Toothbrush with improved interproximal and free gingival margin accessibility

A toothbrush has a bristle bearing head terminating the supporting stem thereof which extends from a handle. The head is disposed with its major axis at right angles to the length of the stem providing lateral extensions having bristles arranged for interproximal and free gingival margin engagement of both the maxillary and mandibular teeth. The supporting stem has a portion adjacent the head offset from a handle connecting end, the latter having a snap-in bearing connection with the handle providing easy separation and assembly and relative rotation of the handle with respect to the stem and head.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates generally to toothbrushes and more particularly is 
directed to a bristle bearing head, supporting stem and handle 
construction providing accessibility to the interproximal spaces and 
beneath the free gingival margin and enabling the user to more easily 
manipulate the head on the buccal, labial and lingual surfaces of the 
maxillary and mandibular teeth. 
2. Description of the Prior Art 
It is currently recognized that while it is desirable with each brushing to 
remove as much bacterial plaque as possible from the interproximal spaces 
and from beneath the free gingival margin as well as from the surfaces of 
the teeth, the bacteria in the plaque which are responsible for tooth 
decay and gingival deterioration are inactivated for periods of time up to 
twenty-four hours by isolation of the bacteria from their grouping in a 
plaque form, that is, by disturbing the plaque formed on the teeth and 
breaking up the grouping of the bacteria. Accordingly, it is being urged 
that teeth be brushed in a rotary motion in an attempt to reach beneath 
the free gingival margin rather than in a reciprocating movement parallel 
to the occlusal plane and also by such rotary motion to avoid tooth 
structure erosion caused by reciprocating brushing. 
Inasmuch as the structures of the toothbrushes currently available do not 
promote the use of the desired rotary brushing motion nor provide means to 
facilitate reaching into the interproximal spaces and beneath the free 
gingival margin, there is a present need to provide a toothbrush which 
will not only discourage brushing parallel to the occlusal plane and 
encourage as well as facilitate the desirable rotary brushing movement but 
will also provide means for reaching the interproximal spaces and beneath 
the free gingival margin. 
SUMMARY OF THE INVENTION 
Among the objects of the invention is to provide a toothbrush construction 
having bristles shaped, sized, located and flexible for reaching into the 
interproximal spaces and under the free gingival margins and which will be 
particularly adapted for penetrating those relatively inaccessible areas 
of the molars and bicuspids from the lingual cavity and the buccal cavity 
where the accumulation of plaque is relatively heavy, and promoting the 
desirable rotary brushing motion while enabling the teeth of both the 
maxillary and mandibular arches to be brushed simultaneously. 
The invention contemplates a stem which extends from a handle and has a 
leading end section terminating in an elongated bristle bearing head 
having a major axis perpendicular to the longitudinal axis of the stem 
section. The bristle bearing head is formed as a back having a flat 
surface from which a plurality of embedded bristles project in a 
predetermined arrangement which is bilaterally symmetrical with respect to 
the transverse minor axis of the head. The bristle arrangement, which may 
be clustered in a plurality of tufts, includes wedge-like configurations 
of such tufts having one of the tufts located as an apex adjacent each 
opposite end of the back. The length of the head along the major axis 
spaces the bristles comprising the apices a distance apart to facilitate 
penetration into the interproximal spaces and free gingival margins of the 
teeth of both the maxillary and mandibular arches simultaneously when the 
stem, through handle manipulation, is disposed along the occlusal plane 
with the mouth in an open, teeth brushing, position. The tuft forming the 
apex of the wedge-like configuration is centrally located with respect to 
the rounded end of the head on the major axis, or, where the ends of the 
head are tapered, the tuft forming the apex is located along the trailing 
or leading side edges of the head. The slope of the wedge-like 
configuration away from each apex conforms to the scallopped contour of 
the gingival edges thereby improving the ability of the bristles to 
penetrate beneath the free margins thereof and those bristles at the 
apices to penetrate into the interproximal spaces at the gumline. 
A trailing end section of the stem has a stub shaft which removably 
telescopes into the axial bore of the handle providing for separation and 
relative rotation therebetween. The trailing stem section may be angularly 
disposed to the leading stem section to offset the latter from the 
longitudinal axis of the handle about which the relative rotation of the 
stem on the stub shaft occurs to improve handling and orientation of the 
head in the mouth of the user. 
