16 Late lower incisor crowding
Graham is almost 20 years old. He presents with crowding of his lower incisors (Fig. 16.1). What is the cause and how would you treat it?
His lower front teeth were straight until 18 months ago when he noticed crowding developing. He now finds it more difficult to keep his lower front teeth clean. Calculus build-up also seems to occur more easily on the inside of the lower teeth, which he finds annoying. He is also aware of the two wisdom teeth erupting at the back of his lower jaw for the past 18 months. These do not cause him any problems but he wonders if they are making his lower front teeth crooked.
In modern populations, there is a strong tendency for crowding of the mandibular incisor teeth to develop in the late teens. This occurs even if the teeth were well aligned or spaced initially, leading usually to mild crowding, whereas initial mild crowding tends to become worse. Lower labial segment crowding also occurs in patients in whom extractions for relief of crowding and fixed appliance therapy have been undertaken (unless a bonded lingual retainer has been placed).