What are concussion and subluxation?
Concussion is injury to the supporting tissues with no loosening or displacement of the tooth. It will be tender to pressure.
Subluxation is injury to the tooth supporting tissues with abnormal loosening of the tooth but no displacement.
What is the classification for displacement of a tooth?
- Lateral luxation is bodily movement of a tooth within the socket (usually palatally). The tooth is not usually mobile as the root has come through the buccal bone and locked in place. There is rupture of the neurovascular bundle and crushing of the PDL cells in the palatal cervical region.
- Extrusion is apical displacement and the tooth is partially out of the socket. It will be mobile and appears elongated.
- Intrusion is when the tooth is forced upwards into the socket (in developing dentition it may be difficult to tell if the teeth were partially erupting anyway. It is a complex and severe injury. There is crushing of PDL cells and the neurovascular bundle.
- Avulsion is when the tooth is completely lost from the socket, there is ischaemic injury to the pulp and PDL cell death
What structures are involved in displacement of teeth?
The pulp (severing of apical blood supply) and the PDL (rupture and/or crushing of tissues). Crushed periodontal ligament cells cannot repair.
What does the prognosis of the pulp depend on and what ways can the pulp heal?
It depends on the type of injury, age of the patient (stage of apical development) and concomitant injury (other associated injury e.g. enamel-dentine fracture). Pulpal healing can occur with complete healing, pulp canal obliteration (don’t interfere unless sign of pathology) or pulp necrosis (inflammatory resorption).
When are survival rates best for displaced teeth?
Pulpal survival rates at 2 years following luxation is better with an open apex. The survival rate is best with concussion/subluxation. Then extrusion, lateral luxation and intrusion. There is no survival for intrusion with a closed apex so root canal treatment needs to be done.
What are the types of tooth resorption?
- Inflammatory (external or internal)
- Replacement
- Internal
What is external inflammatory resorption?
It is continuation of surface resorption due to toxins from necrotic pulp. It is progressive until bacteria are removed i.e. pulp extirpation. Will be filled in with cementum or bone on healing.
What is internal inflammatory resorption?
It is an infrequent complication due to a necrotic pulp. There is ballooning of the canal and rapid progression. Extirpation and dressing with calcium hydroxide is required.
What is replacement resorption?
It is due to extensive PDL damage. Osteoclasts are in direct contact with dentine. The normal bone turnover process leads to progressive replacement resorption. There is nothing we can do to stop it.
What general advice can be given for concussion/subluxation or displacement injuries?
- Soft diet for 7 days
- Analgesics as necessary - usually paracetamol
- Good oral hygiene
- Chlorhexidine mouthwash or gel for first week where you cannot brush
- Review splint at 48 hours
What is the management of concussion?
Periapical radiograph. No treatment is required. Monitor at 4 weeks and a year - look at sensibility testing, TTP, colour, signs.
What is the management of subluxation?
Periapical, two additional views and occlusal. A flexible splint can be placed for up to 2 weeks if necessary. You generally do not splint unless excessive mobility or tenderness when biting. Monitor at 2 weeks, 12 weeks 6 months and a year.
What is the management of extrusion?
Gentle repositioning with LA. Avoid high speed suction. Flexible splint for 2 weeks (additional 4 weeks if marginal bone breakdown). Monitor at 2 weeks, 4 weeks, 8 weeks, 12 weeks, 6 months, 1 year and yearly for 5 years - anticipating there may be some sequelae.
What is the management of lateral luxation?
Reposition, disengaging tooth from any bony lock (usually with LA). Flexible splint for 4 weeks. Palpate gingiva to feel apex and use one finger to push down over apical end, then use another finger or thumb to push tooth back into socket. Flexible splint for 4 weeks (additional 4 weeks if any marginal bone breakdown. Monitor at 2 weeks, 4 weeks, 8 weeks, 12 weeks, 6 months, 1 year and yearly for 5 years.
What are the pulpal considerations in lateral luxation?
