ortho moh

ORTHODONTI

C 2013

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Concerning hand-wrist radiographs, which of the following statements is correct? A. Bone age is estimated by the presence or absence of osseous centres in particular bones and compared with standards.B. Hand-wrist radiographs are a precise measure of progress in skeletal development in normal children.C. The hand-wrist radiograph is of little value in orthodontic diagnosis.D. The information obtained from

radiographs alone is enough to make an accurate determination of skeletal age.

Orthodontists can compare a hand-wrist radiograph with the atlas and find out a child’s skeletal age. With this data, an orthodontist predicts the next growth spurt and makes a treatment plan that takes advantage of the timing.

http://uofmhealth.org/health-library/tn2826



In cephalometry, the most stable point in a growing skull is the

A. sella turcica. B. nasion.C. Broadbent's point.D. Bolton point.

The stable anatomical structures in the anterior cranial base are:

http://www.angle-society.com/case/guide.pdf



Which of the following patients should be referred for orthodontic treatment to close a diastema between maxillary central incisors?

1. An 8-year old with no abnormal oral habits.2. A 14-year old with no abnormal oral habits.3. A 3-year old with a 4mm overjet.4. An 8-year old with a previous thumb habit.

A. (1) (2) (3) B. (1) and (3) C. (2) and (4) D. (4) onlyE. All of the above

Number one is wrong because the patient is 8 year old so the canine did not erupt yet .So we should wait until the eruption of canine to decide if this case need ortho or no.

Number three is wrong because the overjet is with in the normal range .More than 4mm we must take an action.

3. The developing permanent tooth

A. lies apically and lingually to primary teeth in the anterior region.B. may show deviated eruption times if the primary tooth is lost prematurely.C. has a more protrusive path of eruption in

the anterior region.D. All of the above.

The permanent incisors and canines first develop lingual to the deciduous tooth germs at the level of their occlusal surfaces and in the same bony crypt. As their deciduous predecessorss erupt, they move to more apical position and occupy their own bony crypts.

http://books.google.ca/books?id=0HSNr774GHwC&pg=PA179&lpg=PA179&dq=the+developing+permanent+tooth+ndeb&source=bl&ots=yZe3eN_Erj&sig=K7BvL19XI0GZXuRIaxXZH-4t3U4&hl=en&sa=X&ei=60jDUbrmLsbwiwKqoIDQCg&ved=0CFcQ6AEwBg#v=onepage&q=the%20developing%20permanent%20tooth%20ndeb&f=false

And http://course.jnu.edu.cn/yxy/eruption/zp/english/Englishtext15.htm

http://course.jnu.edu.cn/yxy/eruption/zp/english/Englishtext15.htm

http://course.jnu.edu.cn/yxy/eruption/zp/english/Englishtext15.htm

Primate spacing in the primary dentition is observed between 1. maxillary canines and first molars.2. maxillary canines and lateral incisors.3. mandibular canines and first molars.4. mandibular canines and lateral incisors.

A. (1) and (3) B. (1) and (4) C. (2) and (3) D. (2) and (4)E. (4) only The mandibular primate space is found between the primary mandibular canine and first molar. The maxillary primate space is found between the maxillary primary lateral incisor and canine.Page 86CONTEMPORARY ORTHODONTICS, FOURTH EDITIONandhttp://books.google.ca/books?id=55lKraQcv7cC&pg=PA86&dq=Primate+spacing&hl=en&sa=X&ei=AAvFUbDoFqGCiAKqoIH4Dw&ved=0CDcQ6AEwAg#v=onepage&q=Primate%20spacing&f=false

7.The anterior component of force may be observed clinically as

A. distal movement of a permanent mandibular cuspid.B. mesial movement of a permanent maxillary first molar.C. A. and B.D. None of the above.

