Orthodontics dhenelyn


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Orthodontics dhenelyn

  1. 1. Orthodontics 2011 NDEB Questions Pages 27-53
  2. 2. Page- 47 Question 6. In cephalometry, the most stable in growing skull is the A. Sella Turcica B. Nasion C. Broadbent’s Point D. Bolton point  Answer: A. SELLA TURCICA  Explanation: Sella Turcica is the center or pituitary fossa in cranial base.  Ref. Orthodontics Dental Decks Page 23
  3. 3. Page- 47 #. 7. Which of the foloiwng patient should be referred for orthodontic treatment to close a diastema between maxillary central incisor. 1.An 8 yrs old with no abnormal oral habits 2. A 3 yrs old with no abnormal oral habits 3. A 3 yrs old with a 4mm over jet 4. An 8 yrs old with previous thum habit. A. 1,2,3 B. 1 and 3 C. 2 and 4 D. 4 only E. All of the above  Answer: D- 4 only  Explanation: About 98 % of children at ages 6 yrs old have median maxillary diastema. Spaces tend to close as permanent canine erupts. The permanent canine erupts at age 11. However if oral habits such as thumbsucking is involved, its better to refer patient to orthodontist for consultation to minimize further damage as the child is at the age that its crucial to get rid of the bad oral habits.
  4. 4. Page- 46 1. An 8 yrs old boy has lost tooth 11. The lateral incisor have partially erupted. You would expect that the tooth 12 will erupt A. without encrouching upon the space, B. ecrouching upon the central incisor space. C. and the left central incisor will encrouch upon the space. D. B and C.  Answer: A – without encrouching upon the space.  Explanation: There should be no change on the space because it is only applies to permanent molars – Mesial drifting.
  5. 5. Page-49 1. If there is insufficient arch space for a permanent tooth to erupt, the tooth may A. cause resorption of the root of another tooth B. erupt out of position C. not erupt D. All of the above  Answer: B. erupt out of position  Explanation: It is a usual observation with primary dentition that if the existing decidous tooth is still in place and the adult tooth is coming in, it usually erupt out of position – usually lingually or labially.
  6. 6. Page 49 3. Following very early loss of a primary tooth, the eruption time of the permanent successor could be A.unaltered B. accelerated C. delayed D. None of the above  Answer: C. delayed  Explanation: Usually when the primary tooth loss prematurely, the successor tooth takes longer to erupt, this is because the adult teeth has no more guiding path for eruption. The decidous tooth is a guidline for the the permanent dentition path of eruption by resorbing the root apex slowly.
  7. 7. Page 49 5. In a normally developing occlusion, spaces between decidous or permanent incisor are called. A. physiological spaces B. primate space C. Leeway space D. Freeway space  Answer: B. Primate space  Explanation: Primate space is the gap between the primary teeth of a child. These are normal. They are the result of the jaws growing to accommodate the larger adult teeth. In the mandibular arch, the primate space is between the canine and the 1st molar (or 1st premolar in adults). Whereas, in the maxillary arch, it is between the lateral incisors and canines. Leeway Space -Difference between the combined mesiodistal widths of the deciduous cuspids and molars and their successors. Freeway space-the interocclusal distance or separation between the occlusal surfaces of the teeth when the mandible is in its physiologic rest position.
  8. 8. Page 49 6. The principal growth sites of the maxilla in a downward and forward direction include the 1. frontomaxillary suture A. 1,2,3 E. All of the above. 2. zygomaticomaxillary suture B. 1 and 3 3. pterygopalatine suture C. 2 and 4 4. median palatine suture D 4 only  Answer: A – 1,2,3  Explanation: The maxilla develops entirely by intra membranous ossification. Sutural connective tissue proliferation; ossifications, surface apposition, resorption, and translation are mechanism for maxillary growth. The maxilla is related to the cranium at least partially by the frontomaxillary suture, the zygomaticomaxillary suture, zygomaticotemporal suture and pterygopalatine suture.
