JOVD 2015 #1 Classification and epidemiology of traumatic dentoalveolar injuries in Dogs and Cat:959 injuries in 660 patient visits (2004 - 2012)

Question 1

Aim of study?

Answer 1

to analyze the overall prevalence of TDI, frequency and distribution of specific TDI, and the application of a comprehensive classification system for TDI in dogs and cats

Question 2

STudy Design?

Answer 2

Retrospective

Dogs and cats presented for oral tx at Wisconsin Un. Dentistry Service between 2004-2012 diagnosed with a TDI

Record signalment, tooth injured, # of injuries/patient.

Each tooth injury was classified according to classification used in human (medical record and oral rad review if needed)

Prevalence of TDI calculated by considering total # of patients anesthetized for oral tx during the study period

Question 3

Result

What was the overall prevalence of Traumatic Dentoalveolar Injury (TDI)?

What was the prevalence in dogs and in cats?

Answer 3

Overall prevalence of TDI:

• 621/2523 (26.2%) dogs and cats -
  
  • 612/660 cases (92.7%) dogs
  • 48/660 cases (7.3%) cats

*NB: 621 patients but 660 cases because some paitent had more than 1 event

• Mean of 1.45 injuries/patients

Question 4

Result - (Discussion)

In which jaw occured the majority of all TDI?

Which teeth were most commonly injured?

What % of TDI were classified severe (lateral luxation, intrusive luxation, extrusive luxation, avulsion, enamel-dentin-pulp fracture, crown-root fracture with pulp involvement, and root fracture)? and which teeth were most commonly involved in severe TDI

Answer 4

• Majority of TDI occured in maxilla (71%); mostly rostral
• Most commonly injured teeth:
  
  • canines (36%)
  • premolars (34%).
  • incisor (23%) and molar (8%)
  • so majority in strategic teeth (61%)(canine + carnassial); most frequent carnassial = MxPM4 (92%)
• 67% of TDI were classified severe (higher than in human) Incisor, premolar, canine most commonly involved

Question 5

Result - Disucssion

WhichTDI types identified by the WHO and used in human were identified in this study?

What was the most common and the least common Traumatic Dentoalveolar Injury (TDI)?

Answer 5

All (14) TDI types were identified

Most common: Enamel-dentin-pulp fracture - 50%

% of the other TDI:

• concussion (14%])
• enamel-dentin (uncomplicated) fracture (12%)
• crown-root fracture with pulp involvement (11%)
• enamel fracture (4%)
• root fracture (3%)
• crown-root fracture without pulp involvement (2%)
• avulsion (2%)
• lateral luxation (0.8%)
• alveolar fracture (0.3%])
• enamel infraction, extrusive luxation, and intrusive luxation (0.2%)
• subluxation (0.1%) - true prevalence or underrepresentation due to the inherent challenges in diagnosing luxation injuries in dogs and cats

Question 6

Results

What was the frequency of tooth fracture among TDI?

Of all the fracture injuries, which teeth were most commonly fracture?

Answer 6

• The frequency of tooth fracture (not including alveolar fracture) was 82%.
• most commonly fx teeth: premolar teeth (39.0%) and canine (33.3%), then incisor (21.0%) and molar (6.7%) teeth.
  
  • Enamel-dentin-pulp fx: canine (40%) and strategic teeth
  • Enamel-dentin fx: premolar (36%)
  • Crown-root fractures (with and without pulp involvement): premolar teeth (57%) (with pulp mostly premolar and carnassial teeth
  • Enamel fractures: premolar (49%); incisor (26%)
  • Root fractures: incisor teeth (74%); Mn; less likely in strategic teeth

Question 7

Result

What was the frequency of luxation injuries (which include (concussion, subluxation,lateral luxation, intrusive luxation, extrusive luxation and avulsion)?

and which teeth were most commonly and least commonly affected?

