How much facial changes can we see when changing the vertical dimension of our jaw - Caris Heiniger 

Research undertaken by Caris Heiniger with support from Dr Peter Mei, School of Dentistry.
Walsh & Beck Scholar
A new study is looking at whether we can quantitatively predict the facial changes when changing someone’s vertical dimension between the upper and lower jaw.
Changes in maxilla-mandibular vertical dimension is relevant in several dental disciplines, including orthodontic treatment and inserting prosthetic devices, not only affecting function but also having major aesthetic impacts.
The study looked at the three dimensional face shape changes when the lower jaw is at rest position and when in maximum biting position. This was done using the 3dMD facial scanning system, where two 3D images were obtained from each participant, at maximum biting position and the jaw at rest position.
The 3D imaging techniques have been introduced relatively recently, and they provide a more accurate evaluation of facial soft tissue.
There is an appropriate space between the upper and lower teeth, known as freeway space, so that the teeth do not click together when the subject talks. Orthodontic treatment, dentures, tooth grinding and bite splints, which are all common dental problems, can all affect this vertical relationship between the upper and lower teeth.
This study looked at how such changes directly affect the external facial soft tissues, and hence can sometimes affect the way you look. Appearance and aesthetics, especially when it comes to our face, is of great importance to most people. It is usually the first thing we notice about someone, and hence is also how we are identified.
Therefore, it is of both the dentists and the patients’ concerns how changes in the vertical dimension inside the mouth, can have changes in our facial morphology outside the mouth.
The study also explored the relationship of these facial changes with various facial traits, such as comparing the differences observed for someone with a longer face versus a shorter face.
Previous studies have found that space between teeth when the jaw is at rest is smaller in subjects with longer faces than in subject with shorter faces. It would be interesting to see whether this will influence the amount of facial changes that will be observed as well.