Orthodontics MCQs

Q.1)How much force is required to tip an incisor? a) 20-30gms b) 50-75gms c) 40-50gms d) 10-20 gms Answer is b. Q.2)Dr. E.H angle had published his practical classification of malocclusion for first time in the year? a)1880 b)1899 c)1925 d) none of above Q.3) Wires also called shape memory are? a) stainless steel b) multiflex round wire c) nickel titanium wire d) stainless steel edgewise wire Answer is c Q.4) When the diameter of wire is doubled the force exerted on teeth is? a) 4 times b) 1/2 times c) 8 times d) 16 times ANSWER IS d Q.5) In nitinol wire shape remember in? a) austenite form b) martensite form c) both d) none Answer is b Q.6)Column angle is seen in which malocclusion? a) class 2 division 1 malocclusion b) class  2 division 2 malocclusion c) bilateral posterior cross bite d) class 3 malocclusion Answer is b Q.7) Which contemparay orthodontic wire has maximum surface tension? a) Stainless steel b) Ajw wires c) TMA wires d) niti wires Answer is c Q8) The pitch of hyrax expansion is? a) 0.25mm b) 1mm c) 1.5mm d)0.5mm Answer is b Q.9) Key ridge is a) Present in relation to upper 6 b) Lower point on outline of zygoma c) Highest point on outline of zygoma d) Next to external auditory meatus Answer is b Q.10)Down patient shows ? a) Midline retrusion b) retruded mandible c) protruded mandible d) none of above Answer is a Q.11)Labial displacement of maxillary canine leading to crowding in maxillary anterior segment due to lack of space is mainly caused by a.   Eruption of maxillary canine before that of maxillary first premolar b.   Eruption of maxillary lateral incisor before that of maxillary canine c.   Eruption of maxillary canine before that of maxillary lateral incisors d.   Eruption of maxillary first premolar before that of maxillary canine Answer is a Q.12) The term ‘gingival zenith’ is used to describe the a.   Gingival height b.   Gingival shape c.   The most apical point of the gingival tissue d.   Stippled appearance  Answer is C. For maxillary central incisors & canines gingival zenith is located distal to longtudnal axis of the respective teeth, while for maxillary lateral incisor, it is located on the long axis of the tooth. (Ref. Pg 190 - 1, Proffit) Q.13) Serial extraction is contraindiacted in all of following except? a) open bite b) spaced dentition c) flaring of teeth d) anodontia Answer is c. Reference 3rd edition page 228-229 Q.14) A patient is involved in chronic mouth breathing, the clinical examination of patient reveals a) convex profile, long face b)concave profile , long face c) convex profile,short face d) concave profile,short face Answer is a Reference 3rd edition page 104, The type of malocclusion associated with mouth breathing is called long face syndrome or classical adenoid face and narrow ( Dolichocephalic and leptoprosopic) face short and flaccid lip constricted upper arch and anterior marginal gingivitis are the features Q15) Cartilage differ from bone in that it grows by? a)appositional growth pattern b) interstitial growth pattern c) none d) growth of cells in lacunae Answer is b. Reference profitt 4th edition page 40 Q.16) Change in arch difference in mandibular arch posterior to first molar? a) Decrease by 4mm b) Increase by 1mm c)Increase by 4mm d) Increase by 2mm Answer is a . Reference Mc donald 7th edition page 742 Q.17)Cement used for cementation of orthodontics bracket is? a) composite b) Resins c) Gic d) none Answer is a. Reference Manapalli, 2nd edition page 146 Composite is used in cementation of orthodontics brackets, maryland bridges, ceramic crown,inlay, onlays and laminates venner Q.18) Edge wise appliance are used with a) On incisal edge of anterior teeth b) with rectangular arch wire c) with labial arch at incisal and gingival arch of each bracket d) to obtain edge to edge occlusion Answer is b Q.19)In examining a child patient normal gingiva is diagnosed on basic of follwoing except a) contour b) stippling c) sulcus depth d) depth of vestibule Answer is d Q.20)Primary second molar usually erupt a)8-14 months b)14-20 months c) 20-30 months d)30-36 