Q: What is a root coverage surgery? What is Miller’s classification?
A: Root coverage surgery is a soft tissue grafting procedure that is done to cover exposed root surface. Root surfaces can become exposed (gingival recession) on the lip side of teeth either by brushing trauma or by inflammation. Exposed root surfaces can become abraded easily while brushing, prone to decay and sensitive to cold. Root coverage simply covers the exposed root surface with either autograft (taken from patient’s own body, usually from roof of the mouth) or allograft (commercially prepared human tissue from tissue banks). The graft tissue is placed over the exposed root surface and tucked under the adjacent gum tissues and sutured in place. After the graft tissue heals and matures (3 months for complete healing), the gum tissue will blend in with the surrounding tissues or blended in surgically.
Miller’s classification is a system of classifying the gingival recession. There are 4 classes.
- Class I: gingival recession is limited to the mid portion of a tooth and does not extend past the mucogingival junction (the junction between the hard gum tissue, appearing light pink, surrounding teeth and soft mucosa which usually appears red)
- Class II: gingival recession is limited to the mid portion of a tooth and extends past the mucogingival junction.
- Class III: gingival recession at the mid portion of a tooth and the interproximal surfaces (the surfaces of a tooth next to other teeth) but does not extend beyond the mucogingival junction.
- Class IV: gingival recession at the mid portion of a tooth and the interproximal surfaces and extends beyond the mucogingival junction.
Dr. Perio’s opinion on Miller’s Classification:
The significance of Miller’s classification is that it helps to describe the type of gingival recession and also to predict how successful a root coverage surgery will be. According to my experiences with root coverage procedures, both Class I and III respond well to a subepithelial connective tissue graft (autograft). However, what I used to predict how much root coverage I will get with a graft is the bone level of the tooth.
Questions? Ask Dr Perio.
