Orthodontic Assessment Flashcards
What factors do you need to be aware of in terms of medical history?
Cardiac issues/IE risk 🡪 XLA’s, interproximal reduction, must have good OH etc.
Bleeding disorders 🡪XLA’s, trauma from appliance
Psychological 🡪 Self-image?
Epilepsy 🡪 Okay if well controlled, if pt. seizes regularly – may be swallowed
Diabetes 🡪 Issues with perio, must be stable, general health is a priority
Malignancies 🡪 Can impact developing dentition (chemo)
Autoimmune disorders 🡪 Could affect TMJ
Allergies 🡪 May impact materials you use)
Bisphosphonates 🡪 ONJ of XLA’s
Smoking 🡪 Healing/ OH
What factors do you need to be aware of in terms of past dental history?
Does the patient regularly attend the dentist?
Do they have any current dental issues (these are priority)?
Are they awaiting any dental treatment? DONT get pushed into it by pt.
What treatment have they had in the past –> Restorations/RFT/Extractions
Do they have a history of trauma? May have increased RO root shortening
Do they have TMJ DS?
If they get it during ortho probs not to do with ortho, more likely due to habits etc.
Don’t start ortho if have TMJ problems!
Ortho isn’t going to cure their habits e.g. digit sucking, nail biting, pen chewing
What factors do you need to be aware of in terms of social history?
Is the pt./family motivated to have tx?
Are they willing to wear braces?
Are they able to attend regular appointments? (every 6-8 wks for 2-3 yrs)
What does the pt. do (School/Uni/Job)?
Family history for certain malocclusions (E.g. hypodontia may be genetic or class III)
Have other family members had ortho? (child/fam are more prepared if sibling done it)
For children, who has the right to consent to treatment?
For the EO assessment what planes will be looking at?
Antero-Posterior (AP)
Vertical
Transverse
What is the Antero-Posterior plane? How do we classify it?
Skeletal Pattern:
Class I/II/III.
Head in natural position.
Assess visually or by Kettle’s method:
Use index and middle finger.
Fingers straight = class I.
Fingers sloping down = class II.
Fingers sloping up = class III.
Can also make a skeletal pattern classification using zero-meridian line (line from soft tissue nasion to chin – Gonzalez method):
Class I = upper lip rests on/slightly ahead ZML, chin lines slightly behind. Mandible lies 2-4mm behind the maxilla on palpation
Class II = chin lies behind ZML (retrusive mandible). Mandible appears further behind the maxilla
Class III = chin lies ahead of ZML (protrusive mandible, retrusive maxilla or mix). Mandible appears ahead of the maxilla
Frankfort plane may be used as a substitute
What is the vertical plane? How do we classify it?
Vertical Face Height:
Face should be split into facial thirds:
Trichion to glabella (hairline to between eyebrows).
Glabella to subnasale (base of nose) → upper anterior face height (UAFH).
Subnasale to menton (bottom of chin) → lower anterior face height (LAFH).
The LAFH is assessed in relation to UAFH:
Average: LAFH = UAFH.
Increased: LAFH > UAFH.
Decreased: LAFH < UAFH.
Can also assess by looking at Frankfort mandibular plane angle (FMPA). Frankfort plane runs from bony infra-orbital margin to external auditory meatus. Mandibular plane runs along the lower border of the mandible.
The FMPA can be:
Average – meet at occiput (back of head).
Increased – meet before occiput (more associated with class III).
Decreased – meet behind occiput (more associated with class II).
What is the transverse plane? How do we measure it?
Assess symmetry from above, below and in front.
Make comparisons between bilateral structures and also to the facial midline.
Note down any asymmetry.
Comparison to facial midline (line of best fit down centre of face)
From between the eyebrows
Through tip of nose (if nose = straight)
Through philtrum of upper lip
To chin point
In terms of soft tissues what 3 factors are we considering?
Neutral zone – need to position teeth so ST’s balance the forces to be stable
Facial aesthetics – How does the face look?
Smile aesthetics – How do the lips function when smiling
When assessing the lips what factors should we be paying attention to?
- Competent/ Incompetent/ Habitually competent
Competence 🡪 Lips sit together without muscular activity
Incompetent 🡪 Common in children (development not yet finished) → lips apart
Habitual 🡪 Require muscular effort to bring together → look for mentalis strain
2.Length
3.Naso labial angle
Angle formed between columella + upper lip
Can be affected by nasal tip + upper lip drape
Average 90-110o
4.Relationship of lower lip to upper incisors
Look for lower lip trap
LLT usually occur in class II div 1 malocclusions
Lower lip functions behind incisors: at rest/ swallowing/ eating/smiling
Activity of LI’s proclines UI’s and retroclines UI’s 🡪 further Inc. overjet
If we don’t sort the LLT, patient will relapse
- High lower lip line
An etiological factor of class II div 2 occlusions
More common in patients with reduced vertical proportions
Lower lip covers UCI’s & retroclines them & ULI’s escape the lip (shorter)
Results in the classic class II div 2 appearance - Relationship of upper lip to upper incisors → Average 3mm incisor shows at rest (this reduces with age)
- Smile aesthetics → Slight gingival display during full smile is considered attractive
8.Tone/ fullness → Strap like lower lip
When assessing the tongue what factors should we be paying attention to?
At rest – should rest against teeth or palate → sitting forward between incisors can cause an anterior open bite (AOB); or pushing against palatal surface of incisors can lead to proclination and spacing.
When speaking – tongue thrusting can lead to proclination, spacing and AOB; movement is often associated with lisping.
Adaptive tongue thrust – when lips are incompetent tongue thrusts forward to create an oral seal, this can lead to reduced overbite/AOB.
Endogenous tongue thrust – habitual with high risk of relapse.
Size – for people with small arches, the tongue may be too big (look for crenulations around border).
When assessing the TMJ what factors should we be paying attention to?
Examine as normal note any abnormal findings
Attempts should be made to address any issues prior to ortho tx.
There is no strong evidence that ortho tx. can either cause or cure TMJ DS
Weak evidence that certain occlusal traits are associated with TMD
At what age do we palpate for canines?
9-10 y/o
What are the different classifications for incisor relationship?
Class I – lower incisor edges occlude or lie immediately below the cingulum plateau of upper centrals.
Class II, div. 1 – lower incisor edges lie posterior to cingulum plateau of upper centrals, generally the upper incisors are proclined and there’s an increased overjet.
Class II, div. 2 – lower incisor edges lie posterior to cingulum plateau of upper centrals and the upper centrals are retroclined, the overjet is usually minimal but may be increased.
Class III – lower incisor edges lie anterior to the cingulum plateau of the upper centrals, the overjet will be reduced or negative.
How is crowding classified?
Space required for all the teeth VS the space available in the desired archfrom, mesial to the 6s. NOT the same as contact point displacement.
Mild = 0-4mm crowding → Usually can align teeth without extracting any teeth
Medium = > 4-8mm crowding → May need to extract teeth to create space
Severe = > 8mm crowding → Have to extract teeth to create space
How to measure: Looking at space available for teeth/tooth out of alignment VS how big the tooth is. Then calculate the difference and then classify.
What is overjet and reverse overjet?
Overjet – the distance between the upper and lower incisors in the horizontal plane, normal to have a slight overjet (2-4mm).
Reverse overjet – the lower incisors lie anterior to the upper incisors (i.e. class III incisal relationship). If only 1 or 2 incisors involved it’s termed an anterior crossbite.