months Answer is c Q.21)Compared to a permanent tooth abscess a primary tooth abcess a primary tooth abcess is more diffuse because a) surrounding bone is less dense b) Roots of primary tooth are farther apart c) pain is less, therefore abcess is not detected early d) young patients are less resistant to infection Answer is a Q.22) A stainless steel crown should normally extend below gingival crest approximately? a)1mm b)1.5mm c)2mm d)2.5mm Answer is a Q.23) In performing the pulp amputation for pulpotomy , it is wise to use a spoon excavator to avoid a)perforation of pulpal floor b)pulling out of radicular portion of root c)maceration of pulp at amputation site d)all of above Answer is d Q.24) Basal bone differ from alveolar bone in its a) function b) osteocyte metabolism c) histologic staining property d)all of above Answer is a Q.25)The greatest relative dimension of facial at birth is? a) height b) width c) depth d) all the above dimensions are same at the birth Answer is a Q.26) Prenormal occlusion is? a) class 1 malocclusion b) class 2 malocclusion c) class 3 malocclusion d)bimaxillary protrusion Answer is c Q.27) The midpalatal suture is most likely to open at which of follwoing ages of expansion? a)18 year old b)13 year old c)25 year old d)55 year old Answer is b Q.28) Whip spring is used for correction of a) rotation b) proclination c) crossbite d) open bite Answer is a. Whip spring is a cantilever spring used for roated maxillary anterior. Modified whip spring are used for: a)Disimpaction of mid to severe mesially impacted lower terminal molars b)Flaring of lower teeth Q.29) Normal facial index is? a) 65-75% b) 75-80% c) 80-90% d)100% Answer is c Martin and saller give facial index and cephalic index Cephalic index= maximum skull width/ maximum skull length Index values: Mesocephalic ( Average) 76-81 Brachycephalic ( Broad skull ) 81-85.5 Dolichocephalic (<76%) Facial index = Distance b/w nasion and gnathion/ bizygomatic width Index value: Euryproscopic ( broad) 79-83 Mesocephalic ( average)84-88 Leptoproscopic ( long) 88-93 Q.30) Synostosis is? a) Fusion of two adjacent bone by cartilage b) Early closure of suture or early fusion of bone by bone c)Fusion of adjacent bone by fibrous cartilage d)None of above Answer is b Choice a is synchondrosis choice c is syndesmosis Q.31) Example of fibrous joint is all except? a) sutures b)gumphosis c)syndesmosis d)synchondrosis Answer is d.Choice d is synchondrosis and is primary cartilagenous and sympysis is secondary cartilagenous joint Q.32) Calcification of which bone is important for pubertal growth spurt? a) Hamate b) Pisiform c) sessamoid d) all of above Answer is c Calcification of sessamoid bone is one of important feature of pubertal growth spurt,which is earlier in females than male. Hamate and pisiform - prepubertal growth Adductor+ ulnar sessamoid = Pubertal growth Q.33) Implants and vital staining technique are used to study? a) dynamic change b)static change c) both d) none Reference bhalagi 3rd edition page 13 Implants and vital staining technique are used to study dynamic change occuring during deposition and resorption whereas radiograph shows static change Q34) Maxilla has how many ossification centre? a) 3 b) 2 c) 1 d) 4 Answer is a. Reference bhalagi 3rd edition page 28 For mandible , the answer is b. The maxilla has 3 ossification centre , one primary is for maxilla proper ( which arise at infraorbital foramen above canine fossa) and remaining two ossification centre are for premaxilla Q.35) Oral gratification theory was given by? a) sheldon b) sigmond freud c) benjamin d) sears and wise Answer is a. Oral gratification theory state that if child is not satisfied with sucking feeding period it will persist as symptom of emotional disturbance by digit sucking According to Sigmond freud in oral phase of physchologic development, the mouth is believed to be oro erotic zone. The child has tendency to place fingers or any other thing in mouth According to oral drive theory of sears and wise prolonged sucking leads to thumb sucking Benzamin theory state that thumb sucking