An area of bristles adjacent the transverse minor axis of the head may be 
cut to a shorter length than those bristles located toward the opposite 
ends of the head including the bristles in the wedge-like configuration of 
tufts in order to facilitate the flexing of the latter in achieving their 
hereinbefore described intended simultaneous penetration. 
A modified hourglass-shaped head provides additional wedge-like 
configurations of bristles and tufts spaced apart along the leading and 
trailing side edges of the head between the opposite ends thereof to 
facilitate interproximal and free gingival margin penetration when the 
major axis of the head is held parallel to the occlusal plane to render an 
additional capability to the toothbrush which is particularly useful in 
cleaning the front teeth.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring in detail to the drawing, 10 generally denotes a toothbrush 
constructed to embody the invention comprising a head 11 terminating the 
leading end of supporting stem 15 which extends from handle 20. Head 11 is 
formed as a back 12 which may be molded integrally with stem 15 of a 
suitable plastic material, well known in the art, and supports, by 
embedment therein, a plurality of bristles 13 arranged to project from the 
flat underside 12a thereof in a tuft pattern hereinafter described. Back 
12, and thus the contour of head 11, is generally elongated, having the 
length or major axis x--x thereof extending perpendicular to the plane 
y--y in which stem 15 and handle 20 extend, as seen in FIG. 2. The 
opposite ends 12b of back 12 are rounded, while the sides therebetween are 
substantially parallel providing a uniform width between the rounded 
opposite ends 12b. 
Bristles 13 are suitably arranged on perpendicularly extending head 11 to 
achieve the accessibility to the interproximal spaces and to the free 
gingival margins for the purpose and in the manner hereinbefore described. 
To these ends, bristles 13 may be embedded as tufts 14 in accordance with 
well known brush manuacturing methods. As seen in FIG. 3, the arrangement 
of tufts 14 is bilaterally symmetrical with respect to the minor axis of 
head 11, which axis is seen to lie in plane y--y. Thus, two rows R1 of 
four tufts 14 each are located adjacent each side of plane y--y. A second 
two rows R2 of four tufts 14 each and a single row R3 of three tufts 14 
are located in sequence on each side of plane y--y beyond rows R1 and a 
single terminal tuft R4 is positioned adjacent each rounded opposite end 
12b centralized on the major axis x--x. Rows R3 with terminal tuft R4 
provide a wedge-like contour on each end of head 11 with terminal tuft R4 
as an apex. Also, bristles 13 in the tufts 14 which are centrally located 
on back 12 in the four rows R1 may be shorter than those in rows R2, R3 
and R4, as seen in FIG. 4. The ends of the longer bristles may be cut to 
provide a convex transverse contour with those tufts 14 located on or 
adjacent to the major axis x--x being longer than those located laterally, 
as seen in FIG. 1. Bristles 13 may be natural or made of a suitable 
synthetic material, such as nylon, and have a softness permitting flexure 
of the ends thereof sufficient for entering beneath the free gingival 
margins when normal brushing pressure is applied against the surface of 
the teeth. 
Although head 11, constructed to embody the invention, may be 
perpendicularly mounted on a toothbrush stem and handle which are disposed 
coaxially with each other, an improved construction is shown as stem 15 
and handle 20 in FIGS. 1 and 2. The leading end section 16 of stem 15, 
which terminates at the outer end in back 12, has its longitudinal axis 
fixed in perpendicular relation to the major axis x--x of head 11. The 
opposite or inner end of section 16 is integrally formed with an 
offsetting, angularly disposed section 17 and tapers slightly in thickness 
from its inner end toward head 11, as seen in FIG. 1, leading end section 
16 being of a length to substantially position section 17 entirely on the 
exterior of the lips of the user in all operative positions of head 11. 
Widthwise, section 16 may be broader at the inner end than section 17 and 
also tapers toward head 11, as seen in FIG. 2. This enlargement of section 
16 adjacent section 17 provides an upfacing surface area 16a to which 
pressure may be applied by the index finger or thumb for in turn exerting 
pressure by bristles 13 against the teeth. A cylindrical stub shaft 18 
terminates the rearward end of section 17 and is positioned with its axis 
extending parallel to the longitudinal axis of section 16. 
Handle 20, which is cylindrically shaped and sized to fit the user's hand 
to be grasped thereby for manipulation of head 11 within the mouth in the 
preferred manner, has, at its leading end, an axial bore 21 sized to 
telescopingly engage stub shaft 18 for separation therefrom and rotation 
thereon. Rearwardly of bore 21, handle 20 may be hollow, providing a 
storage chamber 22 fitted with a screw cap 23 which may have a central 
opening 23a for access to chamber 22 when cap 23 is in mounted position. 