Teeth with incomplete root formation:
- Spontaneous revascularisation may occur
- If the pulp becomes necrotic root canal treatment should be initiated as soon as possible
Teeth with complete root formation:
- The pulp will likely become necrotic so watch carefully
- As soon as suspected
- RCT should be initiated in order to prevent infection related resorption
What is the management of intrusion with an immature apex?
An immature apex is when teeth have incomplete root formation.
• Allow spontaneous repositioning to take place regardless of degree of intrusion.
• If no eruption within 4 weeks, recommend rapid orthodontic repositioning
• Monitor pulp status closely. May revascularize but if signs of non-vitality start endodontic treatment immediately
What is the management of intrusion with a mature apex?
What is the follow up for intrusion?
• Allow re-eruption if tooth intruded less than 3mm if no movement after 8 weeks reposition surgically or orthodontically
• If intruded 3-7mm surgical (preferred) or orthodontic repositioning
• If intruded more than 7mm reposition surgically
• Splint for 4-8 weeks once surgically repositioned
• Commence RCT within 2 weeks or as soon as tooth is in a position where endo can be started (we know tooth will become non-vital so we want to avoid sequelae)
Follow up - 2 weeks, 4 weeks, 8 weeks, 12 weeks, 6 months, 1 year and yearly for 5 years.
What telephone advice can be given for avulsion?
Find the tooth, hold by the crown not the root. If dirty rinse with cold water (10 seconds and care not to drop down plughole). Put in milk/saliva. If confident enough place tooth back in socket. Get child to bite down on rolled up tissue and hold in place.
What is the classification of an avulsed tooth?
- PDL cells likely to be viable - tooth replanted within 15 minutes
- PDL cells may be viable but compromised – extraoral dry time of less than 60 minutes
- PDL cells likely to be non-viable – extra-oral dry time is more than 60 minutes
Why does replacement resorption happen after avulsion and what should be considered when deciding whether to re-implant?
There is death in the PDL and therefore bone is in direct contact with the tooth. There will be ankylosis and replacement resorption. In a growing child replacement resorption leads to infraocclusion and ankylosis.
When deciding whether to re-implant consider prognosis, medical status, behavioural aspects, burden of care, child/parent wishes.
What are the advantages and disadvantages of re-implanting?
Advantages:
- Aesthetics
- Space maintenance (avoidance of denture)
- Maintain options (bone preservation, implants)
- Prevent restorative treatment
- Psychological benefit
Disadvantages:
- Infraocclusion
- Loss of gingival contour and bone
- Multiple visits (burden to family and child)
- Tooth will be lost eventually
What did Nguyen et al 2004 find with replantation of permanent incisors?
- 9.1 treatment visits in first year post injury of which 1.2 were emergency attendances
- 7.2 hours of direct treatment time
- Direct treatment cost of $1500
- Loss of work time for 86% of parents
- School missed for 1-2 weeks after injury
- 18% of replanted teeth were extracted within 1st year
- 19% of parents would not replant
- 33% of children would not replant
The default position is to replant but talk to parents/child giving realistic risks and benefits.
What are potential contraindications for replantation of avulsed teeth?
- Immunosuppression - risk of infection
- Severe cardiac disease - risk of infection
- Caries/periodontal disease - tooth already compromised
- Children with severe learning difficulties who would not be able to manage ongoing treatment
- Severe incisor crowding, supplemental incisor
What is the management of avulsion?
Reimplant as soon as possible. Store in milk/saliva. Use LA and gently irrigate the socket to remove the clot. Handle the tooth by the crown and not the root. If contaminated remove debris with saline. If stubborn debris gently dab with saline soaked gauze. Measure the tooth length prior to reimplant to confirm working length for future RCT. Replant tooth with gentle pressure and if won’t replant fully then stop as forcing it will strip periodontal ligament cells off the tooth. Reposition any bony fractures with blunt instrument if required. Place a flexible splint for 2 weeks and prescribe systemic antibiotics. Extirpate pulp in mature tooth within 2 weeks.
