Hard Tissue Examination of the Dentition

Dentitions:

• Primary (A-T)

• Mixed or Transitional

• Permanent (#1-32)

Hard Tissue Exam Procedure:

• Charting existing restorations

  • missing, unerupted teeth, supernumerary

• Assessment of noncarious and carious lesions

  • visual exam

    • differences in color and translucency

    • transillumination

  • review radiographs

  • document findings-existing restorations, developmental lesions, noncarious cervical lesions, carious lesions, other pathology

Occlusion:

• Normal or malocclusion

• Mal Relations of groups of teeth

• Malposition of individual teeth

• Dynamic occlusion- contacts in normal chewing

• Traumatic occlusion

Enamel Hypoplasia:

Disturbance during formation of enamel matrix

• Genetic-enamel partly or wholly missing

• Local-trauma/periapical inflammation around primary

• Systemic

  • Metabolic disturbances

  • Fever-producing diseases (Measles, chicken pox, Scarlet Fever)

  • Chemicals and drugs (fluoride, tetracycline)

  • Nutritional deficiency (Rickets) Vit D Deficiency = softening of bones in children

  • Birth injury/prematurity

Enamel Hypoplasia Appearance

Hereditary

• White, Brown, yellow

Systemic

• Found in teeth where enamel was forming during systemic disturbance

• Single, narrow zone (short period of time)

• Multiple (occurred over time or several times)

• Teeth most frequently affected? (1st molars, incisors, canines)

Local Enamel Hypoplasia

• Single tooth with yellow or brown intrinsic stain

Hypoplasia of Congenital Syphilis

transmission from mother to fetus after 16th week of pregnancy

Hypomineralization:

Occurs during the mineralization stage of enamel

• Etiology

  • Malabsorption and mineral deficiencies (children of celiac disease)

  • Chronic liver or kidney disease

  • Acquired infection (chicken pox and respiratory and urinary tract infections)

  • Chemicals and drugs (fluoride, tetracycline)

• Types

  • Molar incisor hypomineralization appears as yellow or brownish demarcated areas on permanent molars and incisors

Hypomaturation:

Occurs during last stages of mineralization; enamel fractures easily; may appear opaque or discolored

Developmental Defects of Dentin:

• Genetic

  • Dentinogenesis imperfecta

    • Most common

    • Rapid wear and attrition of teeth

  • Dentine dysplasia

    • Inherited form of rickets (RARE)

• Appearance

  • Opalescent brown discoloration

  • Progressive pulp obliteration

Attrition:

wearing away of a tooth from tooth to tooth contact

Bruxism:

• Sleep or awake

• Predisposing factors

  • Psychological, stress, occlusal interferences

• Environmental factors

  • Coarse foods, chewing tobacco, culturally related chewing habits, abrasive dusts (occupations)

Appearance of Attrition:

• Initial lesion - small

• Advanced - gradual reduction

  • Staining of exposed dentin

• Radiographically: pulp chamber & canals may be narrowed and obliterated → formation of secondary dentin

Erosion:

loss of tooth substance by chemical process, not involving known bacterial action

Abrasion:

mechanical wearing away of tooth substance by forces other than mastication

ex. aggressive brushing, abrasive dentifrice

Abfraction:

mechanical loss of tooth structure along gingival margin; not caused by tooth decay (flexural forces)

Fusion:

• Union of 2 teeth

• Joined at the dentin or pulp

• *Key to identification = “neighbor” missing

• *More common in deciduous teeth

Gemination:

• Single root, single tooth

• Crown appears to be divided

• *Key to identification = normal # of teeth

• Deciduous = usually mand. incisors

• Permanent = usually max. incisors

Fractures of the Teeth:

• Description

  • Line of Fracture

    • Horizontal, diagonal, vertical

• Radiographic Signs of Trauma

  • Widened PDL space

  • Radiolucent fracture line

  • Radiopaque areas where fracture segment overlap

  • Tooth displacement

Classification of Dental Injuries: Fracture of;

