The placement of a retentive pin in the proximal regions of posterior teeth would MOST likely result in periodontal ligament perforation in the
distal of a mandibular first molar.
mesial of a mandibular first premolar.
distal of a mandibular first premolar.
mesial of a mandibular first molar.
1 explanations
Honey
Characteristics of mandibular first molar
(1) Buccal aspect
•.MB cusp is the widest than DB and D cusps
•.MB and DB grooves extend to buccal surface
(2) Lingual aspect
•.ML and DL cusps of equal size
• Lingual groove extends midway on lingual surface
• Cervical 1/3 is flat or concave
(3) Proximal aspect
• Both mesial and distal contact areas are at the middle third
(4) Occlusal aspect
• The outline is pentagonal shaped, Broader buccally than lingually
• 5 Cusps: two lingual cusps and three buccal cusps (MB, DB, and distal—in order of decreasing size)
(4) Root
• 98% two roots: mesial and distal
• Chance of two canals: 6.7%, three canals: 65%. Four canals: 29%
Honey