  9. 9. Page 50 1. If a patient loses a maxillary first permanent molar before the age of 10 the A premolar drifts distally B maxillary second molar erupts and moves forward C. opposing tooth erupts into the space created D. overbite increases  Answer: B- maxillary second molar erupts and moves forward.  Explanation : The contemporary view is that mesial drift is a phenomenon of the permanent molars only. The major reason these teeth move mesially when a space opens up is their mesial inclination, so that they erupt mesially as well as occlusally.
  10. 10. s. The frankfort plane 1. Extends from the Porion to the Orbitale A. 1 only 2. is parallel with the maxillary plane. B. 1,2,3 3. describes the cranial base dimensions C. 1 and 3 D. 1 and 2  Answer : A – 1 only  Explanation : a plane used in craniometry that is determined the highest point on the upper margin of the opening of each external auditory canal and the low point on the lower margin of the left orbit and that is used to orient a human skull or head usually so that the plane is horizontal.
  11. 11. 3. The facial profile associated with a Class III malocclusion is A. Concave B. Convex C. either concave or convex D. Straight  Answer: B- convex  Explanation: This is a profile Facial view of class III Malocclusion http://www.columbia.edu/itc/hs/dental/D5300/Classificati on%20of%20Malocclusion%20GALLOIS%2006%20final_BW.p df
  12. 12. 4. An 11 year old child has an open bite caused by active thumbsucking. You would A. insert a habit-breaking appliance B. refer to psychologist for evaluation c. encourage the child to accept help in discontinuing the habit and observe periodically. D. refer to an orthodontist.  Answer: D- refer to an orthodontist.  Explanation: Because of the patients age It is best for Orthodontist to evaluate the child if the open bite so correction can be made earlier. A habit breaking appliance might not correct the open bite created by the active thumbsucking.
  13. 13. 5. Spacemaintainer in the posterior segment will: A. Prevent extrusion of opposing teeth B. Prevent the eruption of the permanent teeth C. Retard eruption of the permanent teeth D. maintain arch length  Answer: D. Maintains arch length  Explanation: Spacemaintainers are define as the appliance that prevents loss of arch length and which in turn guide the permanent tooth into a correct position in the dental arch.
  14. 14. 6. Occipital and / or cervical extra-oral anchorage is used to 1. restrict anterior tooth movement A. 1 and 3 2. enhance maxillary forward growth B. 2 and 4 3. enhance mandibular forward growth c. 3 and 5 4. encourage anterior tooth movement D. 1 and 5 5. restrict maxillary forward growth E. 2 and 3  Answer: C – 3 an 5  Explanation: Uses of cervical extra oral anchorage : -Restrict maxillary growth -Retract maxillary dentition - Camouflage by extraction of upper premolars -Advance the mandible -Advance mandibular dentition
  15. 15. 7. The root of the first permanent molar should be completely formed by the age of A. 6 years B. 7 years C. 9 years D. 11 years E. 13 years  Answer: D. – 11 years old  Explanation: For Max. and Mand. the year t he root is completely form for the permanent first molar is 10 ½- 10 ¾years this is then closer to 11 yrs old.
  16. 16. 8. As the mandible grows down ward and forward, bone deposition takes place A. on all surfaces of the mandible B. on the posterior border of the ramus C. on the anterior border of the ramus D. on the alveolar margins E. B and D  Answer: B- on the posterior border of the ramus  Explanation: The body of the mandible grows longer as the ramus moves away from the chin, this occurs by removal of bone from the anterior surface of the ramus and depostion of bone on the posterior surface.
  17. 17. Page 51 3. The roots of primary molars in the absence of their permanent succesors 1. sometimes partially resorbed and ankylosed 2. may remains for years with out significant resorption 3. may remain for years partially resorbed 4. are always resorbed A. 1,2,3 B. 1 and 3 C. 2 and 4 D. 4 only E. all of the above  Answer: E – all of the above  Explanation: Although there is no permanent succesor , the root of the primary molars eventually resorbed and sometimes can stay for many years partially resorbed , but its unknown why the resorption process happens. Most of the time when there is no succesor the primary tooth is submerge into the gums and ankylosed.  Akylosis – is a hard tissue union between the bone and tooth.
