Introduction to orthodontics Flashcards
What is malocclusion?
Variation in occlusion which has dental and/or psychosocial implications
Malocclusion is a variation not a disease
What is dentofacial orthopaedics?
Modify growth to improve relationships between facial bones
What are the 3 types of appliances?
Fixed
Functional
Removable
How does a removable appliance work?
Tipping movements - applied a single-point contact force to the crown of the tooth, the tooth tilts around the fulcrum
Movement of blocks of teeth because connected by baseplate
Influencing the eruption of opposing teeth
How does a functional appliance work?
Utilise, eliminate or guide forces of muscle function, tooth eruption and growth to correct a malocclusion
Work by the principle of posturing the mandible forwards in growing patients
What are functional appliances use for?
Most effective in correcting the anterioposterior occlusion between the upper and lower arches usually in patients with moderate-mild class II skeletal Reduced overjet
What are the dental health benefits of orthodontic treatment?
Caries Periodontal disease Trauma Masticatory function Speech Unerupted/ectopic
What are the psychosocial benefits of orthodontic treatment?
removes the social handicap
Positive judgements by others
Increased self-esteem
what appliance can be used when patient has a posterior crossbite?
Quad helix on first permanent molars expands arches
Why do people with an increased overjet have poor perio?
Incompetent lips - gingiva exposed to air, inflamed gingiva
People with increased overjet dont like their teeth so dont look after them well
But, people who have had ortho treatment dont have better health
What is the incidence of increased trauma if have an increased overjet?
14% with OJ 0-3mm
39% with OJ >6mm increased overjet
What is the other treatment option to correct OJ?
Functional/headgear - 2-phase treatment: once when patient is 8-10 and again in adolesence when have all teeth
One phase treatment: in adolescense more economical to restore the trauma
How can fixing malocclusion affect speech?
There is no proof that alteration of tooth position can improve articulation disorders
Difficult to learn how to talk
What is the problem with unerupted/ectopic teeth?
Resorption of surrounding roots
Cystic change
What are the psychosocial well being benefits of treatment?
Social handicap - positive vs negative social judgement
Negative judements of others - teasing and bullying, but psychological distress is not proportional to the severeity of malocclusion
What are the reasons for orthdontic treatment?
Health is a state of complete physical, mental and social well-being not just the absence of disease - aiming to improve their health and social well-being
What are the risks/problems with orthodontic treatment
Cost/inconvenience Pain and discomfort incomplete treatment - if not looking after teeth will ust stop treatment Medical disorders - bleeding, epilepsy Oral hygiene/gingival/perio health Demineralisation/caries Root resorption Relapse
What is the mean resorption fot maxillary incisors?
0.9mm
17% had root shortenings >2.5mm for one or more maxillary incisors
What are the patient factors for root resorption?
Genetic Systemic disease nutrition Age Gender habits
What are the dental factors for root resorption
Short roots Blunt/pipette shaped History of trauma Ectopic canines Increased overjet Endo treated Alveolar bone density
What are the Treatment factors for root resorption?
Length of treatment Fixed appliance Rectangular arch wires class II elastics Continuous forces Type of movement Degree of force Jiggling forces
What are the 2 components of the IOTN?
Dental health component and aesthetics
What is the incisor relationship?
Assess the position of the lower incisor tip in relation to where it occludes with the upper incisor cingulum plateau
What is a class I incisor relationship?
Lower incisor tip occludes with or below the cingulum plateau of the upper incisor
What is a class II div I incisor relationship?
Lower incisor tip occludes behind the cingulum plateau of the upper central incisors are of average inclination or proclined
What is a class II div II incisor relationship?
Lower incisor tip occludes behind the cingulum plateau behind the upper incisor
Upper central incisors are retroclined
What is a class III incisor relationship?
Lower incisor tip occludes in front of the cingulum plateau of the upper incisor
What is a class I buccal relationship?
Mesio-buccal cusp tip of upper 6 occludes in the mid-buccal groove of the lower 6
What is a class II buccal relationship?
Mesio-buccal cusp tip of upper 6 occludes anterior to the mid-buccal groove of the lower 6
What is a 1/2 unit class II buccal relationship?
Mesio-buccal cusp tip of upper 6 occludes cusp-to-cusp with the mesio-buccal cusp tip of the lower 6
What is a class III buccal relationship?
Mesio-buccal cusp tip of upper 6 occludes posterior to the mid-buccal groove of the lower 6
What is a 1/2 unit class III buccal relationship?
Mesio-buccal cusp tip of upper 6 occludes cusp-to-cusp with the disto-buccal cusp tip of the lower 6
