5. Normal Occlusal Relationship in the Primary, Mixed and Permanent Dentition

Question 1

Normal Occlusal Relationship in Primary, Mixed and Permanent Dentition

Occlusion definition

Answer 1

• Relation of maxillary and mandibular teeth when jaws in closed centric relation
• Without strain of musculature or displacement of condyles in fossae

Question 2

Normal Occlusal Relationship in Primary, Mixed and Permanent Dentition

Ideal occlusion characteristics

Answer 2

• Coincident midline
• No crowding, spacing, or rotations
• Overjet of 2-3mm
• Correct crown inclination and angulation
• Class I molar and canine relationship
• A flat or slightly upwards curve of Spee

Question 3

Normal Occlusal Relationship in Primary, Mixed and Permanent Dentition

Difference between ‘ideal’ and ‘normal’ occlusion

Answer 3

• ‘Ideal’ occlusion hypothetical concept or standardized goal
• ‘Normal’ occlusion implies variations around average mean value

Question 4

Normal Occlusal Relationship in Primary, Mixed and Permanent Dentition

Normal occlusion in anterior segment in sagittal plane

Answer 4

• Buccal surfaces of mandibular anterior teeth occlude w/ palatal surfaces of maxillary teeth

Question 5

Normal Occlusal Relationship in Primary, Mixed and Permanent Dentition

Normal occlusion in posterior segment in the sagittal plane

Answer 5

• Each permanent maxillary tooth occludes w/ two teeth in mandibular arch (antagonist and distal tooth)
• Except for the mandibular central incisors and the maxillary third molar

Question 6

Normal Occlusal Relationship in Primary, Mixed and Permanent Dentition

Normal occlusion pattern in the anterior segment in the transverse plane

Answer 6

• Maxillary and mandibular midlines coincide
• Incisive points of upper and lower arches lie on midline

Question 7

Normal Occlusal Relationship in Primary, Mixed and Permanent Dentition

Normal occlusion in posterior segment in transverse plane

Answer 7

Buccal cusps of mandibular posterior teeth occlude w/ central fossae of maxillary posterior teeth

Question 8

Normal Occlusal Relationship in Primary, Mixed and Permanent Dentition

Normal occlusal relationship in anterior segment in vertical plane

Answer 8

Upper incisors overlap lower incisors by 1/3 of mandibular incisors’ clinical crown

Question 9

Normal Occlusal Relationship in Primary, Mixed and Permanent Dentition

Normal occlusion in posterior segment in vertical plane

Answer 9

• Posterior teeth=>maximum intercuspidation
• Point contacts of maxillary posterior lingual cusp tips and mandibular posterior buccal cusp tips