TRANSCRIPT:

Alright, so we went over a lot of important information on maxillary and mandibular anatomy. Make sure to check out the notes that I wrote for you. There's some key takeaway points there, but there are also some concepts that I want to draw out for you on pen and paper, just to explain them a little bit more explicitly.

So for mandibular premolars, you often run into this situation right here. Let's say this is the mandible. Pardon my drawing; I'm actually a pretty good artist, but it might not look like it right now. So, let's say that's the molar. Here's a premolar and then you have the mental foramen in like right here. In some cases, it might look like this actually. Alright, and you have your inferior alveolar nerve right here exiting right here and say there's like a little anterior loop or something.

Mandibular premolar really often is tricky because if you put your implant right here you're going to run into trouble. You're going to end up with a little itty bitty implant or you're going to hit this mandibular foramen. Well, you can do two things. You can place a smaller implant, a shorter implant, or you can scoot your implant position over a little bit distally and place the implant back here. So let's say you place it back there and that's all good, right. That's fine. But the only thing now is that your crown is going to have an overhang, and you're going to get an area right here of a food trap. So you're going to be trapping food right here. And if you don't tell your patient beforehand, they're going to be pretty upset. So it's just one thing I want to mention to you that the mental foramen sometimes can cause you to either use a shorter implant or scoot your implant site over, and if you are scooching it over a little bit, you're going to have that overhang. You got to tell your patients beforehand so they're not mad at you about it.

One more thing to get this out of the way. So let's say that you're placing an implant at number 30, and this is a cross-section of the mandible. The cross-section of the mandible, and you have your inferior alveolar nerve right here. And this right here is what Dr. Aptikar was talking about, and as far as for the lingual cavity. This is the buccal side and this is the lingual side, and let's say their tongue is like right here. If you stick your finger in their mouth, you can put your finger right here and feel that it dips in right there. Some people have more pronounced than others, some people's lingual concavity, let's see.

Some people's lingual concavity looks like that, and there is some vasculature around here so if you place your dental implant, and you're drilling and you break past this cortical plate right here, you're going to be in some trouble. Granted this bone right here is very thick, so you have to drill pretty hard to drill past it. It usually, I'm not going to say that you always have to drill hard to get past it, but usually, there's like a thick cortical plate, and you can't break past it too easily. But anyway, it's dangerous if you do. There are other patients that their cross-section looks something like this. And this is the perfect kind of patient to start on. There's like no lingual concavity at all. So you don't have to worry about perforating any of the vasculature around here. So this patient, you can just place your implant and call it a day.

So sometimes just to avoid the alveolar nerve. For example, let's say it looked something like this. Let's say you had one of those x-rays that looks kind of like a weird blob there and you're not exactly sure where the inferior alveolar nerve is and you're nervous about placing your implant in this spot. Sometimes. I would say that it's an easy mistake to place it too far lingually. Sometimes it'll look good in the mouth and I'll place it so lingual to avoid this nerve that it'll end up being like, you know, after I take an x-ray later it'll look like this. And I have this little thin shell of bone on the lingual here so you got to be careful not to be so paranoid of hitting the IA that you're placing your implant all the way over here. You've got this little thin shell of lingual plate. You definitely want to be a little bit more centered. You just got to keep your You do have to keep your safety distance of 2 millimeters from the inferior alveolar canal.

Lesson Summary

During the discussion on maxillary and mandibular anatomy, several important concepts were covered. Here are some key takeaways:

• Mandibular premolars can pose challenges due to the presence of the mental foramen. Placing an implant too close to the foramen can result in complications, such as a smaller implant or damage to the foramen.
• To avoid these issues, the implant can be placed slightly distally, but this may cause an overhang in the crown and a food trap. It is essential to inform the patient about this beforehand.
• When placing an implant at number 30 in the mandible, it is crucial to consider the cross-section of the mandible. Pay attention to the lingual concavity and the thickness of the lingual cortical plate.
• In some cases, the lingual concavity may have significant vasculature, making it necessary to drill carefully to avoid damage.
• Patients with minimal or no lingual concavity are ideal for implant placement, as there is less risk of perforating any vasculature.
• It can be a common mistake to place the implant too far lingually to avoid the inferior alveolar nerve. However, this can result in a thin lingual plate, which is not desirable.
• It is important to maintain a safety distance of 2 millimeters from the inferior alveolar canal when placing the implant.