MDS PREP
Bone tissue grows by
1) Apposition
2) Interstitial growth
3) Osteoclastic growth
4) Mesenchymal tissue growth
Orthodontics Answer: 1
SOLUTION
Interstitial growth, simply means that it occurs at all points within the tissue. When mineralization takes place so that hard tissue is formed, interstitial growth becomes impossible.
What is the Angle classification of occlusion based upon?
Orthodontics Answer: 3
1. The position of the maxillary incisors relative to the mandibular incisors
2. The position of the maxillary incisors relative to the mandibular incisors
3. The position of the maxillary canines and first permanent molars relative to the mandibular canines and first permanent molars.
4. The position of the upper lip relative to the lower lip
The position of the maxillary canines and first permanent molars relative to the mandibular canines and first permanent molars
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.
The most common permanent tooth found to be ankylosed is
1) 1st molars
2) 2nd molars
3) Canines
4) Premolars
Orthodontics Answer: 4
ankylosed teeth are also known as submerged teeth.
submerged teeth are decidous teeth most commonly mandibular second molars
Most common permanant tooth found to be ankylosed is premolars.
Ashley-Howe model analysis is used to predict
1) Tooth material excess
2) Maxillo - mandibular relationships
3) Basal bone-transverse relationship
4) Growth prediction
Orthodontics
Answer: 3
Ashley-Howe Model Analysis
The Ashley-Howe model analysis is a method used in
orthodontics to assess the relationship of the dental arches and the position of
the teeth, particularly in the context of planning orthodontic treatment. This
analysis is particularly useful for evaluating the transverse dimension of the
dental arches and understanding how the maxilla (upper jaw) and mandible (lower
jaw) relate to each other.
Measurement Parameters:
The analysis involves measuring specific distances and angles on dental
casts or models. Key measurements may include:
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 help in determining the transverse relationships of
the dental arches.
Classification:
The results of the Ashley-Howe analysis can help classify the dental
arch relationships into different categories, such as:
Normal: Where the measurements fall within the
expected range.
Narrowed: Indicating a constricted arch that may
require expansion.
Widened: Indicating a broader arch that may need to
be reduced or managed differently.
Clinical Application:
The Ashley-Howe model analysis is particularly useful in treatment
planning for orthodontic cases involving:
Crossbites: Where the upper teeth are positioned
inside the lower teeth.
Crowding: Where there is insufficient space for
teeth to erupt properly.
Expansion Needs: Determining if a patient requires
arch expansion to correct transverse discrepancies.
Treatment Implications:
Based on the analysis, orthodontists can decide on appropriate treatment
modalities, which may include:
Orthodontic Appliances: Such as expanders to widen
the arch.
Extraction: In cases of severe crowding or when
space needs to be created.
Comprehensive Orthodontic Treatment: To align the
teeth and improve occlusion.
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
The philtrum of the upper lip is formed largely by the
1) Lateral nasal processes
2) Globular process
3) Maxillary processes
4) Mandibular processes
Orthodontics
Answer: 2
Explanation: The philtrum is the vertical groove located in the middle of the upper lip. It is primarily formed by the fusion of the medial nasal processes, which include the globular process. The globular process is a key structure in the embryonic development of the face, contributing to the formation of the upper lip and the philtrum.
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.