Dr. Tran Ngoc Quang Phi
Backgrounds Angle classification Six keys Andrew keys Andrew Crown form Arch form Bolton analysis Golden proportion
Angle Classification
Malposition → individual tooth
Malocclusion → anteroposterior relationships of permanent first molars and canines. Canine relationship:
Buccal or labial, lingual, mesial, distal, torso (rotation), infra and supra. Impacted
The upper canine fits distal to the lower canine
Molar relationship
Class I: normal relationships → mesial buccal cusp UFM≡mesial sulcus LFM. Class II: distal buccal cusp UFM≡mesial sulcus LFM Class III: buccal cusp USP≡mesial sulcus LFM
Angle classification extension
Class II division 1:
Class II division 1 subdivision: class I on one side. Class II division 2:
Narrowing of the of the upper arch, lengthen and protruding UC. Abnormal function of the of the lips, nasal obstruction, mouth breathing.
Crownding, overlaping and lingual inclination UC Normal nasal and lip function
Class II division 2 subdivision: class I on one side. Class III subdivision: class I on one side. Mild class II: between class I and class II Mild class III: between class I and class III
Class I Molar or Class I Canine?
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Four items that you "must complete" for successful orthodontic treatment 1. The teeth must be straight at the end of treatment. of treatment. 2. There must not be any spaces any spaces between the front teeth. 3. There must not be any overjet any overjet (the patient refers to overjet as "overbite"). 4. The teeth must (generally) bite together at the end of treatment. of treatment. It is OK to have a bicuspid out of occlusion, but the teeth must not be open molar to molar.
Six keys Andrew 1.
Molar relationship :
Class I Angle Cusp‐embrasure relationship buccally Cusp‐fossa relationship lingually
2. Crown angulation: All tooth crowns are angulated mesially (mesio‐distal tip) 3. Crown inclination: Incisors are inclined labially Upper posterior teeth are inclined lingually, similarly from similarly from the canine to the premolars; upper molars are inclined slightly more slightly more than the canine and the premolars.
Angulation and inclination
Lower posterior teeth are inclined lingually, progressively from progressively from canine to molars
4. Rotations: Rotations are not present 5. Spaces Spaces are not present between teeth of Spee 6. Curve of Spee The plane is either flat or slightly curve slightly curve
Curve of of Spee Spee Yes
No
Anterior Crown form Central incisor crown form: Triangular‐shaped incisors: need to be reshaped to avoid one‐ point contact (→ black triangle and unstable) Rectangular‐shaped incisors: good esthetics Barrel‐shaped incisors: do not provide ideal esthetics •
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Canine crown form
Relatively flat Relatively flat facial contour
Narrow and pointed incisally
Markedly curved Markedly curved facial contour
Wide and flattened incisally
Arch form Square
Ovoid
Tapered
The original arch form is considered the most stable position since this is the "in balance" position of the of the teeth and surrounding muscles: the neutral zone. Any alteration Any alteration of this of this position may result may result in instability in retention. Relapse tendency after tendency after changing arch form (De La Cruz‐1995, Burke‐1998): inter‐canine width. canine width. Expansion the lower arch form: 10%. Tapered
Japaneses Caucasians
Ovoid
12% 44%
Square
42% 38%
46% 18%
Systemized management of of arch arch form
Determine the arch form at the start of treatment of treatment
Template ♦ Computerized cast analysis @
Arch wire Arch wire stocked:
Round arch wire arch wire (NiTi and SS): ovoid only .019/.025 (.018/.025 ) HANT: three shapes
45% ovoid 45% square 10% tapered
.019/.025 (.018/.025 ) SS: ovoid only →
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Bolton analysis
Anterior Bolton analysis
Overall Bolton analysis
Max 6: 40.0 – 54.5 (+0.5) Mand 6: 30.9 – 42.1 (+0.4) Max 12: 85 – 110 (+1) Mand 12: 77.6 – 100.4 (+ 0.9)
Ideal ratio → canine class I Determine distance between hooks or loop Bolton discrepancy → proper solution
Anterior Bolton analysis
Full archBolton analysis
Ideal ratio in Bolton analysis Maxillary 6 Maxillary 6
Mandibular 6
Maxillary 12
Mandibular 12
40.0
30 . 9
85
77.6
40.5
31.3
86
78.5
41.0
31.7
88
80.3
41.5
32.0
89
81.3
90
82.1
48.0
37.1
91
83.1
48.5
37.4
96
87.6
97
88.6
51.5
39.8
103
94.0
52.0
40.1
10 4
95.0
10 6
96.8
Application? Chose the T –loop arch wire arch wire Adjust for the best fit occlusion
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Golden proportion
a + b a
=
a b