arise from rooting reflex. Rooting reflex is movement of infant head and tongue toward on object touching cheek. The rooting reflex disappear in normal individual by 7-8 months of age Q.28) The articular angle is large if mandible is? a) retrognathic b) prognathic c) none d) any of above Answer is a. Articular angle is S-AR-GO. If angle is large mandible is small and vice versa Q.29)Active component of fixed appliance is? a) Bracket b) buccal tube c) ligature d) seperator Answer is d Active component of fixed appliance include seperators, elastics, arch wire and spring Passive component of fixed appliance is bracket , buccal tube,ligature wire and lock pin Q.30) uprighting spring is used to? a) derotate a tooth b) move the root in mesiodistal direction c)move the root in palatal direction d) closure of space Answer is b A option - elastic thread c option uprighting spring d option elastic chain, elastic module Q31) If value of bjork sum is >400 it indicates a) vertical growth pattern b) horizontal growth pattern c) both d) none Answer is a Q32) M spring is used for? a)closure of midline diastema b)for treatment of open bite c) for treatment of posterior cross bite d) for occlusal settting Answer is a. For b , box elastics are used. and for c cross elastics are used. Q32) Cetlin appliance is used for? a) Molar distilization' b)anterior cross bite c) posterior cross bite d) for midline diastema Answer is a. Q.33) Coffin spring is used for? a)expand the dental arches b) move canine distally c) move canine palatally d) retraction of protrusion Answer is a Q34) Development of palate occurs at a) 5th week IUL b) 8th week IUL c) 9th week IUL d) 11 week IUL Answer is c Q35) Force required in tongue is? a) 10-20 gm b) 25-30gm c) 30-50gm d) 50-60gm Answer is d Q36) shape of maxillary sinus at birth? pyramidal rectagular tubular Q37)Noonan Syndrome which is not seen?? Long face wide mouth retrognathism delayed erruption Q38)Reinforced anchorage example is? a) bite plane anterior b) posterior bite plan c) inclined plane d) all of above Answer is c Reference 3rd ed page 208. In reinforced or multiple anchorage more than one type of resistance unit is utilized. Orthopedic appliance , anterior inclined plane and transpalatal arch are example of reinforced anchorage. Closure of midline diastema, split expansion appliance and correction of cross bite are example of reciprocal anchorage Q.39) Moment to force ratio for bodily movement is a) 6 b) 8 c) 10 d) >10 Answer is d Movement                   Moment to force ratio Controlled tipping         1 to 7 Bodily movement            8 to 10 Torque                     Greater than 10 Q.40)  Sunday bite is defined as: a)  Habitual forward posturing of mandible to Class I.  b)  Posturing of mandible to Class III due to a premature contact. c)  Posturing the mandible laterally to establish maximum cuspation  in bilaterally narrow maxilla cases. d)  Posturing the mandible back to Class II, when actually in Class  I. e)  Under closure of jaw. Answer is a Q.41)Anterior Boltan ratio is: a)  91.3%. b)  100%. c)  61.7%. d)  82.3%. e)  77.2%. Key: e Q42 1s t  order bends are: a)  Tipping bends. b)  Toquing bends. c)  In and out bends. d)  Anchorage bends. e)  Up and down bends. Key: c Q43)  Face mask is primarily used to produce: a)  Dorsal effect. b)  AP effect. c)  Ventral effect. d)  Transverse effect. e)  Vertical effect. Key: b Q.44)Bite of accommodation means: a)  Habitual forward posturing of mandible to Class I.  b)  Posturing of mandible to Class III due to a premature contact. c)  Posturing the mandible laterally to establish maximum cuspation  in bilaterally narrow maxilla cases. d)  Posturing the mandible back to Class II, when actually in Class  I. e)  Underclosure of mouth. Key: c Q45)The type of wires that are preferred for alignment during orthodontic treatment are a.   Round in crossection b.   Rectangular in crossection c.   Square in corssection d.   