How Is Gum Recession Measured?

how is gum recession measured

If you’ve been told that your gums are receding you may be wondering how gum recession is measured by dental professionals.

The good news is that it’s quite a simple procedure, dental professionals simply measure the distance between the crown of the tooth and the top of the gum line with a dental probe.  A positive number means that the gums have receded.

This post aims to explain how gum recession is measured and what it means.

What Does Gum Recession Look Like?

Most people do not know that their gums are receding as it happens gradually. The first sign may be tooth sensitivity or teeth that look longer. You may be able to feel a notch where the gum has receded.

photo showing gum recession

Signs and Symptoms

The signs and symptoms are:

  • Longer tooth line
  • Tooth Sensitivity
  • Exposed root surfaces
  • Cavities below the gum line
  • Gaps between the teeth due to a lack of gum tissue
  • Two color teeth. The cementum which covers the surface of the root is a yellow color so it looks different to the white enamel that covers the crown of the tooth. 
  • Loose teeth

How Is Gum Recession Measured?

To check if your gums have receded dental professionals measure the width and the height of any gum recession in millimeters (mm).

They use a periodontal measure (sometimes called a probe) to measure the distance between the cementoenamel junction (CEJ) and the gingival margin (top of the gum).

The CEJ is the visible border that lies between the enamel of the crown of the tooth and the cementum that covers the root of the tooth. In health, the top of the gum lies on top of the CEJ.  

The gums are said to have receded when a gap exists between the gum and the CEJ exposing the tooth root. The dental probe will give a positive number.

What Do The Measurements Mean?

This is what the numbers indicate: 

  • Zero (0) – There has been no gum recession. The gum is level with the CEJ.
  • Positive (+) numbers – The level of the gum is below the CEJ, the root is exposed, and there has been gum recession. The bigger the number, the greater the degree of recession.
  • Negative (−) numbers – these mean that the top of the gum line is above the CEJ. There is excessive growth of gum tissue or the tooth has not fully erupted.

How Many Millimeters Is A Concern?

If you’re an older adult and have some mild recession of 1-2mm around a few teeth this would be considered normal. But, if your gum recession is progressing, if the numbers are getting bigger it could be more of a concern. The stability of the tooth would start to become an issue.

To prevent further recession and an increased risk that your teeth will become wobbly and fall out, treating the underlying cause such as periodontal disease, poor oral hygiene, smoking, trauma from your bite and poor nutrition need to be addressed sooner rather than later. 

How Often Are Measurements Taken?

Measurements are taken between 6 months and every 2 years. However, the exact frequency may vary between clinics and depend on your unique situation.

There are also digital advances in dentistry, such as intra-oral scanners which create 3D images of the gums to track the health of your gums.

What Is Normal?

Many people ask how many mm of gum recession is normal. Despite being very common, there is no “normal” level.

The percentage of people with receding gums increases with age. This correlation may be because of the longer period of exposure to the things that result in periodontal disease and gum recession such as poor oral hygiene, poor nutrition and smoking.

If you are 50 and have 1mm of recession it may be perceived as normal as it is frequently seen in older people. If you are 15 and have 1mm of gum recession this wouldn’t be seen as normal. 

Are Periodontal Pocket Measurements and Gum Recession Measurements the Same Thing?

No, measurements for periodontal pockets and receding gums are different.

Periodontal pockets are gaps that form when the gums are swollen and inflamed and pull away from the teeth. This happens in periodontal disease which can lead to bone loss and gum recession. A normal pocket depth is usually between 1 and 3 millimetres (mm). Pockets deeper than 4 mm suggest you have periodontitis.

What Causes The Gums To Recede?

Whilst gum recession increases with age, it’s not a characteristic of old age. Causes include

  • Chronic trauma – such as aggressive brushing and oral piercings are suspected when only one tooth is involved 
  • Misaligned teeth
  • Orthodontic treatment – where teeth have been over expanded
  • Bruxism – tooth grinding may aggravate the periodontal disease and bone loss and thus gum recession
  • Periodontal disease and inflammation – this is the main cause of receding gums. We discuss it in detail below. 
  • Smoking – is a major cause of gum recession and periodontal disease
  • Poor oral hygiene – poor oral hygiene is a major risk factor for the development of periodontal disease, bone loss and thus receding gums  
  • Poor nutrition – poor nutrition has been linked with reduced bone health and the ability to fight infections. The body’s response to plaque bacteria may be reduced leading to increased inflammation resulting in increased bone loss and gum recession.  
Beat Gum Disease Now

Can Gum Tissue Grow Back?

Unfortunately not. Not even mild recession can be reversed. Gum tissue cannot grow back but the good news is that you can prevent it from getting worse by taking steps to control or eliminate the factors that contribute to receding gums. Find out more about how permanent gum recession is.

Can You Live With Gum Recession?

Yes, you can live with gum recession. But, if it progresses you may experience hypersensitivity, pain and tooth loss. For these reasons treating the underlying causes of your receding gums should be addressed. 

How To Prevent Gum Recession?

Developing and maintaining good oral hygiene – gently brushing the teeth and carefully cleaning the interdental spaces with the correct techniques is the best way to gently disrupt plaque bacteria without damaging the delicate gum tissue. 

Effectively disrupting the plaque bacteria twice daily will help prevent and control periodontal disease, and thus bone and gum tissue. Using a Gum Pocket Brush means you’ll successfully reach those areas inaccessible with a normal toothbrush.

Eating a nutrient-rich diet which is low in saturated fats and sugars, quitting smoking and controlling diabetes will benefit your oral health and your general health. 


Gum recession is measured using a dental probe. The distance between the top of the gum and where the surfaces covering the crown and the root meet are measured in mm. A positive number indicates that some gum tissue has been lost. 

Unfortunately, it is not reversible but steps can be taken to prevent further tissue loss. The best way to do this is by eliminating risk factors such as poor oral hygiene. 

You can find out more about preventing and controlling periodontal disease and gum recession with good oral hygiene here:

Beat Gum Disease Now


Gareth Edwards image

Written by Gareth Edwards

Co-Founder & GDG Dentist

Dr. Gareth Edwards BDS (Hons) MFDS (RCPS Glasgow) is GDG Co-Founder and Gum Disease Expert.

He is a practicing dentist based in Bournemouth, UK and has treated thousands of patients with gum-related diseases.

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