Permanent Maxillary Premolars PDF

Permanent Maxillary premolars Salma Ahmed Mohammed Shammet Introduction ⬢ Learning Objectives: 1. Describe the anatomical features of maxillary premolars. 2. Differentiate between first and second maxillary premolars. 3. Discuss clinical considerations for maxillary premolar...

Permanent Maxillary premolars Salma Ahmed Mohammed Shammet Introduction ⬢ Learning Objectives: 1. Describe the anatomical features of maxillary premolars. 2. Differentiate between first and second maxillary premolars. 3. Discuss clinical considerations for maxillary premolars. 2 General Characteristics ⬢ Transitional teeth between anterior and posterior dentition. ⬢ Play a role in tearing and grinding food. ⬢ Maxillary premolars are broader buccolingually than mesiodistally. 3 Development and eruption ⬢ First premolar: - Eruption at 10-11 years - Root completion at 12-13 years. ⬢ Second premolar: - Eruption at 10-12 years - Root completion at 12-14 years. 4 Numbering system 1st premolar Right Left Universal 5 12 Palmer 4 4 International 14 24 5 Numbering system Mandibular Right Left Universal 4 13 Palmer 5 5 International 15 25 6 Detailed Anatomy of Maxillary first premolar 7 Crown Features: ⬢ Labial/Buccal Surface: - Shape: Pentagonal. - Features: Prominent buccal ridge, sharp cusp tip, mesial slope longer than distal. - Developmental features: Three lobes form the buccal surface. 8  Crown Features: ⬢ Lingual Surface: - Shape: Smooth and convex. - Features: Lingual cusp is shorter and less pointed than buccal cusp. - Developmental features: Formed from a single lingual lobe. 9 Crown Features: ⬢ Mesial surface: - Shape: Trapezoidal. - Features: Mesial marginal groove, mesial concavity/depression extending to the root. - Clinical notes: Mesial concavity can complicate scaling. 10 Crown Features: ⬢ Distal surface - Shape: Similar to mesial but without concavity. - Features: No marginal groove or deep depression. - Contact Point: Mesial is higher (occlusal third) than distal. - Cervical Line Curvature: Mesial has a greater curvature - Clinical notes: Easier to clean than the mesial surface. 11 Crown Features: ⬢ Occlusal table: - Shape: Hexagonal outline with sharp line angles. - Cusps: Two well-defined cusps (buccal larger than lingual). - Grooves: Prominent central groove dividing the table; mesial marginal groove extends onto the mesial surface. - Ridges: Buccal and lingual triangular ridges form a transverse ridge. - Fossae: Mesial and distal triangular fossae with pit formations. 12 Root feature ⬢ Usually bifurcated (buccal and lingual roots). ⬢ Mesial surface shows a distinct groove. ⬢ Clinical notes: Bifurcation makes endodontic treatment more complex 13 Dimensions and measurements ⬢ Crown length: 8.5 mm. ⬢ Root length: 14 mm. ⬢ Mesiodistal Diameter: 7 mm. ⬢ Labiolingual Diameter: 9 mm. 14 Detailed Anatomy of Maxillary second premolar 15 Comparative features to 1st premolar ⬢ Crown Shape: 2nd Premolar is Rounder, with a less prominent concavity. 1st premolar is more angular. ⬢ Cusps: 2nd Premolar cusps are closer in size, with the lingual cusp being more prominent. ⬢ Root: 2nd Premolar has more rounded appearance and minimal root depression. ⬢ Fissures and Grooves: 2nd Premolar has More supplementary grooves and fewer developmental grooves. 16 Crown Features ⬢ Buccal Surface: - Shape: Similar to the first premolar. - Features: Buccal cusp is less pointed. 17 Crown Features ⬢ Lingual Surface: - Shape: Smoother and more symmetrical than the first premolar. - Features: Lingual cusp is nearly equal to the buccal cusp. - Developmental features: Symmetry is a key distinguishing feature. 18 Crown Features ⬢ Mesial surface: - Shape: Trapezoidal. - Features: No mesial concavity or marginal groove. - Clinical notes: Easier access for cleaning. 19 Crown Features ⬢ Distal surface: - Shape: Similar to mesial. - Features: No deep depressions or grooves. - Contact Point: Mesial and distal are at similar levels (middle third). - Cervical Line Curvature: Both surfaces have similar, less pronounced curvature. - Clinical notes: Symmetrical and straightforward morphology. 20 Crown Features ⬢ Occlusal table: - Shape: More rounded and symmetrical outline compared to the 1st premolar. - Cusps: Buccal and lingual cusps are nearly equal in size. - Grooves: Shorter central groove with more supplemental grooves, creating a wrinkled appearance. - Ridges: Buccal and lingual triangular ridges form a less prominent transverse ridge. - Fossae: Mesial and distal fossae are smaller and closer together. 21 Root Features ⬢ Usually single root. ⬢ Longer root than the first premolar. ⬢ Clinical notes: Single root simplifies endodontic treatment. 22 Dimensions and measurements ⬢ Crown length: 8.5 mm. ⬢ Root length: 14 mm. ⬢ Mesiodistal Diameter: 6.8 mm. ⬢ Labiolingual Diameter: 8.8 mm. 23 Clinical Relevance of permanent Canines 24 ⬢ Examination and Diagnosis: - The first premolar is commonly affected by caries, especially along the mesial surface near the mesial marginal ridge. - Second premolar is more resistant to dental caries, more suitable for restorative work with less risk of stress fractures from occlusal forces. ⬢ Root Canals: - The 1st maxillary premolar often has two roots (buccal and palatal), with deep developmental depression in mesial root which complicate root canal treatments. - The 2nd maxillary premolar usually has one root with one or two canals with more straightforward RCT. 25 ⬢ Extraction and Prosthodontic Considerations: - 1st maxillary premolar is prone to fracture during extraction and is known among dentist as “KING OF FRACTIRE” 26 Any Question? Conclusion ⬢ Maxillary premolars play a transitional role in the dental arch. ⬢ Understanding their anatomy aids in clinical procedures and restorations. 28