1. Technical Field
The present invention relates to a toothbrush for a pet dog, and in particular to a toothbrush for a pet dog in which a groove is longitudinally formed in a center of a head in a direction of a handle, and a cushion material is provided in a surrounding surface, a lower surface and the groove. When a pet dog bites a toothbrush with teeth during a tooth brushing, it is possible to prevent teeth from fracture while preventing a lot of pain occurring when teeth collide with a hard toothbrush. Toothbrush hairs planted in a head are shaped depending on a tooth shape of a pet dog, so it is possible to reliably to remove the plague attached on the upper side of a cervical ridge of maxillomandibular premolars and molars of a pet dog without applying over stimulation on the gum.
2. Background Art
As shown in FIG. 15, the maxillomandibular premolars and molars of a pet dog have specific crown structures depending on a cusp development of a carnivorous animal as compared to an aspect structure development of maxillomandibular premolars and molars of a human being. According to the characteristics of cusp development teeth, a groove is deeply formed between the cusps.
As shown in FIG. 16, a gingival line curvature of maxillomandibular premolars and molars of a pet dog is formed in one gingival line portion in one crown of the maxillomandibular premolars and molars of a human being, whereas two gingival line curvatures are formed in one crown.
In addition, as shown in FIG. 17, an undercut is not formed in cervical area of the maxillomandibular premolars and molars of a pet dog as compared to a human being who has an undercut in cervical area of the maxillomandibular premolars and molars.
As shown in FIG. 18, when the maxillomandibular molars are occluding with each other in a pet dog, the maxillary molars fully overlap the mandibular molars as compared to a human being in which when the maxillomandibular molars are occluding, the maxillary molars partially overlap the upper portions of the mandibular molars.
In addition, as shown in FIG. 19, the plague accumulation portions of the maxillomandibular premolars and molars of a pet dog are formed on the upper side of a height of contour of the crown in the upper side of the protruded structure of the cervical ridge, whereas the plague accumulation portions of the maxillomandibular premolars and molars of a human being are formed in a lower side of a height of contour of the crowns near the cervical ridge.
A common toothbrush might over scratch the gum of a pet dog having a poor clean state due to an anatomical structure of the teeth and gum of a pet dog which is distinguished from a human being.
In addition, a tooth brushing time should be shorter than a normal tooth brushing of a human being due to a patience of a pet dog.
If a tooth brushing time is extended or a pet dog does not like tooth brushing, the pet dog might bite the toothbrush with teeth, and the teeth collide with the hard head of the toothbrush.
So, the teeth of a pet dog might be hurt, and the teeth might be fracture.
The US patent application laid-open number US 2002/0083539A discloses a toothbrush for a pet dog in which strong hairs are planted in a head having a V-shaped groove. The strong hairs vertically planted in a horizontal surface of an upper side of a V-shaped groove brush the gum, not teeth when brushing the premolars except for the maxillary right and left fourth premolars, so the gum might be hurt by means of an over brushing.
The strong hairs are generally planted shorter. When brushing the junction portions of the molars, the bottom portions of the shorter strong hairs might collide with the lingual cusp of the occlusal surface or the head frame, so the teeth might be broken by means of a sideward pressure applied to the teeth.
The thickness and lengths of the teeth of the pet dog are different due to the kinds of pet dogs, and even in the dentulous dental arch, the thickness and the lengths of the teeth are different. So, it is impossible to use one toothbrush for multiple kinds of pet dogs.
In addition, since the shorter strong hairs are fixedly planted in the V-shaped grooves, it is needed to insert the strong hairs of the head deeper into the teeth so as to brush the maxillomandibular first premolar which is generally thin and small. In this case, over stimulation might be applied to the gum.
In case of the maxillary right and left fourth premolars relatively being large and thick and the mandibular right and left first molars, when the fixed V-shaped space is adapted, an effective brushing of the strong hairs is a lot limited due to a partial narrowness and a partial wideness.