|Year : 2016 | Volume
| Issue : 2 | Page : 107-110
Displacement of lower third molar to Submandibular fossa during extraction
Mohamed Said Hamed1, Prathibha Prasad2
1 Department of Dental Surgical Sciences, College of Dentistry, Gulf Medical University, Ajman, United Arab Emirates
2 Department of Basic Dental Sciences, College of Dentistry, Gulf Medical University, Ajman, United Arab Emirates
|Date of Web Publication||6-Jan-2017|
Mohamed Said Hamed
College of Dentistry, Gulf Medical University, Ajman
United Arab Emirates
Source of Support: None, Conflict of Interest: None
Complications during the procedure of extraction can be immediate or postoperative. Some of the immediate complications are fracture of the tooth, fracture of alveolar plate, fracture of mandible, loss of tooth or root into either pharynx or soft tissues, damage to nerves or vessels, soft tissue damage, involvement of maxillary antrum, dislocation of temporomandibular joint, etc., whereas hemorrhage, dry socket, osteomyelitis, swelling, pain, ecchymosis, trismus, prolonged anesthesia, and infective endocarditis are the various postoperative complications of extraction. This report discusses a case of displaced mandibular third molar into submandibular space while attempting extraction of the same.
Keywords: Displaced third molar; extraction; submandibular space
|How to cite this article:|
Hamed MS, Prasad P. Displacement of lower third molar to Submandibular fossa during extraction. Indian J Multidiscip Dent 2016;6:107-10
|How to cite this URL:|
Hamed MS, Prasad P. Displacement of lower third molar to Submandibular fossa during extraction. Indian J Multidiscip Dent [serial online] 2016 [cited 2019 Sep 22];6:107-10. Available from: http://www.ijmdent.com/text.asp?2016/6/2/107/197769
| Introduction|| |
Complications during the procedure of extraction can be immediate or postoperative. Some of the immediate complications are fracture of the tooth, fracture of alveolar plate, fracture of mandible, loss of tooth or root into either pharynx or soft tissues, damage to nerves or vessels, soft tissue damage, involvement of maxillary antrum, dislocation of temporomandibular joint, etc., whereas hemorrhage, dry socket, osteomyelitis, swelling, pain, ecchymosis, trismus, prolonged anesthesia, and infective endocarditis are the various postoperative complications of extraction. ,, This report discusses a case of displaced mandibular third molar into submandibular space.
| Case Report|| |
A 28-year-old female patient visited the dental center complaining of severe pain and swelling in her left jaw. In her anamnesis, the patient gave a history of badly decayed third molar and there was an attempt of extracting it 2 days ago which lasted for 2 h. The patient was unable to eat or drink for the past days after attempted extraction. She also complained of persistent numbness of the left half of the tongue. Examination revealed that the patient's mouth opening was limited. She was prescribed antibiotics and anti-inflammatory drugs and to follow-up after 3 days. After 3 days, the patient was able to open her mouth. On examination, the area of lower left third molar was congested, reddish in color, inflamed, empty socket, with a blood clot covering the socket. Foul smell was emanating from the oral cavity. Paresthesia was limited to the anterior two-third of tongue and lower lip was not affected.
Orthopantomogram did not show any finding. Computed tomography (CT) scan showed the location of the tooth in the submandibular space [Figure 1]. A frontal and lingual view of the mandible presented in three-dimensional reconstruction by means of multislice CT, to illustrate the position of the tooth was analyzed. Frontal view showed the fracture of lingual plate of mandibular bone but there was no sign of lower third molar [Figure 2]. The lingual view showed the fractured lingual plate and displaced mandibular 3 rd molar into submandibular fossa [Figure 3].
|Figure 1: Computed tomography scan showed the location of the tooth in the submandibular space|
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|Figure 2: A frontal view of the mandible, presented in three - dimensional reconstruction by means of multislice computed tomography showed the fracture of lingual plate of mandibular bone but there was no sign of lower third molar|
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|Figure 3: The lingual view of the mandible, presented in three - dimensional reconstruction by means of multislice computed tomography showed the fractured lingual plate and displaced mandibular 3rd molar into submandibular fossa|
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The patient was operated under general anesthesia in the hospital. Routine preoperative investigations were carried out. The socket was examined thoroughly. The lower third molar was palpated and located from the lingual side. A lingual flap was raised adjacent to the fractured lingual plate and submandibular space was approached using large artery forceps and the tooth was grasped while the free hand was guiding the forceps to the position of the tooth which took a laborious ½ h, and finally was removed. Repositioning of the fractured lingual plate of bone was done.