8. If a child's teeth do not form, the primary effect will be on the growth of the A. alveolar bone. B. mandible.C. maxilla.D. palate

A Class II dental occlusion in the mixed dentition will likely A. develop into a Class I occlusion after normal exfoliation of the primary molars.B. worsen with forward growth of the maxilla.C. develop into a Class I occlusion with late

mandibular growth.D. develop into a skeletal malocclusion with

growth of the maxilla and mandible.E. not change as the maxilla and mandible

grow.

Not sure no reference

Alveolar bone is undergoing remodeling A. through the primary dentition.B. until the end of mixed dentition.C. until the complete eruption of permanent

teeth.D. throughout life. Although bone may appear superficially as a static tissue, it is actually very dynamic, undergoing constant remodeling throughout the life

http://en.wikipedia.org/wiki/Bone_remodeling_period



6. The best time to correct a permanent maxillary central incisor cross-bite is A. after the canines erupt. B. after the central incisors erupt. C. after the lateral incisors erupt.D. during the eruptive stage of central incisors.

if the incisor is in crossbite , it should be corrected as soon as possible ( while it is erupting )Dental Deck page 9 orhto card

Class II malocclusions can be prevented by

A. maintaining the integrity of the primary dentition.B. preventing thumbsucking and lip biting habits.C. correcting mouth breathing as early as

possible.D. None of the above.

As class II malocclusion can’t be prevented.

The mechanism of adjustment to maintain the shape and proportions of bone throughout its growth period is called A. remodeling. B. cortical drift.C. area relocation.D. translatory growth.

Bone remodeling is a continuous process of bone resorption and formation for the purpose of maintaining normal bone mass.

http://en.wikipedia.org/wiki/Bone_remodeling

http://www.wisegeek.org/what-is-bone-remodeling.htm





The most frequent cause of malocclusion is A. thumbsucking.B. mouth breathing. C. heredity.D. ectopic eruption.

Malocclusion is most often hereditary, which means the condition is passed down through families. There may be a difference between the size of the upper and lower jaws or between jaw and tooth size, resulting in overcrowding of teeth or in abnormal bite patterns.http://health.nytimes.com/health/guides/disease/malocclusion-of-teeth/overview.html

http://health.nytimes.com/health/guides/disease/malocclusion-of-teeth/overview.html



In the mandibular dental arch of a 12-year old boy, the permanent first molars are in contact with the first premolars and the crowns of the second premolars have erupted lingually. The likely cause is A. ankylosis of the mandibular second premolars.B. lack of space.C. teeth too large for the dental arch.D. premature loss of deciduous second

molars.E. faulty lingual eruption of the second

premolars.

http://www.angle.org/doi/pdf/10.1043/0003-3219(1965)035%3C0249%3ATEOPLO%3E2.0.CO%3B2

http://www.angle.org/doi/pdf/10.1043/0003-3219(1965)035%3C0249:TEOPLO%3E2.0.CO;2



Thumb sucking in most cases does not cause permanent harm to the dentition if the habit is

A. discontinued before four years of age. B. discontinued before eight years of age.C. practised only at night.D. is light in intensity. .E. None of the above.

Most children stop sucking on thumbs, pacifiers or other objects on their own between 2 and 4 years of age. No harm is done to their teeth or jaws until permanent teeth start to erupt. http://en.wikipedia.org/wiki/Thumb_sucking

http://books.google.ca/books?id=bs8HqMFRDakC&pg=PA70&dq=Thumbsucking+in+most+cases+does+not+cause+permanent+harm+to+the+dentition+of+the+habit+is&hl=en&sa=X&ei=m9fDUeqoEMaJiAL9hoGoCw&ved=0CC4Q6AEwAA#v=onepage&q=Thumbsucking%20in%20most%20cases%20does%20not%20cause%20permanent%20harm%20to%20the%20dentition%20of%20the%20habit%20is&f=false

http://en.wikipedia.org/wiki/Thumb_sucking

http://en.wikipedia.org/wiki/Thumb_sucking

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