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Orthodon(c Treatment
Problems • Posterior crossbite
– Dental – Skeletal (Class III)
• Anterior crossbite – Dental – Skeletal (Class III)
• Excess overjet – Dental – Skeletal (Class II)
• Anterior open bite – Dental (simple) – Skeletal (complex)
• Deep overbite – Dental – Skeletal (Class II)
Crossbite
• Teeth overlap improperly – AP for anterior – Transverse for posterior
• Anterior, Posterior, Skeletal, Dental
Anterior Dental Crossbite
• Incisor crowding causing maxillary incisors to erupt palatally
• Pseudo Class III malocclusion • Tooth wear, perio • Tx: (p maxillary incisors labially
Removable Appliance
• Adams clasps= reten(on • Acrylic base • Spring= labial (pping • Labial bow= stop (?) • Bite plane/plate= separa(on
Paperclip
Finger Spring (Single Can(lever)
• Ac(ve arm • Helix (3mm) • Reten(ve arm • 2-‐3mm of ac(va(on • 1mm/month
Finger Spring
• Helix should be opposite to direc(on of intended tooth movement
• Usually MD
Z-‐Spring (Double Can(lever)
• Second beam with a second helix
• 2mm of ac(va(on per helix
• Usually FL
Fixed Lingual Arch
• Whip spring – 15mm long – 1mm/month
• Tip incisors labially
Fixed 2x4 Appliance
• 2 molars banded • 4 incisors bonded
Hawley Retainer
• Best reten(on following correc(on of a crossbite
Anterior Skeletal Crossbite
• Basically Class III
Reverse Pull Headgear
• Age 7 or 8 before skull fissures fuse • For maxillary deficiency
Chin Cup
• For mandibular excess • Not used anymore
Class III Elas(cs
• Age 11, TADs with mature bone • Fixed edgewise appliance
Posterior Crossbite
• “Rule of thumb” – Dental= normal palate, lingual (pping – Skeletal= narrow palate, Class III
• Thumb-‐sucking habit – Maxillary constric(on from buccinator – Unilateral posterior CB due to func(onal shi` – Tooth wear, dental compensa(on, crowding
Posterior Dental Crossbite
• Palatal (pping of maxillary teeth • Tx: expansion lingual arches (slow expansion) for primary and early mixed
W-‐arch
• 36 mil (.036”) SS • Age 8 to 11, midpalatal suture open
• 2mm/month (1mm per side)
• Suture opening
Quad Helix
• 38 mil (0.038”) SS • 4 helices—befer range of ac(on
• 2-‐3 months of tx • 3 months of reten(on
Cross-‐Elas(cs
• For unilateral or individual teeth
• Mandibular lingual arch to stabilize lowers
• Extrusion (bad for open bite) • 150-‐170g
B L
Posterior Skeletal Crossbite
• Narrow palatal vault • Tx: – expansion lingual arch (slow) for primary and early mixed
– palatal expansion (rapid or slow) for late mixed
• Needs to be completed prior to end of growth spurt
Palatal Expander • Turn jackscrew • Rapid
– 0.5mm ac(va(on and expansion/day
– 10-‐20lb pressure – Microfractures in interdigitated bone spicules
• Slow – 1mm/week – 2lb pressure – Suture intact, same long-‐term results with less trauma
Palatal Expansion
• Preadolescents à quad helix or W arch • Adolescents à rapid or slow palatal expander • Tends to extrude posterior teeth and cause anterior open bite
Excess Overjet
• Class II Elas(cs • Tip back maxillary incisors with removable
Anterior Open Bite
• Simple= dental • Complex= skeletal
Simple Anterior Open Bite
• Prolonged thumbsucking habit – Flaring maxillary incisors, lingual (pping mandibular incisors (overjet)
– Maxillary constric(on (posterior crossbite) – Overerup(on of posterior teeth – Open bite
• Tx: – Primary à no treatment – Mixed à thumbsucking therapy
Anterior Crib
• “Helping hand” • Age 6 or 7, most changes will resolve spontaneously
Complex Anterior Open Bite • Long face • Ver(cal discrepancy in adolescents and adults
• Features: – Posterior maxilla (ps down – Downward and backward rota(on of mandible
– Steep MPA – Excessive erup(on of posterior teeth
• Tx: growth modifica(on, jaw surgery
High Pull Headgear • Maintain ver(cal posi(on of maxilla • Intrude upper molars and close bite • Force vector through trifurca(on • Afached to maxillary splint for all maxillary teeth
TOUGH TO TREAT
Bite Blocks • Blocks erup(on of posterior teeth • Allows erup(on of anterior teeth • Usually combined with func(onal appliance
Deep Bite
• Dental • Skeletal
Dental Deep Bite
• Overerup(on of mandibular incisors • Class II malocclusion • Tx: intrude anteriors, allow erup(on of posteriors
Skeletal Deep Bite
• Short face • Features:
– Long mandibular ramus – Upward and forward rota(on of mandible
– Low MPA – Class II Division 2 – Decreased erup(on of posterior teeth
• Tx: growth modifica(on
Cervical/Low Pull Headgear
• Extrude upper molars and open bite
REASONABLE TO TREAT
Deep Bite Func(onal Appliance
• Only allows mandibular posterior teeth to erupt • Levels an excessive Curve of Spee