Tandem wire . Use of tight fitting rectangular wires during this stage can slow down the alignment process and also increase the possibility of root resorption. (Rf. Pg 553, Proffit) Q46) If the frankfort plane and mandibular plane meet beyond the occipital plane then patient is a)horizontal grower b) vertical grower c) cant predict d)deep bite Answer is a Q.47) Curve of wilson for mandibular teeth is? a)concave b)convex c)none d) both Answer is a. Curve of wilson is curve that contacts buccal and lingual cusp for mandibular teeth. It is a cross arch cross tooth curve indicating the height difference between supporting and non supporting cusps in occlusion Lingual inclination of mandibular molars is basis for curve of wilson ie. curvature for mandibula ie. concave and maxillary teeth is convex Q.48)Orthodontic tooth movement in pulpless teeth compared to vital teeth is a.   Same for all teeth          b. More in maxillary teeth c.    Less in maxillary teeth d.    Depends on number of roots of the tooth Answer is a. Q.49) Unfavorable mixed dentition analysis is an indication for: a)  Space maintenance and space regaining. b)  Space maintenance and space supervision. c)  Space regaining and gross discrepancy cases. d)  Space supervision and gross discrepancy cases. e)  Space maintenance. Key: d Q.50) Blanch test is used to identify a) incompetant lips b) deviated nasal septum c) a shift in mandible during closing d) abnormal frenal attachment answer is d Q.51)Overbite is defined as .. overlap of the incisors. a. Horizontal b. Vertical c. Transverse d. Mesiodistal ANSWER IS B Q52)At what age should a child be referred for an orthodontic examination? a. Three years b. Six years c. Seven years d. Fourteen years ANSWER IS C Q53)The line of occlusion is a smooth (catenary) curve passing 1-Through the central fossae of upper molars and across the cingulum of the upper anterior teeth. 2- through the central fossae of lower molars and across the cingulum of the lower anterior teeth. 3- Along the buccal cusps and incisal edges of the upper teeth. 4- Along the buccal cusps and incisal edges of the lower teeth. a. 1 and 2 b. 2and 3 c. 1 and 4 d. 2 and 4 ANSWER IS A ,The line of occlusion is a smooth (catenary) curve passing through the central fossa of each upper molar and across the cingulum of the upper canine and incisor teeth. The same line runs along the buccal cusps and incisal edges of the lower teeth, thus specifying the occlusal as well as interarch relationships once the molar position is established. An excellent mathematical description of the natural dental arch form is provided by a catenary curve, which is the shape that a loop of chain would take if it were sus pended from two hooks. The length of the chain and the width between the supports determine the precise shape of the curve. When the width across the first molars is used to establish the posterior attachments, a catenary curve fitsthe dental arch form of the premolar-canine-incisor segment of the arch very nicely for most individuals. Exceptions include patients whose arches would fall into the prosthodontists' classifications of square or tapering arch forms. For all individuals, the fit is not as good if the catenary curve is extended posteriorly, because the dental arch normally curves slightly lingually in the second and third molar region (Figure 12-46). Most of the preformed arch wires offered by contemporary manufacturers are based on a catenary curve, with average intermolar dimensions. Although these arch wires are a good starting point, it is apparent that even if one accepts the catenary curve as ideal, their shape should be modified if the first molarwidths are unusually wide or narrow. Modifications to accommodate for a generally more tapering or more square morphology are also appropriate, and the second molars must be "tucked in" slightly. Another mathematical model of dental arch form, originally advocated by Brader and often called the Brader arch form, is based on a trifocal ellipse. The anterior seg ment of the trifocal ellipse closely approximates the anterior segment of a catenary curve, but the trifocal ellipse gradually constricts posteriorly in a way that the catenary curve does not . The