ϕ = 1 . 618
= ϕ
→
DIAGNOSIS
Collect data
Orthodontic questionaire Clinical examination X ‐rays : POG and CEP Models Pictures
Cephalometric analysis Model anlysis Diagnosis: problem list
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Orthodontic Questionaire MEDICAL HISTORY
Under a physician's care at this time? Yes/No. time? Yes/No. Explain
Taking any medication any medication at this time? Yes/No. time? Yes/No. Specify Allergic to any medication? any medication? Yes/ Yes/ No. Specify
Any other Any other allergies? Yes/No. allergies? Yes/No. Specify
Need to be premedicated (antibiotics) for routine dental procedures? _Yes _No. Specify and Specify and reason
Following diseases or conditions? (If yes, yes, explain and date):
AIDS__ Bleeding disorder __ __ Anemia__ Anemia__
Lung disease__ Cerebral palsy__ Heart condition__
Arthritis__ Hepatitis__ Kidney disease__Rheumatic Kidney disease__Rheumatic fever___ Asthma__ fever___ Asthma__ Diabetes__ Epilepsy__
Injury to Injury to face/head__
Tonsil/adenoid surgery__ Previous surgery__
Females: Is the patient pregnant? __ __ Yes Yes __ No
DENTAL HISTORY
Date of last of last dental examination
Any injury Any injury to to the face/teeth/gum? Explain and date.
Any previous Any previous orthodontic treatment/consultation?
Does the patient:
Grind his/her teeth at night? Bite his/her fingernails? Suck thumb, finger, pacifier, etc.?
If yes, yes, at what at what age was age was the habit discontinued? __years Has another member of the of the family had family had orthodontic treatment? Whom? treatment? Whom?
Medical conditions to be considered in orthodontic treatment Medical condition
Asthma Allergies
Implications
reR sooropttion Arlelearcgticon
Action
Monitor every 6 every 6 mo for evidence of EARR of EARR Determine materials causing allergy
Coagulation diso disord rder erss
Blee Bleedi ding ng risk
Extraction?
Diabetes
Periodontal disease
Monitor tor adequate control of diabetes
Epilepsy, High blood pressure
Gingival hypertrophy
Plaque control, gingivectomy if necessary
Heart valve Heart valve conditions Endocarditis
Premedication when extraction, fitting bands
Rheumatoid arthritis
Monitor TMJ
Xerostomia
TMJ degeneration Caries
Fluoride supplement
PATIENT'S ATTITUDE AND MOTIVATION
Is the patient aware of the of the problem?
Consultation here prompted by _________________ by _________________
Patient's interest in having treatment is:
__ Wants __ Wants treatment ___ ___ Willing Willing if necessary if necessary __ __ Unwilling
If the If the patient’s teeth were teeth were to be changed, how would how would you you like them changed? _______________________________
If any If any features features of the of the face could be changed, what changed, what would would you like to see? ___________________________________
GROWTH STATUS: (child patients only)
Height__________ cm
Weight _________kg
Females: Has the patient started her menstruation? __ Yes __ Yes __ No. If yes, yes, at what at what age? ________
Males: Voice Males: Voice changes? __ __ Yes Yes __ No Facial hair growth? __ __ Yes Yes __ No Has the patient had any recent any recent rapid growth? ___________ If so, If so, how much?_______________
Rational for Orthodontic questionaire
Chief complaints Chief complaints
Medical and Dental history
Determine patient’s motivation, expectation Reveal the causes of problems of problems Relation between the patient’s conditions and orthodontic treatment
Growth and development
Timing of orthodontic of orthodontic treatment
CLINICAL EXAMINATION
Esthetic analysis
Macro esthetics: facial proportion Mini esthetics: tooth – lip relationships Micro esthetics: dental appearance
Functional analysis
TMJ Occlusion Periodontal health Bad habit
Macro esthetics: facial proportion
General view General view
Dolicofacial, brachyfacial, mesiofacial
Frontal view Frontal view
Vertical
Horizontal
Proportion Chin height Lower face height Proportion: rule of fifth
Midline asymmetry
→
Vertical proportion
Horizontal proportion
The lower third @ A. Increase face height:
Dolicofacial pattern Vertical maxillary excess maxillary excess (VME) ♦
High lip line: anterior teeth display too display too much Gummy smile Gummy smile Lip length: normal ≠ Short lip ♦
Excesssive chin height ♦ B. Decrease face height Brachyfacial pattern Vertical maxillary deficiency maxillary deficiency Mandibular defienciency ♦ Short chin height ♦
Dolicofacial
Long and thin faces. Weak faces. Weak muscles of mastication of mastication that are not strong enough to hold the teeth together during orthodontic treatment. Non extraction treatment of these cases may result may result in bite opening during the treatment. When extraction, space closes quickly. Be careful when treating a protrusion case •
