MDS PREP
Which of the following shows 200 % of its adult growth by age 9-10 years
1) Lymphoid
2) General
3) Genital
4) Neural
Orthodontics
Answer: 1
The lymphoid system, which includes lymph nodes, spleen, and other lymphatic tissues, undergoes significant growth during childhood. By the age of 9-10 years, the lymphoid tissue can reach approximately 200% of its adult size due to the increased demand for immune function during this period. This growth is part of the body's preparation for increased exposure to pathogens as children interact more with their environment.
The diameter of labial-bow of the maxillary plate
1) 0.5-0.6 mm
2) 0.6-0.8 mm
3) 0.7-0.8 mm
4) 0.8-1.0 mm
Orthodontics
Answer: 3
The labial bow is a component of the maxillary denture framework that helps in stabilizing the denture and providing support. The diameter of the labial bow is typically measured to ensure proper fit and function. The standard range for the diameter of the labial bow is generally accepted to be between 0.7 mm and 0.8 mm
In mixed dentition, which of the following may be considered as a self correcting problem with age?
1) Unilateral loss of primary canine
2) Lack of interdental spaces
3) A distal step
4) Open bite
Orthodontics Answer: 2
SOLUTION
The possibility that a distal step would become class II is very real, and this not self correcting problem. When the central incisors erupt, these teeth use up essentially all of the excess space in the normal primary dentition. With the eruption of the lateral incisors, space becomes tight in both arches.
Normal child will go through a transitory stage of mandibular incisor crowding at age 8 to 9 even if there will eventually be enough room to accommodate all the permanent teeth in good alignment. In other words, a period when the mandibular incisors are slightly crowded is a normal developmental stage.
Continued development of the arches improves the spacing situation, and by the time the canine teeth erupt, space is once again adequate.
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
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
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.
Flaccid lip, digit sucking, high frenum attachment & poor muscle tone are the etiology of :
1) Anterior cross bite
2) Diastema
3) Anterior bite
4) Posterior cross bite
Orthodontics Answer: 2
Midline diastema Etiology
Normal developing dentition - (Ugly Ducking Stage)
Parafunctional habits
- Flaccid lips along with poor muscle tone
- Simple Tongue thrust can cause anterior open bite as well as diastema
- Thumb sucking or digit sucking for a prolonged time period
Retrognathic mandible/ Prognathic mandible
Frenum attachments
Mesio-distal angulation of teeth
Tooth anomalies (eg. supernumerary teeth, peg laterals, absence of laterals)
Pathological (Juvenile periodontitis)
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