  18. 18. 6. Which of the following factors is related to a malocclusion caused by thumbsucking? A. Duration B. Frequency C. Intensity D. All of the above  Answer: D- all of the above  Explanation- if the habits persist beyond the time that the permanent teeth begin to erupt, however, malocclusion characterized by flared and spaced maxillary incisors, lingually positioned lower incisors, anterior open bite, and a narrow upper arch is likely result. The characteristic malocclusion associated with sucking arises from a combination of direct pressure on the teeth and an alteration in the pattern of resting cheek and lip pressure.  How much the teeth are displaced should correlate better with the hours per day of sucking than with the magnitude of the pressure.
  19. 19. Page 52 1 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  Answer: D. throughout life  Explanation: With out a tooth there is no Alveolar bone. Alveolar bone holds the tooth in place. Through out life it continues to remodels as it needed. When orthodontic force is applied the alveolar bone goes through a process of remodeling to compensate for the movement of the tooth being moved by the appliance.
  20. 20. 5. During orthodontic treatment, poor oral hygiene may result in 1. marginal gingivitis A. 1 and 2 2. gingival fibrosis B. 1,2,3 3. ulcerative gingivitis C. 1 and 3 4. acute periodontitis D. 1,3,5 5. juvenile periodontitis E. all of the above  Answer: A 1 and 2  Explanation:  Marginal Gingivitis an inflammation of the gingivae localized to the marginal gingivae and interdental papillae – Right answer.  Gingival fibrosis -Gingival enlargement may be caused by a multitude of causes. The most common is chronic inflammatory gingival enlargement, when the gingivae are soft and discolored. This is caused by tissue edema and infective cellular infiltration caused by prolonged exposure to bacterial plaque, and is treated with conventional periodontal treatment, such as scaling and root planing –right answer .  Juvenile periodontitis occurs in children and young adults and can be classified into: periodontitis which occurs in otherwise healthy individuals, and periodontitis which occurs in juveniles with systemic disease. – NOT the right answer  Acute periodontitis is a sharply localized, acute inflammatory process involving the interproximal and marginal areas of two or more adjacent teeth, characterized by severe pain, purulent exudate from edematous inflamed gingivae, general malaise, fever, and sequestration of the crestal aspects of the alveolar process. It is now considered a stage of periodontal disease. – Not the right answer  Necrotizing ulcerative gingivitis (NUG) is a condition affecting the gums that is caused by a bacterial infection. It is a form of periodontal (gum) disease. But unlike other forms, it typically develops quickly and causes moderate to severe pain.- Not the right answer.
  21. 21. 7. The term “ Dental Age” refers to the A. State of dental maturation B. Eruption time of given tooth C. number of year elapse since a given tooth erupted D. None of the above.  Answer: B. Eruption time of given tooth  Explanation: Dental age is determined from three characteristics. The first is which teeth have erupted. The second and third, which are closely related , are the amount of resorption of the roots of primary teeth and the amount of development of the permanent teeth.
  22. 22. Page 53 3. The most frequent cause malocclusion is A.Thumbsucking B. Mouth breathing C. Heredity D. Ectopic Eruption  Answer: A. and C  Explanation: The most frequent cause of malocclusion is - Hereditary causes related with the development of jaws and teeth Tooth loss related with non hereditary factors such as diseases or trauma Oral habits that affect the teeth and jaws health- like thumbsucking.
  23. 23. 5. Orthodontic tooth movement in an adolescent Is easier than an adult because of A. difference in tissue/bone reaction B. difference in growth C. difference in cooperation D. all of the above  Answer: D – all of the above  Explanation: Various factors must be given considerations, which demand special consideration for adults.  Psychosocial factors-adults demand best treatment results in a short Period of time.  Perio-restorative problems  Age related considerations Lack of growth potential Aging of tissues Vulnerability to Root resorption Vulnerability to TMD
  24. 24. 6. Labioversion of maxillary incisor teeth is associated with A. thumbsucking B. spaced maxillary incisor teeth. C. lack of normal tonicity of the labial musculature D.All of the above Answer: A. Thumbsucking Explanation: Angle Class II Division 1 is an example of labioversion of maxillary incisor. Prolonged oral habits is a clear cause of some malocclusion.