Answer 7

Overall luxation injuries: 17.3% - most affected teeth canine/incisor (79%)

• most common luxation injuries was concussion
  
  • most frequent teeth affected by concussion: canine 46% and incisor 30%
  • least affected teeth: MxPM4, MnM1 (4%)

Question 8

Result

What was the most common age for dogs and cats with Traumatic Dentoalveolar Injury (TDI)?

Answer 8

3 - 6 years of age - 33%, then 7 - 10 years - 31.3%

but luxation injuries more frequent in < 3 yo

Question 9

Result

What breed of dog had the most Traumatic Dentoalveolar Injuries (TDI)

Answer 9

Labrador - 17.9% of TDI

German shepherd (8.6%)

Golden retriever (6.8%)

Border collie (4.1%)

mixed breed (3.3%)

Question 10

Result - disussion

What breed of cat had the most Traumatic Dentoalveolar Injuries (TDI)

Answer 10

Domestic short hair - 62.5% of TDI

Domestic medium-hair (10.4%)

Domestic long-hair (6.3%)

Siamese (4.2%) and Abyssinian (4.2%)

Question 11

Result - Discussion

Was there a sex status more prone to TDI?

Answer 11

No significant relationship between sex and the prevalence of TDI

• sexually intact patients were more likely to lateral luxation, but this is more related to age than sex
• this different than in human where males are more prone to TDI

Question 12

Discussion

1. How the prevalence of TDI in this study compared to human prevalence and previous vet studies?
2. Why we would expect the enamel-dentin fx to be the most common fx instead of Enamel-dentin-pulp fx?
3. How can be explain that enamel-dentin-pulp fx was more common in strategic teeth?
4. Why premolar teeth are more prone to crown-root fx?
5. Why frequency of root fx increase with age and are more frequent in incisors?
6. Why more luxation injuries in patient < 3 yo
7. Why age categorization may not accurately reflect true distribution in population?
8. What were the recommendations concerning the classification of TDI?

Answer 12

1. similar to human 1 out of 4; lower than previous vet studies that include MM fx/Highrise syndrome and higher to one that evaluate teeth not under anesthesia
2. injuries that require less mechanical force would occur with a higher frequency, as in humans; this was not found here probably because they were not recorded in the discharge note and the dental chart was not review.
3. given the demand placed on these teeth and the forces to which these teeth are subjected,
4. because they are subjected to high shear stresses during mastication
5. because degree of flexibility of PDL and alveolar bone decreases with age, so energy remain primarily in the tooth, leading to root fracture; incisors have smaller volume of dentin, so more prone to fx
6. because PDL/alveolar bone mon flexible, so energy from traumatic force transferred from tooth to periodontium causing luxation instead of dental fx
7. according to previous study, injuries were incidental findings in 35.5 % of all dental fractures in dogs. In this study cause and timing were often unknown; it is possible that patients had sustained TDI at a younger age.
8. existing AVDC classification system for tooth fractures be expanded to include tooth concussions, luxations, avulsions, and alveolar fractures as TDI

Question 13

Conclusion?

Answer 13

TDI are common and represent a significant animal health concern.

Prospective study needed to gather information regarding predisposing factors, places of injury, seasonal variations, and specific etiology

Biomechanical studies designed to assess the energy leading to TDI

Outcome studies to assess treatment and prognosis should be pursued

Question 14

What is the difference between the AVDC tooth fracture classification and the WHO human TDI classification system?

Answer 14

AVDC: Enamel infraction; Enamel Fx; UCF; CCF; UCRF; CCRF; RF (7)

WHO human TDI: Concussion; Subluxation; Extrusive luxation; Intrusive luxation; Lateral luxation; Avulsion; Enamel infraction; Enamel Fx; Enamel-dentin Fx; Enamel-dentin-pulp Fx; Crown-root Fx (w/o pulp inv); Crown-root Fx (w pulp inv); Root Fx; Alveolar Fx (14)