Shapes, Sizes, Colors and Appearance
F.Spiva jr. CDT MDT CD
Ever wonder how denture teeth are selected? Denture teeth are purchased from a Dental Supply House and they are ordered on what is called "Cards"..like the two "cards" you see above. The top Card is Six (6) front Upper teeth and the bottom Card is the Eight (8) Upper back teeth, making a total of (14) which does not include Wisdom teeth, which are never used on dental appliances.
The lower teeth come Carded the same way. The Six (6) lower front teeth on a Card and the back Eight (8) molar teeth on a Card. Sometimes the cost of a Dental appliance is a bit higher because some brands of teeth are only sold by the full card. That means if you are getting a Partial Denture that only needs three (3) teeth on it, a full card of six (6) will have to be purchased. Depending on the brand and the supplier, it's possible to order only the specific individual teeth needed.
When and if the person your buying your appliance from tells you they only have a limited choice of tooth color or size, that is not true....Each tooth card is produced in about 20 sizes and shapes as well as about 15 different colors....and most are also made in either Plastic (composite) or Porcelain.
The back teeth come in a variety of chewing surfaces. Some are "Flat" appearing on the chewing surface but actually have cutting grooves. There are teeth that have various angels to the chewing cusps...They are called ten (10) degree cusps, twenty (20) degree cusps and thirty (30) degree..That in reality is how the slope from the top of the cusp down to the bottom of the cusp is defined.
There is another type of back denture tooth as well. It's called a "Cutter Bar" tooth. Cutter Bar molars are produced as a single unit, meaning that all four (4) molars, upper or lower, are created attached together...A metal bar in a straight or zig zag pattern is length wise down the central groove of the teeth from one end of the four to the other. The chewing surface will be flat overall but the bar will extend slightly above the chewing surface....We in the business sometimes like to define it as working like a knife and bread board..the cutter bar is the knife blade and the opposing plain flat tooth surface is the bread board. Look at it this way. The cutter bar is in the upper back teeth and the lower back teeth is simply flat....When the cutter bar comes against the flat tooth surface on the bottom it's like a knife blade on a bread board.
The cutter bar teeth are usually used in dental appliances for patients who have a weak biting ability, such as someone who has had a stroke and been left weak on one or both sides of the jaws. Sometimes just a persons age and general health can be a reason to use cutter bars.
Now, keep in mind that denture teeth come in basic shapes designed to balance with the face and body...The basic shapes are Square, Ovoid and Tappering.Then their are combinations of those such as Square/Ovoid. Square/Tapering ect. Your denture provider has an enormous choice of size, shape, length and color to choose from and all of those choices should be dictated by your body and facial features....Example: Tooth color, if you want to look balanced color wise, the denture teeth should be a balance matched between your Hair, Eye's and Skin tone. Teeth should not draw attention because they are stark white or any other shade. They should not draw attention because they are to big or to small for you mouth. There are body features that also balance with teeth..One example is that if you draw a straight vertical line or hold a straight edge at the side of the nostril of the nose so that the line or straight edge extends down past the mouth and you smile, that line or straight edge will go directly down the middle of the Eye tooth. That is true with at least 95% percent of people.
Another interesting measurement that proves out in the majority of people is that you can place a pencil dot on the center of the tip of the nose and another on the center of the point of the chin. If you then measure the distance between the centers of the pupils of the eye's and have the patient or person close their teeth together and compare the two measurements, the one between the pupils and the one from the dot on the nose to the dot on the chin, you will find that in the majority of people, the measurements will match....If the one between the nose and chin is closer together than the pupils measurement, that usually means the jaws are "over closing" and the bite is to close together. If on the other hand the measurement between the nose and chin is greater than that of the pupils, it usually means the teeth are coming together to quickly, the bite is to open.
When the bite is to close, the lips fold in and have a thin appearance. A crows foot appears at the corners of the mouth and a deep crease forms from the side of the nose down to the corner of the mouth. When the bite is to far open the jaws can't rest..and that can cause aching and soreness..When you close your teeth together, swallow and relax, the teeth should open and rest apart about the thickness of one or two dines...That is called the "REST" position. If the opening between the teeth in the rest position is such that you can place your tongue between them, without opening the jaws, the teeth are not touching soon enough when you close them together, meaning they are "Over closing". Using these old methods can work miracles when a patient comes in without teeth or and old denture and they say, "These never really looked like my old natural teeth and makes my face look different." Picking the right size, shape and color of teeth and setting them in a proper jaw opening will always be the difference between patient success and patient failure....if the proper precision impressions and jaw relationship is achieved.
I have had patients come in and ask if it's possible to restore some of their natural appearance before they lost their teeth...I've used the measurements described above as a guide and after delivering the finished dentures had patients bring in an old photo they found after I made the dentures. They wanted to show me how much the new dentures gave back a great deal of their old appearance..Of course I always asked for a good photo of them smiling before they lost their teeth to use as a guide to arrange the new teeth..and make any changes they personally wanted in the arrangement.
These kinds of choices in denture teeth, design and arrangement can take time and I don't know of a single "One Day Denture" that can be created that uses all the available information and individual custom measurements. People and mouths are like fingerprints, no two are alike and production line dentures created with cheap materials will always fail to provide a patient with the best possible outcome.
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F.Spiva Jr. CDT MDT CD
The Denture Pro