Esthetic Management of a Flat Periodontium Through Orthodontic Extrusion

Patients that are prone to generalized interproximal anterior bone loss are an esthetic dilemma that plagues many restorative dentists. Treatment of these patients often results in extremely rectangular looking teeth since the periodontium is most likely flat.

The patient in the picture above is an example of a very flat periodontium and the teeth have been restored to close the open gingival embrasures that existed. Luckily, she stated from the beginning of treatment that she was willing to do anything that would produce the most ideal results possible.

The goals for her treatment are to end up with normal length contacts across the anterior teeth. For the centrals this means the tip of the papilla should be 5-6mm from the incisal edge, currently hers are 7.5mm.

In addition the papilla height between the centrals should be 4.5-5mm, measured from the gingival margin to tip of papilla, hers is currently 2.5mm. And finally the overall length of the centrals should end up 10.5-11mm, currently hers are 10mm.

Using orthodontic extrusion followed by facial crown lengthening is really the only way to achieve the most esthetic result in these types of patients, and this was the treatment plan from start to finish:

Step 1: Determine why the periodontium is flat. Some patients simply have an excess of facial gingiva that results in the appearance of a flat periodontium, so the treatment plan starts with an assessment of her existing soft tissue to bone relationship. This patient was anesthetized so I could evaluate this relationship, after sounding to bone on the facial and interproximal, her gingiva to bone relationship is perfectly normal. The facial gingiva is 3mm above bone and the interproximal papilla 4.5mm above bone. This means the appearance of the periodontium is due to an extremely flat bony profile, which is why the contact length in the restorations is excessive.

Step 2: Start treatment planning. Once I determined that flat bone was the challenge, I created a treatment plan based on the desired position of three fundamental things: the incisal edges, gingival margins and the papilla.

• Incisal edge: Her incisal edge was appropriate when her lip was at rest. In addition looking at the buccal cusps of the posterior teeth, shortening her anterior teeth incisally would have created a reverse smile line.
• Gingival margins: Her width to length ratio was at 95 percent - essentially “square teeth.” I wanted to get her ratio down to 77-80 percent to achieve attractive looking central incisors. However, since she is a smaller woman with a high smile line, the length of the centrals was a huge concern. An average central incisor is 10.5 – 11mm long; the challenge in this patient is that in order to get to 77 percent with the existing incisal edge position her centrals would end up being around 13mm long. My goal was to make the length of the teeth 11mm while giving the illusion of being narrower.
• Papilla: In an ideal world, I wanted the papilla to end up halfway between the gingiva and incisal edge. In her case, it's about 7.5mm from the incisal edge to the tip of the papilla with a 3.5mm papilla height. My target for her was to use orthodontic eruption to move the papilla 2 – 2.5mm more coronally. By shortening the incisal edges as the teeth are erupted the contact length can be shortened to 5-5.5mm.

Step 3: Prep/Orthodontic extrusion. This particular patient had metal ceramic crowns on her teeth that needed to be removed and replaced with temporaries before sending her to the orthodontist. The prep length was reduced to 3mm in to prevent them from being exposed as the incisal edges of the temporaries are shortened during the extrusion. I then bonded the temporaries with resin cement in place to keep them from coming loose during the orthodontics. The orthodontist then slowly extruded the teeth .5mm per month to insure the bone and gingiva followed. By the end of six months the papilla had been moved coronally 2.5mm. The final distance from central incisal edge to the papilla was 5mm.

Step 4: Facial only gingival surgery. At this point, the tooth measured 7mm and I adjusted the length to our pre-planned goal of 11mm. The beautiful thing about extrusion is that as the teeth come down, they bring the bone and attached gingiva with them. I performed a simple gingivectomy and prepped to that gingival position and placed new temporaries. She was then sent to a periodontist who reflected a facial flap and adjusted the facial bone levels to establish the desired final crown length.

Step 5: Final restoration. After the surgery, and 12 weeks of healing she came back for a simple final impression and the final restorations. We were both very happy with the final result. I also think procedures like this one show you the endless possibilities of what the combination of orthodontics and periodontal surgery can do for patients with a flat periodontium.

Frank Spear, D.D.S., M.S.D., is co-founder of Spear Education and a member of Spear Resident Faculty.