All about the hooked tooth root

hooked tooth root

A hooked tooth root is unusual among the general population, and hearing from your dentist that you have a hooked tooth root can be terrifying. Teeth with curved roots pose difficultly during root canal treatement and removal. In this article, I will discuss all you need know about the hooked tooth roots under the following headings: 

  • What do hooked tooth roots mean? 
  • What causes hooked tooth root?
  • Which teeth frequently have twisted roots
  • How to know if you have hooked roots 
  • How dentists manage them

What is the root of the tooth?

The root of the teeth is the portion of the tooth embedded within the bone. Roots allow teeth to hold firmly in the bone. Healthy roots are essential for the longevity of a tooth. 

Do all teeth have roots?

Yes, all teeth have roots. Front teeth have a single root. The large molars have two or three roots. The roots absorb and transmit heavy chewing forces to the bone.

What do curved tooth roots mean (hooked tooth roots)?

A hooked or twisted tooth root is considered when the angle or bend between the terminal (apical) part of the root and the long axis of the tooth is more than 20 degrees.  

In other words, the deviation of apical portion of root away from its normal path for more than 20 degress is regarded a hooked root.

A bend can vary from 20 to 90 degrees. The severe curvatures can be pretty challenging to treat.  

what causes curved tooth roots?

You often ask, why are my tooth roots curved when others have straight roots. The prevalence of hooked root tooth in different ethnic groups fall between 0.3-17%.

The main reason behind a hooked root tooth is disruption in the tooth’s root development due to an injury to its predecessor that pushes it towards the developing permanent tooth. The injury deviates the root from its usual growth path, forming a kink at that site. Dentists call it a root dilaceration.

Other causes of hooked roots are as follows:

  • Facial clefting
  • Advanced infection of baby molars that spread in the bone affecting the growing adult tooth roots.
  • Lack of space in lower molars due to encroaching nerve canal. 

Which teeth frequently have hooked tooth roots?

Hooked tooth roots frequently occur in first, second and third molars (wisdom teeth). The root curves in either forward or backward direction.

In front teeth, lateral incisor (upper second tooth from the center) and impacted upper canine are likely to develop a twisted root.   

Different casts and creeds present with varying percentages of twisted roots. For instance, Iraqi descent represents 11% fused roots, 88% separate roots, and 11% exhibited splayed roots teeth.    

Impacted canine teeth with hooked roots

A tooth with long roots is more likely to have curved roots. This is commonly seen with canines that become impacted in the roof of the mouth. Impacted teeth are the teeth that remain hidden in the bone or gum past the age of eruption. 

During the eruption, the terminal end of the root remains at the same position, and the crown portion of the tooth moves out of the bones and gums. But, if there is no space for the tooth to erupt or guidance from the lateral incisor, the tooth will not come out of the bone. Its root, however, will continue to grow. 

Canines have thick and long roots. In the roof of the mouth, the midline palatal sutures and nasal cavities will resist its growth. The root development will deviate from their usual path, and a hooked root develops. 

Is it good to have long roots?

Yes, it’s better to have long tooth roots for the firm tooth grip in the bone. The length of the root is determined by your tooth’s crown height. Ideally, a root should be 1.5 to 1.8 times longer than the crown of a tooth.

So, if you have large teeth, you will have longer roots. However, teeth with long roots are likely to develop hooked roots if get impacted or injured during development. . 

Curved molar roots

The root curvature of the first molars is important because the bite is built on this tooth when it erupts at age 6. These teeth are also the most frequently infected teeth in the mouth, and dentist tries to save them as best as they can. 

Molar curved tooth roots pose a great deal while disinfecting the canals during root canal treatment. Instrument breakage occurs considerably in curved canals and is a main cause of root canal failure. 

Wisdom tooth with hooked root

Wisdom teeth have the most variable root anatomy. Most wisdom teeth have one large conical root with 2 or 3 canals. Others have two or three roots. Wisdom teeth with two or three roots often have one or more twisted roots. The wisdom tooth hook faces backward in majority of the people.

A hooked wisdom tooth causes no harm if it remains healthy. However, it can be pretty challenging to remove if it gets infected and requires removal.

Moreover, wisdom tooth hooked roots require a lot of bone cutting, risking lower jaw fracture or injury to nearby vessels and nerves. 

With the increased number of roots, the diameter of individual root decreases, increasing the chances of breakage during extraction. Also, with age, the bone gets denser, so it’s best to remove wisdom teeth before 30. 

An erupted wisdom tooth with hooked root is easier to remove than an impacted tooth.

Impacted wisdom teeth are more prone to have curved roots because the lack of space in the bone prohibits root elongation, so it deviates from its path and becomes hooked. 

How do you know if you have hooked tooth roots 

The shape of the root hidden in the bone can be seen on the x-ray. It also helps in notifying you in advance how aggressive a surgery can be.