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Mesiofacial
Mesiofacial is not long and thin facial features, and not short and square facial features. In these cases you cases you can extract and the extraction spaces will spaces will close "normally". You can treat these case types non extraction and the teeth will remain in occlusion during treatment. •
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Brachyfacial
Short, square faces with faces with very strong very strong muscles of mastication. Short clinical crowns with crowns with some excess enamel wear enamel wear on the occlusal surface of the of the teeth. In these cases, if you you extract, then the extraction spaces will spaces will close slowly. •
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Pre‐orthodontic orthodontic@
Post‐
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Short lip: @ Philtrum height < commisure height Inverted lip
Asymmetry
Upper midline asymmetry
Lower midline asymmetry Cause
Orthodontist : < 2mm Dentist : 2 – 4mm Non‐professional person: >4mm
Upper : missing tooth, impacted tooth, crowding… Lower: causes as upper arch, esp: TMJ
Always the tough cases
Profil view
Proportion Convex, straight, concave Straight: anterior divergence, posterior divergence Mandibular plane angle Lower face
Lip
Maxillary projection Maxillary projection Mandibular projection Chin projection Lip posture and incisor prominence Lip fullness Labiomental sulcus
Throat form
Chin – throat angle Throat length Submental contour
Profil view
Black pattern
Convex treatment?
Be careful not to set the patient's expectations too high for reducing a convex profile: it takes 2‐3mm of tooth retraction to result in 1mm of lip of lip retraction. Move the chin forward to reduce feeling convex Lefort I + BSSO for comprehensive treatment
Mini esthetics: Tooth Tooth – – lip relationship
Philtrum height Commisure height Interlabial gap Incisal display at display at rest Smile analysis
Emotional smile and social smile Incisal display on display on smile Gingival display Smile arc Buccal coridor width Arch form Transverse cant
Vertical measurements
A: Philtrum height
A: Incisal display on display on smile
B: Commisure height C: Interlabial gap
B: Crown height and width and width C: Gingival display
D: Incisal display at display at rest
D: Smile arc
Emotional smile and social smile
Major zygomaticus muscle
Risorius muscle
Smile arc
The contour of the of the incisal edges of the of the maxillary anterior maxillary anterior teeth relative to the curvature of the of the lower lip during a social smile
Transverse cant
Gummy smile
Crown lengthening Orthodontic treatment Lefort I Osteotomy Plastic surgery
Micro esthetics: gingival and dental appearance
Tooth proportion: crown height and width and width Width relationship and golden proportion Gingival height , shape and contour Connectors and embrasures Tooth shade and color
Crown height and width
The width The width of central of central upper incisor should be about 80% of it’s of it’s height. The disproportion should be done before orthodontic treatment is completed.
Width relationship and golden proportion
Gingival shape and contour Gingival shape of upper of upper central incisors and canines is more elliptical. Gingival shape of upper of upper lateral incisors and mandibular incisors is a symmetric half ‐oval or half ‐ circular one. The gingival zenith of central and canine is located distal to the longitudinal axis. The gingival zenith of lateral of lateral incisors coincides with coincides with the longitudinal axis.
Connectors and embrasures Connector # contact point area: Include the areas above and below the contact point. Greatest between the central incisors and diminish from the centrals to the posteriors. Embrasures: triangular spaces incisal and gingival to the connector. Gingival embrasures are filled by interdental papillae. Short interdental papillae → black triangle. Tapered crown form → black triangle
Clinical considerations
Open bite Tongue thrust Functional shift Missing tooth Lower Anterior Lower Anterior Tissue Thickness
Open bite Principle: Teeth erupt erupt until until they they hit hit something. something.
Open bite: the lower incisor does not contact the upper incisor. There are obvious open bite cases where cases where the teeth are separated in the anterior. In some class II cases where the amount of overlap of the of the upper incisor vs. incisor vs. the lower incisor is normal (1/3 coverage), but the lower incisor does not contact the tooth nor the palate.
