Dr Dawson, why do you call your lecture series ‘The concept of complete dentistry?’
Dentists are the only medical professionals responsible for the health of the entire masticatory system. The teeth do not hang out in space; they must work together in harmony with the masticatory musculature and the temporomandibular joint. Complete dentistry has four comprehensive goals: optimum oral health, anatomic harmony, functional harmony, and occlusal stability. If each goal is achieved, treatment success is assured. When the entire system is healthy, there is a harmony of form and function, and the relationships are stable, then the treatment can be considered complete. Aesthetic requirements will also be fulfilled because the appearance of the smile is dependent on the same harmony of form that is necessary for the harmony of function.
What is centric relation and why is it so important?
Centric relation (CR) is the single most important factor of occlusion and determination of it is the most important skill required for predictable occlusal treatment. CR is defined as the relationship of the mandible to the maxilla when the properly aligned condyle-disc assemblies are in the most superior position against the eminentiae irrespective of vertical dimension or tooth position. The condyles are in CR if four criteria are fulfilled:
1. The discs are properly aligned
2. The condyles are at their highest point against the eminentiae
3. The medial poles are braced against bone
4. The inferior lateral pterygoid muscles have released their contraction and are passive. Because occlusion plays a dominant role in almost everything a dentist does, not understanding that role causes a major amount of wasted time and makes it impossible to be predictive about complete patient comfort.
What is the envelope of function and vertical dimension of occlusion?
JC: The envelope of function (EOF) may be one of the most critical concepts to understand today for the practicing dentist. It refers to the path that the lower incisors travel as the mandible opens and closes during all functional movements. Some EOFs are straight up and down, whereas others are horizontal. Patients that function horizontally tend to have increased wear, and restoration fractures on their front teeth. Patients who function vertically tend to put our restorations at less risk. When restoring anterior teeth, it is extremely important that they be constructed in harmony with the individual patient’s EOF, Dr Dawson has taught this concept for years, and it works wonderfully to construct restorations that are stable, beautiful, and comfortable.
When done properly, we do not have to talk our patients into accepting restorations that do not allow for clear phonetics or do not feel completely natural. Vertical dimension of occlusion (VDO) is the vertical relationship of the upper jaw to the lower jaw, when the teeth are together. We believe that the VDO is determined by the repetitive contracted length of the muscles of mastication. It is the repetition that creates the interocclusal space in which the teeth erupt. While this is a complicated subject, the restorative dentist today must understand VDO. Some occlusal problems simply cannot be addressed without altering the VDO, and yet with other patients you do not want to alter it at all. The key is to learn the difference.
What problems can result from a malocclusion?
JC: I believe occlusal disease is the most prevalent problem that patients have today. Occlusal
disease is the number one cause of tooth loss, patient discomfort, patient dissatisfaction, and orofacial pain. It is the number one missed diagnosis. Occlusal disease can manifest as worn dentition, splayed teeth, abfractions, sensitive and sore teeth, loose teeth, and painful
musculature. Dental assistants and hygienists should be trained to recognise the signs of occlusal
instability and disease.
What would your advice be to a young dentist wishing to practice cosmetic dentistry?
GdP: I would suggest to the young dentist that he/she commit to learning how the whole stomatognathic system works so that their beautiful aesthetic dentistry has
predictable long-term stability. Also, commit to being a continual student. Realise that
functional aesthetics that lasts is not accomplished through using
averages but through an understanding of how the joints, muscles, teeth, and periodontium all interact in that individual.
What are the major advances in dentistry in the last five years?
GdP: I think dentistry has advanced in numerous ways. Some of these that come to mind are the increased use of digital photography in our treatment planning and laboratory communication. This combines with an increased ability to communicate this information digitally to laboratories and other specialists. Another advancement is in the materials area with improved porcelains and ability to bond restorations. This would include the use of Allograft materials in periodontics, which allows us to graft tissue with much less discomfort. This, along with a greater utilisation and improvement in bone grafting, has allowed us to be able to successfully restore the severely debilitated patient very predictably.
There has also been a greater understanding of the TMJ and muscles as they relate to the occlusion with devices like the T-scan and EMG studies in order to allow us to help the severe parafunctional patient with greater predictability.
How did you get involved with the Dawson Academy?
IB: When I came across John Cranham about 10 years ago, he was the first speaker I had heard who described a logical, systematic approach to providing not only beautiful aesthetics, but also the underlying function that makes for comfortable, long-lasting restorations. Fulfilling the needs and desires of the patient while always acting in their best interest was of paramount importance.
Perhaps most importantly for me, Dr Cranham showed a genuine interest in my development, which has involved extensive and varied courses with many of the dental luminaries of our time. Working through the Dawson Academy curriculum was at the centre of all this and I have been
fortunate to learn from Glenn DuPont, Witt Wilkerson and, of course, Dr Dawson. It is a great honour and a privilege to now be part of their teaching faculty.
What are your plans for the future of the Dawson Academy?
We have recently revamped the whole of our curriculum to ensure that our courses reflect modern practice, particularly aesthetic dentistry, while maintaining the timeless principles of the Dawson philosophy. We are particularly excited to be bringing the whole of our core curriculum – lectures and hands-on, to the UK in 2009.
John Cranham is presenting his seminar ‘Managing the worn dentition’ on Friday 27 March in London. Ian Buckle is presenting an optional ‘Treatment planning workshop’, the next day. For information and to book, call Independent Seminars on 0800 371652 or visit www.independentseminars.com.