Brader arch form, therefore, will more closely approximate the normal position of the second and third molars. It also differs from a catenary curve in producing somewhat greater width across the premolars. Preformed arch wires prepared to an average Brader arch form are available commercially in a limited range of sizes, which can reduce the amount of individualization necessary. Like the catenary curve, however, the Brader arch form represents what the prosthodontists would call a mid-range arch form, which will require some alteration Q.54)Which of the following is defined as IOTN grade 5 ? a. Increased overjet greater than 9 mm. b. Increased and complete overbite with gingival or palatal trauma. c. Anterior crossbite with greater than 2 mm discrepancy between CR and ICP. d. Presence of supernumerary teeth. ANSWER IS D Several indices for scoring how much the teeth deviate from the normal, as indicators of orthodontic treatment need, were proposed in the 1970s. Of these, Grainger's Treatment Priority Index (TPI)30 is the most prominent because it was used in the 1965-1970 U.S. population surveys. None of the early indices were widely accepted for screening potential patients, however. More recently, Shaw and co-workers in the United Kingdom developed a scoring system for malocclusion, the Index of Treatment Need (IOTN), 31 that places patients in five grades from "no need for treatment" to "treatment need." Grade 5 (Extreme/Need Treatment) 5.i I mpeded eruption of teeth (except third molars) due to crowding, displacement, the presence of supernumerary teeth, retained deciduous teeth, and any pathological cause. 5.h Extensive hypodontia with restorative implications (more than one tooth per quadrant) requiring preprosthetic orthodontics. 5.a I ncreased overjet greater than 9 mm. 5.m Reverse overjet greater than 3.5 mm with reported masticatory and speech difficulties. 5.p Defects of cleft lip and palate and other craniofacial anomalies. 5.s Submerged deciduous teeth. Q55)Who developed circumferential supracrestal fibrotomy? a) angel b) edward c)ricketts d)merryfield answer is b The first method, originally developed by Edwards, I I is called circumferential supracrestal fibrotomy (CSF) where gingival fibres are incised to prevent relapse.Percision is performed under local anaesthesia with no 11 blade Q56) X Occlusion is? a) buccal crossbite in australian arborigines b) seen in south pacific isllanders c) seen in oriental population d) seen in african population answer is a The findings are noted in present population groups that have remained largely unaffected by modern development: crowding and malalignment of teeth are uncommon, but the majority of the group may have mild anteroposterior or transverse discrepancies, as in the Class III tendency of South Pacific islanders 12 and buccal crossbite (X-occlusion) in Australian aborigines Q.57)When the gold wires were replaced by steel arch wires the reduction in the slot in the edgewise system was found to be? a) 22 mil bracket b) 28 mil bracket c) 24 mil bracket d) 18 mil bracket answer is d When steel arch wires replaced gold, Angle's original engineering calculations were no longer valid because steel wire of the same size was so much stiffer. An alternative was to redesign the edgewise appliance, optimizing the bracket slot size for steel. A reduction in slot size from 22 to 18 mil was advocated for this purpose. Even with this smaller slot size, full dimension steel wires still produce slightly greater forces than the original edgewise system did, but the properties of the appliance system are close to the original. Good torque is possible with steel wires and 18 mil edgewise brackets. Q58)The artistic positioning bends are a)first order bend b) second order bend c)third order d)none Answer is b In the original edgewise appliance, second-order bends, sometimes called artistic positioning bends, were an important part of the finishing phase of treatment . These bends were necessary because the long axis of each tooth is inclined relative to the plane of a continuous arch wire .Without adequate second-order bends, the incisor teeth are positioned too straight up and down with the roots too close together, producing an effect sometimes disparagingly called the "orthodontic look". The contemporary edgewise brackets that have a built-in tip for maxillary incisor teeth routinely produce a more esthetically pleasing arrangement of the incisors than was achieved in many instances with the early fixed appliances Q58)In mc namara analysis which of following plane is used? a) frankfort horizontal plane b)basion nasion line c) both of above d) none answer is c McNamara Analysis. The McNamara analysis, originally published in 1983, 2 ` still represents the state of the art in cephalometric measurement analysis reasonably well. It combines elements of previous approaches (Ricketts and Harvold) with original measurements to attempt a more precise definition of jaw and tooth positions. In this method, both the anatomic Frankfort plane and the basionnasion line are used as reference planes. The anteroposterior position of the maxilla is evaluated with regard to its position relative to the "nasion perpendicular," a vertical line extending downward from nasion perpendicular to theFrankfort plane The McNamara analysis has two major strengths: (1) It relates the jaws via the nasion perpendicular, in essence projecting the difference in anteroposterior position of the jaws to an approximation of the true vertical line. (Using a true vertical line, perpendicular to the true horizontal rather than anatomic Frankfort, would be better yet; the major reason for not doing so in constructing the analysis is that the cephalometric films from which the normative data were derived were not taken in NHP) (2) The normative data are based on the well-defined Bolton sample, which is also available in template form, meaning that the McNamara measurements are highly compatible with preliminary analysis by comparison with the Bolton templates Q59) Lower anterior inclined plane is at what degree to occlusal inclined plane? a) 60 b)30 c)45 d)90 Answer is b for upper answer will be a Q60) Whip spring is? a) fixed b) semifixed c) removable d) functional Answer is c One of the simplest fixed appliances for anterior cross bite purpose is a maxillary lingual arch with fingersprings (sometimes referred to as whip springs). This appliance is indicated for a very young child or preadolescent with whom compliance problems are anticipated. It consists of a 36 mil maxillary lingual arch to which 22 mil springs are soldered . The springs are usually soldered on the opposite side of the arch from the tooth to be corrected, in order to increase the length of the spring and are most effective if they are approximately 15 mm long. This length provides exceptional flexibility and range, but occasionally a spur is needed to serve as a guide wire to keep the wires from slipping over the incisal edge of the incisors Q61) Amount of force required to protact maxilla is? a)12oz b) 12-16oz c) 16-20oz d) 24 oz Answer is d Q62)Moyer mixed analysis give more accurate value for unerrupted teeth at a)75 percent probability b)50 percent probability c) 70 percent probability d)85 percent probability answer is b Q63)Example of fixed functional appliance is? a)churro jumper b)Mandibular anterior reposition applianace ( MARA) c)sabbagh universal spring( sus) d) all of above answer is all of above Removable functional- activator bionator, frankel Semi fixed appliance- denholtz,bass appliances Fixed functional appliance - herbest , jasper jumper, churro jumper, SUS appliance Q64)Which is the correct colour code for tracing consective cephalograms (pretreatment,progress end of treatment, retention) a)black,blue,red, green b) black , red, green, blue c)blue , red, green black d)black,blue, green , red Answer is a Q65) Amount of force required to applied by chin cap to stop mandibular growth? a) 1200-1600gms b)1000-1200gms c)400-800gms d)1600-2000gms Answer is b Q66) The marrow found in maxilla is? a) all fatty marrow b) all red marrow c) all fibrous marrow d) a combination of fatty