotatable body for rotating in an angular direction about said rim.