Lower Jaw Treatment Options
Posted on 7/17/2023 by Greg Kammeyer
|When a patient is going to lose or has lost there lower teeth, there are 5 basic treatment options. A 2 implant overdenture, a 4 implant overdenture, a 4 implant bar over denture or fixed teeth: All on 4 or All on X or bridge work. I’ll review the pros and cons of each. Asking the patient what they expect from the teeth will help you decide which choices to offer.
2 implant overdenture with free standing implants: Tissue supported The advantages: This method requires the least surgery, is the cheapest and the simplest. Often a beginner at implant surgery will favor this choice or a patient with cost limitations or lower expectations of the result will prefer it. It is easy to clean the implants and it is much better than a lower denture and for many people, an affordable option. If it doesn’t satisfy the patient, and IF the first 2 implants are placed in the lateral incisor position, it can be upgraded to any of the other 4 choices below. This is a great way to spread out the cost of treatment for patient convenience and potentially please a patient with a simple solution. If the patient may proceed longer term to a 4 implant bar overdenture or ALL-on-X, these implants will need to be placed much lower with alveloectomy to accommodate future prosthetic component thickness/height requirements. The disadvantages: Much like a denture, food gets caught under the denture in the posterior, causing pain when chewing. This choice still accelerates bone loss in the back of the mouth. The maintenance is usually high (especially with plastic teeth) as there is a lot of pressure at the implant sites, as the attachments wear out and need replacement yearly on an average. Lining the prosthetic with a metal mesh during construction, decreases these problems significantly as well as having a well-fitting denture to begin with. Patients report it is only about 30% as good as natural teeth. For many having removable teeth is also not desired. These teeth are very bulky, since they are a still a denture. For the cost most people with low expectations of the results are happy.
Implant Overdenture with 4 free standing implants: Tissue supported The advantages: This upgrade from 2 implants, holds the denture down in the posterior and gives significantly more retention and support. Attachments should last longer and the surgery is somewhat more invasive. A metal mesh again will help decrease post-operative material breakdown. If this prosthetic gets upgraded to a bar overdenture or ALL-on-X, again the implants much be placed more inferiorly and the operator, should pay more attention to AP spread, given the posterior implants are vertical not, tilted so you may have fewer teeth than an ALL-on-X. The disadvantages: There can still be tissue pain when chewing, it still accelerates bone loss in the back of the mouth, and the maintenance is usually high, especially with plastic teeth. There is a lot of pressure at the implant sites, so teeth popping off is common. The attachments wear out needing replacement yearly, on an average. Again a well-fitting denture is critical. Patients report it is about 45-55% as good as natural teeth. For many having removable teeth is also not desired. These teeth are very bulky, since they are a still a denture and for the cost some expect more than then the results.
4 Implant Bar Overdenture: Bone Supported The advantages: 4 implants connected with a bar, will support a denture putting all the pressure of chewing on the bone, with none on the soft tissue. Patients say this is 65-75% as good as natural teeth. They are easy to clean the implants and no bone is lost from the pressure of a denture biting on the tissue. Over time the bone distal to the prosthesis increases in size and density, much like the below choices. The disadvantages: This takes more skill to make than the 2 or 4 implant overdenture and as well, takes planning, and a number more visits. The attachments wear out and need replacement yearly, on an average. These can be made to feel like fixed teeth, with permanent, yet removable attachments (Lew Passive attachments or Swivel Lock attachments) and are less bulky than a traditional denture. If the teeth are plastic they will require maintenance. Very little food gets underneath this overdenture, yet if food gets under it, it isn’t bothersome when they chew. These teeth are a significant investment and close to the cost of Fixed All-on-4 teeth.
Fixed Teeth: All-on-4 or All-on-X: Bone Supported I have recently covered this so in brief;
The advantages: At the day of surgery, the patient walks out with trial fixed teeth and a brand new smile! Like implants used anywhere, the bone work hardens around the implants as well as with the other implant supported choices, the jaw bone gets thicker and bigger. The bone support allows the patient to chew whatever they want, if they are made of a tough material (zirconia or Avadent teeth). The first set of temporary teeth, installed at implant placement surgery gives both you and the patient a “trial run” to be sure each implant takes, so you can verify the esthetics of their smile and occlusion. In the lower jaw, a patient can start with a 2 implant overdenture and upgrade to these fixed teeth over time, as long as adequate interarch space is created or exists. Many times too, if a patient decides to have the teeth be removable before the final teeth are made, the plan can be changed as well. These teeth are bigger than natural teeth yet smaller than the above choices. Overall, these patients have a very high satisfaction rate: 89-94% as they report being able to chew 75-85% as well as natural teeth. Our most common treatment in the mandible, is an All on 4, with the restoring dentist usually choosing a zirconia prosthetic.
The disadvantages: Food collects under the teeth and this is the most common complaint when people have these full arch fixed teeth. Between the implants the bone is not stimulated over the years and it shrinks, so more food collects under the spaces between implants. Sometimes this food collection can be compensated for, again depending on what material is used for the teeth. These full arch teeth are bulky yet less so than the above choices. We have to remove much more bone, 15mm clearance to accommodate the dental materials for the teeth, like with the bar overdenture. This unfortunately makes cleaning for the patient much more difficult, gets to muscle attachment/muscle pulls and often there is no keratinized tissue at the implant emergence site. This type of treatment is best performed by a surgeon and a restorative dentist that do it often enough to get good at it. This treatment method takes skill, planning, and is a significant investment, taking as many visits as a bar overdenture. Most people that are good candidates for this treatment are grateful for the quality of life changes that it provides.
Fixed Bridge work: Bone Supported
Advantages: This is the ideal option for patients with generalized mild to moderate loss of bone: easiest to clean, most natural size of the teeth, and gives the most life like prosthetic esthetics. Typically in the mandible, I’ll use 6 implants at the positions of the first molar, first bicuspid and cuspid positions. This allows for two, 3 unit posterior bridges and one 6 unit anterior bridge. Since there are more implants, much less bone loss occurs long term. If maintenance is required, it is less complicated to remove a bridge, compared to a full arch prosthetic. The extra implants provide more support so the system is stronger for patients with parafunction. Typically there is little to bone reduction needed. This prosthetic has the highest patient satisfaction rate of all 5 choices.
Disadvantages: This prosthetic will cost more than an ALL-on-4 and may take more chair time. There are fewer prosthetic components (seldom are multi-unit abutments used) which makes placing the temporary teeth (“the Jump”), more challenging. Typically a precision surgical guide is used since the bridge work is screw retained. If the anterior cuspid to cuspid span is too large, or severe parafunction or the anterior arch is particularly curved, then a 7th implant should be placed in a central incisor position for the anterior bridge. With the lower 6 unit bridge, space under the pontics will increase over time, allowing food to trap. This plan requires the most treatment planning, training and skill of the mandibular options.
If I needed a full arch prosthetic, I would choose the bridge work noted above.
I especially enjoy helping people move away from dentures or that are headed toward losing their teeth. If I can be of help, please feel free to call on me.
Yours for better health,
Greg Kammeyer, DDS, MS, DABOI
Board Certified in Implant Dentistry