Diagnosis and Assessment of Orthodontics Flashcards
What is orthodontics?
The branch of dentistry concerned with the treatment and prevention of irregularities of the teeth and jaws.
What is malocclusion?
Malocclusion is a developmental deviation from ideal occlusal relationship that may be considered aesthetically or functionally unsatisfactory.
Outline an orthodontic assessment
- Presenting complaint
- MH, DH, SH
- E/O assessment
- I/O assessment
- Radiographic assessment
- Diagnostic summary
- IOTN
Presenting Complaint…
What is the pt’s main concern?
Is it an aesthetic or functional problem?
If child, are the parents concerned?
Psychological reasons? Bullying?
Is the pt/parents aware of the existing problem?
Why is the MH relevant to orthodontics?
- High risk for endocarditis: prophylactic antibiotics might be indicated for procedures likely to cause bleedings such as extractions
- CVD: contraindication to epinephrine in LA, determine if pt is on anticoagulant drugs, calcium channel blocker s can cause gingival hyperplasia, some meds can cause xerostomia
- Bleeding disorders: pt should not take aspirin or NSAIDS, maintain excellent atraumatic OH, avoid chronic irritation from ortho appliances
- Biphosphonate therapy: ortho tooth movement is decreased after BT
- sickle cell anaemia: extractions CI, carried out by oral surgeon
- Epilepsy: removable appliances utilised with caution due to seizures
- Diabetes: poor OH + risk of PD
- Asthma: high risk of developing root resorption during ortho treatment
- Allergies: to nickel, latex
- Chemotherapy/radiation:: ortho discontinued as treatment can exacerbate thrombocytopenia and agranulocytosis
- Xerstomia: more prone to ulceration, decay
Dental History….
Regular/irregular attender?
Previous dental treatment: extractions/restorations?
Trauma history esp. increased overjet?
Habits e.g. digit sucking - present/past?
Previous ortho? (when, what appliances, problems, retainers)
Assess attitude towards ortho and compliance
SH…
Socioeconomic status
Working/studying? Compliance with appointments
FH…
Anyone in the family will similar dental problem e.g. hypodontia/class III? Anyone in the family with a similar problem e.g. hypodontia/class III?
E/O assessment consists of…
Skeletal assessment:
- Anterior-posterior class 1/2/3
- Vertical: FMPA increased/normal/decreased + LAFH increased/normal/decreased
- Transverse: asymmetry?
- Soft tissues: NLA increased/normal/decreased, Lip competence Y/N
- Habits?
- TMJ?
Anterior-Posterior Skeletal Assessment
The patient is in natural head posture or with the Frankfort plane parallel to the floor. The Frankfort plane runs from the upper border of the external auditory meatus to the lower border of the bony orbit. A point: the most posterior point of concavity on the anterior surface of the maxilla. B point: the most posterior point of concavity on the anterior surface of the mandible. Skeletal class I (normal): the mandible should be 2-4mm behind the maxilla.
Zero-meridian line
The zero-meridian line is a line perpendicular to the Frankfort plane passing through the soft tissue nasion to measure the position of the chin. It is helpful in identifying mandibular retrognathism and prognathism.
How to assess anterior posterior clinically?
Use the forefinger and middle fingers to palpate the alveolar bases in the reflection of the labial sulci of the maxilla and mandible.
Class 1: fingers should be roughly parallel to the floor
Class 2: The middle finger must reach further than the forefinger to palpate the alveolus of the mandible (hand downwards)
Class 3: The forefinger must reach further than the middle finger to palpate the alveolus of the maxilla.(hand upwards)
Vertical: Frankfort Mandibular Planes Angle (FMPA)
The angle formed between the Frankfort plane and mandibular plane. On average they should meet at the back of the head (occipital). Increased FMPA = long face, meet closer than back of head.
Decreased FMPA = short face, meet further than back of head.
Vertical: Lower Anterior Face Height (LAFH)
This is used to assess the facial proportions. Average: equidistant vertical thirds
Transverse
Assess facial symmetry
Most facial asymmetries in chin and nose
Soft tissue assessment: lips
Lip competence: lips are head together at rest, with minimal detectable activity in circum-oral musculature.
