Tuesday, October 16, 2007

Back to basics – the importance of anatomy

Dr Ian Peace explores the areas of periodontal anatomy that are essential to providing quality care.

In a recent article I mentioned John Hunter, the amazing anatomist from the 18th Century. His intricate dissection work led to a greater understanding of the human body and hence the development of many modern surgical techniques.

In the same vein, a detailed understanding of periodontal anatomy, the changes that occur in the disease process and the resultant healing process following treatment, are essential pre-requisites to quality care.

Additionally, by fully understanding the environment in which we are working it may actually elevate the perceived (by many) boring nature of periodontal therapy into a rich area of modern therapies and techniques. A necessary change in perspective! So no apologies for approaching this potentially dull subject.

Points to consider
So what are some of the areas of periodontal anatomy worth considering?
• How about the basics. The ginigival sulcus where the healthy depth is between 0.5mm and 3mm. Anything over 3mm may be perceived as disease especially where there is a change in colour and shape from pink, knife edged and well defined to red and swollen. The question arises as to where health stops and disease starts.

• Apical to the ginigival groove begins the attached gingiva. We now consider that you do not need a minimum depth of attached gingiva to maintain gingival health and as little as 1mm is sufficient. We therefore no longer perform procedures to widen this band.

Where the depth of attached gingival comes into play is when root coverage procedures are to be performed. The wider the attached gingiva and distance between the base of a recession defect and the alveolar mucosa (elastic, mobile tissue) the better prognosis for the outcome of the coverage procedure.

• The gingival crevice is lined by a sulcular epithelium and junctional epithelium. The junctional epithelium forms an epithelial attachment to the enamel via a hemi-desmosomal attachment. This attachment is weak and so can easily be penetrated by overenthusiastic probing. During disease this attachment will migrate onto the cementum surface.

• The junctional epithelium is permeable to gingival crevicular fluid, the cells being widely spaced. This allows defence cells (Polymorph Nuclear Leucocytes) and other immune and inflammatory components such as complement and antibody to reach the sulcus to fight the plaque attack.

Additionally it allows certain drugs such as antibiotics to penetrate the sulcus and therefore give them a chance to reach the site that they are needed. Conversely, the wide spacing of the cells does however allow inflammatory products to permeate the tissues and stimulate an inflammatory response.

So the next time you are in the region of the gums, maybe you can sense the fascinating and intricate world that is before you.

Author : Ian Peace

Ian Peace BDS, MmedSci, runs a private periodontal referral practice in Nottingham, and offers postgraduate periodontal courses aimed at the whole dental team. For further details call 08700 114 512 or email IanDPeace@aol.com