  25. 25. 7. Premature loss of mandibular decidous cuspids in Class 1 and class II cases result in increased 1. Overjet A. 1,2,3 E. all of the above 2. arch width B. 1 and 3 3. overbite c. 2 and 4 4. leeway space D. 4 only  Answer: Not sure Needs help with this one
  26. 26. 8. The maxillary incisor in Angle’s class II Division 2 malocclusion are in A. linguoversion B. labioversion C. infraversion D. supreversion  Answer: A- linguoversion  Explanation: The incisors are inclined lingually.
  27. 27. Othodontics 2012 NDEB Question Pages 27- 53
  28. 28. Page 27 6. In treatment of an Angle Class II Div 2 the Frankel functional regulator is designed to perform all the following except A . Increase vertical dimension B. reposition the mandible C. retract the maxillary molars D. expand the dental arches  Answer: B- reposition the mandible  Explanation: Frankel's Functional Regulator is an activator particularly suitable in malocclusions of Class II at the age of growth. The Frankel use the natural growth spurt and shields from unwanted forces, to encourage the top and bottom jaw to develop a more natural position. Its has shields to remove unwanted forces from the cheeks and labial shields to relieve pressure from the lips.
  29. 29. Page 35 5. The optimal time for orthodontic treatment involving growth manipulation for skeletal class II malocclusions is during A. late primary dentition B. after the eruption of third molars. C. after skeletal growth is complete D. during the period of greatest growth velocity  Answer: D. during the period of greatest growth velocity  Explanation : The concept of two-phase treatment: early use of functional appliances in the mixed dentition, followed by a period of retention and then a second phase of treatment, usually involving the use of fixed appliances. The advocates of early treatment fee lthat starting early will maximize the chances of growth modification (especially in female patients who tend to reach their skeletal maturity earlier), allow for two chances to correct the malocclusion and avoid problems of compliance often encountered in adolescents.
  30. 30. Page 36 7. An anterior cross-bite of a permanent maxillary incisor in a mixed dentition is often associated with A. a functional shift B. unexplainable genetic factors C. lingually situated supernumerary teeth D. prolonged retention of a primary incisor. E. premature eruption of a maxillary incisor  Answer: D. prolonged retention of a primary incisor.  Explanation: Most of the time if the decidous maxillary incisors still in place the succeding tooth will erupt out of position and usually it lingually, this is why sometimes there is an evident of crossbite with maxillary incisor and this gets better as soon as the decidous tooth exfoliate or extracted.
  31. 31. Page 37 1. The principal growth sites of the maxilla in a down ward and forward direction include the 1. frontomaxillary suture A. 1,2,3 E. all of the above 2. zygomaticomaxillary suture B. 1 and 3 3. pterygopalatine suture C. 2 and 4 4. median palatine suture D. 4 only  Answer: A – 1,2,3  Explanation: Everything but Median palatine suture. Growth sutures are the following for the maxilla: 1. Frontonasal suture 2. Frontomaxillary suture 3. Zygomatico Temporal suture 4. Zygomatico maxillary suture 5. Pterygopalatine suture This sutures are oblique and more or less parallel with each other. The growth in these areas would serve to move maxilla downward and forward.
  32. 32. Page 38 1. if a flush terminal plane convers to a mesial step terminal plane (Class I occlusion) without orthodontic intervention, it is primarily a result of A. the absence of mandibular primate space. B. maxillary forward growth exceeding mandibular forward growth C. mesial movement of the mandibular first permanent molars following exfoliation of the mandibular second primary molars. D. distal movement of the maxillary first permanent molars following eruption of the maxillary second bicuspids.  Answer: C. Mesial movement of the mandibular first molars following exfoliation of the mandibular second primary molars. Explanation: When the second primary molars are lost, the first permanent molars move forward( mesially) relatively rapidly using the leeway space. This decreases both arch length and arch circumference , which are related and commonly confused terms. The leeway space is normally used by mesial movement of the permanent molars.
