Dental Anatomy 2: Dental Formulae, Arches, & Eruption Patterns

Dental formula 

• A dental formula = indicates the dentiiton of only 1 side of the mouth but includes both MAX and MAND. Quadrants. 

  
  
  
  

  • Must be multiplied by 2 to provide the number of teeth in entire dentition 

    
    
  
  
  
  



• PERM DENTAL FORMULA: I 2/2: C 1/1 : P 2/2; M3/ 3 = 32 TEETH TOTAL 

  
  



• BABY DENTAL FORMULA: I 2/2: C 1/1: M 2/2 = 10 TEETH TOTAL 

  
  

General Eruption Pattern  

• Deciduous:  

  
  
  
  

  1. MAND Central incisor  

     
     
  
  

  2. MAND Lat incisor 

     
     
  
  

  3. MAX Central incisor  

     
     
  
  

  4. MAX Lat incisor 

     
     
  
  

  5. MAND 1st molar  

     
     
  
  

  6. MAX 1st molar 

     
     
  
  

  7. MAND canine 

     
     
  
  

  8. MAX canine 

     
     
  
  

  9. MAND 2nd molar 

     
     
  
  

  10. MAX 2nd molar  

      
      
  
  
  
  

Decid. Eruption Ages in Months 

1. Central incisor mand = 6 

   
   



2. Central incisor max = 7.5 

   
   



3. Lat incsor mand = 7 

   
   



4. Lat incisor max = 9 

   
   



5. Mand canine = 16 

   
   



6. Max canine = 14 

   
   



7. Mand 2nd molar = 20 

   
   



8. MAX 2nd molar = 24  

   
   

Perm dentition erupt sequence: with ages in years 

1. Mandibular 1st molar = 6-7 

   
   



2. Max 1st molar = 6-7 

   
   



3. Mand C. incisor = 6-7 

   
   



4. Mand L. incisor = 7-8 

   
   



5. Max C. incisor = 7-8 

   
   



6. Max L. incisor = 8-9 

   
   



7. Mand canine = 9-10 

   
   



8. Mand 1st premolar = 10-11 

   
   



9. Max 1st premolar = 10-11 

   
   



10. Mand second premolar = 11-12 

    
    



11. Max second premolar = 11-12 

    
    



12. Max canine = 11-12 

    
    



13. Mand 2nd molar = 11-13 

    
    



14. Max 2nd molar = 12-13 

    
    



15. Mand 3rd molar =17-21 

    
    



16. Max 3rd molar = 17-21 

    
    

Numbering systems 

• Universal numbering system  

  
  
  
  

  • Perm = Upper right third molar is #1 and then you go all the way to number 16. Start the next arch off at lower left 3rd molar = #17 and then lower right third molar = #32 

    
    
  
  

  • Deciduous teeth = Numbered 1-20 in the same fashion as perm teeth but lowercase "d" is added after the number. Most common, just use letters to address baby teeth, A-T retrospectively.  

    
    
  
  
  
  



• Palmer notation method 

  
  
  
  

  • Breaks mouths into 4 quadrants of 8 teeth 

    
    
    
    

    • 1 = C.incis 

      
      
    
    

    • 2 = Lat.incis 

      
      
    
    

    • 3 = canine DDA 

      
      
    
    

    • 4 = 1st PM 

      
      
    
    

    • 5 = 2nd PM 

      
      
    
    

    • 6-8 = 1-3rd molars  

      
      
    
    

    • Use letters A-E for baby teeth  

      
      
    
    

    • Signs tell the quadrants  

      
      
    
    
    
    
  
  
  
  



• FDI system  

  
  
  
  

  • Binomial system = the first number = quadrant and second number = tooth # (1-8) 

    
    
  
  

  • PERM = 1 at top right, two, 3 = LL, 4 = LR 

    
    
  
  

  • BABY = 5,6,7,8