5: Orthodontics and Pediatric Dentistry

5 Orthodontics and Pediatric Dentistry

OUTLINE OF REVIEW

1.1 Epidemiology of Malocclusion

Since malocclusion is not a disease, but a variation away from what is considered ideal, it is difficult to estimate its prevalence in the population. Studies have instead focused on the prevalence of characteristics of malocclusion such as the presence of incisor crowding or irregularity, overjet (usually accompanying Angle Class II malocclusions), reverse overjet or anterior crossbite (usually associated with Angle Class III malocclusions), midline diastema, deep or open bite, and posterior crossbite. Various characteristics of malocclusion are seen more commonly in different age groups and in different ethnic groups.

1.2 Growth and Development

Sites of Growth in the Craniofacial Complex

D. Mandible

image

Figure 5-1 Diagrammatic representation of the synchondroses of the cranial base, showing the location of these important growth sites.

(From Proffit WR, Fields HW, Sarver DM: Contemporary Orthodontics, ed 4, St Louis, Mosby, 2007.)

Timing of Growth

Cleft Lip and Palate and Other Developmental Abnormalities

TABLE 5-1 STAGES OF EMBRYONIC CRANIOFACIAL DEVELOPMENT

STAGE TIME (HUMANS, POSTFERTILIZATION) RELATED SYNDROMES
Germ layer formation and initial organization of structures Day 17 Fetal alcohol syndrome (FAS)
Neural tube formation Days 18–23 Anencephaly
Origin, migration, and interaction of cell populations Days 19–28 Hemifacial microsomia
Mandibulofacial dysostosis (Treacher–Collins syndrome)
Limb abnormalities
Formation of organ systems    
Primary palate Days 28–38 Cleft lip and/or palate, other facial clefts
Secondary palate Days 42–55 Cleft palate
Final differentiation of tissues Day 50–birth Achondroplasia synostosis syndromes (Crouzon’s, Apert’s, etc.)

(From Proffit WR, Fields HW, Sarver DM: Contemporary Orthodontics, ed 4, St Louis, Mosby, 2007.)

1.3 Development of Occlusion

A. Stages of normal dental development

2. The primary dentition stage

3. The mixed dentition stage

B. Dimensional changes in the dental arches

1.4 Orthodontic Diagnosis

The first step in orthodontic treatment planning is gathering the data required to make a diagnosis. The information comes from talking to the patient and/or parents, clinical examination, and diagnostic records.

B. Oral examination

3. Dental/occlusal characteristics

b. Interarch (in three dimensions)

Discrepancies may be dental or skeletal in origin. For example, a patient with a Class II interarch relationship may have a Class I skeletal relationship (the maxilla and mandible are in good relationship) or may have a Class II skeletal relationship with the maxilla forward, or the mandible back, or both.

5. Skeletal relationships—cephalometrics

Cephalometric radiographs are standardized two-dimensional films of the skull. Subsequent films can be superimposed to evaluate growth and/or treatment effects. Individual films can evaluate dentofacial proportions or help clarify the anatomical basis for a malocclusion. This information should be used to confirm information from the clinical examination. Measures can be used to compare an individual to population norms, taking into account that there is much normal variation in the population.

Jan 5, 2015 | Posted by in General Dentistry | Comments Off on 5: Orthodontics and Pediatric Dentistry
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