An x-ray also reveals the proximity of roots to vessels, nerves, and sinus floor to avoid any damage to them during tooth extraction. 

A panoramic or full mouth x-ray is carried out to ascertain the number of tooth roots, shape, and proximity of roots to nerves and blood vessels. For a more detailed and three-dimensional view, a cone beam CT may be required for wisdom tooth impactions. 

How to treat teeth with hooked tooth roots 

There are two ways to treat a tooth with a hooked root. 

Complications during root canal treatment with hooked roots 

The decision to treat an infectious tooth hooked root with root canal therapy banks on the severity of root curvature. Minor curvature can be treated with root canal treatment. However, a severe kink in the root requires extraction. 

An inward directed hook may be missed on the regular x-ray as these x-rays produce a 2-dimensional image of a 3-dimensional object (tooth). 

During root canal cleaning, the odds of creating a step or perforation in a hooked canal are higher than a straight canal. These mishaps during root canal therapy can lead to root canal failure.

A hooked root requires thin and flexible files to allow their smooth passage beyond the hook to reach the tooth apex (tip) to facilitate complete canal disinfection.

[The files are needle-like instruments use to clean root canals].

Why does a root canal treatment is not carried out in wisdom teeth?

A vast variation of root anatomy in wisdom teeth interferes with the success of root canal therapy and precludes them from root canal treatment.

Hooked root tooth extraction

Curved root tooth extraction requires surgical removal of the tooth. In simple extractions, teeth are loosened from the bone by an elevator and removed with a forcep. No gum and bone cutting is required in simple extractions.

Why are teeth extracted?

The following reasons or signs and symptoms in teeth indicate their extraction:

  • An impacted wisdom tooth 
  • Frequent infection in gum flap surrounding the partially erupted wisdom tooth 
  • Deep infection or decay in wisdom tooth
  • Loose teeth due to Loss of gum support
  • For orthodontic reasons 
  • A cyst or tumor around the tooth 

extraction procedure

 In a surgical extraction, the gum tissue is cut to expose the bone and tooth. The tooth is sectioned in pieces with a dental drill to retrieve individual roots without breaking. 

Curved root tooth extraction pain: Bone and gum tissue removal create a larger wound that leads to more pain, bleeding, swelling, and difficulty in mouth opening after the surgery and takes longer to heal. 


Following complications can occur during the curved root tooth removal:

  • In lower impacted wisdom teeth, roots may lie close to or wrap around the nerves and blood vessels, and their removal can risk nerve injury. The inferior alveolar and lingual nerves are at risk of damage. An injury to the inferior alveolar nerve can lead to temporary or complete loss of sensation in the chin and lower lip. Lingual nerve injury may cause loss of tongue sensation. The damage to the artery can lead to an enormous blood loss. 
  • In the upper jaw, wisdom often penetrates the sinus floor. An excessive pressure during their removal can fracture the sinus floor and form an oral-antral (mouth to sinus) communication. Moreover, any fluid or food particles can enter the sinus and cause infection. 
  • While removing an impacted lower wisdom tooth, a jaw fracture can occur if excessive pressure is applied to remove the tooth. 

coronectomy  – a technique to save nearby nerves and blood vessels

Coronectomy is a surgical procedure where the tooth’s crown is removed, leaving behind the roots. It is considered in teeth where the roots lie very close to a vessel, nerve, or sinus and could risk them if removed. 

The hooked roots often lie close to these vital structures and coronrctomy is often considered in teeth with healthy roots, for instance, frequent infection in the gum flap of partilally erupted wisdom teeth.

Teeth with infected roots need to be removed as they will continue to hurt you. 

Coronectomy procedure: A horizontal cut is placed at the junction of the crown and roots with a dental drill, the crown is removed, and the roots are left behind.

The socket is closed and stitched with threads. Over time, the embedded roots may rise in 15% of cases and can be extracted if get infected. 

Risks of coronectomy: You may experince pain after coronectomy. Experiencing a throbbing pain after coronectomy indicates infectious roots that need prompt removal. 

Coronectomy recovery: The recovery time depends upon the degree of tissue damage. However, coronectomy requires less gum and bone removal and heals faster than extraction. 


Teeth with hooked tooth roots are difficult to treat. 

The hooked roots are caused by the deviation in its usual growing path because of any of the following factors:

  • An infection of baby teeth spreading in the bone, hurting the developing adult tooth beneath it
  • An injury to baby teeth affecting the growth of adult teeth roots
  • Scar tissue due to Facial clefts may cause hindrance in root completion
  • Infringing nerve canal may cause developing root to deviate from its path forming a hook

Deep infections in teeth with mild curvatures may undergo root canal treatment. However, root canal may lead to a step formation or perforation in the root canal if proper care is not taken.

Teeth with severe kinks require surgical removal of the teeth by cutting and removing the gums and bone. 

Comment below if you find this blog infomative or if you have any questions, i will get back to you ASAP.

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