Artificial molar teeth

• US 8,696,355 B2
• Filed: 03/01/2010
• Issued: 04/15/2014
• Est. Priority Date: 08/21/2009
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Shofu
• Original Assignee: Kabushiki Kaisha Shofu
• Inventors: Kadobayashi, Yusei
• Primary Examiner(s): Singh, Sunil K
• Application Number:
  US12/714,699
• Publication Number:
  US 20110045441A1
• Time in Patent Office: 1,506 Days
• Field of Search: 433167-172, 433181-183, 433/186, 433196-198
• US Class Current: 433/197
• CPC Class Codes: A61C 13/097 characterised by occlusal profiles , i.e. chewing contact surfaces

Abstract

Maxillary molar teeth and mandibular molar teeth are formed so as to be different in intersection angles (vertical line angles) between vertical lines extending in a vertical direction to occlusal facets and occlusal planes. That is, the maxillary molar teeth and the mandibular molar teeth are formed so as to be different in intersection angles of vertical lines of the protrusive occlusal facet and retrusive occlusal facet respectively. The occlusal facets of at least one of buccal cusps of the maxillary molar teeth and lingual cusps of the mandibular molar teeth are designed so that at least one of the width in the mesiodistal direction and the width in the cuspal-cervical direction is smaller than the occlusal facets of the opposite cusps of the antagonist molar teeth.

Claims

1. Artificial molar teeth having maxillary molar teeth and mandibular molar teeth arranged in plates to be fitted to the upper jaw and lower jaw, respectively, in an oral cavity as a dental prosthetic appliance,

wherein the maxillary molar teeth and the mandibular molar teeth have occlusal facets mutually contacting with each other in each cusp,

wherein each of the maxillary molar teeth has an occlusal facet that defines an intersection angle β

formed by a first line that is normal to the occlusal facet of the maxillary molar tooth and an occlusal plane,

wherein each of the mandibular molar teeth has an occlusal facet that defines an intersection angle α

formed by a second line that is normal to the occlusal facet of the mandibular molar tooth and the occlusal plane,

wherein, for each of the maxillary molar teeth, the first line that is normal to the occlusal facet is a normal line relative to a contact plane containing a crossing point of a central line between a mesial side outer end position and a distal side outer end position in the mesiodistal direction, and a central line between a cusp side outer end position and a cervical side outer end position in the cusp-cervical direction of the maxillary molar tooth,

wherein, for each of the mandibular molar teeth, the second line that is normal to the occlusal facet is a normal line relative to a contact plane containing a crossing point of a central line between a mesial side outer end position and a distal side outer end position in the mesiodistal direction, and a central line between a cusp side outer end position and a cervical side outer end position in the cusp-cervical direction of the mandibular molar tooth,

wherein the occlusal plane is a plane including a middle point of a line between a pair of anterior teeth cutting end corners of the lower jaw, and distal buccal side cusp tops of a pair of mandibular second molar teeth,

wherein the intersection angle α

of the mandibular molar teeth is larger than the intersection angle β

of the maxillary molar teeth,

wherein, among the maxillary molar teeth, the intersection angle β

becomes smaller toward the mesial side, and

wherein, among the mandibular molar teeth, the intersection angle α

becomes smaller toward the mesial side.

2. The artificial molar teeth of claim 1, wherein the cusp of each molar tooth has a protrusive occlusal facet and a retrusive occlusal facet.

3. The artificial molar teeth of claims 2, wherein the protrusive occlusal facets are generally parallel to each other, and the retrusive occlusal facets are generally parallel to each other.

4. The artificial molar teeth of claim 3, wherein the angle of the occlusal facets vary among the molar teeth in the mesiodistal direction.

5. The artificial molar teeth of claim 1, wherein the occlusal facets are formed in first molar teeth, second molar teeth, and second premolar teeth.

6. The artificial molar teeth of claim 1, wherein the maxillary molar teeth and the mandibular molar teeth have buccal cusps and lingual cusps, respectively.

7. The artificial molar teeth of claim 6, wherein the occlusal facet of at least one of the buccal cusp of the maxillary molar teeth and the lingual cusp of the mandibular molar teeth is smaller than the occlusal facet of the opposite cusp of the antagonist molar teeth, at least in one of the width in the mesiodistal direction and the width in the cuspal-cervical direction.

