and Answers
A 20-month-old female presents with her mother to your office for her first check-up. Her
mother is concerned because her daughter only has a few erupted teeth. Upon
examining the patient, which teeth should you expect to find?
A. Primarycentralsandlateralsonly
B. Primarycentrals,laterals,canines
C. Primarycentrals,laterals,firstmolars,second molars
D. Primary centrals, laterals, first molars
E. Primary centrals, laterals, first molars, canines - Answers-The correct answer is E. By
19 months, a child should have mandibular and maxillary central and lateral incisors, all
first molars, and all ca- nines. According to answer choice A, primary central and
laterals should be found by 7 months of age. Answer B is incorrect also in terms of
sequence—if the canines were present, the first molars should also be present. By the
time the second molars erupt, the canines should already be present in the mouth.
Primary centrals, later- als, and first molars should erupt by 15 months of age.
.A5-year-oldgirllivesinanareawith0.4ppmFin the city drinking water. How much
supplemen- tal fluoride should you prescribe for the patient to consume the optimal
amount of fluoride?
A. 0 B. 0.25mg C. 0.33 mg D. 0.5 mg E. 1.0 mg - Answers-The correct answer is B. In a
population with 0.3- to 0.6-ppm fluoride in the drinking water, a 0.25-mg supplement is
the recommended amount. According to answer choice A, no fluo- ride supplements are
recommended from birth to 6 months, in populations where 0.6 ppm or more is present,
or for a patient aged 6 months to 3 years in a 0.3- to 0.6-ppm fluoridated area. 0.33 mg
is not included as a recommended amount of fluoride supplementation. 0.5 mg is the
recommended dose for a child aged 3 to 6 years in an area of less than 0.3-ppm
fluorida- tion, and for 6- to 16-years old in a 0.3- to 0.6-ppm area. 1.0 mg is
recommended for a child aged 6 to 16 years in a population with less than 0.3-ppm
water fluoridation.
.A child presents to your office after a fall from a tree, during which his primary maxillary
central incisor was avulsed. The mother has brought the tooth in a cup of milk and says
the fall occurred 2 hours ago. What is the best treatment for this patient?
A. Replantthetooth,stabilizethetoothfor1to 2 weeks at which time a pulpotomy should be
performed
B. Replantthetooth,stabilizefor1to2weeks, and then perform a pulpectomy
C. Replant tooth, stabilize for 1 to 2 weeks, and begin apexification if pulp necrosis is
evident
D. Take a radiograph, irrigate socket, do not replant tooth - Answers-The correct answer
is D. A primary tooth has a poor prognosis if replantation is attempted; therefore,
primary teeth are very rarely re- planted. A radiograph should be taken to visu- alize if
any fragments of the tooth remain. If the tooth was a permanent tooth, the tooth may be