Serial extractions are indicated when there is - PGCEE MDS Entrance 2025

 # Serial extractions are indicated when there is -

a) No skeletal discrepancy with dental crowding > 10 mm

b) No skeletal discrepancy with dental crowding between 5 - 7 mm.

c) Skeletal discrepancy >5°

d) Skeletal discrepancy >10° with dental crowding < 5mm

The correct answer is A. No skeletal discrepancy with dental crowding > 10 mm

 Serial extraction is indicated in cases of severe dental crowding. For this reason, it is best used when no skeletal problem exists, and the space discrepancy is large i.e., >10 mm per arch.

If the crowding is severe, little space will remain after the teeth are aligned, which means there will be little tipping and uncontrolled movement of the adjacent teeth into the extraction sites. If the initial space discrepancy is smaller, more residual space must be anticipated.

The commonest teeth involved in transposition are: PGCEE MDS Entrance 2025

 # The commonest teeth involved in transposition are:

a) Maxillary central incisor and lateral incisor

b) Maxillary canine and first premolar

c) Maxillary 1st premolar and 2nd premolar

d) Maxillary canine and Lateral incisor

The correct answer is:

b) Maxillary canine and first premolar

Explanation:

Tooth transposition is a rare developmental anomaly where two adjacent teeth exchange their positions within the dental arch. The most commonly involved teeth in transposition are the maxillary canine and first premolar. This occurs due to disturbances in tooth eruption patterns, genetics, or space constraints in the dental arch.

Other less common transpositions include:

• Maxillary canine and lateral incisor (less frequent but still observed)
• Mandibular canine and lateral incisor (rare)

The free gingival groove is most commonly associated with which tooth? PGCEE MDS Entrance 2025

 # The free gingival groove is most commonly associated with which tooth? 

a) Maxillary canine 

b) Mandibular incisor 

c) Maxillary first molar 

d) Mandibular premolar

The correct answer is:

b) Mandibular incisor

The free gingival groove is a shallow linear depression that demarcates the free gingiva from the attached gingiva. It is more prominent in some individuals and may not always be present. However, when it is visible, it is most commonly associated with the mandibular incisors due to their relatively thin and well-defined gingival anatomy. This aligns with standard dental textbooks like Carranza’s Clinical Periodontology, which highlights the mandibular incisors as a common site for the free gingival groove.

Well aligned deciduous dentition is an indication of: PGCEE MDS Entrance 2025

 # Well aligned deciduous dentition is an indication of:

A. Potential crowding

B. Disto occlusion

C. Mesio occlusion

D. Well aligned permanent teeth

The correct answer is:

A. Potential crowding

Explanation:

• Well-aligned deciduous dentition (primary teeth) with little to no spacing is often a predictor of potential crowding in the permanent dentition.

• Primary teeth are smaller than permanent teeth, and deciduous arches typically exhibit natural spacing ("primate spaces") to accommodate the larger permanent successors. If primary teeth are tightly aligned, it suggests insufficient space for the eruption of larger permanent teeth, increasing the risk of crowding.

• D. Well-aligned permanent teeth is incorrect because spaced (not tightly aligned) primary teeth are actually a better indicator of sufficient arch space for proper alignment of permanent teeth.

• B. Disto-occlusion and C. Mesio-occlusion refer to malocclusions (Class II and Class III bites, respectively) and are unrelated to primary tooth alignment.

Key Takeaway: Tightly aligned primary teeth (lacking spacing) often signal future crowding, as permanent teeth require more space. Spaced primary dentition is ideal for alignment of permanent teeth.