What Are Occlusal Contacts in Dental Anatomy?

TL;DR

Occlusal contacts are the interactions between the functioning cusps of teeth during biting and chewing. Understanding the coronal, axial, and sagittal planes, along with the 'bull rule,' is essential for mastering dental anatomy and preventing complications in occlusion. The picket fence diagram serves as an effective visual aid for recognizing these relationships.

Transcript

foreign this video is sponsored by bootcamp.com check it out for inbde prep and use coupon code mental Dental for 10 off hey everyone Dr Ryan here and welcome back to our Dental Anatomy series this video is entitled occlusal contacts but first I want to talk about biology a core tenet of biology is the relationship between structure and function at... Read More

Key Insights

• 🔬 Biology and structure: The relationship between structure and function is a core tenet of biology, including in dental anatomy. The structure of every permanent tooth has been covered in the series so far.
• 🦷 Function of teeth: Teeth function in three dimensions, and there are three planes to be familiar with - coronal (left to right), axial (superior and inferior halves), and sagittal (front to back). Understanding these planes is crucial for understanding tooth function.
• 🗺️ Coronal plane: In the coronal plane, the functioning cusps of the molars should be in contact with the opposing teeth, while the non-functioning cusps hold soft tissue (cheeks and tongue) away from the biting surfaces.
• 🔷 Bull rule: The "bull rule" states that the buckle upper cusps and lingual lower cusps should not be in contact during occlusion. Involvement of these cusps can lead to various dental problems.
• 🕹️ Axial and coronal plane connections: The blue and magenta curves in the axial and coronal plane images show the connection between functioning facial cusps and functioning lingual cusps. This represents the facial and lingual range of occlusion.
• 🔀 Sagittal plane: The sagittal plane is crucial to memorize for board exams. It shows how the teeth fit together like puzzle pieces or spokes on a gear. A simplified version called the "picket fence diagram" can be used as a memory tool.
• 🗒️ High-yield facts: In an ideal class 1 occlusion, the maxillary canine is the only tooth that contacts both an anterior and a posterior antagonist. All teeth (except mandibular central incisor and maxillary third molar) occlude with two other teeth.
• 🔢 Tooth identification: The picket fence diagram can be used to identify specific tooth numbers and their occlusal contacts, such as the distal marginal ridge or mesial lingual cusp. Tooth numbers in each row often add up to 33, 32, or 34 depending on the arch and occlusion.

Questions & Answers

Q: What are the three planes of dental function and why are they important in understanding occlusal contacts?

The three planes of dental function are the coronal, axial, and sagittal planes. These planes are important because they help us understand how teeth function together and how they should come into contact with each other during occlusion. The coronal and axial planes help us understand the location and orientation of the teeth, while the sagittal plane shows us the front-to-back relationship of the teeth.

Q: What is the "bull rule" and why is it important in occlusal contacts?

The "bull rule" stands for Buckle upper lingual lower, referring to the cusps that should not be involved in occlusion. These non-functioning cusps, if involved in occlusion, can lead to complications such as abfraction, recession, TMD, and cheek biting. It is important to understand and follow this rule to maintain an ideal occlusion and prevent dental problems.

Q: How can the picket fence diagram help us understand occlusal contacts?

The picket fence diagram is a visual tool that represents the relationship between teeth and their occlusal contacts. Each segment of the diagram represents a tooth, making it easier to identify which teeth should be in contact during occlusion. By referencing the diagram, we can answer questions about specific occlusal contacts and understand the ideal class 1 occlusion.

Q: What are two high-yield facts about occlusal contacts mentioned in the video?

The first high-yield fact is that in an ideal class 1 occlusion, the maxillary canine is the only tooth that contacts both an anterior and a posterior antagonist. The second high-yield fact is that all teeth, except for the mandibular central incisor and the maxillary third molar, occlude with two other teeth. These facts are important to remember for the board exam and have implications for dental treatment planning.

Summary & Key Takeaways

• The video explains the three planes of dental function: coronal, axial, and sagittal, and how each is important in understanding occlusal contacts.

• The "bull rule" is introduced, which highlights the cusps that should not be in contact during occlusion to prevent complications.

• The picket fence diagram is presented as a helpful visual tool for understanding occlusal contacts and tooth relationships.