Orthodontic Classification, Terminology and IOTN Flashcards
What questions in family history are specific to an ortho patient?
Does the family have any similar dental problems?
- Eg) Missing teeth or Skeletal III
Previous history of orthodontic treatment in the family?
- Shows attitudes and compliance towards ortho
What are some questions about past dental history you may ask an orthodontic patient? (3)
- Have they had any treatment in the past such as extractions
- Have they had any past trauma
- Any digit sucking habits
Define A-P Skeletal Patterns:
- I
- II
- III
I = Normal relationship
II = Mandible relatively retrusive (behind upper jaw)
III = Mandible relatively protrusive (infront of upper jaw)
(Class III can appear to look completely flat from chin to top of lip)
Name these two lines of the image
Going across - Frankfurt plane
Going down - Zero Meridian line
What are the 3 components of a skeletal relationship that we need to assess?
Anteroposterior (A-P)
Vertical
Transverse
Assess these patients Frankfort Mandibular Planes Angle (FMPA)
- High angle (Lines cross in front of the occiput)
- Average angle (Lines cross at occiput)
- Low angle (Lines cross behind occiput)
When assessing the lips, if they are deemed incompetent what does this mean?
Lips do not meet at rest
At rest when you lift the patient’s upper lip where should the lower lip cover until?
Cover lower third of upper incisior
Describe the lip morphology of these 3 patients
- Normal Lips
- Thin Lips
- Full Lips
How can a skeletal II relation in a patient lead to lip incompetence?
The mandible is so far back in a patient that the lips meeting at rest causes to much strain on the patient
What is the line in this picture?
Ricket’s E-Line
This can help show if a patients lips are protrusive or retrusive of this line
What does this image display?
Incisal Display
How would you assess the tongue in a soft tissue assessment?
Check the size of the tongue in relation to the oral cavity. It shouldn’t be too large, or too small.
The resting position should be:
- Constantly resting forward against the lower lip
What are the 3 components of a dental arch assessment?
- Alignment of teeth (any rotations)
- Spaces or Crowding
- The inclination of the teeth
What are the 3 ways teeth can be inclined?
Normal
Proclined
Retroclined
When giving a measurement of crowding in mm’s what are you refering to?
How much space is there missing for all the teeth to be in line
How many mm’s is considered
- Mild crowding
- Moderate crowding
- Severe crowding
- <4mm
- 4-8mm
- >8mm
How do you classify spacing in your notes?
Spacing can be either generalised or localised
What is the dental term of a “gap”?
Maxillary median diastema
Describe a normal inclination of incisors
The crown of the tooth is more buccal (anterior) than the root.
Upper: 109 degrees (+/- 5 degrees) to the maxillary plane.
Lower: 93 degrees (+/- 6 degrees) to the maxillary plane.
Describe what you can see in this image clinically
Proclined incisor
Describe what you can see in this image clinically
Retroclined incisor
Describe the different classes of incisor relationships based on the relation between lower incisors to palatal aspect of upper incisors
- Class I
- Class II
- Class III
- Occlude at cingulum plateua
- Occlude posteriorly to cingulum plateua
- Occlude anteriorly to cingulum plateua
What type of incisor relationship is this?
Class I
What type of incisor relationship is this?
Class II division 1:
Incisal edges of the mandibular incisors occlude palatal to the cingulum plateau of the upper incisors. The maxillary incisors are proclined. There is usually an increased overjet.
What type of incisor relationship is this?
Class II division 2:
The incisal edges of the mandibular incisors occlude palatal to the cingulum plateau of the upper incisors. The upper incisors are retroclined.
What type of incisor relationship is this?
Class III:
The incisal edge of the mandibular incisors occlude anterior to the cingulum plateau of the upper incisors.
What is overjet?
Horizontal distance between incisal edge of upper incisors and labial face of lower incisors
What is overbite?
Vertical overlap of lower incisors by upper incisors
What is the red line showing?
Overjet
What is the red line showing?
Overbite
Describe where you would see the upper incisors overlap the lower inscisors for
- A normal overbite
- A reduced overbite
- A increased overbite
- Anterior open bite
- Complete/Incomplete
- Normal: in middle 1/3rd of lower incisor
- Reduced: in incisal 1/3rd
- Increased: in gingival 1/3rd
- NO vertical overlap
- Contact with teeth or mucosa/no contact
Describe:
- A class I molar relationship
- A class II molar relationship
- A class III molar relationship
- Class I: Mesio-buccal cusp of maxillary first molar occludes in the mid-buccal groove of the mandibular first molar
- Class II: Maxillary first molar occludes mesial to class I position
- Class III: Maxillary first molar occludes distal to class I position
Describe clinically what you see
Class I molar relationship
Describe clinically what you see
Class II molar relationship
Describe clinically what you see
Class III molar relationship
What is a crossbite?
Mandibular deviation between centric relation and centric occlusion.
Upper teeth should occlude buccal to lower teeth.
What are the types of crossbites?
Anterior or Posterior
Unilateral or bilateral
What type of crossbite does each image represent?
What is the aetiology of malocclusion?
- Genetic control (skeletal relations)
- Environmental factors (soft tissues + dento-alveolar + habits)
What are the aims of malocclusion treatment?
- Facial:
- Accept or address skeletal pattern - Dental:
- Relieve dental crowding & align teeth
- Reduce the overbite & overjet
- Achieve class I incisor +/- molar relationship
- Eliminate cross-bite & associated mandibular displacement
- Retention.
What are the 6 keys of an ideal occlusion?
- Molar Relationship
- Correct angulation
- Correct inclination
- No Rotations
- No spacing
- Flat curve of Spee
What are the two components needed for the Index of Orthodontic Treatment Need (IOTN)?
- The Dental Health Component
- Grades 4 & 5 – definite need for Tx
- Grade 3 – borderline need for Tx
- Grades 1 & 2 – low need for Tx - Aesthetic Component
- Grades 8-10 - definite need for Tx
- Grades 5-7 - borderline need for Tx
- Grades 1-4 - low need for Tx
In order to see if a patient can receive orthodontic treatment they must be judged against the “dental health component” of the IOTN using the abbreviation MOCDO.
What does MOCDO stand for?
Missing teeth (impacted teeth)
Overjet (>+6mm or >-3.5mm)
Crossbites (displacements >2mm)
Displacement of contact points (>4mm)
Overbite with trauma