8. The artificial molar teeth of claim 1, wherein the intersection angle β

of the maxillary molar teeth is smaller than the intersection angle α

of the mandibular molar teeth by 0.1 to 2 degrees.

9. The artificial molar teeth of claim 1, wherein the intersection angle β

of the maxillary molar teeth is smaller than the intersection angle α

of the mandibular molar teeth by 0.3 to 0.8 degrees.

10. The artificial molar teeth of claim 1, wherein the cusp of each of the molar teeth has a protrusive occlusal facet and a retrusive occlusal facet,

wherein, among the maxillary molar teeth, the intersection angle β

becomes smaller for each occlusal facet in a direction toward the mesial side, and

wherein, among the mandibular molar teeth, the intersection angle α

becomes smaller for each occlusal facet in a direction toward the mesial side.

11. The artificial molar teeth of claim 10, wherein the intersection angle β

of the maxillary molar teeth is smaller than the intersection angle α

of the mandibular molar teeth by 0.1 to 2 degrees.

12. The artificial molar teeth of claim 10, wherein the intersection angle β

of the maxillary molar teeth is smaller than the intersection angle α

of the mandibular molar teeth by 0.3 to 0.8 degrees.

13. Artificial molar teeth having a maxillary molar tooth and a mandibular molar tooth arranged in plates to be fitted to the upper jaw and lower jaw, respectively, in an oral cavity as a dental prosthetic appliance,

wherein the maxillary molar tooth and the mandibular molar tooth have protrusive occlusal facets and retrusive occlusal facets in each cusp, and the protrusive occlusal facets of the maxillary molar tooth and the mandibular molar tooth mutually contact with each other, and the retrusive occlusal facets of the maxillary molar tooth and the mandibular molar tooth mutually contact with each other,

an intersection angle γ

formed by a first line that is normal to the protrusive occlusal facet and a second line that is normal to the retrusive occlusal facet of the maxillary molar teeth is set to be different from an intersection angle δ

formed by a third line that is normal to the protrusive occlusal facet and a fourth line that is normal to the retrusive occlusal facet of the mandibular molar teeth,

wherein the first line that is normal to the protrusive occlusal facet is a normal line relative to a contact plane containing a crossing point of a central line between a mesial side outer end position and a distal side outer end position in the mesiodistal direction, and a central line between a cusp side outer end position and a cervical side outer end position in the cusp-cervical direction of the maxillary molar tooth,

wherein the second line that is normal to the retrusive occlusal facet is a normal line relative to a contact plane containing a crossing point of a central line between a mesial side outer end position and a distal side outer end position in the mesiodistal direction, and a central line between a cusp side outer end position and a cervical side outer end position in the cusp-cervical direction of the maxillary molar tooth,

wherein the third line that is normal to the protrusive occlusal facet is a normal line relative to a contact plane containing a crossing point of a central line between a mesial side outer end position and a distal side outer end position in the mesiodistal direction, and a central line between a cusp side outer end position and a cervical side outer end position in the cusp-cervical direction of the mandibular molar tooth,

wherein the fourth line that is normal to the retrusive occlusal facet is a normal line relative to a contact plane containing a crossing point of a central line between a mesial side outer end position and a distal side outer end position in the mesiodistal direction, and a central line between a cusp side outer end position and a cervical side outer end position in the cusp-cervical direction of the mandibular molar tooth, and

wherein the intersection angle γ

of the maxillary molar tooth is set to be larger than the intersection angle δ

of the mandibular molar tooth.

14. The artificial molar teeth of claim 13, wherein the protrusive occlusal facets are generally parallel to each other, and the retrusive occlusal facets are generally parallel to each other.

15. The artificial molar teeth of claim 14, wherein each occlusal facet is changed in angle gradually toward the mesial side.

16. The artificial molar teeth of claim 13, wherein the occlusal facets are formed in first molar teeth, second molar teeth, and second premolar teeth.

17. The artificial molar teeth of claim 13, wherein the maxillary molar teeth and the mandibular molar teeth have buccal cusps and lingual cusps, respectively.

18. The artificial molar teeth of claim 17, wherein the occlusal facet of at least one of the buccal cusp of the maxillary molar teeth and the lingual cusp of the mandibular molar teeth is smaller than the occlusal facet of the opposite cusp of the antagonist molar teeth, at least in one of the width in the mesiodistal direction and the width in the cuspal-cervical direction.