cephalometric diagnosis
TRANSCRIPT
Cephalometric diagnosis
Constituents: Clinical examination, lateral cephalometry, photography, dental cast, additional Xray,
additional data
Lateral cephalometry make quantitative identification of facial harmony and its underlying causes
Patient positioning of lateral Ceph: natural head position, intercuspal position, relaxed lip posture
Tracing
1. Cranial base: S, Ba
2. Orbit & Nasal area: Or, N
3. Maxilla: ANS, A, PNS, Ptm
4. Mandible: B, Pog, Me, Gn, Go, Cd, Ar
5. External auditory meatus: Po
6. Facial soft tissue profile: G, N’, Pn, Cm, Sn, A’, Ls, ULP, Stm, LLP, Li,, B’, Pog’, Me’
Measurement
Skeletal: SNA,SNB,ANB,Wit’s appraisal, A to Nper, Pog to Nper, FMA, Go angle, LAFH ratio
Dental: U1 to SN, U1 to FH, IMPA, FMIA, IIA, U1 to APog, L1 to APog, U1 to Stm
Soft: E line, NLA
Limitation of cephalometry: transverse discrepancy, arch length discrepancy, pathologic condition
Cephalometric diagnosis
Photograph
1. Intraoral photography
F>22 with ring flash, manual focus
V-&U- shaped retractor, Mirror, lip hook
Front view
Occlusal upper
Occlusal lower
Buccal right & left
2. Facial photography
Frontal view (rest)
Frontal view (smile)
Oblique view
Profile view
Photograph
Basic model analysis
1. Bolton ratio
Correction: IPR, restorative build up
Overall 91.3%, Anterior 77.2%
2. Curve of Spee
Flattening the curve of Spee positional change of lower incisor
3. Intermolar width
Correction: palatal expansion, inclination control
Arch perimeter increase is about 0.7 times the intermolar width increase
4. Arch length discrepancy Availab
le space – required space
Correction: incisor advancement, extraction, distalization, lateral expansion, interproximal r
eduction
5. Overjet/overbite
Result of normal occlusion
6. Molar key
Premolar occlusion is more important
7. Qualitative inspection
Basic model analysis
Panorama
*Information
Tooth pathology
TMJ pathology
Maxillary sinus
Bone pathology
CO-CR discrepancy (MI-CO discrepancy)
*Check by
Stabilization splint T
MJ manipulation Or
thodontic leveling
Panorama / CO-CR discrepancy
Bracket & wire
Line of occlusion
1. The line of greatest normal occlusal contact (1906, Angle)
2. A distinctively individual line at the inciso-buccal contact with a location, position & form
to which the teeth must conform to be in normal occlusion (1997, Ricketts)
1st order: lateral inset, canine eminence, molar offset
2nd order: angulation (tip)
3rd order: inclination (torque)
DBS -Bracket height guide objectives
1) Leveling marginal ridges
2) Improve intercuspation of the posterior teeth
3) Define the overbite for the anterior teeth
Recommended vertical axis
1. Incisor center mesiodistally
2. Canine & premolar labial cusp tips
3. Molars buccal grooves
Procedure
1. Tooth surface treatment
2. Bracket placement
Checklist
1. Height
2. Vertical axis error
3. Mesiodistal deviation
4. Adhesive resin thickness
Bracket & wire
Ideal archwire bending
1) 1st, 2nd, 3rd order bending
2) Arch coordination
Six keys to Normal Occlusion
1. Molar relationship
2. Crown angulation
3. Crown inclination
4. Rotation
5. Space
6. Occlusal plane
In Straight Wire Appliance (SWA), we can get a good aligned dentition without wire bending due t
o creation of preadjusted bracket
*Comparison of various commercial preadjusted bracket prescriptions
Bracket & wire
Bracket slot
1. 018 slot: earlier torque control with lighter force, less inventory of wire sizes
2. 022 slot: less wire deformation
Torquing play
Tube
1. Single
2. Double
3. Combination
4. Triple
Banding preparation
1. Separating plier
2. Band remover
3. Band pusher
4. Positioning gauge
5. Separation ring
6. Orthodontic molar band set
Bracket & wire
Welding: contacting metal surfaces are joined by the heat obtained from resistance to electric curr
ent
Soldering: Two metals are joined together by melting and putting a filler material (solder) into the
joint
Orthodontic wire
