Injuries To The Periodontium

 

 

Luxation Injuries


 

Luxation injuries normally involve damage to the periodontium and the dental pulp. The periodontal damage may range from a light concussion to total avulsion of the tooth. Surface root resorption(s) and marginal bone breakdown
are common healing responses to minor periodontal injuries and may be observed during the first month after injury. They heal uneventfully.
Properly treated, extrusive luxation rarely shows more than surface root resorption, which normally heals. Lateral luxation, which involves some compression damage to bone and root surfaces
may, in some instances, result in replacement
resorption with permanent or transient ankylosis. Replacement resorption is common in cases with intrusive luxation and avulsion with long extraoral time. The resulting ankylosis, which may be diagnosed radiographically within 2 months, is a serious complication. Ankylosis may often be clinically diagnosed earlier due to the metallic percussion sound from an ankylosed tooth. If rigid fixation is required, it should be kept to a minimum in time to reduce the risk for the development of ankylosis.


Inflammatory resorption is mostly a complication following pulp tissue infection, which has not been promptly diagnosed or successfully eliminated. Proper endodontic treatment with root canal disinfection normally arrest the resorption but sometimes the destruction of the root can be extensive leading to the rapid loss of the tooth.


Pulp of mature permanent teeth will nearly always lose vitality while the pulp of less mature teeth has a higher rate of survival. The seriousness of pulp damage is also directly related to the extent of injury to the tooth. Endodontic treatment must be started if normal pulp response to electric pulp testing cannot be obtained 2-3 weeks after the injury.


In immature permanent teeth the chances for pulp survival is better and careful assessments should be made before endodontic treatment is initiated. If the pulp is necrotic, treatment damage to the growth zone of the Hertwig’s epithelial root sheath must be avoided to allow for continuous apical root formation.


In immature teeth the pulp necrotic tissue may revascularize. The reorganized tissue is not true pulp tissue but connective tissue of periodontal origin. This tissue is non-responsive to thermal pulp testing. The tissue will respond to electrical pulp testing at elevated levels. Root formation will almost always continue but the already formed root structure will not strengthen as new dentin cannot derive from the connective tissue that replaced the pulp. The pulp space tissue will be calcified. There are no odontoblasts present in the reorganized tissue so the calcified areas consist of cellular cementum and mineral deposits but not dentin. Although the pulp space may appear totally obliterated there is nearly always tissue remnants present. Since late breakdown and necrosis of this tissue (1% /year) may occur, long term observation is required to allow early intervention in case of periapical osteolysis that occurs in approximately 15% of totally calcified teeth. (Jacobsen and Kerekes 1977).


Concussion and Subluxation (S 03.20)


Clinical observations: There is increased tenderness to percussion and palpation (concussion) and sometimes slight mobility (subluxation). There may also be some gingival bleeding.


Treatment objective: To prevent additional periodontal damage and monitor pulp injury.


Treatment: The unsupported tooth is painful during mastication. Therefore a slight occlusal adjustment to remove immediate contact may be helpful. If necessary a semi-rigid splint can be applied for 1-2 weeks. The health of the dental pulp is of major concern and pulp survival must be monitored for at least six months. Mature teeth are more likely to sustain pulp injuries than immature ones. If pulp necrosis is diagnosed endodontic treatment should be initiated immediately.


Prognosis: The long term prognosis after concussion and subluxation is excellent. Although pulp and periodontal damage occurs rarely, these teeth must be monitored every 3 months for the first year and treated aggressively if breakdown of the pulp tissue is diagnosed.


Extrusive Luxation (S 03.21)


Clinical observations: The tooth is extruded. There is gingival bleeding. The crown of the tooth may be dislocated or rotated. The root of the tooth is more or less out of the bone socket, which will appear partially empty on a radiogram. The periodontal ligament is ruptured. In mature teeth the pulp circulation may be severed.


Treatment objectives: To reposition the tooth/teeth and splint them in their pre-trauma position. Establish pulp diagnosis and initiate treatment if necessary after the fixation period.


Treatment: Reposition the tooth in apical direction. This may require continuous pressure until the tooth is correctly seated. Splint the tooth for 2-4 weeks. The health of the dental pulp is of major concern and pulp survival must be monitored for at least six months. Mature teeth are likely to sustain pulp injuries while this complication is less common in immature ones. If pulp necrosis is diagnosed endodontic treatment should be initiated immediately.


Prognosis: The long term prognosis is fair to good and dependent on pulp survival. Regular follow-ups are important (Table 2a). Untreated pulp necrosis will lead to external inflammatory root resorption and root damage (Figure 1). Immature permanent teeth have a better chance than mature teeth for pulp survival. Severe periodontal damage leading to ankylosis is rare.

 


Lateral Luxation (S 03.20)


Clinical observations: The crown of the tooth is displaced. Lingual displacement is more common. The tooth is rotated around a fulcrum located at the marginal bone. A lingual displacement of the crown will result in an apical facial bone fracture and compression of the lingual marginal bone. The root of the tooth is out of the socket, which will appear empty on a radiogram. Although displaced, the tooth is often wedged in place and may therefore have little mobility. There is gingival bleeding.


Treatment objectives: To reposition the tooth/teeth and splint them in their pre-trauma position. Establish pulp diagnosis and initiate endodontic treatment, if necessary, at the end of the fixation period.


