How long or short to make the new porcelain veneers or crowns, this is a very important question! The cosmetic dentist will make this decision based on several subjective and objective criteria, and then after determining the length it must be verified and approved of by the patient during the “trial smile” stage.
The most important question the dentist should ask with regards to the length of the new teeth is direct to the patient, “How do you feel about the length of your teeth? When you look at yourself in the mirror or in photos, do you think they are too long, too short, or just right for your face and smile?” If the patient wants them longer, and the dentist shorter, almost always the patient’s wishes supersede. Even after going through the Snow teeth whitening process, you should focus on the overall strength of your teeth.
Next, the cosmetic dentist will look at the patient’s mouth in a rested state (called “repose”), with the teeth apart, jaws relaxed and not clenched, breathing slightly through the mouth, and with the lips relaxed. Usually, a younger adult, aged 25-40, who has a normal length upper lip, will show about 1-3mm of teeth. As a general rule, younger patients show more, and older show less.
Another criterion the cosmetic dentist will use is viewing the teeth in a full smile. Do the edges of the upper teeth follow the curve of the lower lip, called following “the smile line”. A frequent challenge with this is many times the patient has asymmetrical lips and/or lip musculature, so when they smile one side does not mirror the other. It is always best that the cosmetic dentist point this out to the patient at the beginning of treatment, as the patient and dentist will have to choose which side to follow. Very rarely would the dentist create teeth with an asymmetrical smile line to follow asymmetrical lips? When checking the “smile line”, the cosmetic dentist may ask the patient to say the letter “E” and hold it, as in “…eeeeeeeee”. Similar to amateur the photographer asking the subject to say “cheese”, this produces a full smile for evaluation.
When smiling, most patients show at least 90% of their front teeth. If that’s the case, there are well-established parameters for the most esthetic proportion of the upper front teeth. Given that there isn’t much a dentist to do to increase the width of the teeth (unless they are spaced or crowded), most cosmetic dentists recognize that the ideal central incisor (front tooth) is rectangular, and longer than it is wide. Also, the proportion of the length to width of an ideal upper central incisor is 75-80%. Put another way, based on the available space for the width of a central incisor, the ideal length is about 1.29 times longer.
Average teeth length is also something that cosmetic dentists keep in mind. The average length of an unworn upper central incisor is 10.5-11.5mm. A person with a smaller stature would more often use a smaller number, and likewise someone with a larger face a larger number. These averages are only used as a guide to reinforce to the patient that they are within some normal ranges. We’ve successfully made porcelain veneers for some patients as short as 9mm and as long as 15mm.
There are a number of other guides that come into play but beyond the scope of this article. Some involve facial proportions and the well-established Golden Proportion found in nature, mathematics, and art.
Once the cosmetic dentist and patient have determined a tentative length of the upper front teeth it must be verified with phonetics – how the patient speaks with the new teeth. This is done in the “trial smile” stage (see the section on the “trial smile” also on this blog). If the patient’s new teeth are too long he/she will have difficulty saying words with “v” or “f”. The cosmetic dentist will watch the patient say words like “victory” and be asked to count from 55 to 59.
Thus it can easily be appreciated that how long or how short to make porcelain veneers or porcelain crowns for the upper front teeth can be a complicated decision based on many factors and variables. The cosmetic dentist should work together with the patient to create “front teeth” (i.e. porcelain veneers or crowns) with lengths that are appropriate for the individual, esthetically pleasing and allows the patient to function and speak properly.