The practical utility and operation of toothbrush 10 will now be apparent. 
To brush one side of the mouth, toothbrush 10 is comfortably gripped in 
the opposite hand, as for example, by three fingers being curled around 
handle 20 so that angularly disposed section 17 extends between the thumb 
and index finger for disposing leading end section 16 along the occlusal 
plane to readily position head 11 in the buccal or lingual cavity with 
bristles 13 engaging the teeth. The jaws are held open sufficiently but in 
a relaxed fashion to position tufts R4 of the opposite ends of head 11 at 
the gumline of both the mandibular and maxillary arches as illustrated in 
FIG. 5. The brushing, to achieve the desired result of breaking up 
organized bacterial plaque, is performed by applying light pressure 
against the teeth sufficient to flex the ends of the longer bristles 13 in 
rows R2, R3 and R4. Head 11 is moved in a circular motion, which more 
precisely may be elliptical, with the major axis of the ellipse extending 
vertically and parallel to the major axis x--x of head 11. The 
perpendicular disposition of the major axis x--x of head 11 with respect 
to stem 15 and the arrangement of tufts 14 in accordance with the 
invention is particularly adaptable to and facilitates this desirable 
brushing motion whereby the wedge-like contour of tufts 14 provided by 
rows R3 and R4 penetrates the interproximal spaces at the base of the 
teeth and by said flexure of bristles 13, the latter also extend beneath 
the free gingival margin along the entire width of each tooth. The 
circular brushing motion is applied while slowly advancing stem 15 along 
the occlusal plane. In this manner the buccal surfaces of the teeth of the 
entire half of the mouth may be carefully brushed, and then by rotating 
stem 15 180.degree. in handle 20, the lingual surfaces of the teeth of the 
same half of the mouth may likewise be brushed. The offset of leading end 
section 16 with respect to handle 20 makes the lingual surfaces as well as 
the buccal surfaces of the teeth readily accessible. The other half of the 
mouth is then similarly brushed holding handle 20 in the opposite hand. 
The use of toothbrush 10 is not necessarily limited to the simultaneous 
brushing of the mandibular and maxillary arches but is also adaptable to 
brushing each arch individually by the same hereinbefore described rotary 
movement particularly when brushing the canines and incisors at the front 
of the mouth. 
The occlusal surfaces of the teeth are brushed by conventional short 
reciprocating strokes but utilizing the bristles 13 on one half of head 
11, or, if desired, handle 20 may be held perpendicular to the arches 
thereby aligning axis x--x for reciprocal movement along the arches and 
brushing with the bristles of the entire head 11. 
Head 11 of toothbrush 10 may be proportioned for the intended use thereof, 
for example, in a regular adult size and in a smaller child size. For 
adult use, an average overall length for back 12 of approximately 24 mm. 
and width of 10 mm. satisfy the size requirements of most adult mouths. 
The length of the longer bristles 13 in rows R2, R3 and R4 are preferably 
10 mm. while rows R1 are approximately 8 mm. long. 
In keeping with the concept of providing a wedge-like configuration of 
tufts 14 formed by rows R3 and R4 at each of the opposite ends of back 12, 
FIG. 7 shows a modification thereof as head 41 having a back 42 integrally 
formed with stem 15. The opposite ends 42a of back 42, instead of being 
rounded as ends 12a of back 12, are tapered forwardly so that terminal 
tuft R14 may be positioned adjacent the trailing side edge 42d which 
because of said taper is longer than leading side edge 42e. Rows R1, R2 
and R3 of tufts on back 42 are in the same arrangement as those on back 
12, but terminal tuft R14, as the apex of the wedge-like configuration, is 
located to one side of major axis x--x. It will be apparent that, the 
tapered end 42a tapering from a longer trailing side edge 42d to a shorter 
leading side edge 42e as illustrated in FIG. 7 conforms to the contour of 
the buccal and lingual cavities in the molar region of the mouth 
facilitating brushing therein in the manner hereinbefore described and 
minimizing irritation to the mucco-buccal fold. 
