Smile Design

What makes that perfect smile?

There are many different attributes involved in what we consider to be a beautiful smile.  Partly instinct, partly psychosocial conditioning since infancy—we know a nice smile, a friendly face, when we see one.  And most of us associate an attractive smile with straight, white teeth.  But there are a host of other factors which are less obvious, yet just as important. Even though most of us may be only aware of these nuances at a subconscious level, these particular features impart a natural beauty to the smile because it looks healthy.  And health is the essence of beauty.

If you are considering a smile makeover, these are some of the things which you should consider when talking to your Dentist, so that you can get the best result possible.  Because the upper teeth tend to show much more than do the lowers, these details become much more important with respect to the upper teeth in the development of a beautiful smile.

Tooth Shape

It should come as no surprise that teeth are not perfectly rectangular.  In fact, each tooth has a very specific anatomic form which is associated with its function throughout evolution.  For example, the canine teeth (or “eye teeth” because of their alignment with the pupils) are normally pointed, and developed in mammals for the purpose of grasping and holding prey.  Obviously, this ability is of no use to modern humans, however the teeth retain this same basic shape, but are much shorter.  Additionally, the point is not centered.  It normally lies closer to the front one-third of the tooth edge.   This gives the appearance that the tooth is leaning slightly forward.  If we were to see a canine with a centered tip, it would subconsciously appear strange to us, though we would not necessarily know why.  And what if the points are worn flat?  This subconsciously gives the impression of advancing age.  Similarly, the four incisors (or cutters) appear to bend slightly forward due to their shapes, and can make you look older if the edges are worn.  To maintain overall sense of balance, general shape of your teeth should be in harmony with the shape of your face, i.e. round, square, ovoid, etc.

Relative Tooth Size

Natural teeth tend to vary in size depending on the tooth type.  Specifically, lateral incisors are typically slightly shorter and narrower than the central incisors and canines.  Teeth that are made too similar in size may take on a fake appearance because this deviates too much from nature.

Tooth Proportion

The sizes of the teeth themselves, and also as they relate to one another follows a mathematical concept called the Golden Ratio.  This ratio (1 : 1.6) is ubiquitous in nature, and has been a standard proportion used by artists and scientists since the Renaissance.  It is thought that objects which conform to this proportion are esthetically pleasing.  When applied to teeth, the ratio dictates that the length of each tooth is 1.6 times the measurement of the tooth’s width.  Further,(when you view your smile from the front) that the central incisors (two middle teeth) appear 1.6 times wider than the lateral incisors.  And likewise, the lateral incisors appear to be 1.6 times wider than the canines even though they are actually much smaller.


Even a subtle variation in size or shape from one side to the other can result in a crooked appearing smile.  It is also important that the midline contact between the central incisor teeth is perfectly vertical and is aligned with the center of the face.  Ideally, the left side will be a perfect mirror image of the right side.

Gradients of Color

Natural teeth are slightly more yellow near the gum-lines, and gradually become whiter and somewhat translucent near the biting edges.  Often, the canine teeth are slightly darker than the four incisors.  This is not necessarily a bad thing, since the subtle contrast in colors may have the effect of making the incisors appear to be whiter.  (An old joke along the same lines is that if you want whiter teeth, wear dark red lipstick.)


The general consensus among Cosmetic Dentists is that in most attractive smiles, the upper lip covers about three-quarters of the front teeth when the lip is relaxed.  And when smiling broadly, the teeth should show entirely plus a little bit of the gums.

Gum Line

The gum-line plays a crucial role in the appearance of a smile.  The level of scalloping of the gum tissue provides a reference point by which the length of the teeth is observed.  In other words, regardless of how the biting edges line up, the teeth may appear longer or shorter depending upon the gum level.  Often as part of a smile makeover, the gums are contoured so that the gum-lines are at the same level.  Trimming of the gum tissue can also help a gummy smile.  Additionally, the gum tissue between the teeth should look pointed.  In cases of gum disease, this point is lost due to gum recession.  This leaves behind unsightly dark triangular spaces between the teeth.

Gaps and Spaces

Most people agree that gaps between the teeth tend to look less attractive than having all adjacent teeth touching.  But some empty spaces are good, though it’s probably not what you might think.  We have all heard the term “broad smile”, but have we ever stopped to think--- how broad is too broad?  Well, here is the answer:  When we smile, the corners of our mouths are drawn outward.  Suddenly, a set of perfectly aligned white set of teeth appears.  But what else?  You have probably never noticed this unless you attended dental school, but there is black that appears on the sides!  This darkness is the natural spaces which are created when the cheeks retract.  In Dentistry, we call it “freeway space”.  And if you don’t have this freeway space, the smile looks disproportionately wide.  Also when we smile, the jaw opens slightly.  This reveals darkness between the upper and lower teeth, and helps to give your smile a natural, healthy appearance.