The socket from which the tooth was displaced was sutured. Fixing the fractured lingual cortical plate of mandible was done. Oral antibiotics and anti-inflammatory drugs were prescribed for 5 days. After a week, the patient regained her mouth opening to full extent. Suture removal was done. The patient continued to experience paresthesia of the tongue indicating damage to lingual nerve, a marked permanent complication while attempting extraction by the previous dentist. The patient was followed up at intervals of 2 weeks, 1 st , 2 nd , 3 rd , and 6 th months. There were no other complications noted during the last visit except the irreversible damage to lingual nerve and the resulting paresthesia of anterior two-thirds of the tongue.
| Discussion|| |
Complications related to the third molar removal are many and vary from immediate to postoperative. When inferior dental canal is very closely situated to the tooth being extracted, it could result in direct trauma to nerves and vessels in the canal.
At times, parts of the tooth or whole tooth can be dislodged and disappear as seen in this patient's case. The patient might have swallowed it; it might have slipped into soft tissues or into pharynx in the worst case scenario. The displacement of lower third molar/part of tooth into facial tissue spaces is a rare complication during its extraction.  The most common sites of dislodgment of an impacted mandibular third molar fragment are the sublingual, submandibular, and pterygomandibular spaces.  In our case, the tooth had slipped into submandibular space. A limited literature is documented related to tooth displacement into submandibular space, shows that lingual location of the tooth, fenestration of the lingual cortical plate with root exposure, following inadequate surgical technique are some of the causes. According to Brauer's report, this complication has incidence <1%.  In the literature review of displaced mandibular impacted teeth carried out by Huang et al., he found out that out of five tissue spaces, submandibular space was the most common space involved.  The most common cause of this complication is lingual plate fracture or perforation during extraction. Inadequate pressure applied with the elevators may possibly move the root into deep anatomic spaces. On many occasions, attempts to remove the fragment without adequate visibility and a lack of surgical skills can result in deeper displacement of the tooth or root fragment. Hence, the patient should be immediately referred to an expert oral surgeon. When the fragment is not palpable and the panoramic or occlusal films are inconclusive, a CT scan should be mandated.  Three-dimensional reconstruction by means of multislice CT has the added advantage of illustrating the position of the tooth and its anatomic relations as was done in this case. 
Management plan for displaced teeth in submandibular space depends on fragment size and palpability. Immediately, if the tooth slips away during extraction, it can be stabilized by placing a finger on the medial side. The extraction socket may then be widened with a help of fissure bur avoiding interdental canal and the tooth being teased back through the socket. Fragment may also be removed by taking a flap intraorally; if this is unsuccessful, extraoral approach may be utilized by giving submandibular incision. A modified approach also exists in which lingual plate is osteotomized to retrieve the tooth or fragment of tooth. , In this case, the surgeon approached the tooth through the fractured lingual plate using artery forceps in one hand while palpating the location of the tooth lingually by another hand. Once the tooth was locked by the forceps, it was removed. Hence, depending on the location, size of the tooth, and decision based on the expertise of the surgeon the technique varies.
Anesthesia, paresthesia, or dysesthesia are more worrying sequelae of a complicated extraction if either inferior alveolar nerve or lingual nerve gets damaged during the procedure. Taste could be altered if lingual nerve is damaged. The sensation could improve over a period of 1 year, but there is also a greater chance they might not. Injury to the lingual nerve during third molar removal could be unintended and is a result of the anatomical proximity of the tooth to the nerve, separated by just the periosteum. The sensory disturbances caused as a result of nerve injury can be troublesome and is one of the most common causes of medico-legal litigations.
Various classifications of nerve injuries have been recorded in literature. Seddon classifies it into three categories. 
- Neuropraxia: An interruption in conduction of the impulse down the nerve fiber. This is a more common type of nerve injury. The recovery in such cases takes place without Wallerian degeneration, and henceforth, it is considered to be the mildest form of nerve injury and patient usually recovers within the first 3 months
- Axonotmesis: The loss of relative continuity of the axon and its covering of myelin but preservation of the connective tissue framework of the nerve
- Neurotmesis: Loss of continuity of not only the axon but also the encapsulating connective tissue.
Axonotmesis and neurotmesis are much more severe and result in long-standing injuries.
Our case had developed paresthesia in relation to anterior two-third of the tongue depicting damage to lingual nerve. Cheung et al. carried out a study in which it was seen that of all the lower third molar extractions performed by various grades of operators, 0.69% developed lingual nerve deficit. Studies have shown that if the paresthesia due to extraction is transient and it resolves within 6 months. In our case, the patient was followed up for 6 months and did not show any improvement. If there is no improvement in the sensation even after 2 years of follow-up, it represents a permanent deformation. 
| Conclusion|| |
Mandibular third molar extraction is a routine dental procedure and is associated with risk factors such as other minor surgical procedures. Complications such as neural injuries and displacement of tooth/tooth part into tissue spaces can be avoided by adequate preoperative evaluation of the patient and meticulous surgical technique by an expert oral surgeon.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]