Traumatology Flashcards
Q229 : Following a lateral luxation injury, what are the chances that a tooth will maintain its pulp vitality?
There is a 60- 75% chance that a tooth can maintain its vitality following a lateral luxation injury. The vital pulp may undergo calcification in 25-40% of the cases** (Ferrazzini Pozzi & Von Arx, Dental Traumatol - 2008, Nikoui et al, Dent traumatol - 2003)**.
It should be noted that the change of survival of the pulp relies to a great extent on the stage of root development Roots with closed apex are more likely to develop pulp necrosis following lateral luxation and repositioning.
Q230 : Which of the following predisposing factors is the most associated with invasive cervical root resorption?
Orthodontic treatment / Dental trauma / Internal bleaching / Periodontal treatment
According to Heithersay (Quintessence Int - 1999), of the potential predisposing factors causing invasive cervical root resorption:
- 24.1% from orthodontic treatment
- 15.1% from dental trauma
- 14.4% Intra-coronal restorations
- 5.4% from oral surgical procedures
- 3.9% from intra-coronal bleaching
- 16.4% - no identifiable predisposing factor
Q231 : What are the probabilities of pulp revascularization following avulsion and replantation of permanent teeth? and what are the factors affecting this type of healing?
Andreason et al. (Endod Dent Traumatol - 1995) showed that the pulps of around 34% of replanted permanent teeth can revascularize.
Factors affecting pulp revascularization:
a) Immediate placement (less than 5 mins)
b) Immature teeth
c) Teeth with shorter distances from the apical foramen to the pulp horns
Q230 : Which of the following is more important for the success of replanted avulsed tooth?
PDL in the socket // PDL on the root surface
Oswald et al. (JOE - 1980) & Van Hassel et al. (JOE - 1980), in a 2-part study, showed that the viability of the PDL on the root surface is far more important than the viability of the PDL in the socket for the success of replanted avulsed teeth.
Q231 : How to minimize root resorption following replantation of an avulsed tooth?
1- Flexible splinting
2- Avoid long term splinting (not more than 1 month) (Nasjleti et al, Oral Surg - 1982).
3- Systemic Tetracycline antibiotics since it has anti-resorptive properties. lt could be an alternative to amoxicillin after avulsion injuries (Sae-Lim et al, Dent Traumatol - 1998).
4- Topical use of dexamethasone has been shown to enhances healing and results in fewer resorption complications (Sae-Lim et al, Dent Traumatol - 1998).
Q232 : Explain how internal root resorption can be triggered and propagate?
According to Tronstad (Dent Traumatology - 1988) : Damage to the predentin layer due to:
a) Low-grade irritation of the pulpal tissue localized to a small area of the root canal, i.e. chronic irreversible pulpitis or partial necrosis.
b) trauma or application of extreme heat to the tooth.
- The pulpal tissue apical to the resorptive lesion must have a viable blood supply to provide nutrition to the clastic cells.
- Infected, necrotic, coronal pulp tissue provides stimulation for those clastic cells.
- Bacterial is required to sustain the pathologic process
In an experimental model by Wedenberg & Lindskog (Dent Traumatol - 1985), it was suggested that internal resorption may be divided into a transient type and a progressive type, the latter requiring a continuous stimulation by infection.
Internal resorption may be associated with resorption of the dentin and a subsequent deposition of hard tissue that resembles bone or cementum but not dentin (Haapasalo & Endal, Endodontic Topics — 2006).
Q233 : How can internal bleaching causes cervical root resorption?
The underlying mechanism for this effect is unclear, but it has been suggested that the bleaching agent reaches the periodontal tissue through the dentinal tubules and initiates an inflammatory reaction (Cvek & Lindvall, Dent Traumatol - 1985).
It has also been speculated that the peroxide, by diffusing through the dentinal tubules, denatures the dentin, which then becomes an immunologically different tissue and is attacked as a foreign body.
Q234 : What type of splint should be used to stabilize teeth with horizontal root fracture & why?
