Dentosphere : World of Dentistry

# Ugly duckling stage affects: a) Maxillary anterior teeth b) Mandibular anterior teeth c) Both Maxillary and mandibular teeth d) Cause decrease in vertical height  The correct answer is A. Maxillary anterior teeth.  Ugly duckling stage is seen in maxillary central incisor region between 8 -9 years of age. This condition is seen during eruption of permanent canines. The developing canines displaces the roots of central and lateral incisors mesially and causes distal divergence of the crowns of the central incisors resulting in midline diastema.  This type of malocclusion is not seen in lower arch because lower anteriors erupt almost simultaneously. Also, the path of eruption of mandibular canine is different from that of maxillary canines. CLICK HERE FOR MORE MCQs

# Canine placed anterior to the orbital plane: a) Protraction b) Abstraction c) Attraction d) Expansion The correct answer is A. Protraction. CLICK HERE FOR MORE MCQs

# An ANB angle 2 ° on the cephalogram usually indicates: a) An unfavorable relationship of mandible to maxilla b) A favorable relationship of maxillary alveolar base to mandibular alveolar base c) Poor cranial growth with poor prognosis d) Retruded maxillary incisor The Correct answer is B. A favorable relationship of maxillary alveolar base to mandibular alveolar base. SNA angle relates maxilla to the cranial base. The mean value is 82°. A Larger value indicates prognathic maxilla while a smaller value is suggestive of retrognathic maxilla. SNB angle relates mandible to cranial base. Its average value is 80°. Larger values indicate prognathic mandible while smaller values indicates retrusive mandible. AN B angle denotes the relative position of maxilla and mandible to each other. Mean value is 2° . An increase in this angle indicates class-II skeletal tendency while an angle that is Less than normal or a negative angle is suggestive of a skeletal classIII ...

# Frankfort's horizontal plane is formed by joining: a) Porion and Orbitale c) Porion and sella b) Nasion and se lla d) Porion and Nasion The correct answer is A. Porion and Orbitale. FHP or Frankfort horizontal plane =  Formed by joining Porion and orbitale SN plane or anterior cranial base = Formed by joining nasion and sella Cranial base length = Nasion and Bolton line Upper facial height = Nasion to ANS (anterior nasal spine) Lower facial height = ANS to menton Total facial height = Nasion to menton CLICK HERE FOR MORE MCQs.

# Prolonged retention of primary tooth may lead to a) Altered path of permanent tooth eruption b) Root resorption of adjacent tooth c) Ankylosis of permanent tooth d) Warping of roots of adjacent teeth The correct answer is A. Altered path of permanent tooth eruption. CLICK HERE FOR MORE MCQs.

# In a patient with competent lips together at rest, the lip line is opposite the tips of the upper incisors. The lip line is then described as: a) Average b) High c) Incomplete d) Low # Following are "essential diagnostic criteria" according to Graber except: a) Case history b) Facial photographs c) Periapical x-rays d) Lateral cephalograms # Incompetent lips refer to: a) Inability of the Lips to cover the incisors in the mandibular relaxed position b) Inability of the lips to cover the incisors in occlusion c) The lips come in between the upper and lower incisors d) Tongue thrusts against the lips during swallowing # Mentalis muscle contraction causes the lower lip to: a) Retrude b) Protrude c) Inversion d) Eversion # Transposition of teeth refers to: a) Bucco rotation of 120° b) Hypodontia c) Teeth erupted in unusual position i.e, one tooth erupts in place of another d) Inverted supernumerary teeth # Carpel radiograph is used for assessment of...

# Predominant bacteria found in two days old plaque is: A. Streptococci B. Bacteroides C. Spirochetes D. Actinomyces The correct answer is: A. Streptococci.  - Plaque can be defined as a complex microbial community, with greater than 10^10 bacteria per milligram.  - The formation of pellicle is the first step in plaque formation. - "Primary colonizers" : The pellicle coated tooth surface is colonized by Gram- Positive aerobic cocci bacteria such as Streptococcus sanguis, Streptococcus mutans, and Actinomyces viscous.  - Secondary colonizers: After 1 to 3 days, the secondary colonizers are gram negative anerobic rods and filaments that include Fusobacterium nucleatum, Prevotella intermedia, and Capnocytophaga species.  Tertiary colonizers: After one week of plaque accumulation, other gram negative species may also be present in plaque. They include Porphyromonas gingivalis, Campylobacter rectus, Eikenella corrodens, Actinobacillus actinomycet...