Treatment: Repositioning of the tooth, which may take some force. Pull the tooth in a coronal direction before pushing the apical part back into the socket. Splinting is necessary for at least 2-4 weeks. The health of the dental pulp is of major concern and pulp survival must be monitored for at least six months. Mature teeth are more likely to sustain pulp injuries than immature ones. If pulp necrosis is diagnosed endodontic treatment should be initiated immediately.


Prognosis: Prognosis is fair to good. Regular follow-ups are important (Table 2a). Revascularization of pulp space tissue may occur in immature permanent teeth but in mature teeth the pulp will usually become necrotic, requiring endodontic treatment. Periodontal tissue injury is common due to the compression of periodontal tissues and the resulting replacement resorption which occurs. Rebuilding of the periodontal tissue with root surface resorption is common and normally inconsequential.
Intrusive Luxation (S 03.21)


Clinical observations: The tooth is intruded. There is gingival bleeding. Although the tooth appears intact there is significant damage to the periodontal supporting structures including compression injury to the bone. There is no mobility as the tooth is wedged into the socket. The pulp circulation is almost always completely compromised, even in immature permanent teeth.


Treatment objectives: To reposition the tooth/teeth and splint them in their pre-trauma position. Establish pulp diagnosis and initiate treatment if necessary at the end of the fixation period .


Treatment: The tooth should be repositioned as soon as possible, preferably with orthodontic force. Relocation with forceps results in less favorable periodontal healing and should only be considered if orthodontic extrusion is not possible. The time allowed for repositioning is short as endodontic treatment must begin before the necrotic pulp becomes severely infected (Figure 2). Repositioning can normally be completed in 3 weeks. If repositioning is done with forceps, the tooth must be splinted for a month in a semi-ridged fashion to avoid replacement resorption.

 


Mature teeth require endodontic treatment while the pulps of immature permanent teeth may revascularize. Inflammatory resorption and replacement resorption are common after intrusive luxation. Inflammatory resorption is mostly associated with infected pulp necrosis and can be successfully prevented in most cases by early endodontic intervention. Replacement resorption, for which there is no treatment, is the result of periodontal compression injury. Its occurrence is very unpredictable. Due to the high risk for ankylosis any fixation should be brief and not rigid.

Prognosis: Intrusive luxation is the luxation injury with the worst prognosis. The prognosis is poor to guarded due to high frequency of replacement and inflammatory resorption. Regular follow-ups are important (Table 2a). Pulp necrosis is common regardless of root development.


Avulsion (S 03.22)


Clinical observations: The tooth is completely out of the socket. Important information for the determination of treatment is extraoral time, extraoral storage medium, and accident environment. Pulp tissue is permanently damaged and contaminated by microorganisms.


Treatment objectives: To replant the tooth/teeth and splint them in their pre-trauma position. Initiate endodontic treatment.


Treatment: The tooth should be replanted as soon as possible after it has been thoroughly cleaned by rinsing with sterile saline. Do not scrape the root surface! Do not use disinfectants! In most cases the tooth will not be immediately replanted after the accident and it is important to know the extraoral time in order to determine expected outcome and treatment. Depending on storage medium an extraoral time of up to one hour may be acceptable. The patients should be instructed to carefully put the tooth back into the socket. If this is not possible store the tooth wet. If the tooth has been stored in a good medium replantation may be done after one hour and still allow for a good outcome. Good storage media are skim milk, saliva (in the mouth), or some commercially available tissue culture salt solutions. Hank’s Balanced Salt Solution (HBSS) has been shown to be an excellent storage fluid. Every sports organization where traumatic injuries may occur should have this inexpensive solution available. It may be purchased in 100 mL units from any biological supply company.


After the tooth has been rinsed in saline and gross debris has been removed it should be replanted. The blood clot in the socket should be removed and the socket cleaned of debris. Do not scrape the socket unnecessarily and avoid damage to root surface. The treatment of the root surface with doxycycline or the socket with Emdogain (Straumann, Andover, MA) has been suggested, but there is little evidence that this extra treatment is essential. The tooth should be carefully but firmly seated in the socket. Splint the tooth with a semi-rigid fixation to prevent ankylosis. Antibiotic should be given at a therapeutic level and tetanus prophylaxis should be considered. Amoxicillin 500 mg qid for seven days or in case of allergy Clindamycin 150 mg qid may be used with the usual precautions.


An avulsed tooth should always be treated endodontically. There are reports of pulp revascularization but in those rare instances where this takes place, the pulp space tissue is greatly compromised resulting in an unpredictable and unstable long term status (Kling et al. 1986). If the tooth has been out of the socket for more than 30 minutes it may be advisable to rapidly extirpate the pulp tissue before replantation and place calcium hydroxide in the pulp space as a temporary dressing. This will not significantly extend the extraoral time and protect the pulp space from becoming infected. The procedure is equally applicable to mature and immature teeth. When performing the endodontic treatment the tooth must be kept wet and damage to the periodontal ligament avoided. If endodontic treatment is not done before replantation, it should be initiated within the first 2 weeks following injury. Failure to initiate endodontic treatment will result in a very high risk of inflammatory root resorption.


Prognosis: For teeth with an extraoral time of less than one half hour the long term prognosis is fair to good. Wet storage increases the prognosis. Extraoral time over one half hour and unfavorable storage conditions such as water or disinfectants result in a poor to guarded prognosis. Regular follow-ups are important.
 

A summary of treatment options, a follow-up schedule and prognosis for these various injuries can be found in table 2a.