00:27Hello, I'm Dr Park Jong Chol. When it comes to implanted surgery, understanding anatomy is very important. We need to understand the morphology of the,
00:39The surgical area to conduct appropriate surgery and we need to understand where blood vessels and nerves are running. How to avoid the risk during surgery and to minimize the side effects.
00:53So we need to understand each structure and morphology of that more than anything else. In this lecture we are going to talk about anatomic considerations for implant placement. First, the mandible.
01:17Today we are going to talk about anatomic mandible. Primarily three things, first when we do the implanted surgery, we need to be careful when it comes to the mandible morphology.
01:31When it comes to the mandible morphology second blood supply of mandible. Three sensory nerve of mandible. After that, I'm going to summarize briefly what was discussed.
01:44First, let's have a look at the mandible morphology. If you look at a face, the bone at the bottom of the face is mandible. The bone is thicker than maxilla.
02:00So mandible has dense compact bone. Which is favorable environment for placing implant. This is not always the case, but when we place the implant. The angulation of the implant is similar to natural teeth. Therefore, we need to understand the direction and angulation of teeth. In the mandible,
02:27All teeth in the mandible are inclined to the mesial side. So that forms a natural speed curve, curve of speed. Therefore when you place an implant like in the left.
02:42The inclination should be similar to the natural teeth of mandible. So it should be medially inclined. It is in line with the direction of the masticatory muscle contraction. From the mechanical perspective, a mandible implant should be placed with mesial inclination.
03:01On the right, the distally inclined implant may damage the mesial tooth root and also from the mechanical perspective. There is a danger or risk of about one towards crew fracture.
03:15Therefore, when implant is placed on the mandible. It should be easily inclined. If you look at the buccolingual inclination of lower natural teeth. The anterior teeth are a bit obviously inclined but all posterior teeth are slightly lingually inclined.
03:35Forming natural curve of wilson. So when you place an implant at lower molar area, like in the right. The buccally inclined implant is not good for the opposing teeth and also mechanical investigatory perspectives.
03:53So when you place an implant, there is a risk of lower lingual perforation. You need to be careful. However, when the alveolar ridges is severely reserved. Sometimes it is difficult to incline the implant lingually. When there are teeth in a normal case, maxilla covers the mandible class 1 relation.
04:16The mandible is measurably inclined and functional cusp of lower teeth go into the central fossa of the upper teeth. However, when a lower tooth is extracted and the reach is vertically horizontally resorbed and the implant is placed considering the resolved bone. The implant will tend to incline lingually too much. In this case the lingual-inclination angle should be reduced to place the implant more vertically then,
04:43The fabrication of prosthesis can be made easy. For an implant placement angle pre-op diagnosis, surgeons experience and judgments are very important. Recently digital guided surgery became available, if you use it implant positioning can be made good. However, if you place an implant with less lingual inclination on the lower lingual side. There are sublingual submandibular glands in this fossa.
05:13When you place an implant you need to be very careful not to perforate this area. Another structure that you need to be careful in the mandible is the inferior alveolar canal and the mental foramen.
05:27Before surgery, we need to identify the locations of these on the x-ray. So when you place an implant you need to be careful not to touch them because nerve and the blood vessels are running there.
05:50Next blood supply of mandible. The blood supply comes from the heart. So jawbone blood is applied from below. From external carotid artery branches the maxillary artery. From there, branches the inferior aviola artery.
06:10Which goes through the mandibular foramen and into the inferior alveolar canal from mental frame and mental artery comes out. The incisive artery runs in the anterior region to supply blood. Blood supply of mandible is a keratin artery from their maxillary artery.
06:30From here, there are three parts from men double apart if your alveolar artery comes out. From there, mental and incisive arteries are branched. Three main vascularization characteristics. First, blood is supplied from posterior to anterior.
06:55The blood comes from the heart. From posterior region to the anterior region, blood is running. Second the vessels run parallel to the alveolar bridge.
07:07Three they run parallel like this. Therefore, the edentulous alveolar ridge is covered by a one to two millimeter wide a vascular area.
07:20As you have seen. The three main vascularization characteristics is very important in designing the incision for implant placement. The details will be covered in the flap design lecture. Regarding the vessels we need to be careful.
07:47Mandibular lingual concavity. In the lingual side of the mandible, as discussed before. Submandibular gland and sublingual gland run in this fossa. Implant is placed very well in c.
08:05However, if they are placed in a or b in the case of b it is too abundantly inclined then perforation can be occurring in the lingual side. If submandibular fossa is severe, if you place a long implant like this. It can end up like a perforation the perforation like this can occur.
08:32In this case, we need to be careful not to make the perforation by using short implants. When you make a perforation drilling can damage blood vessels running below. Which can result in severe bleeding so you need to be careful.
09:00Next sensory nerve of mandible. In the dentistry, nerves are primarily from the trigeminal ganglion and the ophthalmic nerve goes to the eyes and the maxillary nerve goes to the maxilla and the mandible nerve is branched from there to go to mandible. The mandibular nerve is branched into six nerves.
09:29And we need to be careful. When we place an implant long buccal nerve and the lingual nerve, inferior alveolar nerve and the inferior alveolar nerve goes through the mandible foramen to mandible.
