Parents believe teething causes Fever Pain Irritability Sleep

Parents believe teething causes: Fever, Pain, Irritability, Sleep disturbances, Mouthing/biting, Drooling, Red Cheeks, Diaper Rash, Ear Pulling, Feeding problems, Runny nose, Loose stools, and Infections. Wake et al. (1999) J. Paediatr. Child Health 35(5): 446 -9.

3 Phases, 5 Stages of Eruptive Movement

3 Phases, 5 Stages of Eruptive Movement 1. Preeruptive Phase preeruptive movement

3 Phases, 5 Stages of Eruptive Movement 2. Prefunctional Phase • preocclusal • mucosal penetration • intraosseous 1. Preeruptive Phase preeruptive movement

3 Phases, 5 Stages of Eruptive Movement 3. Functional Phase • postocclusal 2. Prefunctional Phase • preocclusal • mucosal penetration • intraosseous 1. Preeruptive Phase preeruptive movement

A. Preeruptive Phase 1. Preeruptive Movements Repositioning of developing tooth prior to upward movement.

Preeruptive Movement Relates to Space in Developing Dentition 6 mo. old TC 10 -3 7 yr. old

A. Preeruptive Phase 1. Preeruptive Movements Repositioning of developing tooth prior to upward movement. • Regional expansion • Translocation

A. Preeruptive Phase 1. Preeruptive Movements

A. Preeruptive Phase 1. Pre-eruptive Movements

A. Preeruptive Phase 1. Preeruptive Movements

Incisors & Canines • primary & secondary teeth Lingual Preeruptive Phase Labial Eruptive Phases

Primary Molars & Secondary Premolars Lingual Preeruptive Phase Buccal Eruptive Phases

B. Prefunctional Phase Movement of tooth from its developmental position to its functional position.

B. Prefunctional Phase Movement of tooth from its developmental position to its functional position. Major Root Growth

B. Prefunctional Phase Cervical Loop: • Epithelial Proliferation • Bell Stage - Crown Stage

B. Prefunctional Phase Outer Enamel Epithelium Ameloblasts Inner Enamel Epithelium Cervical Loop: • Epithelial Proliferation • Bell Stage - Crown Stage

B. Prefunctional Phase Outer Enamel Epithelium Ameloblasts Inner Enamel Epithelium Root Sheath

B. Prefunctional Phase • Morphogenesis of Root Outer Enamel Epithelium Ameloblasts Inner Enamel Epithelium Epithelial Diaphragm

B. Prefunctional Phase • Morphogenesis of Root Outer Enamel Epithelium Ameloblasts Inner Enamel Epithelium Apical Foramen Epithelial Diaphragm

Chapter 5 -1

B. Prefunctional Phase • Morphogenesis of Root 2 Roots Apical Foramen

B. Prefunctional Phase • Morphogenesis of Root 2 Roots

B. Prefunctional Phase • Morphogenesis of Root 2 Roots

B. Prefunctional Phase • Morphogenesis of Root 2 Roots

B. Prefunctional Phase • Cytodifferentiaion of Root Dental Papilla

B. Prefunctional Phase • Cytodifferentiaion of Root Odontoblasts Preodontoblasts Dental Papilla

B. Prefunctional Phase • Cytodifferentiaion of Root Dentin Odontoblasts

B. Prefunctional Phase Cementogenesis Epithelial Cell Rests of Malassez Root Sheath

Cementogenesis Future

Chapter 5, frame 2

Cementum Distribution on Erupted Tooth

B. Prefunctional Phase • Root Growth • Zone of proliferating cells relatively constant,

B. Prefunctional Phase • Root Growth • Zone of proliferating cells relatively constant, • Root growth generally upward, • Corresponds with upward movement of tooth.

B. Prefunctional Phase of Eruptive Movement 2. Intraosseous Eruption Crown Stage Tooth Dental Follicle Alveolar Bone Root Dentin

B. Prefunctional Phase of Eruptive Movement 2. Intraosseous Eruption Crown Stage Tooth Dental Follicle Alveolar Bone Root Dentin Osteoclast Activity • Remodeling of bony crypts, • Eruption Pathway Forms.

B. Prefunctional Phase of Eruptive Movement 2. Intraosseous Eruption Dental Follicle Eruption pathways differ… Dental Follicle Deciduous Tooth Adult Tooth

B. Prefunctional Phase of Eruptive Movement 2. Intraosseous Eruption Dental Follicle Gubernacular Cord Dental Follicle Deciduous Tooth Adult Tooth

Gubernacular cord Chapter 6, frame 7

B. Prefunctional Phase of Eruptive Movement 2. Intraosseous Eruption Dental Follicle Osteoclast Activity

B. Prefunctional Phase of Eruptive Movement 3. Mucosal Penetration Oral Epithelium Reduced Enamel Epithelium Chapter 9, frame 3

B. Prefunctional Phase of Eruptive Movement 3. Mucosal Penetration Oral Epithelium Reduced Enamel Epithelium Fusion • Oral epithelium and reduced enamel epithelium fuse.

B. Prefunctional Phase of Eruptive Movement 3. Mucosal Penetration Apoptosis

B. Prefunctional Phase of Eruptive Movement 4. Preocclusal Eruption Chapter 9, frame 5

B. Prefunctional Phase of Eruptive Movement 4. Preocclusal Eruption Formation of the Gingiva Oral Epithelium Junctional Epithelium • forms seal between oral epithelium and tooth; hemidesmosomes. • attachment dynamic; high rate of cell turnover.

C. Functional Eruptive Phase 5. Postocclusal Eruption

C. Functional Eruptive Phase 5. Postocclusal Eruption Fortification of support for new tooth position: • alveolar bone, • periodontal ligament • completion of root.

C. Functional Eruptive Phase 5. Postocclusal Eruption • External environment, • Growth, • Wear.

Disturbances in Tooth Eruption • Eruptive direction CT scan, coronal view, 12 yr old Extracted ectopic tooth

Disturbances in Tooth Eruption Impaction: • Cessation of eruption because of mechanical interference, • Caused by a physical barrier such as supernumerary teeth or cysts. Chapter 9, frame 7

Disturbances in Tooth Eruption 8 year old, retained permanent M 1 Primary Retention: • Cessation of tooth eruption before emergence, • No systemic cause, no barrier, • Rare.

Disturbances in Tooth Eruption Ankylosis: • Results from the fusion of cementum or dentin with the alveolar bone, • Involved teeth may become fixed in place during or after eruption, • More common in the primary dentition.

Mechanisms of Tooth Eruption • Periodontal Ligament • Hydrostatic Pressure • Root Formation • Bone Remodeling • Dental Follicle

Shedding of Primary Dentition • Root Resorption • Loss of Periodontium • Masticatory Force

Shedding of Primary Dentition • Root Resorption • Loss of Periodontium • Masticatory Force

Shedding of Primary Dentition Chapter 9, frame 1 • Root Resorption • Loss of Periodontium • Masticatory Force

Conclusions: • Tooth eruption begins only after crown formation is complete, and occurs simultaneously with root formation and development of periodontal tissues. • The stages of tooth eruption are distinctive histologically. • Eruption is a multifactorial process, with the dental follicle acting as a critical regulator of formation of the intraosseous eruption pathway.