What You Need to Know About Crown to Root Ratios

Have you ever wondered about what crown-to-root ratios are and what the optimal crown to root ratio should be before ortho starts? When developing a treatment plan, crown-to-root ratios can significantly impact the approach you take. In line with this, we’ve outlined some key things you should know to help.
Always Start with a Panoramic X-ray
Before ortho starts, one of the first tips we recommend is to take a panoramic x-ray. Indeed, a panoramic allows you to check more pathology, further helping inform your decision without worrying about blind spots or unknowns.
What Should the Crown to Root Ratio Be?
In most cases, you’ll want to make sure that at least 50% of the tooth is in the bone when creating an orthodontics treatment plan. In other words, the crown to root ratio should be 1:1 or better (i.e., with more of the root embedded in the bone).
Always consider the patient’s history of periodontal disease as well when making your treatment plan. If there was a history of periodontal disease or if the crown to root ratio was not correct when ortho starts, there’s a chance of poor prognosis (potentially even with the teeth falling out).
Always Consider Individual Cases
In some cases, it’s worth noting that individual cases might not be as clear-cut. For example, you may have a borderline case that needs a PA x-ray to check the tooth isn’t inclined differently. A periodontist should also check this before ortho starts to make sure orthodontics is safe for the patient; always get the periodontist’s confirmation in writing before progressing if there’s any uncertainty.
And remember: if you have a borderline case, make the treatment plan as gradual and gentle as possible. Make sure that the patient also returns to their periodontist for a check-up regularly (every few months).
The patient also needs to know at the outset that if things aren’t progressing as expected, the treatment plan may need to stop, in which case the patient will be billed for services rendered. You may need to explain “billed for services rendered” to the patient at the outset so they know how this works.