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EQ equilibration
Vet Dentistry
Question | Answer |
---|---|
What length of tooth may be removed from the occlussal surface by odontoplasty at any one time? | 3-4 mm |
When an overgrowth is large, what amount and interval should odontoplasty be performed? | 3-4 mm every 2-3 months |
What is The purpose of incisor examination and correction of malocclusions | to maintain lateral excursion to molar contact within normal limits and to maintain normal shape of incisor arcades |
What is the the power stroke of the chewing cycle? | it lasts from the initial molar contact to the incisor contact as the mandible reaches the neutral (centric) position and as the mandible moves across the mouth where cheek teeth (CT) contact is obtained on the opposite side of the mouth. |
How far do Horses typically move the mandible laterally during the opening stroke? | |
What are the 3 phases of the chewin g cycle? | Opening, closing, power stroke |
In a study by B.A. Rucker, what is normal EMC? | The mean EMC distance for 730 horses was 1.24 ± 0.31 cm. The median was 1.2 cm. |
In a study by B.A. Rucker, how many horses had assymetrical EMC? | 6.54% had differing values for the left and right EMC exceeding 2 mm |
Why is it difficult to determine the percentages of incisor to molar contact? | because it is difficult to push the mandible laterally to its maximum, even in sedated horses |
What is another term for CT angle of occlusion? | transverse or buccolingual plane angle |
How can the CT angle of occlusion be calculated? | push the mandible laterally to molar contact. Make a mark on the upper arcade to locate this point. Second, push the mandible 1 cm beyond this point. Draw An imaginary line from the mark on the upper arcade to the center of the mandible |
How much incisor separation would be noted during estimation of occlusal table angle with shear mouth? | more separation occurs with a greater slope or angle. |
What is the 'normal' occlusal angle? How does the occlusal angle vary within an arcade? | 10-15 degrees (incisor separation 2-3 mm) greater angle towards caudal CT |
What factors should be considered in the decision to The decision to shorten the length of the incisors? | Body condition chewing ability (dropping grain or quidding) fecal fiber length EMC distance and residual molar reserve crown |
What happens to EMC as incisors become too long? | EMC increases (percentage of molar contact decreases) |
What is a generally safe approach to incisor reduction? | Removing 1 mm at a time and observing the results |
What is normal EMC? | Normally shaped incisor arcades should have an EMC of 1.2 cm + 2 - 3 SDs of 3.1 mm |
When is the term "incisor reduction" used appropriately? | shortening of incisors that are normally shaped but have an excessive EMC. |
What should one do to the incisors if EMC <1.2 cm? | nothing! (except adjust malocclusion) |
How should one treat an incisor smile? | level the lower arcade. After that, if EMC is 1.2 cm +/- 3.2 mm do NOT level the upper arcade |
How are incisor slants described? | by listing the tall quadrants |
How are incisor slants treated? | remove 1 mm at a time from the tallest point on the 2/4 arcades, tapering the amount removed toward the short side. Stop when the EMC to the left side is equal to or slightly less than the right side, even if the incisors are not completely corrected |
When slant incisor malocclusion is caused by inability of the mandible to move to one side because of injury or temporomandibular joint damage, how will the incisors appear? | he upper incisors will be slanted long on that side |
How does the occlusal angle of the CT change with overlong incisors? | becomes flatter b/c only the tall sides of the CT receive wear |
The flatter the occlusal angle, how does EMC change with incisor reduction | Greater change in EMC per mm of incisor reduction (easier to 'overload' CT) |
What should the rostral-caudal slope of the incisor’s occlusal surface be when using the bars as a guide | 15 degrees |
What facial anatomical structure generally approximates the incisor slope? | slope of the facial crest |
What effects can be seen by adjusting the incisor slope? | Adjusting the slope can have the same effect as an incisor reduction. |
In what order should slope adjustment and true incisor reduction be performed when both are indicated? | adjust the slope first, then check EMC to see if additional reduction is needed |
When performing diastema widening, which side of the tooth tends to have the pulp closer to the interproximal edge? Equine Vet J 2011 | caudal (esp. caudopalatal, maxillary 4th pulp horn & caudolingual, mandibular 5th pulp horn) |
What range of distance between pulp horn and interproximal surface was illuminated by the study? Eq Vet J 2011 | 1.3 - 10.8 mm |
What changes are seen regarding distance between occlusal secondary dentin and interproximal surface relative to pulp location as a horse ages? Eq Vet J 2011 | pulps tend to become closer to the interprox. surface and occlusal surface as horses age |
How does occlusal equilibration change the rostro-caudal mandibular (RCM) excursion? JAVMA 2003 | RCM increases after dental float |
Which type of horse tended to have a higher RCM? JAVMA 2003 | draft breeds |
What effect does decreased mandibular excursion (as seen with painful dental dz or feeding short stem diet) on CT occlusal angle? JVD summer 2004 | CT OA gets steeper |
How long can a motorized float be held on a tooth before it overheats? 2012 Equine vet J | rasping for 30 seconds raised the pulp temp above critical threshold in ~20% of teeth tested. variation in subocclusal dentin thickness and water cooling affect the risk of thermal injury among individuals |
According to Dixon (Complications of equine oral surgery." Vet Clin North Am Equine Pract 2008), how much and how often should tall dental overgrowths be reduced? | max 5 mm, no more frequent than q3 months, with filing for 10 consecutive sec or less to prevent thermal pulp damage |
How many degrees must the temperature increase to reach critical pulp temperature? | 14 degrees C may cause pulpar death |