• Enamel (chipping, cracks)

• Crown w/o pulpal involvement

• Crown w/ pulpal involvement

• Root of tooth

• Crown and root with or w/o pulpal involvement

Classification of Dental Injuries: Luxation of tooth-concussion

sensitive to percussion, not loose/displaced

Classification of Dental Injuries: Luxation of tooth-subluxation

loosening without displacement

Classification of Dental Injuries: Luxation of tooth-luxation

loosening with displacement

Classification of Dental Injuries: Intrusion

possible alveolar bone fracture

Classification of Dental Injuries: Extrusion

partial displacement

Classification of Dental Injuries: Avulsion

complete displacement out of socket due to trauma

Dental Caries:

• Preventable disease

• Required:

a. Microorganisms

b. Fermentable carbohydrate

c. Susceptible tooth surface

Simple Cavity:

one surface-buccal, occlusal, facial

Compound Cavity:

two surfaces-MO, OL, OB, DO, MF, DF, ML, DL

Complex Cavity:

more than 2 surfaces-MOD, DOL, DOB, MIFL, MODBL

Early Childhood Caries (ECC)

High levels of Mutans streptococci in saliva and biofilm

Root Caries

• Soft, progressive lesion of cementum & dentin involving bacterial infection & invasion

• Incidence increases with age, NOT because of age

• Gingival recession necessary

Testing for Pulp Vitality:

• any tooth suspected of being nonvital

  • patient history

  • clinical and radiographic examinations

  • diagnostic testing

    • thermal

    • electric

• consider all data

Pulp Testing:

• Loss of Vitality due to:

  • Bacterial

  • Caries

  • Periodontal disease

  • Injury:

  • Mechanical

  • Thermal

• Observation:

  • Clinical

    • Intrinsic discoloration

    • Fracture

    • Large carious lesion/filling

    • Fistula

• Radiographic:

  • Apical radiolucency

  • Bone loss, w/widened PDL

  • Fractured root

Kinds of Pulp Testing:

• thermal-hot/cold

• electric

Pulp Testing False-Negative Responses

• Analgesics, tranquilizers, narcotics, alcohol

• Recently traumatized

• Narrow/calcified pulp canal

• Immature tooth (incomplete closure of apex)

Occlusion Centric:

maximum intercuspation of teeth of opposing arches

Occlusion Angle’s Classification

based on relationship of 1st molars

Malocclusion:

classes describe relationship of mandible to maxilla-molar relation and canine relation

In normal or ideal occlusion…

maxillary teeth slightly overlap mandibular teeth on facial surfaces

Malocclusion: CI II (Distoclusion)

• mandibular teeth distal to normal position

• maxilla protrudes

• class II, division 1

• class II, division 2

Malocclusion: CI III (Mesioclusion)

• mandibular teeth are anterior to normal position

• lower lip and mandible are prominent

• crossbite is common

Malpositions of Individual Teeth: Labioversion

towards lip

Malpositions of Individual Teeth: Linguoversion

toward tongue/palate

Malpositions of Individual Teeth: Buccoversion

towards cheek

Malpositions of Individual Teeth: Supraversion

above line of occlusion (over-erupted)

Malpositions of Individual Teeth: Torsiversion

rotated

Malpositions of Individual Teeth: Infraversion

below line of occlusion (under-erupted)

Dynamic or Functional Occlusion

• All contacts during chewing, swallowing, or other normal action

• Associated with performance

• Pressures created by muscles of mastication transmitted from teeth to periodontium

• Maintains occlusal relationship of teeth and guides teeth during eruption

• Necessary to provide functional stimulation for preservation of healthy attachment apparatus (PDL,

cementum, and alveolar bone)

• Chewing effectiveness depends on type and severity of malocclusion AND # and location of teeth

Function Contacts;

normal contacts made between maxillary and mandibular during chewing and swallowing

Parafunctional Contacts:

Make outside normal range of function

• Accelerated tooth wear = facets & attrition

• Pulpal involvement

• Tooth movement

• Etiology includes:

  • Tooth-to-tooth contacts: Bruxism, clenching, tapping

  • Tooth-to-hard-object: nail biting, occupational use, smoking equipment

  • Tooth-to-oral-tissues contacts: lip or check biting

Proximal Contacts:

• Stabilize teeth position in dental arches

• Prevent interproximal food impaction

• Attrition occurs at proximal contacts

  • Drifting

    • Mesial migration (healthy periodontium)

    • Surrounding periodontal tissues adapt to repositioned teeth

  • Pathologic Migration

    • In presence of disease, migration of a tooth can result

Trauma from Occlusion:

repeated occlusal forces exceeding physiologic limits of tissue tolerance

Primary occlusal Trauma:

excessive occlusal force with normal bone support

Secondary Occlusal Trauma:

• tooth has bone. loss and inadequate alveolar bone support

• impaired ability to withstand occlusal forces

• tooth has lost support of surrounding bone

  • Acute Trauma: unexpected

  • Chronic Trauma: ongoing, long-term pathology

What keeps tooth in socket in a function state?

oral attachment apparatus (PDL, cementum, alverolar bone)

Trauma from Occlusion: Excess Forces

• Damage results when forces of occlusion is greater than can be tolerated by attachment apparatus

• Circulatory disturbances, tissue destruction from crushing under pressure, bone resorption begins

Trauma from Occlusion: Relation to Inflammatory Factors

• Gingivitis, periodontitis, or pocket formation is NOT caused by trauma from occlusion

• Existing periodontal destruction may be aggravated by trauma from occlusion in presence of inflammatory disease

Methods of Application of Excess Pressure: Individual teeth that touched before full closure

Premature contact, excessive force on individual tooth

Methods of Application of Excess Pressure: 2 (or only a few) teeth touch during jaw movement

disproportionate amount of force

Methods of Application of Excess Pressure: Initial contacts on inclined planes of cusps

excess pressure on teeth where initial contact made

Methods of Application of Excess Pressure: Heavy forces not in a vertical or axial direction

pressures exerted laterally=excess force on periodontal attachment appartus

Methods of Application of Excess Pressure: increased frequency, intensity, and duration of contact

during bruxism, clenching, or tapping more than usual

Recognition of Signs of Trauma from Occlusion:

Diagnosis is complex; not finding defines presence of trauma from occlusion

Recognition of Signs of Trauma from Occlusion: Clinical Findings

• tooth mobility, fremitus, wear facets

• sensitivity of teeth to pressure, chewing, and or percussion

• pathologic tooth migration

• chipped enamel, open contacts

• neuromuscular disturbances (muscles of mastication)

• TMJ symptoms

Recognition of Signs of Trauma from Occlusion: Radiograph Findings

widened PDL, angular bone loss, root resorption, furcation involvement, thickened lamina dura

Recommendations for Patients with Orthodontic Need:

• all children see orthodontist by age 7

• observe facial profile

• educate on use of protective equipment (mouth guards) for contact sports

Supernumerary Tooth:

extra teeth

Classification of Caries: Class I

cavities in pits or fissures

a. occlusal surfaces of premolars and molars

b. facial and lingual surfaces of molars

c. lingual surfaces of maxillary incisors

Classification of Caries: Class II

cavities in proximal surfaces of premolars and molars

Classification of Caries: Class III

cavities in proximal surfaces of incisors and canines that do not involve the incisal angle

Classification of Caries: Class IV

cavities in proximal surfaces of incisors or canines that involve the incisal angle

Classification of Caries: Class V

cavities in the cervical 1/3 of facial or lingual surfaces (not pit or fissure)

Classification of Caries: Class VI

cavities on incisal edge of anterior teeth and cusp tips of posterior teeth

Retrognathic is class…

II

Mesognathic is class…

I

Prognathic is class…

III