- Flexible splint
- Experimental studies in non-human primates have demonstrated that rigid splinting or prolonged splinting may lead to PDL healing complications (i.e. ankylosis or external root resorption) (Nasjleti et al, Oral Surg - 1982).
Q235 : Which of the following traumatic injuries is more susceptible to develop external Inflammatory root resorption?
Concussion / Subluxation / Lateral luxation / Intrusion
Andreasen & Pedersen (Dent Traumatol — 1985) showed that in 637 permanent luxated teeth with up to 10 years follow up, external inflammatory resorption was highest in intrusive luxation injuries (38%). All other injuries had very low incidence of resorption:
- No resorption cases after concussion injuries
- 0.5% after subluxation injuries
- 3% of laterally luxated teeth
- 6% of extrusively luxated teeth
- 38% with intrusion
In a study similar, Crona-Larsson et al. (Dent Traumatol - 1991) showed that in 171 traumatized teeth, the highest incident of external inflammatory root resorption was associated with extrusively luxated teeth (60%) followed by intruded teeth (22%).
Q236 : What is the success rate of treating “Heithersay type IV” invasive cervical root resorption (ICRR)?
40% / 32% / 21% / 12%
Heithersay (Quintessence Int - 1999) investigated the treatment outcome of out of 101 cases of ICRR in 94 patients
Class l and Il lesions had a 100% success rate when treated.
Class Ill lesions: 77.8% success
Class IV lesions: 12.5% success
Q237 : What are the different types of healing that can be achieved following horizontal root fracture?
According to Cvek et al. (Dent Trauamtol - 2001), there are 4 different types of healing that can be achieved following horizontal root fracture:
1) Hard tissue healing
2) PDL healing
3) Hard issue + PDL healing
4) No healing
Q238 : What are the factors that may contribute to root resorption?
According to a review by Sak et al. (MicroMedicine - 2016) factors that may result in root resorption can be classified to local factors and systemic factors:
Local factors
1) Trauma
2) Internal Bleaching
3) Pulp necrosis
4) Orthodontic treatment
5) Periodontal treatment
6) pressure from a tumor or cyst
7) Dental abnormalities, e.g. invaginated teeth
8) others
Systemic factors
1) Scleroderma
2) Hormone dysregulation (hyperthyroidism and hypoparathyroidism)
3) Pregnancy
4) Kidney disease
5) Radiotherapy
6) Vitamin A deficiency
7) Hypertension
8) Paget’s disease
9) others
Q239 : Which of the following injuries have the highest incidence of pulp necrosis?
Concussion / Subluxation / Intrusion / Lateral luxation
Tsilingaridis et al. (Dent Traumatol - 2016) evaluate the survival of intruded permanent teeth related to treatment in a large number of patients, with special focus on development on pulp necrosis and replacement resorption. Pulp necrosis was diagnosed in 75%, infection-related root resorption in 25% and replacement resorption in 22%. Root development and degree of intrusion may be important for the development of pulp necrosis and replacement resorption.
Q240 : Describe the different stages of invasive cervical root resorption?
According to Mavridou et al. (JOE - 2016), invasive cervical root resorption can be characterized to 3 different stages:
1) Resorption initiation (injury of the PDL with localized inflammation)
2) Resorption progression: Pericanalar resorption resistant sheet (PRRS) (known as pre-dentin) protects the pulp from resorption either through maintaining normal oxygen content inside the pulp or with its higher mineral content compared to the surrounding dentin
3) Repair Stage: Signs of active and dynamic remodeling of the reparative bone-like tissue were visible; active resorption of dentin, active repair by osteoid formation and remodeling of bone-like tissue were observed to occur simultaneously at different areas of the tooth.
Q241 : What are the clinical factors that can contribute to periodontal healing without resorption following avulsion?
Andreasen et al (Dent Traumatol — 1995) found 4 factors that can contribute to periodontal healing without resorption following avulsion and replantation:
1) Stage of root development (fully formed teeth had the lowest healing)
2) Length of the dry extra-alveolar storage period (the shorter the better)
3) Immediate replantation
4) Length of the wet extra-alveolar storage period