Tongue thrust
A test A test for anterior tongue thrust is to: Take a small sip of water. water. Close the teeth together with together with the lips open. Swallow. A patient A patient with with an anterior tongue thrust will thrust will either: Not be able to keep his/her lips open. Will tilt his/her head back for gravity to gravity to keep the water the water from squirting forward. Will squirt the water the water between the teeth forward onto their shirt (child patient). A good A good exercise to give a patient with patient with an anterior tongue thrust (especially in (especially in the presence of open of open bite or excess anterior overjet) is: Take a small sip of water. water. Close the teeth together with together with the lips open. Swallow with Swallow with the throat muscles. Tell the patient to hold their hand on their throat as they learn they learn this exercise to feel the muscle contraction.
Functional Shift
Forward functional shift Lateral functional shift
Unilateral crossbite Dental midlines not centered. The asymmetric face from the frontal view. frontal view.
Missing Tooth
This seems very seems very obvious, obvious, but in many cases many cases where where a tooth has been lost, the space has closed spontaneously by spontaneously by dental dental drifting. It is very is very easy easy to to not notice a missing tooth in a dental arch when arch when doing your examination. Be certain that you that you count 4 incisors, 2 canines, 4 bicuspids, etc. in each arch, before checking "none."
Lower Anterior Tissue Thickness Principle: The lower arch lower arch is considered the considered the limiting arch in edgewise diagnosis. To align crowded teeth, advancement (forward movement) of the of the teeth will teeth will inevitably occur. inevitably occur. If the If the advancement of the of the lower incisors is significant, then a periodontal defect (stripping of gingival of gingival tissue is the most common) can occur. Advancement of incisors of incisors with with "thin tissue" has more risk than advancement with advancement with "thick tissue" labial to the lower inci inciso sors rs.. As the teeth advance, the tissue will tissue will become thinner .
Cephalometric analysis: lanmarks
Planes
Growth direction
SNB Mandible is protrusive if > if > 83 Mandible is average if 76 – 82 Mandible is retrusive retrusive if <75 if <75
Cephalometric Cephal ometric analys analysis is – – Skeletal Description
Measurement
Mean
Range
Pal. plane to Md. Plane: Skeletal Open/closed
ANS‐PNS to Md. plane
280
Closed 240 – 33 0 Open
Md. Plane angle: Skeletal Open/c n/clos losed
FH – MA: Child Adult
260 220
Closed 200 – 30 0 Open 240 – 33 0
59 0
Hor. 570 – 62 0 Vertical
Y – Y – Axis
Vert/Hor Growth
SG FH ‐ N
Maxilla to Cranium
N ⊥ A
+1mm
Retruded ‐1 to +3 Protruded
Maxilla to Cranium
SNA
820
Retruded 760 – 83 0 Protruded
Mandible to Cranium
N ⊥ Po : Child Adult
7mm ‐1mm
Retruded ‐10 to ‐4 Protruded ‐4 to ‐1
Mandible to Cranium
SNB
790
Retruded Retruded 750 – 83 0 Protruded
Maxilla to Mandible
ANB
20
Class I : + 20 to +4.50 Class III tendency: +0.50 to +1.50
Wits
A, B
0 mm
Class I : ‐1 to +2
⊥
Occlusal plane
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Cephalometric analys Cephalometric analysis is – – Dental Description
Measurement
Mean
Range
1300
Best finish 125 0 – 1300
1
Interincisal Angle
1
to
Lower Incisal Inclination
1
to MP
920
Retroclined 890 – 98 0 Proclined
Lower Incisal Protrusion
1
to N B
+4mm
Retruded +1 to +6 Protruded
Lower Incisal Protrusion
1
to
Upper Incisal Inclination
1
1
APo
to S N
Upper Incisal Protrusion
1
to
Upper Incisal Protrusion
1
to A vertical vertical
APo
(to FH)
+2mm 1030 5mm 4mm
Retruded to t0o +4 Protruded Retroclined 990 – 1060 Proclined Retruded +2to +7 Protruded Retruded +2 to +6 Protruded
Cast analysis
Cast analysis by software
Advantages of of computerized computerized analysis
Accurate Easy More information:
Arch form Loop distance (Bolton analysis) Determine asymmetric Arch asymmetric Arch Space analysis Rotation Prediction
DETERMINE THE PROBLEMS
Kind of problems: of problems:
Dental problems Skeletal problems Facial problems Occlusal problems TMJ problems Periodontal problems
Causative factors Degree of problems of problems
Ackerman and Proffit diagram
Aligment (spacing and crowding) Profile (convex, straight, concave) Sagittal deviation (Angle class) Vertical deviation (deep bite, open bite) Transsagittal deviation (combine Angle (combine Angle class and cross bite) Sagittovertical deviation (combine Angle (combine Angle class and deep bite or open bite) Verticotransverse deviation (combine cross bite and deep bite or open bite) Transsagittovertical deviation (combine of problems of problems in three planes of space) of space)
DENTAL PROBLEMS
Intra‐arch problems Inter‐arch problems Causative factors Degree of the of the dental problems
Intra‐arch problems
Position :
Rotation Angulation Inclination:
Procline or recline
Spaces:
Protrusion or retrusion of incisors of incisors Malposition Impaction
Spacing or crowding
Curve of Spee of Spee
Inter‐arch problems
Molar relationship
Canine relationship
Overbite, deep bite, open bite
Horizontal relationship:
Class I, II, III
Vertical relationship:
Class I, II, III
Overjet, end‐to‐end, anterior crossbite. Posterior crossbite
Upper and lower incisor angulation Inter‐arch discrepancy Midline relationship:
Midline asymmetry
Causative factors
Spacing
Large jaw Large jaw Small teeth Missing teeth Lateral over‐expansion of arches of arches or forward proclination of anterior teeth.