Incompetent lips: apart at rest
Lip trap: lower lip is trapped between the upper incisors and lower incisors which causes upper incisors to procline
At rest: lower lip should cover lower 1/3 of upper incisor
Smiling: should show 1-2mm of the upper gingiva and edges of the lower incisors
Upper lip length: measure from nasal base to vermillion border, average 22-24mm
Nasiolabial angle
average 90-110 degrees
Intra-oral Assessment…
- Overall assessment: OH, BPE, gingival recession, caries and restorations, MIH and enamel hypoplasia, poor prognosis teeth.
- Presence of teeth: teeth clinically present, dental development, hypodontia, supernumerary
- Individual arch assessment (upper and lower arches): degree of crowding/spacing, rotations, displacement, labial segment inclination
- Occlusion
How to measure crowding?
Crowding is the discrepancy between the arch length (space available) and the size of the teeth (Space required)
Space available: brass wire measurement, sections for each arch
Space required: measured the mesiodistal width of all teeth mesial to the 1st permanent molar
How is crowding classified?
Mild 1-4mm crowding
Moderate 5-8mm crowding
Severe >8mm crowding
How to assess mixed dentition crowding?
Using average population size teeth, the contralateral side as a guide, x-rays (take into account magnfication)
Incisor angulations normal radiographically…
UI to maxillary plane 109+-6 degrees
LI to mandibular plane 92+-6 degrees
What is the incisor relationship?
A classification based on the antero-posterior position of incisors.
Class I incisor relationship
The lower incisor edges occlude or lie immediately below the cingulum plateau (middle part of the palatal surface) of the upper central incisors.
Class II divison 1 incisor relationship
The lower incisor edges lie posterior to the cingulum plateau of the upper incisors with an increase in overjet and the upper incisors are usually proclined
Class II division 2 incisor relationship
The lower incisors lie posterior to the cingulum plateau of the upper incisors with the upper central incisors being retroclined and the overjet is usually minimal but increased
Class III incisor relationship
The lower incisor edges lie anterior to the cingulum plateau of the upper incisors. The overjet is reduced/reversed.
Molar relationship (A-P plane)
Relationship between the upper molar mesiobuccal cusp to the lower buccal groove.
Canine relationship
Class I: tip of upper canine in embrasure between lower 3 and4
Class II: tip of upper canine in embrasure anterior to lower 3 and 4
Class III: tip of upper canine in embrasure posterior to lower 3 and 4
Overjet
Horizontal distance between the labial surface of upper and lower incisors in antero-posterior plane (mm)
Average 2-4mm
Overbite
Vertical overlap of the lower incisors by the upper incisors
Decreased <1/3 lower incisor coverage
Average 1/3-1/2 lower incisor coverage
Increased> 1/2 lower incisor coverage
Open bite
Lack of overlap vertically
Types: Anterior open bite and Lateral open bite
Crossbite
A discrepancy between the buccolingual relationship of upper and lower teeth
Types of crossbite
Anterior & Posterior
Unilateral & Bilateral
Buccal & Lingual
Anterior crossbite
1 or more of the upper incisors are in linguo-occlusion relative to the lower arch
Posterior crossbite
Crossbites of the premolar and molar region, involving 1 or more teeth or an entire buccal segment
Mandibular Displacement
A sagittal and/or lateral movement of the mandible on closing from centric relation into centric occlusion as a result of an occlusal interference.
It is a discrepancy between the RCP and ICP
Always important to look for a displacement which may be associated with a crossbite
Scissors bite (lingual crossbite)
The buccal cusps of the lower teeth occlude lingual to the lingual cusps of the upper teeth (non-functioning)
Dental Midline
The dental midline of the 2 central incisors: relate upper dental midline with facial midline, relate lower and upper dental midlines, relate lower to mid point of chin
Radiographs taken in ortho
OPG
Lateral Cephalometry
Intraoral: anterior occlusal
CBCT