and fibrous marrow Answer is a Q67) Who was first to comment on craniofacial deformity? a) celsus b) hippocrates c) fauchard d) angle Answer is b Q68)In normal occlusion the teeth have? a) Marginal contact b) Edge to edge contacts c) Cusp to cusp contacts d) Surface contacts Answer is d Q69) Mills retractor is modification of? a) Palatal canine retractor b) buccal canine retractor c) labial bow d) adam clasp Answer is c Q70) At what age child is expected to have 12 erupted primary and 12 erupted permanent teeth? a) 4.5 years b)6.5 years c) 8.5 years d)11.5 years answer is c Q71) The first cephalometric analysis which emphasis vertical and horizontal relationship and interaction between them is? a) down analysis b) sassoni analysis c) steiner analysis d) harvold analysis Answer is b Q72)The incidence of cleft lip and palate is? a) 1 in 600 b) 1in 700 c) 1 in 800 d) 1 in 900 Answer is c Q73) Orthognathic decompasation is done? a) is done at time of injury b) in done before the surgery c) is done after the surgery d) nature itself decomponsate for dental decompression Answer is 2 Reference peterson 4th edition page 466 Q74) Amount of magnification possible with panoramic radiograph is? a)20-25% b)10-15% c)5-10% d)15-30% Answer is c Q75) Angle, the father of orthodontics had interest in which branch of dentistry? a) Prosthodontics b) Community dentistry c) Pedodontics d) Periodontics Answer is a Angle's original interest was in prosthodontics, and he taught in that department in the dental schools at Pennsylvania and Minnesota in the 1880s. His increasing interest in dental occlusion and in the treatment necessary to obtain normal occlusion led directly to his development of orthodontics as a specialty, with himself as the "father of modern orthodontics Q78) Natal teeth are defined as: a)  Teeth present at the time of birth. b)  Teeth erupting in the 2 nd -3rd  month. c)  Teeth erupting between 6 months to 2 year. d)  Teeth erupting after 1 year of age. e)  Teeth erupting after 2 years of age. Answer is a Q79)ANB angle is used to assess: a)  Sagittal jaw discrepancy. b)  Vertical jaw discdrepancy. c)  Soft tissue profile. d)  Dental pattern. e)  Crowding. ANSWER IS A Q80)Bite of accommodation means: a)  Habitual forward posturing of mandible to Class I.  b)  Posturing of mandible to Class III due to a premature contact. c)  Posturing the mandible laterally to establish maximum cuspation  in bilaterally narrow maxilla cases. d)  Posturing the mandible back to Class II, when actually in Class  I. e)  Underclosure of mouth. Key: c Q81)Orthodontic appliances should not be reactivated more frequently than at a. 1 week interval                    b. 2 week interval c. 3 week interval     d. 4 week interval  Ans. C. Activating the appliance too frequently short circuits the repair process & can produce damage to the teeth or bone that a longer appointment cycle would have prevented or atleast minimized Q82)The most efficient orthodontic tooth movement is produced by a.  Light & intermittent forces   b. Light & continuous forces c.  Heavy & intermittent forces  b. Heavy &  continuous forces Answer is B. Heavy & intermittent forces, though less efficient, can be clinically acceptable. Q83) The sequence of completion of facial growth by plane of space is? a)height, width, depth b)depth width and height c)width height and depth d)width depth and height answer is d Q84)Which is not a essential diagnostic aid in orthodontics? a)study models b) opg c)photographs d)hand wrist radiographs answer is d Q85) A chin cap should be worn by patient for at least a)6 hours a day b)10 hours a day c)14 hours a day d)20 hours a day answer s c Q86)Stationary anchorage refers to anchor teeth which? a) are banded b) cannot move c) are not free to tilt d) are supported by extraoral forces Answer is c Q87)The first evidence of cartilage getting converted to bone in craniofacial skelton occur during? a) Fourth post natal week b) Eight prental week c) Fourth prenatal week d) Eight postnatal week Answer is b. Reference bhalaji 4th edition page 25 The cranial base will