Most commonly submerged tooth is:

 # Most commonly submerged tooth is:

A. Mandibular primary first molar

B. Mandibular primary second molar

C. Maxillary primary first molar

D. Maxillary primary second molar

The correct answer is B. Mandibular primary second molar. 

‘Submerged’ teeth are deciduous teeth, most commonly mandibular second molars, that have undergone a variable degree of root resorption and then have become ankylosed to the bone. This process prevents their exfoliation and subsequent replacement by permanent teeth. After the adjacent permanent teeth have erupted, the ankylosed tooth appears to have submerged below the level of occlusion. This illusion is explained by the fact that there has been continued growth of the alveolar process and also that the crown height of the deciduous tooth is less than that of the adjacent permanent teeth, so that the relative level of occlusion has been changed, not the position of the deciduous tooth. 

The mandibular primary molars are the teeth most often observed to be ankylosed. In unusual cases all the primary molars may become firmly attached to the alveolar bone before their normal exfoliation time. 

Angular osseous defects cannot occur in:

 # Angular osseous defects cannot occur in:

A. Mandibular anterior region

B. Mandibular molar region

C. Maxillary premolar region

D. Maxillary molar region

The correct answer is A. Mandibular anterior region.

Angular osseous defects cannot occur in the mandibular anterior region due to the absence of cancellous bone between the cortical plates.

Which of the following is not a risk indicator for periodontitis?

 # Which of the following is not a risk indicator for periodontitis?

A. HIV/AIDS

B. Bleeding on probing

C. Infrequent dental appointment

D. Osteoporosis

The correct answer is B. Bleeding on probing.

• A risk factor is an environmental, behavioral, or biological factor that, if present directly increases the probability of a disease (or adverse event) occurring and, if absent or removed, reduces that probability.

• A risk indicator is a probable risk factor that has not been confirmed by carefully conducted longitudinal studies. 

• A risk predictor is a characteristic that is associated with an elevated risk for a disease (or adverse event), but may not be part of the causal chain. 

Risk determinants/background characteristics for periodontal disease 

• Genetic Factors 

• Age 

• Gender 

• Socioeconomic status 

• Stress 

Risk indicators for periodontal disease 

• Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome 

• Osteoporosis 

• Infrequent Dental Visits 

Risk markers/predictors for periodontal disease 

• Previous History of Periodontal disease 

• Bleeding on Probing 

Workhorse of periodontal therapy is:

 # Workhorse of periodontal therapy is:

A. Double papilla flap

B. Apically repositioned flap

C. Coronally displaced flap

D. Laterally repositioned flap

The correct answer is B. Apically repositioned flap.

An apically displaced (positioned) flap (APF) is a full-thickness or partial-thickness mucoperiosteal flap. It has a relatively high degree of predictability and is a "workhorse" of periodontal therapy.