MDS PREP
Which dimension in which arch is considered as a safety value for pubertal growth spurts?
1) Maxillary intercanine dimension
2) Mandibular intercanine dimension
3) Maxillary intermolar width
4) Mandibular intermolar width
Orthodontics Answer: 1
SOLUTION
Intercanine width serves as safety valve for dominant horizontal basal mandibular growth spurt.
According to Angle, the key to normal occlusion in adults is the anteroposterior relationship. His description of teeth relationships in normal occlusion remains a fundamental observation. Angles observations are based on which teeth that are most reliable to understand occlusion
1) First molars and canines
2) First molars and first Premolars
3) Canines and first Premolars
4) First molars and central incisors
Orthodontics Answer: 1
SOLUTION
The mesial incline of the upper canine occludes with the distal incline of the lower [canine];
the distal incline of the upper canine occludes with the mesial incline of the buccal cusp of the lower first premolar.
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.
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.
Ideally, Orthodontic traction to pull an impacted tooth to line of arch should begin at
1) 2-3 months post surgically
2) As soon as possible after surgery
3) After a waiting period of at least1.5 months
4) Only the method of traction is critical, not the time
Orthodontics Answer: 2
SOLUTION
Mechanical approaches for aligning unerupted teeth. Orthodontic traction to pull an unerupted tooth toward the line of the arch should begin as soon as possible after surgery
Ideally a fixed orthodontic appliance should already be in place before the unerupted tooth is exposed, so that orthodontic force can be applied immediately.
If this is not practical, active orthodontic movement should being no later than 2 or 3 weeks post-surgically.
Baker anchorage utilizes
1) Intermaxillary anchorage with screws
2) Intramaxillary anchorage with screws
3) Intermaxillary anchorage with elastics
4) Intramaxillary anchorage with elastics
Orthodontics Answer: 3
SOLUTION
Intermaxillary anchorage or Baker's Anchorage. This type of anchorage involves using elastics from one jaw to the other, in the form of either Class 2 elastics (moving upper teeth back) where lower molar teeth serve as anchors, or Class 3 elastics (moving lower teeth back) where upper molars serve as anchors.
Intramaxillary anchorage is also used in the form of E-chain, when elastics are used from the back molar teeth to the front teeth in the same jaw to move teeth back of the mouth.
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
Considering the 3D growth of the face, it ceases last in which direction?
1. A-P
2. sagittal
3. transverse
4. vertical
Orthodontics
Answer: 4
for facial growth order of growth is
width > depth > height