be cartilagenous form till 7th week of prenatal form.After that , the bones of cranial base undergo both endochondral as well as intramembranous ossification.The first bone to show both intramembranous and endochondral ossification is occipital bone. Q.88)Who proposed the nasal septum theory of craniofacial growth? a)mass b)sicher c)latham d)vander linder answer is c Rerence Ms rani 3rd edition page 77 Q89) Safety valve mechanism is? a)The anteroposterior increment in maxilla at 14 years b) Increase in mandibular intercanine width at 14 years c) increase in mandibular height at 12 years d) Increase in maxillary intercanine width at 12 years Answer is d Reference Text book of orthodontics by Sridhar Prem kumar1st ed page 20 In both males and females the maxillary intercanine dimesnsion act as safety valve during pubertal growth, where there is basal horizontal mandibular growth partly unmatched by growth of maxilla as mandibular growth downward and forward.The maxillary intercanine dimesnsion is brought forward, thus elliminating the flush terminal plane relation or residual class 2 tendencies Q90) Ugly duckling stage coincides with transition pahse a) First transition phase b) Second transition phase c) Intertransition phase d) All of above Answer is b. Reference bhalaji 3rd edition page 38 Q91) Steiner line use --- as reference plane? a) gonion menton b) Ans-Pns c)Porion orbitale d)gonion- gnathion Answer is d Reference bhalaji page 151 Analysis                      Reference plane Down                          Gonion- menton Steiner                       Gonion gnathion Tweeds                        Tangent lower border of mandible Q92)Facial axis connect? a) ptm point and gnathion b) nasion and pogion c)line between most anterior point of soft tissue nose and soft tissue chin d) none Answer is a A- Facial axis B- Facial plane C-Esthetic plane Reference , bhalaji 3rd edition page 149 Q93) Perversion stands for? a)Impacted teeth b) lower anterior teeth crowding c)open bite d)buccal non occlusion ANSWER IS A A- PERVERSION B- IMBRICATION C- APERTOGNATHIA D- SCISSOR BITE Q94) Step 4 in ackerman profit classification represent? A) Saggital relationship b) vertical relationship c) transverse relationship d) alignment Answer is b a- step 4 b- step 5 c- step 3 d- step 1 Reference bhalaji 3rd edition page 79 Q95) Typically rapid palatal expansion is done with a jack screw that is activated at rate of? a)1.00 to 2.00 mm/week b)1.00 to 2.00mm/day c)0.5  to 1.00 mm/week d)0.5 to 1 mm/day Answer is d Rapid palatal expansion is done typically with twp turns daily of jackscrew 0.5mm activation. This create 10 to 20 pound of pressure across the mid palatal suture which is enough to create microfracture of interdigitation bone spicules.In slow palatal expansion , approximately 0.5mm per week is maximum rate at which the tissues of midpalatal suture can adopt In RPE, the ratio of skelton to dental expansion is 4:1 In Slow palatal expansion the ratio is 1:1 Q96) Mandible takes shape during? a) 8th week b) 6th week c) 5th week d) 4th week Answer is a Q97)Class 3 malocclusion is seen in? a)Pierre robin sequence b)Treacher collin syndrome c)Goldenhar syndrome d) Down syndrome Answer is d. class 2 for a, b, c options Q98) Dewey type 4 modification is? a) crowding b) spacing c) anterior cross bite d) posterior cross bite Answer is d. for a- dewey type 1 for b - dewey type2 for c- dewey type 3 for d- dewey type 4 Dewey type 5- Disrubted molar relation due to early loss of primary second molars Q99) Ricket line is? a) line passing from soft tissue pogonion to tip of nose b) line passing from soft tissue pogonion to most prominent lip c) line passing from soft tissue pogonion to centre of s shape curve formed by passing from nose to upper lip d) none answer is a b is merrifield line c is steiner line Q100) Squeeze film effect was given by? a)bien b) angel c) dewey d) latham Answer is a When very high forces are appplied the interstitial fluid of Pdl get squeezed out and moves towards apex and cervical margin and result in decrease orthodontic tooth movement.