Cross-sectional shape: round, square, rectangular Gro
ss shape: straight, preformed, posted, loop, curved M
aterial: SS, TMA, NiTI
Ligation
1. Metal ligature
2. Elastomeric module (O-ring)
3. Self-ligation bracket
Bracket & wire
Leveling and Aligning
Flow of comprehensive orthodontic treatment
Leveling & alignment Space closure (key correction) finishing &retention
Checklist
1. Leveling
1) Intra-arch leveling phase 1: marginal ridge continuity of all the intra-arch teeth
2) Intra-arch leveling phase 2: vertically straightened continuity of teeth
3) Inter-arch leveling: upper and lower dental arch parallelism
2. Aligning
1) Intra-arch aligning: parabolic archform with smoothly connected contact points
2) Inter-arch aligning: arch coordination with optimal intermolar width difference
General principles
1. Size increasement
2. Stiffness increasement
Verification of leveling & alignment
: passive insertion of working wire into all the brackets
022 slot: 018X025 SS or 019X025 SS
018 slot: 016X022 SS or 017X025 SS
Archwire sequence
022 slot: 014 NiTi 016 NiTi 018 NiTi 018X025 NiTi 019X025 NiTi working wire
018 slot: 014 NiTi 016 NiTI 016X022 NiTI 017X025 NiTI working wire
Leveling and Aligning
Strategy
1. Aligning
1) Inter-arch: expansion
2) Intra-arch: align except severely displaced teeth anchorage reinforcement
*friction during aligning:
A: interproximal friction open coil, IPR, arch expansion, extraction
B: interocclusal friction: scissor bite & crossbite correction
2. Leveling
1) Intra-arch: selective leveling
2) Inter-arch: deep bite control
A: align upper dentition first
B: bracket height modification
C: bite raising: posterior bite turbo, anterior bite plate, stabilization splint
D: intrusion of anterior teeth: reverse curve of archwire, anterior TADs
Leveling and Aligning
Space closure
Extraction is determined according to following 2 factors
1. Upper incisor position at present
2. Crowding amount
Upper extraction strategy ; Decision Flow
1. Determine virtual upper incisor position & required space
2. Determine the method of space creation
3. Determine the method of anchorage
4. Determine the timing of extraction
How to get maximum anchorage
1) Increase the mass of posterior segment
2) Restrict the movement of posterior segment
3) Use other anchorage during space closure instead of posterior segment
Lower extraction strategy:
we should get molar Class 1 in lower dentition related to final upper molar position
Occlusal finish: Class 1 finish, Class 2 finish, Class 3 finish
Method of space closure: one step or two step closure
Retraction force control
1. Continuous force
2. Interrupted force
3. Intermittent force
Space closure
How to prevent vertical bowing of archwire during space closure?
1. Working wire
2. Posted archwire
3. Slight curvature
4. Light force (150~250g for en masse retraction, 70~100g for canine retraction)
5. Postpone space closure
Sliding mechanic
Loop mechanic: sectional loop , continuous loop
Space closure
Finish & Debond
The key to stability is Occlusion (Kingsley, 1880)
Cast-Radiograph evaluation guideline by ABO (2012)
1. Alignment : wire bending or bracket re-bonding
2. Marginal ridge: wire bending or bracket re-bonding
3. Buccolingual inclination: wire torquing
4. Overjet: expansion, archwire exchange, elastic
5. Interproximal contact
6. Occlusal relationship: screw-assisted distalization or protraction, elastic
7. Root angulation: wire bending or bracket re-bonding
8. Occlusal contacts: occlusal adjustment, settling (sectionalization)
Deband & Debond
Removal of residual resin (high speed diamond bur, tungsten carbide fissure bur)
Cause of relapse
1) Elasticity of periodontal fiber
2) Growth
3) Neuromuscular balance
Hybrid (Dual) retention: fixed retainer & removable retainer
Flow of debonding
1. LBR impression
2. Debond, LBR bonding, removable retainer impression
3. Removable retainer delivery
Finish & Debond