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.
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
A single force applied at which point of a tooth will allow complete translation of the tooth.
1) At the apex
2) At the incisal edge
3) At the center of resistance
4) At the center of rotation
Orthodontics Answer: 3
SOLUTION
Center of resistance- Point analogous to the centers of gravity.
Generally it is constant.In single root it lies between one third and one half of the root apical to alveolar crest.
In multi rooted tooth it lies 1-2 mm apical to furcation
Which of the following is a noninvasive method of gaining the space
1) Slenderisation and extraction
2) Expansion and extraction
3) Expansion and distalization
4) All of the above
Orthodontics
Answer: 3
Expansion and distalization are considered noninvasive methods for
gaining space in orthodontic treatment.
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.
"Thumb sucking" will
1) Always produce maxillary prognathism
2) Always indicate psychological disturbance
3) Always needs appliance therapy 10 break the habit
4) None of the above. Many times it stops spontaneously
Orthodontics
Answer: 4
Explanation: Thumb sucking is a common behavior in children and does not always lead to maxillary prognathism, psychological disturbances, or the need for appliance therapy. Many children stop thumb sucking on their own without intervention.
In orthodontic treatment, the forces applied should not exceed the ________________ in order to avoid injuries to the tissues.
1) Arterial blood pressure
2) Muscular forces of facial muscles
3) Masticatory retrusion
4) Capillary blood pressure
Orthodontics Answer: 4
SOLUTION
Optimum orthodontic force is one, which moves teeth most rapidly in the desired direction, with the least possible damage to tissue and with minimum patient discomfort.
Oppenheim and Schwarz following extensive studies stated that the optimum force is equivalent to the capillary pulse pressure, which is 20-26 gm/sq. cm of root surface area.
From a clinical point of view, optimum orthodontic force has the following characteristics:
1) Products rapid tooth movement
2) Minimal patient discomfort
3) The lag phase of tooth movement is minimal
4) No marked mobility of the teeth being moved
From a histologic point of view the use of optimum orthodontic force has the following characteristics:
1) The vitality of the tooth and supporting periodontal ligament is maintained
2) Initiates maximum cellular response
3) Produces direct or frontal resorption
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.