Insight 25 — When the Adjacent Tooth Is Missing, the Crown Looks Larger
Clinical explanation
In posterior teeth, under normal conditions the patient mainly sees the buccal surface of the tooth. But when the mesial tooth has been lost, the mesial surface of the crown also enters the field of view.
In this situation the patient may feel that: the crown has been made larger than normal, the tooth is prominent or bulky, or the form of the crown is not in harmony with the other teeth; whereas in many cases the problem arises from an increase in the visible surface, not from a true increase in crown volume.
Key perceptual point
When the adjacent tooth is absent:
the mesial surface, usually hidden, becomes visible
the natural visual border of the dental arch is lost
the true volume of the crown becomes more apparent
and the perception of the tooth's width increases
Distinguishing from true overcontour
In true overcontour we expect:
an abnormal prominence in the buccal profile
disruption of the cleansing pathway and plaque accumulation
gingival inflammation in the marginal area
and a sense of food impaction
But if the buccal profile is correct and there are no functional problems, the patient's complaint may be purely perceptual.
Diagnostic consequence
Recognizing this phenomenon prevents: unnecessary grinding or adjustment of the crown, needless reduction of crown volume, and damage to the functional contour.
️ Suggested clinical approach
In such conditions:
the buccal profile and occlusion should be evaluated against functional criteria
over-adjustment aimed at «making the tooth look smaller» should be avoided
the patient should be told that this perception is due to the missing adjacent tooth
and that with replacement of the lost tooth, the perception of size will become more natural
Clinical summary
Sometimes the problem is not in the restoration; it is in the visual borders of the dental arch.
When these borders are rebuilt, the perception of size also returns to normal.
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