Glossary

What is Orthognathic Surgery?

Patients require orthognathic surgery when one or both of their jaws are misaligned due to either excessive overgrowth or undergrowth. This misalignment results in teeth which don’t seem to fit together properly. The goal of orthognathic surgery is to correct this mismatch of the jaws and teeth. Not only will this allow the teeth to meet correctly and function properly but also it will improve facial appearance as well.

Why won’t Orthodontics alone work to correct this jaw mismatch?

The goal of orthodontics is to correct the crowding of teeth and abnormal tooth angulations and rotations. Orthodontics cannot correct an abnormal jaw position, only orthognathic surgery can fix misaligned jaws. In summary, orthodontics corrects abnormal tooth position; orthognathic surgery corrects abnormal jaw position.

What are typical symptoms that may result from misalignment of the jaw?

Different misalignments in a jaw’s position can produce different symptoms. Common problems associated with misaligned jaws include:

  • Difficulty in biting and chewing food
  • Chronic jaw or TMJ pain
  • Breathing problems
  • Speech problems
  • Abnormal wear and tear on teeth

What do I need to do to get started?

Over the years I’ve performed many orthognathic consultations. I find the challenge in doing these consultations and treatment plans has always remained the same. First, how do I describe the way a patient’s bite differs from a normal bite? Secondly, how do I describe the changes in function as well as dental and facial appearance in terms that a patient will understand? It is my wish for my future patients to gain further insight and education by viewing other patient’s pre and post-surgical dental and facial pictures. All of these cases are patients whom I have personally treated and photographed. In some cases, I have included photos of study models and x-rays to help identify a problem or show some of the intermediate steps required prior to the surgical end result. Most cases, however, are simple before and after photos.

You will note orthodontic braces are a common feature present in many of these case studies. In order to produce quality surgical outcomes, I have to work closely with the orthodontist. I’ve been fortunate to work with many fine orthodontists. I have given them credit, too, as they are an integral part of the surgical outcome.

I recommend trying to find dental and facial appearances which you feel are similar to yours. In describing the patients’ condition, and treatment plans, I purposely tried to avoid using medical or dental terminology but unfortunately some professional jargon is unavoidable. So we can all speak the same language, I’ve tried to “hyperlink” the dental terminology directly to its definition. If you can’t remember what a “Crossbite” is, then click on Crossbite and it’s definition will pop up. Also, if you wish to focus on just one specific clinical feature, let’s say for example, “Underbite”, you can hyperlink to specific cases of Underbites which are listed below the definition of “Underbite” on the terminology page.

Finally, I want to thank my patients for allowing me to use their photographs. Many of these patients have told me the surgery I performed has changed their life in a very positive meaningful way. Recently, one of my assistants told me you can see these changes in the eyes of the patients post-operatively. In reality, sometimes I feel these patients have a greater impact on me than I have on them. There has never been a greater thrill for me than to be involved in giving a patient a pleasing smile. I am grateful for the chance to do so and to have had the opportunity to make a positive impact in the lives of my patients.

Underbite

By appearance, patients with Underbites have a strong jaw with a chin that juts straight out. The lower front teeth are positioned before the upper front teeth. This condition is caused by the horizontal underdevelopment of the upper jaw, the horizontal overdevelopment of the lower jaw, or most frequently a combination of both.

Nonsurgical orthodontic attempts at treating skeletal underbites can result in the chin's already prominent appearance being further accentuated by the orthodontic retraction of the lower front teeth. This occurs because the lower lip (which is supported in its normal position by the lower front teeth) falls backward when the lower front teeth are orthodontically retracted. Finaly, nonsurgical orthodontic attempts to treat skeletal underbites can result in lower front teeth which are periontally compromised.

Examples of Underbites caused by an underdeveloped upper jaw can be found by clicking on: AF, SO, JB.
Examples of Underbites caused by an overdeveloped upper jaw can be found by clicking on: JJ, KP, AR
Examples of Underbites caused by a combination of underdeveloped upper jaw and an overdeveloped lower jaw can be found by clicking on: SD, SH, CM, RM, TM, ED, GG.

Overbite

By appearance, patients with Overbites are "bucktoothed" and have a receding chin. The lower front teeth are positioned; too far behind the upper front teeth. This condition can result from a horizontal overdevelopment of the upper jaw or an underdevelopment of the lower jaw or a combination of both. Some Overbites can be treated by tooth extraction only when the upper and lower jaw are normally sized and positioned: and extraction therapy will not produce flattening of the face or apparent elongation of the nose which occurs when the upper lip (which is supported by the upper front teeth) moves backward when the upper teeth are orthodonticly retracted.

Examples of Overbites can be found by clicking on: AC, CC, JCF, DD, ND, DG, JH, SM, SS.

Crossbite

This occurs when the upper teeth are biting inside the lower teeth. This is frequently the result of a narrow upper jaw. Crossbites also occur because of a mismatch in jaw size and position between the upper and lower jaw. Some crossbites also lead to asymmetry of the lower jaw by causing the jaw to be abnormally deflected to one side when closing the teeth together. Proper diagnosis determines how and when a crossbite needs correction.