  33. 33. Page 43 7. The occlusal parameter most likely associated with maxillary anterior spacing is a/an A. Class II Div 2 dental malocclusion B. Class III skeletal malocclusion C. Accentuated maxillary curve of Wilson D. reverse maxillary curve of Wilson  Answer: C  Explanation: Curve of wilson is the curvature of the cusps, as seen from the front view. The curve in the mandibular arch is concave, whereas the one in the maxillary arch is convex.
  34. 34. Page 42 5. Which of the following conditions is usually present in an Angle Class II Division 2 malocclusion? A. Openbite B. Retroclined maxillary lateral incisor C. Retroclined maxillary central incisor D. Distoclusion of permanent maxillary first molars  Answer: C- retroclined maxillary central incisors.  Explanation: occlusal view of ClassII Div 2
  35. 35. Page 34 7 Which occlusal parameter is the most useful to determine if a posterior crossbite is of skeletal of dental origin? A. Anterior overbite B. Sagittal molar relationship C. Lack of space in the maxillary anterior area D. Lack of space in the mandibular arch. E. Buccolingual angulation of affected teeth  Answer: E. Buccolingual angulation of affected teeth  Explanation: From occlusal view , the actual position of the tooth involve is a big indication of posterior crossbite is of skeletal dental origin.
  36. 36. Page33 5. The most appropriate treatment following the extraction of a first primary molar in 4 years old child is A. regular assessment of arch development B. to perform space analysis C. insertion of a space maintainer D. extraction of the contra-lateral molar E. extraction of the opposing molar  Answer: C – insertion of spacemaintainer  Explanation : Because of the age of the patient, it is important to preserve the space by inserting a band and loop spacemaintainer in order to preserve the space for the succedaneous tooth.  According to the eruption table its not until 9-11 years old when the primary molar is ready to exfoliate.
  37. 37. 7. Closure of a 2 mm maxillary midline diastema by orthodontic treatment is best accomplished A. Prior to complete eruption of the maxillary central incisors B. Prior to eruption of the maxillary lateral incisors C. after complete eruption of the maxillary lateral incisors D. during intra-oral emergence of the maxillary canines C. After complete eruption of the maxillary canines  Answer: C – after complete eruption of the maxillary canines  Explanation:
  38. 38. Page 49 8. A Bolton relationship has determined a - maxillary “12” excess of 3.5mm - maxillary “6” excess of 3.0mm What effect could this Bolton relationship have on a Class I malocclusion? 1. Deeper overbite 2. Maxillary crowding 3. Reduced overjet 4. Increased overjet A. 1,2,3 B. 1 and 3 C. 2 and 4 D. 4 only E. all of the above  Answer:  Explanation:
  39. 39. Page 51 8. An overjet of 8mm is usually associated with A. Class I cuspid relationship B. Class II cuspid relationship C. Class III cuspid relationship D. Class I molar relationship  Answer:  Explanation:
  40. 40. Page 52 6. Which of the following maxillary incisor angulations complicates a functional appliance contrustion bite? A Retroclined central incisor B. Proclined lateral incisors C. Retroclined lateral incisors D. Proclined central incisors  Answer:  Explanation:
  41. 41. Orthodontics 2013 NDEB Questions Page 27-53
  42. 42. Page 51 1. The primary stimulus for growth of the mandible is A. Genetic B. Epigenetic C. Environmental D. Functional E. A and D  Answer:  Explanation
  43. 43. 3. In patient with an Angle Class ! Malocclusion arch length in the mandible changes between 5 and 18 years of age . It is usually A increases 0-1 mm B. increases 3-4 mm C. decreases 0-1 mm D. decreases 3-4 mm  Answer:  Explanation:
  44. 44. Page 53 6. The eruption of which of the following permanent teeth signals the beginning of the mixed dentition stage? A. Maxillary central incisor B. Maxillary canine C. Mandibular first molar D. Mandibular central incisor  Answer:  Explanation:
  45. 45. 7. The interocclusal relationship of the primary second molars 1. The interocclusal relationship of the primary second molars h