Another modified form of toothbrush head is shown in FIG. 6 as head 31 
which comprises a back 32 integrally formed with stem 15 and having a flat 
underside 32a from which bristles 33 project in a predetermined pattern of 
tufts 34. Back 32 has an hourglass contour which provides a pair of 
opposite end sections 32b, each having a rounded or circular shape, 
interconnected by a constricted midportion 32c. In a manner comparable to 
head 11, tufts 34 are in a bilaterally symmetrical arrangement with 
respect to the minor axis of head 31, that is, with respect to plane y--y, 
whereby two rows R11 of two tufts 34 each are adjacent to each side of 
plane y--y. Thereafter, located in sequence on each side of plane y--y 
beyond rows R11 are one row R22 of four tufts 34, one row R33 of five 
tufts 34, one row R44 of four tufts and a single terminal tuft R5 
positioned at the extreme opposite ends of back 32 on the major axis x--x. 
In addition to using toothbrush 10, when fashioned with head 31 having 
opposite end wedge-like configurations provided by tufts 34 located in 
rows R5 and R44, in a manner similar to that hereinbefore described for 
head 11, the tufts 34 located at the opposite ends of rows R22, R33 and 
R44 form a wedge-like configuration on the opposite sides of each end 
section 32b whereby head 31 may be applied to the teeth with major axis 
x--x extending parallel to the occlusal plane instead of perpendicular 
thereto by holding handle 20 in a vertical position. Circular or 
elliptical brushing movement, imparted by head 31, particularly for 
brushing the front teeth, will enable the tufts 34 in the wedge-like 
configurations located along the sides of head 31 to penetrate the 
interproximal spaces and the free gingival margins in a manner similar to 
that of the wedge-like configurations at the opposite ends of heads 11 and 
31 when the latter are held perpendicular to the occlusal plane. 
Fewer than the twelve rows of tufts 14 and 34 may be used within the scope 
of the invention as dictated by the dimensions of backs 12, 42 and 32 and 
the size of the respective tufts 14 and 34. Thus, one row R2 on each end 
of backs 12 and 42 and/or fewer than four rows R1 may be provided. Also, 
tufts 14 may be three abreast instead of the four abreast illustrated in 
FIGS. 3 and 7. Likewise, fewer than four rows R11 may be used on back 32 
and tufts 34 in each of the rows R11, R22, R33 and R44 may be reduced in 
number. The bristles 33 in rows R11 of back 32 may be shorter than those 
of the rows of end sections 32b in a manner similar to back 12. However, 
the transverse contour of bristles 33 of end sections 32b may be flat 
rather than convex as bristles 13 shown in FIG. 1. 
Where so desired, bristles 13 and 33 may be mounted in backs 12, 41 and 31, 
respectively, as unitary or pairs of bilaterally symmetrical tufts having 
configurations providing the wedge-like contours shown and described with 
respect to heads 11, 41 and 31. 
By requiring as well as facilitating the hereinbefore described circular or 
elliptical brushing motion on the buccal and lingual surfaces of the 
teeth, the perpendicular relationship between major axis x--x of heads 11, 
41 and 31 and the longitudinal axis of leading end section 16 and handle 
20, embodying the invention, also prevents, or at the very least greatly 
discourages, continued use of the undesirable brushing habit of taking 
long and hard strokes across the buccal and lingual surfaces of the teeth 
in a direction parallel to the occlusal plane. Thus, erosion of the 
surface layer of the teeth, particularly along the dento-enamel junction, 
the cause of which has been attributed, to a large degree, to such 
parallel brushing, is substantially eliminated or at least materially 
reduced by the use of toothbrush 10 fitted with heads 11, 41 or 31. 
The readily separable connection between handle 20 and stem 15 permits one 
handle to service a plurality of stems 15 each fitted with a toothbrush 
head embodying the invention, one or more for each member of the family, 
or also fitted with a gum massaging instrument such as a periodontal aid. 
The offset feature of leading end 16 with respect to handle 20 may be 
preserved without the relative rotation of stem 15 in handle 20 by 
enlarging integrally formed stub shaft 18 to a convenient handle size. 
Storage chamber 22 may be used to house a spool of dental floss (not 
shown), the leading end of which may be fed through central opening 23a in 
screw cap 23, or, when traveling, a small tube or container of tooth paste 
or powder may be carried therein. 
The toothbrush constructions herein disclosed are seen to achieve the 
several objects of the invention and to be well adapted to meet conditions 
of practical use. As various possible embodiments might be made of this 
invention, and as various changes might be made in the disclosed 
toothbrushes, it is to be understood that all matters herein set forth or 
shown in the accompanying drawing are to be interpreted as illustrative 
and not in a limiting sense.