09:47It becomes the inferior alveolar nerve that controls the sensation of the mandible. The nerve from the mandible of raymond is divided into mental nerve and incisive nerve.
10:00The mental nerve comes from the foramen and controls the sensation of lower lip. The mental foramen location is very important, because it can be damaged during implant placement. Therefore, mental foramen location should be identified before surgery. In dentate mandible,
10:24It is located halfway between the alveolar ridge and the inferior border. Generally, below the roots of premolars. When there are teeth mental foramen is located inferior to a primordial root in general in edentulous case.
10:45If the location is not clearly shown on the x-ray, it can be confusing. In edentulous case it is one-fourth of the mandelbrot synthesis to the posterior border of ramus on the panorama x-ray.
11:00So on the panorama x-ray, it is one-fourth of the mandible synthesis to the posterior border of ramus. The mental foramen has the anterior loop according to mission crawford in 12 of the cases the anterior loop is a three millimeter high.
11:26According to the arousement in 92 - 96 percent of the cases the anterior loop has two millimeter or longer. So when you place an implant in the interior of mental foramen, the anterior loop is three millimeters.
11:46And the safe space of two millimeters should be secured. Therefore, an implant needs to be placed at least five millimeters away from foramen.
11:58This patient had implants placed at another clinic for over denture and came to my junior alumni office complaining about the leap sensation problem. The junior called me saying the mental nerve seems to have been touched and another dentist said there was no problem with the implant placed anterior to the mental foramen.
12:21If you trace what appears to be the mental nerve and the inferior alveolar nerve. It looks like the anterior loop of the mental foramen is touched. To double check using the approach to find the mental foramen in edentulous reach. The mental foramen is located at one-fourth of the mandelbrot synthesis to the posterior border of ramus.
12:44And the implant is close to the anterior loop and the mental nerve injury is suspected. Just avoiding the foramen is not good enough, the safe space of five millimeters from the foramen should be secured when placing an implant. Next case, releasing incision was made.
13:06And the mental nerve was injured. After implant placement, bone graft is done to pull soft tissue. Releasing incision was made. Mental nerve was checked.
13:21So the incision was made avoiding that nerve, but the sensation problem lasted one and a half years. Therefore, when you place an implant in the mental nerve area. Soft tissue needs to be handled with care. If your alveolar canal is bent.
13:45Under the third molar 50 percent of the cases. In terms of distance two teeth it is closest to the root of the second molar. Inferior alveolar nerve is running in the inferior alveolar canal. When the nerve is injured, it will become an incredibly hard problem catastrophe.
14:10There are many reasons for the injury. The first reason, direct injury by drilling. Second thrombosis over the nerve, the compression can cause the injury. Third, as implant is placed the bone fragments can compress the nerve for it is rare but,
14:34The sight heals and the bone grows over the nerve and the compression from the bone can cause the injury. I've been fortunate that I have not injured the nerve yet, but this is my senior doctor's case at 46 and 47.
14:56Implants were placed at 46 if you look at the implant there. The inferior alveolar canal was invaded. It was removed immediately and placed again above it, but irreversible paresthesia occurred. So if you are a dentist.
15:16Who does the implant placement to whether you are skilled or a beginner. You always need to be careful when you work near nerves.
15:29Next, let's talk about the lingual nerve. The lingual nerve is the lingual branch of the mandible nerve. It controls the sensation for mouth floor and two-thirds of the tongue. The lingual nerve comes from the mandible nerve.
15:50And it runs closest to the alveolar ridge at the lingual side of the third molar and as it goes further to anterior it goes away from the ridge. It is close to the lingual side of the ridge and also horizontally runs close to it. Lingual nerve, some people ask whether lingual nerve is in bone.
16:12But the nerve is always in soft tissue. It is very close to the alveolar reach and the lingual side of the third morla. Therefore it requires the greater caution when you make a flap in the lingual side.
16:32The lingual nerve is found to be injured more often than the mental nerve. According to some report, so you need to be very careful.
16:43The long vocal nerve is the buccal branch of mandible nerve and it controls this incision for cheek skin and mucosa. To make a flap in the vocal mucosa, anesthesia is used for this nerve. To now, we have talked about the anatomy of mandible in relation to implant placement.
17:10I talked about the three main things. Let me briefly summarize what I have presented.
17:21First, mandibular form implants should be placed in the angulation, similar to natural tooth angulation.
17:31Second, the blood supply of mandible. The characteristics of a blood vessel in the mandible. The due to lingual form of the mandible perforation can occur. So we need to be careful not to make lingual perforation.
17:46Third, sensory nerve of mandible. Incisive nerve mental nerve inferior alveolar nerve and long vocal nerve we need to be careful when we place implants about the nerves.
18:02We fed up with anatomy classes in dental school and how was it today.
18:10I believe understanding anatomy is understanding our body. That is the basis for successful implant placement.
18:20Through the experience I believe the understanding will be enlarged and the successful outcome of implanted surgery can be achieved even though this is a boring subject I believe.
18:34You need to understand the anatomy very well. I hope this lecture proves to be helpful for your successful implanted surgery, thank you very much.
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