What are Retained Wisdom Teeth?


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The definition of retention describes a position of the wisdom tooth in which, by completion of the root growth phase, the chewing level has not been reached.

A tooth is called ‚partly retained‘when part of the crown reaches the mouth cavity or is connected to the mouth cavity via the periodontal apparatus of the neighbouring tooth. Fully retained teeth are those which show no connection to the mouth cavity at all.

In medical jargon one also finds other definitions, such as impaction, meaning the tooth is completely embedded in the bone. Deflected teeth are those whose axis or position varies from the regular direction of eruption.

When should a wisdom tooth be removed? When it’s retained, partially retained, or not impacted at all or when the tooth first gives us problems? By problems we usually mean pain! But pain is a very unreliable sign in medicine. A malignant tumour only hurts shortly before the end and high blood pressure doesn’t hurt at all.

Since pain is not reliable, there must be other considerations which can lead us to the extraction of a wisdom tooth. In this respect, clinical and radiological symptoms need to be considered, such as:

  • recurring infections in the wisdom tooth area
  • extension of the radiological pericoronary area (this is the area in which surrounds the tooth crown)
  • pericoronary swelling (possibly as a result of cysts developing)
  • pain or pulling in the facio-mandibular area
  • development of pockets and bone resorbtion away from the last molar
  • resorbtion in neighbouring teeth
  • caries damage to the wisdom tooth


Retained Wisdom Tooth

Retained Wisdom Tooth

Symptomless deflected wisdom teeth can be observed in young patients which back up these investigations. In the case of the wisdom teeth planned for extraction by the 18th year, around 30% come to develop regularly in position by the 30th year. Furthermore with increasing age several complications may result from surgical removal (e.g. reduced regeneration of the periodontal area and higher danger of lower jaw fractures).

The use of wisdom tooth extraction to avoid tertiary lack of space in the lower front teeth after the completion of an orthodontic treatment hasn’t been described in a study, though admittedly the leaving the wisdom teeth resulted in clearly greater shortening of the length of the line of the front teeth.

A general recommendation cannot be made. Before the decision to extract the tooth is made an exact evaluation of the findings, including x-ray examination, needs to be made to completely assess the situation of the tooth and its relevant surrounding anatomical structures. Occasionally further useful examinations, such as vitality checks of the neighbouring teeth, a sensitivity check (N. Lingualis and N. Mentalis), the establishment of periodontal parameters (pocket depths), computer tomography or digital volume tomography in the case of critical relationships of the tooth’s position in relation to surrounding structures, in particular to the N. Alveolaris inferior, could be advantageous.

Wisdom Tooth Extraction

Wisdom Tooth Extraction

Before an extraction the possibility of a transplantation of the tooth should be considered. In the case of badly damaged 6th teeth and an as yet incomplete growth of the root of the 8th tooth, a wisdom tooth transplantation could be a valid idea for treatment. An alternative to transplantation is also the moving of the tooth by means of a brace. With the help of a brace a wisdom tooth can often be brought into the correct position and in the case of existing gaps this could be an alternative to implantation.

Treatment under general anaesthetic/sedation may be indicated due to expected problems with cooperation from the patient, to the large total area of the dento-alveolary measures, to manifest local risk factors or on the express request of the patient. Inpatient treatment may be required in the case of severe general illness or particular operational procedures.

What are the expected risks? There’s a difference between local risk factors which may make the extraction difficult and systemic risk factors, such as raised tendency to bleed for patients with coagulation disturbances. The following assessment results will give rise to higher local risk factors of complications for extraction:

  • existing acute or chronic infection
  • root anomalies
  • close position to neighbouring teeth
  • projection of the nerve development of the mandibular canal onto part of the retained tooth
  • ingrown teeth
  • difficult position of the wisdom tooth
  • exposure of the jawbone


Possible complications include:

  • damage to sensitive branches of the trigeminus nerve
  • postoperative infections
  • damage to the neighbouring second molars
  • broken jaw
  • perioperational bleeding complications
  • anaesthetic damage
  • postoperative pain and swelling


Whilst the extraction of clinically or radiologically symptomatically suitable teeth is broadly uniformly recommended in literature, a general recommendation to extract wisdom teeth not displaying symptoms is not scientifically supported. All in all the indication exists:

  • for an acute or chronic infection (dentition difficilis)
  • for exposure of the pulpa through caries
  • for teeth damaged beyond repair by caries or inflammation of the dental nerve which cannot be treated
  • for untreatable periapical changes
  • for manifest pathological structures in connection with tooth follicles (e.g. cysts, tumours) or the suspicion of changes of this type
  • for resorption of neighbouring teeth
  • in connection with the treatment and limitation of the progress of periodontal illnesses
  • for teeth which would disturb other teeth in orthodontic and/or reconstructive surgery
  • for teeth which are in the break of a broken jaw and which would hinder the treatment of the break
  • use of the teeth for transplantation purposes
  • for elongated or tilted wisdom teeth which display a manifest disturbance of the occlusion


An indication for extraction does not exist:

  • as long as an unassisted, regular position of the wisdom tooth in its row is to be expected
  • when the extraction of other teeth and/or orthodontic treatment including correcting the teeth makes sense
  • in the case of deeply impacted and deep-lying teeth without associated illness, where a high risk of operative complications exists


Click here to see the video: Wisdom Tooth Removal


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