Altered Passive Eruption: Hard Tissue

Teeth are composed of two basic, visible parts—the root portion and the crown (enamel-covered) portion. The term crown does not refer to the type of tooth replacement fabricated by a dental laboratory. Rather, it is the part of the tooth that is normally seen when you speak.

The present-day esthetic dental philosophy, demonstrated by people who have beautiful teeth and smiles, shows that there must be a certain amount of enamel-covered tooth visible for an attractive smile. The ratio is about 1.6:1, length to width. Teeth that are shorter than this look progressively less attractive. They look short and stubby. If they are actually worn down from a clenching or grinding problem, this is a different type of problem. But it may not be that the teeth themselves are too short. It could be that there is not enough of the crown of the tooth that can be seen. The remainder that should be seen is covered with gum or gum and bone tissue. This is known as altered passive eruption. It is not entirely clear why this happens. It may become obvious as early as age 14. The teeth may have a pleasing color and be very straight, but they still leave something to be desired because they are too small and too much gum shows when you smile.

This can be a severe cosmetic problem when coupled with the type of lip line that frames the teeth. A low lip line will probably hide most or all of the gum covered part of the tooth, so there is less of a need to correct the defect. A medium or high lip line, especially a high lip line, will show all of the tooth and gum. As the lip line gets higher, the attractiveness of the smile goes down. The situation can be so severe that the patient will train his or her muscles to artificially hold the upper lip stiff or cover the mouth with a hand when smiling. In this way, the short teeth or the great expanse of gum tissue will be hidden from view. It can cause significant psychological problems.

The solution can be easy or complicated, depending on the exact nature of the problem. If there is only a small amount of gum tissue to be removed from a single tooth or multiple teeth, and there is a medium lip line, then the tissue is easily removed with a laser or electrosurgical cutting device. Scalpels and stitches are not needed in small cases. As more gum must be removed and more tooth is exposed, there may be some underlying bone that must be reshaped. Bone removal will be followed, about 2 months later, by the soft tissue removal mentioned earlier. The first surgery must heal long enough for the tissue to reach its final position before the second can be completed. Remember, you are looking at differences of several millimeters to a fraction of a millimeter that will cause the case to be a success or failure. A two-step procedure is better than a one-step procedure.

The biting edges (enamel and/or dentin) of one or more teeth may be reshaped if there is a need not only to lengthen the teeth but also to make it appear that they have actually been placed higher in the smile line. This is for top teeth, of course. If a great deal of tooth must be reshaped to accomplish the desired effect, root or dentin may be exposed, making the tooth sensitive. These teeth will need to be covered with porcelain veneers or crowns to achieve the proper esthetics. Even if only a little amount of tooth is reshaped, the veneers or crowns may be indicated to get the exact appearance you want. We will discuss this with you before you begin treatment. It is important that you know what is being done, how long it will take to complete, and what you will look like when it is finished,

We will make the veneers or crowns and reshape the teeth. We will determine what can be done. We may also do the soft tissue contouring. This is most common. For procedures that involve a reshaping of the bone, you may be referred to our periodontist. Since we will do the restorative treatment, we know exactly where the soft tissue should be. We are the cosmetic specialists. We will establish the final position of the gum line. In extreme cases, the problem will be corrected with a combination of the above-mentioned procedures and orthognathic surgery to reposition the jawbone and teeth. This can be done by our oral surgeon. With a comprehensive examination, we can tell you what is appropriate for you. You do not have to live with an unattractive smile because you have short-looking teeth due to showing too much gum tissue. These problems can be corrected. Let us know what you do not like about your smile or teeth. More than likely, the smile you now have can be made into something you will like to show off.

If you have any questions about altered passive eruption, please feel free to ask us!  

Hymeadow: (512) 250-5012

Jollyville: (512) 346-8424

West William Cannon: (512) 445-5721