Altered Passive Eruption is a condition often described as “gummy smile”.
It’s a non-pathological situation which may sometimes affect, depending on its degree, the aesthetics of the smile in young adults and adults.

Fig.1
Smile dynamic shows how the gingival smile becomes evident

Fig.2
Intra-oral pictures show health of soft and hard tissue

Fig.3
Peri-apical x-rays, taken with the Rinn paralleling system, show the differences between clinical and anatomical crown length. The anatomical crown is much longer than what is clinically visible, and the bone ridge is located close to the Cemento Enamel Junction (CEJ).

Fig.4
Incisions with a 15 C blade follow the anatomy studied in the peri-apical x-rays.

Fig.5
After removing the collar of ‘excessive’ gingiva one can notice how the natural enamel becomes exposed and how immediately the teeth emerge from the upper lip.

Fig.6
Once even the left side of the mouth is treated, the natural enamel wonderfully reflects light.

Fig.7
A full thickness flap is elevated to confirm the x-ray diagnosis. The bone ridge is located at the CEJ. In this case we say this Altered Passive Eruption is a Type 1 (gingiva above the enamel), subtype B (the bone is located near the CEJ).

Fig.8
This problem requires bone resective surgery in order to remove the buccal excess bone, and to create a biologic width for soft tissue attachment.

Fig.9
Once resorbable sutures are placed, the soft tissue perfectly adapts to the newly shaped anatomy

Fig.10
The new smile is clearly a big improvement.

Fig.11
One year follow-up shows perfect stability and adaptation.

Fig.12
The gummy smile long gone and a new bright smile has now taken its place

Fig.13
The history of this case showing the dramatic improvement with a very simple surgical procedure.
Conclusions
Altered Passive Eruption is not a disease, but a condition subsequent to a relationship between the bone, the tooth and the soft tissue after teeth eruption that is today often considered aesthetically unpleasant. We recognize two Types (1 and 2) and two Sub-.types (A and B) depending on the position of the soft tissue and of the bone ridge in relation to the CEJ.
In this case, we faced a Type 1 (gingiva coronal to the CEJ) Sub-type B (bone crest near the CEJ). The diagnosis is made by measuring the clinical length of the teeth, and matching it to the peri-apical radiography. Following this evaluation a gingivectomy and an osseous resective procedure allow the ‘exposure’ of the natural beautiful smile.
Bibliography
Rossi R, Beneddi R, Santos-Morales RI. Treatment of altered passive eruption:
periodontal plastic surgery of the dentogingival junction. Our J Esthet Dent 2008 3(3):2012-23
Coslet JG, Vanarsdall R, Wisgold A. Diagnosis and classification of delayed passive eruption of the dentogingival junction. Alpha Omegan 1977