• This is the most accepted classification given by EDWARD KENNEDY.
• The Kennedy’s classification is based on the relationship of the saddles to the natural teeth.
• It has four main group with modifications of each of the first three of these:

CLASS-1

Bilateral edentulous area located posterior to the remaining natural teeth.

CLASS-2

Unilateral edentulous area located posterior to the remaining natural teeth.

CLASS-3

Unilateral edentulous area with natural teeth both anterior and posterior to it.

CLASS-4

Single bilateral edentulous area located anterior to the remaining natural teeth.

MERITS

• Classification is simple and universally accepted.
• It allows to clearly communicate, to write, or to diagnose the condition of the oral cavity in which teeth are to be replaced.
• It permits visualization of the type of partially edentulous arches being considered.
• Type of design can be decided.
• Easy to apply.
• Forms basis for Applegate, Kennedy and Swenson classification.
• Type of support can be determined.

DEMERITS

• Does not give proper information of teeth present and their positions.
• Does not mention about abutment teeth.
• Not applicable to single standing tooth.
• It tells about spaces but not all teeth to be replaced.

1. Jaw Relations = Recording Vertical Dimensions
2. Horizontal Jaw Relation/ Centric Relation – Methods of Recording

1. Types of Horizontal Jaw Relations
   1. Centric 
   2. Eccentric 
      1. Lateral = right and left 
      2. Protrusive 

CENTRIC RELATION 

1. Definition = When the condyle is in most anterior superior position in the glenoid fossa 
2. When pt has teeth = entire proprioception is derived from PDL 
3. When pt is edentulous = proprioception is derived from TMJ 
4. When pt has teeth = it is centric occluded = also know as maximum intercuspal position 
5. When pt is edentulous = we need to record centric relation 
   1. These pt have habitual prognathism = move mandible forward and chew the food using anterior ridges 
   2. Important muscles = masseter and temporalis 
   3. We ask pt to relax – bring his or her upper jaw forward 
   4. Touch the tongue on most posterior part of hard palate
6. HOW TO RECORD?
   1. PHYSIOLOGICAL 
      1. Tactile 
      2. Pressure 
      3. Pressureless  
   2. FUNCTIONAL = chew in methods 
      1. Needlehouse 
      2. Patterson 
   3. GRAPHIC = tracing in the shape of arrow 
      1. Intraoral 
      2. Extraoral 
   4. RADIOGRAPHIC = identify the position of condyles in fossa 
7. Tactile interocclusal records
   1. Do a tentative jaw relation 
   2. Do teeth arrangement 
   3. Place in patient mouth and take interocclusal record = Using wax or alu wax 
   4. Re-articulate and finalize arrangement 
   5. Wax = 2mm of I/O record 
   6. Technique = static 
8. Pressureless method’
   1. Also called as Nick and Notch method
   2. Best method for reproducibility and cross verification 
   3. Using ZnOE paste or Alu wax 
9. Pressure technique 
   1. Maxillary rim of normal size
   2. Mandible rim = excess height and soft wax 
   3. Ask the pt to bite on it 
   4. Excess wax moves out 
   5. Hence, we can seal the CR record 
10. Needle house
    1. Occlusal rims are not made with wax 
    2. Rims are made with impression compound 
    3. Ask pt to do chewing motions and biting movements 
    4. We will observe = Diamond tracing on the rims 
    5. Hence, CR recorded
11. Patterson 
    1. Trench made in the mandibular rim 
    2. 1:1 carborundum and dental plaster is placed in the trench 
    3. Ask the pt to do mandibular movements = all the excess paste will flow out 
    4. Hence, height is reduced and staple pins are used 
12. Graphic 
    1. Arrow shape tracing = draw 
    2. Tip of the arrow denotes centric relation 
    3. This is a static record 
    4. Most reliable method of recording centric relation = GOTHIC ARCH TRACING 
    5. Mc pt will give rounded or tilted lines instead of ideal straight line
    6. Intra oral and extra oral tracings = records CR in horizontal plane 
    7. Pantographic tracing 
       1. Record all 3 planes
       2. Also record 4th dimension called TIME
       3. NOT USED in CD 
       4. Primarily used in full mouth rehabilitation