Crowding
Small or constricted arches Large teeth Retroclination Mesial drift of posterior of posterior teeth
Openbite
Bad habit: thumb sucking, finger sucking or pacifier using, tongue thrush, lip habit. High tongue posture Airway obstruction: Airway obstruction: allergies, enlarged tonsils, adenoids, septum problem… Intracapsular TMJ problems Skeletal growth abnormalities
Diagnosis of of Impacted Impacted Teeth
Impacted Teeth : not erupted for 2 years following the normal eruption age. The eruption path is blocked, or if the if the eruption stops after the tooth strays to a position labial or lingual to another tooth. The most common impaction: the upper canine.
DIAGNOSIS OF AN OF AN UPPER IMPACTED CANINE
Panoramic x‐ray: Any ray: Any overlap overlap of the of the canine crown with crown with the lateral incisor roots → impaction?. Palatal or labial?
Palpate the labial tissue Occlusal x‐ray
Crowding and impacted tooth
The "impacted tooth" may be may be BLOCKED OUT of the of the arch because of crowding: of crowding: in a good position but cannot erupt due to a lack of space of space →blocked out. Evaluate the root formation to determine eruption potential: incomplete root formation → eruption potential. Tx: space is made with made with open coils or extraction and a deadline # 12 months is set to wait to wait for its eruption.
Consideration in impacted tooth
Position: labial (good) or palatal Angulation: the more vertical more vertical the more success Space available: enough? The path to the correct position? The age: best under 25 The risk:
Ankylosis Damage the adjacent teeth
Degree of of problems: problems: Diagnostic Parameters Canine and molar relationships: RM, RC, LM, LC Angle classification Overbite Overjet Stage of dental of dental development Presence of crossbite: of crossbite: with with or without or without functional shift 7. Space analysis 8. POG interpretation 9. CEP interpretation 1. 2. 3. 4. 5. 6.
1.
Canine and molar relationships: RM, RC, LM, LC Class I b. Class II* c. Class III* fully erupted d. Not fully erupted a.
2. Angle classification a. Class I malocclusion b. Class II malocclusion, division 1, 2 and subdivision* c. Class III malocclusion, subdivision*
3.
Overbite a. b. c. d. e.
Normal (5 % ‐ 20%) Moderate deep bite (20% ‐ 50%) Severe deep bite ( > 50%)* Edge to edge Anterior open bite
4. Overjet a. Normal (1 – 3mm) b. Excessive ( > 3mm)* c. Edge to edge d. Underjet (negative overjet)
5.
Stage of dental of dental development a. b. c. d.
Deciduous dentition Early Mixed Early Mixed dentition Late Mixed dentition Permanent dentition
of cross bite: with bite: with or without or without functional shift 6. Presence of cross a. None b. Anterior c. Posterior d. Both
7. Space analysis a. Adequate arch length ( +1 to ‐1mm) b. Mild crowding (‐2 to ‐3mm) c. Moderate crowding (‐4 to ‐6mm) or Severe (> ‐6mm) d. Mild spacing (1 – 3mm) e. Moderate spacing (4 to 6mm) or Severe (> 6mm) 8. POG interpretation a. Normal b. Abnormal: missing, supernumerary, ectopic, impacted tooth) 9. CEP interpretation a. Normal b. Beyond the normal range: 1 SD c. Beyond the normal range: 2 SD d. Beyond the normal range: 3 SD
