MDS PREP
If PMBAW% is 44 in Howe"s analysis, it indicates
1) Extraction case
2) Expansion case
3) Borderline case
4) None of the above
Orthodontics
Answer: 3
The primary purpose of Howe's Analysis is to assess the width of the
dental arches and to identify any discrepancies between the maxillary
(upper) and mandibular (lower) arches. This is particularly important in
cases of malocclusion, where the alignment of the teeth and the relationship
between the jaws may be compromised.
The analysis involves measuring specific distances on the dental casts,
including:
Intercanine Width: The distance between the cusp
tips of the canines.
Interpremolar Width: The distance between the cusp
tips of the first premolars.
Intermolar Width: The distance between the cusp
tips of the first molars.
These measurements are used to calculate the Percentage of
Maxillary Buccal Arch Width (PMBAW%), which is a key indicator in
the analysis.
The results of Howe's Analysis can indicate different treatment needs:
Normal Case: A PMBAW% within a certain range
(typically around 50-60%).
Narrow Case: A PMBAW% below the normal range,
indicating a need for arch expansion.
Wide Case: A PMBAW% above the normal range, which
may suggest the need for extraction or other interventions.
Borderline Case: A PMBAW% around 44, indicating
that the arch width is at a threshold where careful consideration is
needed for treatment options.
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.
A child is 7-year-old skeletal class I relation. He has the habit of thumb sucking. There is slight overjet and anterior spacing. If he discontinue the habit
1) Overjet will reduced
2) Overjet increases as permanent canines erupt
3) Lower incisors incline labially
4) Result in crowding of anterior teeth
Orthodontics
Answer: 1
In a child with a skeletal Class I relationship and slight overjet, thumb sucking can contribute to the maintenance of the overjet due to the anterior teeth being pushed forward by the thumb. If the child discontinues thumb sucking, the anterior teeth may naturally reposition themselves, leading to a reduction in overjet.
Option 2 is incorrect because while the eruption of permanent canines can influence the occlusion.
Option 3 is also incorrect; the lower incisors would not necessarily incline labially if the thumb sucking habit is stopped.
If the edgewise bracket is not pressed completely on to a tooth on the mesial side while bonding, the side effect would be
1. intrusion
2. extrusion
3. rotation
4. breakage of bracket
Orthodontics
Answer: 3
we are applying force distally only..force vector will rotate the tooth distally
The angle of convexity
1) SNA
2) NAPog.
3) ANB
4) SNB
Orthodontics Answer: 2
SOLUTION
Angle of Convexity The angle of convexity is formed by the intersection of line from N to point A, to point A to pogonion.
Relative to a heterogenous population the incidence of malocclusion in a homogenous population is
1. lower
2. slightly higher
3. significantly higher
4. about the same
Orthodontics
Answer: 1
In a homogeneous population, the genetic variation is less compared to a heterogeneous population. Malocclusion is influenced by both genetic and environmental factors. A homogenous population, which is more genetically similar, would be expected to have a more uniform expression of dental traits, including a lower incidence of malocclusion, assuming that the specific genetic factors for malocclusion are not prevalent in that particular population. In a heterogeneous population, the greater genetic diversity can lead to a higher incidence of malocclusion due to a wider range of genetic combinations contributing to dental misalignments.
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.
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.