Examples of Crossbites can be found by clicking on: SD, IF, SH, RK, PL, CM, SO, KP, AR, SR.

Open Bite

This occurs when the upper front teeth can not meet or overlap the lower front teeth even though the back teeth have closed together. Clearly this makes eating difficult. It's hard to eat a slice of pizza when your front teeth don't meet! Open bites are caused by the overdevelopment of the back portion of the upper jaw in a vertical direction. As the back portion of the upper jaw grows vertically downward, the lower jaw will open in a clockwise direction. This explains why open bite patients have a long facial appearance. (Put a pen between your back molars and look in the mirror and see how your face has grown vertically longer in appearance. )

Examples of Open Bite can be found by clicking on: JCF, JCM, BF, SH, RK, PL, CM, SM, NP, ST.

Lip Incompetence and Lip Strain

When the upper jaw has become overdeveloped in a vertical direction, the upper and lower lip may not meet together at rest. This condition is know as lip incompetence. People do not like to walk around with their lips wide open. Consequently they must constantly contract their chin muscles to forcibly (hence the term lip strain bring their lips together).

Examples of Lip Incompetence can be found by clicking on: JCF, DD, KD, SD, SH, PL, CM, SM, NP, SR, ST.

Gummy Smile

When the upper jaw has become overdeveloped in a vertical direction this may lead to a very gummy smile and "horsey appearance." Not only is the situation cosmetically undesirable, it can also result in sore, red, bleeding gums from chronic exposure to air (a phenomenon call air gingivitis).

Examples of Gummy Smile can be found by clicking on: DD, KD, SH, TM, ST

Paranasal Deficiency

When the upper jaw is horizontally underdeveloped (backward positioned), there is a flattening or shallowness on either side of the nose. This "dished-in" appearance will actually make the nose look larger than it really is. Advancement of the upper jaw has the effect of decreasing the apparent size of the nose.

Examples of Paranasal Deficiency can be found by clicking on: DD, KD, SD, AF, SH, PL, CM, RM, TM, SO, NP, SR, ST.

Asymmetries

An asymmetry will occur when there is a difference of growth between the right and left sides of either the upper jaw, lower jaw, or both. The lower jaw asymmetry can be identified because the chin point will be deviated off to one side. The upper jaw asymmetry can be identified by looking at the position of the two front teeth. If the upper jaw is symmetrical, the line dividing the two upper middle teeth should be the same as the line dividing the face into two equal halves (the facial midline).

Examples of Asymmetries can be found by clicking on: IF, SH, RK, CM, TM, ED.

Maxillary Cant

This is also a form of asymmetry. In this particular form of asymmetry the upper jaw is being rotated-about a frontal midpoint. This occurs when one sides of the upper jaw becomes much more vertically overdeveloped than the opposite side.

Examples of Maxillary Cant can be found by clicking on: TM, ED.

Mental-Labial Fold

This is the groove between the chin and the lower lip. A vertically long chin can have an underdeveloped mental-labial fold. Occasionally, severe Overbites cause a deepening of this mental-labial fold by causing the lower lip to turn outward.

Examples of Deep Mental-Labial Folds can be found by clicking on: AC, CC, ND, DG, JH, SS.
Examples of Shallow Mental-Labial Folds can be found by clicking on: JCF, SG, SH, RM, SM, NP, ED.

Genioplasty

This is a surgical procedure which is performed to recreate the normal shape of the chin. A large chin may require both a vertical and horizontal reduction, while a small chin may require vertical and/or horizontal augmentation to create an esthetic chin appearance. In addition to the obvious cosmetic benefits, a genioplasty procedure will help reduce lip strain and lip incompetence.

Examples of Reduction Genioplasty can be found by clicking on: PL, SH, KP, NP, ED.
Examples of Augmentation Genioplasty can be found by clicking on: JCF, SG, CM, RM, SM, FP, SR.

Dental Compensation

This is mother nature's way of camouflaging a skeletal bite deformity. Let's say a lower jaw grows out in an excessive horizontal forward fashion to create an Underbite. In an effort to minimize the size of the Underbite, the lower front teeth will "compensate" by tipping backwards (opposite the direction of the excessive horizontal forward growth). The upper front teeth will also "compensate" by tipping forwards in effort to meet the lower front teeth. Unfortunately this "compensation" is not good for the health and longevity of the front teeth. In preparation for surgery the orthodontist will remove this dental compensation and put their teeth in their ideal position. Continuing our example, this means the orthodontic "decompensation" will make the Underbite appear more severe presurgically. (If an Overbite existed, the Overbite would appear to get worse presurgically. Fortunately, this is only a temporary condition as the repositioning of one or both jaws will completely correct the more dramatic Underbite (or Overbite).

Examples of dental compensation and its orthodontic presurgical correction can be seen by clicking on: SH, PL.