MCQs on OCCLUSION

In the left lateral movement of the mandible, the LINGUAL cusp of the maxillary RIGHT first premolar may appear to pass

1. into the facial embrasure between canine and first premolar

2. toward the tip of the mandibular second premolar

3. into the lingual embrasure between first and second premolars

4. into the lingual embrasure between canine and first premolar.

non working side's Max cusps run buccaly distally on the man teeth. max 1st pm's lingual cusp is far from Man canine. even it doesnt occludes with canine in CO .

In rigth laterotrusive movement ,the lingual cusp of a maxillary rigth second premolar passes through which of the following mandibular structures?

a)facial groove of the rigth first molar

b)lingual groove of the rigth first molar

c)embrassure between the rigth first premolar and the rigth second premolar

d)embrassure between the rigth second premolar and the rigth first molar

lingual cusps of mx premolars occlude in the fossa.and when md moves laterally ,mx seems to move distally n lingually therefore lingual cusp will pass thru the embrasure distal to it

Which of the following is not normally an alterable factor in the articulation of teeth

Incisal Guidance

Postural Position

Compensating Curve

Cusp-Fossa Relationship

Posterior tooth morphology.

postural control-coz that is completely muscle guided.Rest can be modified.

Cusp-fossa relation can be modifed as in giving class 3 in some pts or given flat cusps.

 The immediate side shift (Bennett movement) influences the

a. mesiodistal position of cusps. (asda)

b. faciolingual position of cusps.

c, position of the central fossa.

d.depth of the distal fossa.

The condyle on the working side generally rotates about a

sagittal axis only.

horizontal axis only.

horizontal axis and translates laterally.

vertical axis and translates laterally.

A working movement involves condyles rotating in a circular way around vertical axis and mandible moves toward that side so its translation.

In a right lateral excursion, the mesiofacial cusp of the maxillary right first molar passes through which of the following grooves of the mandibular right first molar?

Lingual groove

Central groove

Facial groove

Distofacial groove

Which of the following occurs in a right lateral movement?

A. Rt condyle primarily rotates

B. Rt condyle moves down the eminentia

c. Facial cusps of md left side pass under mx left facial cusps

D. Facial cusps of md rt side pass under mx rt lingual cusps.

The concept of using a lateral checkbite record to set a respective condylar inclination implies which of the following?

a.That the non-working side condyle has traveled against the posterior wall of the fossa

b.That the working side condyle has traveled down the slope of the articular eminence

c.That the non-working side condyle has moved anteriorly and medially

d.That the working side condyle has moved toward the medial wall of the glenoid fossa

choice 3 is rite coz 1) the non working condyle moves anteriorly and medially so cannot contact posterior wall of fossa 2)the working side condyle moves mainly laterally so it cannot moved forward as in choice b

which part of tmj is most sensitive?...capsule ,peripehery or synovial fluid?

-periphery

Moving the mandible from maximum ICP to retruded contact position, the following will result:

-increase vertical occlusal dimension

-decrease vertical occlusal dimension

-decrease horizontal overlap

-increase vertical overlap

Which of the following anatomic factors will restrict the amount of lateral shift that can occur on a working condyle?

A. Medial wall of the articular fossa on the working side

B. Superior wall of the articular fossa on the non-working side

C. Capsular ligaments.. my answer

D. Stylohyoid ligament marked answer

E. Stylomandibular ligament

 After seating a crown on #30 patient is asked to slide their jaw to the left. what muscle does patient use to move her jaw

1.rt ltrl pterygoid

2. lft ltrl pterygoid

3.rt medial pterygoid

4.lft medial pterygoid

is there teeth contact in centric relation or not?

its a ligament guided movement and normally it doesnt allow teeth of oposite arches to contact..that happens in CO in which maximum intercuspation of teeth occours bw the opposite arches but sometimes teeth contact has been reported even in CR...a simple examle is that move ur mandible on any side say right.when u stretch ur mandible to the maximum tooth contact gets lost and thats when the condyle of the mandible comes in the most anterior and superior position inside the glenoid fossa..mind u it only allows the rotaional movement around a horrizontal hinge axis..

the jaw jerk reflex is an example of which of the following reflexes?

a load

b flexor

c withdrawl

d dynamic strech reflex

http://video.google.com/videoplay?docid=-6867872866767275986

dynamic stretch reflex.The motor division of CN 5 supplies the muscles of mastication (temporalis, masseters, and pterygoids). Palate the temporalis and masseter muscles as the patient bites down hard. Then have the patient open their month and resist the examiner's attempt to close the month. If there is weakness of the pterygoids the jaw will deviate towards the side of the weakness

Reflex activity in the EMG of the jaw-closing muscles is produced when these muscles are stretched during isometric clenching or when a downward directed load is applied during voluntary closing of the jaw. This so-called jaw-jerk reflex is the result of stretching the muscle spindles.

In a healthy state , the height of interproximal alveolar bone is most directly related to -

1- COnvexity of F and L surfaces of crown

2- convexity of proximal surfaces of crown

3- relationship of proximal contacts occlusocervically

4- relationship of proximal contacts faciolingually

5-relationship of cemento enamel lines of adjacent teeth

 In right lateral excursion max right first molar mesiofacial cusp passes through which of following grooves of mandibular first molar..

marked answer .. lingual groove.

The max mesiofacial cusp doesn't occlude, but lies facial to the facial groove. The max distofacial cusp doesn't occlude, but lies facial to the distofacial groove.

1. Lingual groove - the mesiolingual cusp travels through it.

2. Central groove - this groove only has a cusp traveling through it in protrusive / retrusive movements

3. Facial groove - the mesiofacial cusp travels through it since this cusp is what is lying facial to the facial groove when the man. travels laterally across the mesiofacial cusp

4. Distofacial groove - the distofacial cusp travels through it

In lateral excursion on a patient with ideal occlusion, the mesial cusp ridge od mandibular 1st molar contacts the..

1 distolingual surface of the maxillary canine

2 distolingual slope of the buccal cusp of the maxillary 1st molar

3 mesiolingual slope of the buccal cusp of the maxillary 1st premolar

4 none of the above

In intercuspal position MMR of mand first molar is in facial embrasure between max 2nd premolar and max 1st molar. The don't specify the side of lateral movement neither the side of the molar tooth asked but in any case if it is a working movement no cusp of max 1st molar can touch MMR of mand M because max ML cusp goes to mand lingual groove and max MB cusp goes to mand mesiobuccal groove. The only slight chance I would say is for distal part of buccal cusp of max 2nd premolar to touch MMR of mand 1 st molar since maxillary premolar's buccal cusp turns more distal( but this is not in answer choices) In case of non morning movement there should be no contacts at all

The immediate side shift (Bennett movement) influences the

A.mesiodistal position of cusps.

B.faciolingual position of cusps.

C.position of the central fossa.

D.depth of the distal fossa.

Bennett movement influences mesiodistal position of cusps. "Bennett movement" is a medial and protrusive movement of the condyle (and subsequently the entire mandibular arch). This is the function of the lateral pterygoid muscle opposite that of the direction the chin points.

By Shweta Thambad