Anterior Mandible and Incisive Nerve: Any danger of placing implants?


Please review the images provided of the mandible. The alveolar nerve was traced by a Anatomage lab technician before fabrication of a surgical guide. Upon evaluation of the mental nerve, specifically how it continues anteriorly and turns into incisive nerve as well as the location of the planned implant sites, one can observe that the incisive nerve will in fact will be damaged by placement of the implants. I was wondering if someone could tell me if my patient is in danger of having implants placed in area 27/26. I once read that neuropathic pain may occur after implant placement in the interforaminal region due to the perforation of the incisive canal and nerve. I was wondering if someone who performs All-on-4 or someone who has expertise could help me with this case as this is my first case of placing implants in the anterior mandible. I am planning to use a tooth supported surgical guide made by Anatomage.

9 Comments on Anterior Mandible and Incisive Nerve: Any danger of placing implants?

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Not a good first case. The tracing by the technician is likely a blood vessel and not necessarily a nerve. The planning gets way too close to it. Do you trust this tech to read the CT? Can you manage a bleed in case this is an artery that you drill through by accident? The incisive canal is on the maxilla between the centrals and from the courses I've taken does not cause neuropathic pain if damaged. I haven't tried. Guides are far from fool-proof, even with tooth support. Improper fit leading to a margin of error of a fraction of a millimeter or a fraction of a degree is going to put you right through the thing. Refer this one out and wait for a more appropriate first case.
Good day. No problem in drilling the incisive branch of the nerve. It is done all the time when placing anterior implants on the edentulous patient. However you planning brings questions. Why not extract all lower teeth and place 4 implants in the anterior mandible for a complete reconstruction, either fixed or bar retained? Look at the bone level of the implant next to the natural tooth. Not ideal. And the implant should probably be place a little more apically to be in basal bone. I would certainly convince the patient to go for a better option, more comfort and longevity. I must agree with previous post that I am not comfortable to see a technician trace the nerves. But you allways have the option of verifying his work. Why not trace it yourself and then send to the lab. You will be more informed of the situation and feel more secure. Good luck with your case!
The naso-palatine or incisive nerve is in the anterior maxillary midline. For this case what is your prosthetic plan? There is a huge step from the top of the implant platform to the incisal edges of the remaining teeth- you will have very long crowns. What are your plans for posterior support? I always consider posterior support of occlusion before restoring anterior teeth if possible. Otherwise the patient will be banging on your new implant crowns. The remaining dentition looks to have a poor long term prognosis. Think this through a little bit more before proceeding with the present treatment plan.
The mandibular incisive canal is a bony canal within the anterior mandible that runs bilaterally from the mental foramina usually to the region of the ipsilateral lateral incisor teeth. After branching into the mental nerve that exits the foramen of the same name, the inferior alveolar nerve continues anteriorly within the mandibular incisive canal as the incisive nerve, providing innervation to the mandibular first premolar, canine and lateral and central incisors. The mandibular incisive nerve either terminates as nerve endings within the anterior teeth or adjacent bone, or may join nerve endings that enter through the tiny lingual foramen. Do you really think people that have CT scans in their office do not know how to read scans. Or do really think these people do not know the difference between nasopalatine nerve vs mandibular incisive branch. I wonder how much stupidity some people express when they change the topic of the conversation and try to make themselves appear more important and discredit as well as belittle someone else opinion and work. I was under impression that the whole purpose of this forum is help each other succeed and not to discourage people that try hard to learn their profession.
This is a patient with severe mandibular atrophy. It is always important for the doctor to plan the case so they are aware of the anatomy and safety zones. I agree with my colleagues that perhaps the remaining teeth need to be sacrificed if only to insure that implants platforms can be level. I also agree that perhaps a bar overdenture or locator type denture may be an option worth considering as you may not have enough A-P spread for a fixed prosthesis. I would encourage you to have a mentor to discuss osteoplasty to create a better platform, shorter implants to avoid any nerves and a minimal safety zone of 5-7 mm anterior to the mental foramen bilaterally. Alternatively you may also discuss with a mentor the advantages of grafting with titanium cages and BMP, block grafts, or ridge spreading to see what other options exist. Having a surgical guide is not going to keep you safe if you are trying to thread the needle with implants as there is potential for surgical guide movement and drilling error as well as guide error. This is in my opinion an advanced case and you may wish to watch someone do it that has more surgical experience. Thanks for sharing.
Manjunath P N
Agree with Dr Ernest The incisive canal is an anterior extension of the Mandibular Canal. The continuation of the Inferior Alveolar Nerve in the Incisive canal is the Incisive branch. The Incisive branch is the Neurovascular Supply to all Anterior Teeth & the chin closer to the midline. Incisive canal & nerve on the Maxilla is different from the Mandible.
Hi, can you please load the original CT scan immage ? it will be easier to understand the situation and better elaborate and comment the issue. Thanks.
dr nisarg shah
i have been using icat and anatomage in vivo software for last 6 yrs. there is mainly extension of the mental artery anteriorly into the chin region called as incisive artery which anatomizes with the opposite one. normally there is little chance of any neurological damage in this area, unless there is large nerve extension of the inferior alveolar nerve after it exits the mental foramen. the challenge is the anterior extension of the case it is truamatised there could be an emergency in the chair. symptoms are swelling and echimoses in the floor of the mouth , the tongue is lifted upwards, and is pushed posteriorly blocking the airway leading to difficulty in breathing. this is a worst case scenario. i have place multiple implants and performed numerous surgeries in the chin region but i have never encountered such acomplication. the above description i read in journal a few yrs ago. just be careful.
mwj, dds, ms
this is a failry straight forward treatment plan of removing the remaining teeth, trimming the alveolus then placing 4-5 implants between the mental foramina for a fixed hybrid or bar retained overdenture. We cannot tell the A-P spread from the posted images but I imagine that there's enough curvature of the anterior mandible to be successful. Posterior support is quite important for long term success. Pleas make sure you have a comprehensive treatment plan in place before embarking on expensive implant reconstructions. Possibly contact a prosthodontist and/or surgeon to help you understand the options. No bone graft should ever be needed in this case since, be trimming the alveolus, you'll get to bone that is thick enough for implants; that's why you need to sacrifice the remaining anteriors.