Permanent Dentition Revision GN PDF

Permanent dentition  Mandibular first molars Chronology 5 cusps; ML, DL, MB, DB, D. Initial calcification Birth or slightly before MB is larger than DB cusp. Crown completion 2...

Permanent dentition  Mandibular first molars Chronology 5 cusps; ML, DL, MB, DB, D. Initial calcification Birth or slightly before MB is larger than DB cusp. Crown completion 2 ½ -3 years ML is larger than DL cusp. Eruption 6-7 years D is the smallest cusp. Oval crown shape. Root completion 9-10 years 2 buccal developmental grooves with curved wall; mesial is deeper and longer. 2 roots; mesial and distal; mesial root wider and marked central groove. 3 or 4 root canals, 5 pulp horns. Maxillary first molars 4 cusps; MB, DB, MP, DP. Chronology MP is the largest, DP is the smallest. Initial calcification Birth or slightly before Equilateral rhomboid. Crown completion 2 ½ -3 years Oblique ridge dividing occlusal surface; runs from DB cusp—MP cusp. Eruption 6-7 years P cusps lie further onto occlusal surface. Root completion 9-10 years 3 roots; MB, DB, P; 3 or 4 root canals, 4 pulp horns. Cusp of Carabelli may be present palatal surface of MP cusp. Mandibular central incisors Flat labial surface and concaved Chronology lingual surface. Initial calcification 3-4 months after birth Distal-incisal angle slightly Crown completion 4-5 years more rounded. Eruption 6-7 years Cervical undulation. Root completion 9 years Small marginal ridges and cingulum on lingual surface. 1 root, 1 root canal, 2 pulp horns; mesial and distal. Maxillary central incisors Convexed labial and concaved palatally. Chronology Sharp MI angle and rounded DI angle. Initial calcification 3-4 months after birth Mesial and distal marginal ridges, meet Crown completion 4-5 years centrally to form convexed cingulum. Eruption 7-8 years Hollow cingulum pit. Root completion 10 years CEJ undulates mesially and distally. 1 root, 1 root canal, 2 pulp horns (mesial and distal).  Mandibular lateral incisors Chronology More fan shaped than lower central. Initial calcification 3-4 months after birth Mesial-incisal angle sharp. Disto-incisal angle rounded. Crown completion 4-5 years Concaved lingual surface. Eruption 7-8 years More pronounced distal root groove. Root completion 10 years Small cingulum 1 root, 1 root canal, mesial and distal pulp horns. Maxillary lateral incisors Chronology Smaller, less bulky and narrower. Pronounced rounding of DI angle. Initial calcification 10-12 months after birth Mesial and distal marginal ridges palatally. Crown completion 4-5 years Cingulum with pit more pronounced. Eruption 8-9 years CEJ undulates mesial and distal. Root completion 11 years 1 root, 1 root canal, 2 pulp horns; mesial and distal. Occasionally has 2 roots or bi-lacerated roots. Can be ‘peg’ shaped or missing. Mandibular canines Less bulky than upper canine. Convexed labial surface, more bolbus Chronology distally. Initial calcification 4-5 months after birth Shorter mesial slope. Crown completion 6-7 years 1 cusp that inclines distally. Eruption 9-10 years Less pronounced mesial and distal marginal ridges. Root completion 12-14 years Mesial and distal lingual fossae, larger distally. 1 root, 1 root canal, no pulp horns. Maxillary first pre-molars 2 cusps; buccal and palatal. Chronology Buccal cusp is larger. Initial calcification 18-21 months after birth Longer mesial slope. Crown completion 5-6 years Tip of palatal cusp is displaced mesially. Eruption 10-11 years Mesial and distal marginal ridges. Root completion 12-13 years One central groove with 2 fossae. Developmental groove mesial root between 2 cusps. Canine fossae - concavity on mesial root surface which houses distal bulge on canine. 2 roots, 2 roots canals and 2 pulp horns (buccal and palatal). Root formation can vary with 1 or 2 roots, the 2 roots can be partly fused.  Maxillary second pre-molars 2 cusps; buccal and palatal. Chronology Larger buccal cusp and longer distal slop. Initial calcification 2-2.5 years Tip of palatal cusp is displaced mesially. Crown completion 6-7 years Mesial and distal marginal ridges. One central groove with 2 fossae. Eruption 10-12 years Apex has distal inclination. Root completion 12-14 years More prominent distal developmental groove. 1 root, 1 or 2 root canals and 2 pulp horns (buccal and palatal). May have an additional cusp on distal slope or bi-furcated root. Mandibular first pre-molars 2 cusps; 1 large buccal and small lingual. Chronology Buccal cusp angled mesially and leans lingually. Shorter mesial slope and bolbus distal surface. Initial calcification 1 ¾-2 years One central developmental groove. Crown completion 5-6 years 2 fossae; distal fossae larger. Eruption 10-12 years Lingual cusp overhangs root. Root completion 12-13 years 1 root, 1 root canal, single pulp horn. Mandibular second pre-molars 3 cusps; 1 large buccal and 2 lingual. Chronology ML cusp large than DL cusp. Initial calcification 2 ¼ -2 ½ years Shorter mesial slope buccally. Crown completion 6-7 years Larger than lower 4’s. Eruption 11-12 years Distal inclination at apex. Root completion 13-14 years 1 root, 1 root canal, 2-3 pulp horns. Maxillary canines Chronology Initial calcification 4-5 months after birth Convexed labial surface, Crown completion 6-7 years concaved palatal surface. Eruption 11-12 years Distal slope longer and surface Root completion 13-15 years more bolbus. Pronounced medial and distal marginal ridges; large cingulum, can be pointed. Mesial and distal palatal fossae. Distal root groove more prominent than mesial. 1 long root with distal inclination, 1 root canal, no pulp horns. Can be impacted.  Lower second molars 4 cusps; MB, DB, ML, DL. MB cusp is higher than DB cusp. Chronology ML cusp is higher than DL cusp. Initial calcification 2 ½ -3 years Wider mesially than distally. Crown completion 7-8 years Cross-shaped groove pattern occlusally. Eruption 11-13 years Convexed buccal surface. Wide and grooved mesial root. Root completion 14-15 years 4 fossae occlusally. Buccal and lingual groove, buccal is deeper. 2 roots, 3-4 root canals, 4 pulp horns. Upper second molars 4 cusps; MB, DB, MP, DP. Chronology Smaller DP cusp than maxillary 6’s. Initial calcification 2 ½ -3 years Oblique ridge and palatal fissure present. Crown completion 7-8years Not equilateral. 3 roots; P, MB, DB (less divergent), 3/4 root Eruption 12-13 years canals, 4 pulp horns. Root completion 14-16 years May have fused roots or missing DP cusp. Lower third molars 4, 5 or 6 cusps. Chronology Very convexed buccal surface. Initial calcification 8-10 years Bolbus crown. Crown completion 12-16 years Wider mesial root. Eruption 17-25 years Marked root distal inclination. Root completion 18-25 years Variable number of roots and root canals. Variable in size, shape, presence, impaction and root fusion. Upper third molars Chronology 3 cusps; P, MB and DB. Initial calcification 7-9 years There is a very small DP cusp or not. Crown completion 12-16 years Triangular occlusal shape. Eruption 17-25 years Roots often curve distally. 3 roots; often fused, 3 root canals. Root completion 18-25 years Variations in shape, sizes, presence, impaction and root fusion.