MDS PREP
Slow progression in molar uprighting in an adult patient is due to
1) Occlusion not being relieved
2) Overcontoured spring
3) Back of anchorage control
4) All of the above
Orthodontics
Answer: 1
Slow progression in molar uprighting can occur if the occlusion is not
adequately relieved. If the opposing teeth are still in
contact, it can hinder the movement of the molar being
uprighted.
Supervision of child"s dentition is critical at or in
1) 3-6 years primary dentition
2) 7-10 years mixed dentition
3) 11-14 years permanent dentition
4) 14-17 years post permanent
Orthodontics
Answer: 2
Supervision of a child's dentition is critical during all developmental stages, but the 7-10 years age range, which is the mixed dentition stage, is a particularly important time for monitoring. This is because it is the period when both primary (baby) and permanent (adult) teeth are present in the mouth. During this stage, children are at risk for various dental problems such as crowding, malocclusion, and the loss of primary teeth that can affect the eruption of permanent teeth.
If a coil and tag of a palatal canine retractor are placed too far distally
1) Base plate is weakend
2) Tooth movement will be slowed
3) Tooth will tend to be moved buccally
4) Tooth will tend to be moved palatally
Orthodontics
Answer: 3
If the coil and tag of a palatal canine retractor are placed too far distally,
the force applied will tend to move the tooth buccally
(toward the cheek) rather than palatally (toward the
palate), which can hinder the intended movement.
Which of the following is not one of the consequences of using Herbst appliance in treatment of Class II malocclusion?
1) Increase in mandibular growth
2) Over corrected Class I molar relation
3) Increase in SNB angle
4) Increase in overjet
Orthodontics Answer: 4
Solution
The following are the effects when Herbst appliance used for treatment of Class II malocclusion:
1. Class I molar relation or over-corrected Class I molar relation.
2. Increased mandibular growth
3. Distal driving of maxillary molars which helps to achieve molar relation.
4. Reduction of overjet by increasing mandibular length and proclination of mandibular incisors.
5. Inhibitory effect on sagittal maxillary growth
6. Weislander suggested double contour of glenoid fossa which indicates anterior transformation of glenoid fossa
7. Increased SNB angle and decreased SNA angle.
If maxillary canines are placed forward to orbital plane, they are said to be in
1) Protraction
2) Retraction
3) Abstraction
4) Contraction
Orthodontics Answer: 1
SOLUTION
Simon used the orbital plane (a plane perpendicular to the F-H plane at the margin of the bony orbit directly under the pupil of the eye).
According to Simon, in normal arch relationship, the orbital plane passes through the distal axial aspect of the maxillary canine
Malocclusions described as anteropostenor deviations based on their distance from the orbital plane are as follows:
1. Protraction: The teeth, one or both, dental arches, andYor jaws are too far forward, i.e. placed forward or anterior to the plane as compared to the normal where the plane passes through the distal incline of the canine.
2. Retraction: The teeth, one or both dental arches and/or jaws are too far backward, i.e. placed posterior to the plane than normal
The basic principle of Orthodontic spot welder lies on the concept of :-
1 Heat technique
2) Quenching
3) Diodelasers
4) Electrode Technique
Orthodontics Answer: 4
SOLUTION
The type of welding used to join Orthodontic components is called Spot welding. The heat source usually a high amperage electricity. Orthodontic spot welders employ the electrode technique, in which current is conducted through two copper electrodes. The copper electrode in a welding unit serve the following purposes :
1. Transmit current to the metals to be joined so as to cause a rapid increase in temperature.
2. The electrodes help in conducting the heat produced away from the area so as to preserve the properties of stainless steel around the weld spot.
3. The electrode also help in holding together the two metals to be joined.
4. The electrodes are designed to apply pressure on the metals being joined. As soon as the temperature increases, the pressure exerted by the electrodes helps in squeezing metal into each other.
An increase or decrease in the Y axis is related to:
1) The growth pattern
2) Extrusion of molars
3) Intrusion of molars
4) All of the above
Orthodontics Answer: 1
SOLUTION
What dental relationship is present in an Angle Class I occlusion?
Orthodontics Answer: 3
1. The buccal cusp of the maxillary second premolar aligns with the mesiobuccal groove of the mandibular first molar.
2. The cusp of the maxillary canine aligns with the cusp of the mandibular canine.
3. The mesiobuccal cusp of the maxillary first molar aligns with the mesiobuccal groove of the mandibular first molar.
4. The mesiobuccal cusp of the maxillary first molar aligns with the embrasure between the mandibular first molar and second premolar.
The mesiobuccal cusp of the maxillary first molar aligns with the mesiobuccal groove of the mandibular first molar.