Classification of Malocclusion - Flashcards

Malocclusion Overview

• Malocclusion refers to the abnormal relationship between maxillary and mandibular teeth upon closure, indicating improper tooth alignment.
• Identifying malocclusion does not inherently require treatment, as not all malocclusions are physiologically significant.

Importance of Classifying Occlusion

• Classification aids in defining malocclusion by establishing a normal occlusion benchmark.
• Offers various criteria for diagnosis and progress monitoring, enhancing communication among dental professionals.

Causes of Malocclusion

• Can be attributed to skeletal, dental, or a combination of both factors.

Primate and Leeway Spaces

• Primate Space: Natural spacing in primary dentition; located between lateral incisors and canines in the maxilla, and canines and first molars in the mandible.
• Leeway Space: Size difference between primary posterior teeth and their permanent successors, usually wider for primary teeth.

Class Molar Relationships

• Class I: Normal molar relationship, but teeth may be crowded.
• Class II: Molar distally positioned; often increases overjet.
• Class III: Molar mesially positioned, indicating mandibular growth excess.

Flush Terminal Plane

• Results in Class I when primate space is present; Class II when absent.
• Can switch to Class I with late mesial shift, utilizing leeway space.

Mesial and Distal Step Relationships

• Mesial Step: Typically leads to Class I, may suggest growth irregularities.
• Distal Step: Often results in Class II.

Angle's Classification of Occlusion

• Provides a systematic approach to diagnose and plan treatment based on the alignment of the first permanent molar.
• Has been expanded to include dental and skeletal relationships, influencing growth patterns.

Normal Occlusion Characteristics

• Defined by Class I molar relationship; teeth should align in a linear occlusion.
• Maxillary first molars serve as a key stability reference.

Overjet and Overbite

• Overjet: The horizontal distance between maxillary and mandibular incisors.
• Overbite: The vertical overlap of incisors.

Causes of Crowding

• Results from large teeth, excess teeth, small jaws, or premature tooth loss, amongst other factors.

Treatment Implications

• Understanding the implications of specific classifications can assist in identifying potential treatment strategies to address malocclusions.
• Facial growth patterns correlate with Angle's classifications, influencing prospective orthodontic approaches.

Occlusal Relationships and Contacts

• Premolars and molars have specific contact points critical for classification accuracy.
• Anterior teeth typically have lighter contact forces owing to their design.

Crossbite and Open Bite Conditions

• Anterior Cross-bite: Mandibular incisors positioned in front of maxillary incisors.
• Open Bite: Lack of vertical overlap between incisors, indicating significant alignment issues.

Facial Profiles and Growth Patterns

• Class I: Mesiognathic profile, normally shaped face.
• Class II: Retrognathic profile with dental prominence due to jaw alignment.
• Class III: Prognathic profile, where the mandible appears excessively prominent.

Clinical Evaluation Techniques

• Assess occlusal relationships through dental casts and occlusal photographs to facilitate understanding and treatment planning.
• The mid-sagittal plane is used to evaluate transverse asymmetry.

Variations in Classifications

• Classifications might vary as some patients may have unique skeletal arrangements or occlusal patterns that do not fit neatly into standard definitions.