Transcript Orthodontia

DH220 Dental Materials
Lecture #13
Prof. Lamanna RDH, MS
Orthodontia
Orthodontia
Definition: the specialty in dentistry concerned
with the supervision, guidance and correction
of all forms of the growing or mature dentofacial
structures.
Responsibilities of the Orthodontist:
Diagnosis, prevention, interception and treatment
of all forms of malocclusion of the teeth and
surrounding structures.
Benefits ---- which become the indicators for ortho treatment
1. Psycho-social function - self-esteem.
2. Oral function – chewing, swallowing, speech, TMD
3. Dental disease – malocclusion can contribute to decay, perio disease,
inadequate OH
Contraindications:
1. Lack of bony support
2. Rampant caries
3. Poor general health/mental health
4. Poor OH
5. Lack of interest, lack of cooperation
6. Lack of financial means
Wilkins –
chpt 16
Angle’s Classification
• Class I
• Class II
Div. 1
• Class II
Div. 2
• Class III
Most common Ortho problems
• Crowded malaligned teeth
• Overjet
• Overbite
• Open bite
Causes:
• Developmental: congenitally missing teeth, malformed teeth,
supernumery teeth, interference with eruption (i.e. impaction), ectopic
eruption (located away from normal position)
• Genetic: Discrepancies in size of jaw and size of teeth –
inherit small jaw from one parent and large teeth from another.
• Environmental:
a. Birth injuries
b.
▪ Fetal molding – limb of fetus presses against another part of
body. Ex: arm is abnormally pressed against mandible,
pressure distorts growing areas.
▪ Trauma during birth – usually due to forceps in delivery
Injuries throughout life
▪ Trauma to 1° teeth/premature loss of 1° teeth
▪ Direct injury to permanent teeth
• Functional:
Sucking habits: thumb, tongue, lip, finger;
abnormal tongue posture/activity (tongue thrust)
3 Phases:
1.
Preventive – recognition and elimination of irregularities
and malposition in developing dentofacial complex
•
•
Caries control – avoidance of premature loss of 1° teeth
resulting in loss of space for permanent tooth
Use of space maintainers – saves space for permanent tooth
•
Correction of oral habits
•
Early detection of congenital anomalies
2. Interceptive - steps taken to prevent or intercede as
they are developing
▪ Removal of 1° teeth that may be interfering with
eruption/proper alignment of permanent teeth.
▪ Serial extraction of teeth – critical overcrowding of
teeth – referred to DDS or oral surgeon.
3. Corrective
▪ Removable appliances
▪ Fixed appliances (cemented into place – not removable by pt)
▪ Orthognathic surgery – for severe cases
Mechanism of action
of orthodontic appliances:
How does it begin? Diagnostic Records
• Study Models
• Photographs – extra/intraoral – front and side (profile) views
• Radiographs –
a. Panoramic films: broad view – pathology
– impaction – supernumery teeth
* b. Cephalometric films: evaluate
dentofacial proportions and clarify
anatomic basis for malocclusion
Types of Appliances
• Removable - primarily used as retainers or in “tipping teeth”.
Originally, not used for major tooth movement. Currently, more tooth
movement can be accomplished with tray aligners.
– Retainers
- Invisalign
• Fixed Appliances
“Braces” attach to teeth and assist in tooth
movement
- Can be in (6) six directions: M, D, L, F,
apically or occlusally
- Can also be rotated on its axis (left or rt)
®
Applied force points
MTM® Clear•Aligner
• Before attachments are places, soft brass wire
separator or elastomeric ring separators are used
to open tight interproximal contacts so the bands
can be properly seated.
- Brass 5 -7 days, elastomeric leave up to 2 wks.
Components of fixed appliances:
• Attachments – bands, brackets
• Auxillaries – head gear tubes, elastic hooks
• Arch wire – align dentition
• Ligatures – wire, elastomeric ties
Review of components:
E.
Headgear
An orthopedic device used to control growth & tooth
movement. Two parts:
1. Facebow - used to stabilize or move maxillary
1st molars distally and create more room in the arch.
2. Traction Devices - applies external force
used to achieve desired treatment results.
* Review ortho diagrams in Dental Materials Lab workbook
Oral Hygiene and Dietary concerns
• Tooth Brushing: Charters method (45° at ging margin towards occ/inc
surfaces). Use interproximal brush to clean under arch wire. Multiple
styles available that are more conducive to ortho.
• Flossing: Use bridge threaders
• Fluoride Rinses: Daily
• Rinse with water frequently and thoroughly to remove food particles.
• Avoid hard foods, sticky foods - avoidance of band breakage or bending
of archwires
4 more slides
to go!!
• Removal of bands/brackets
- goal: removal of bands/brackets & residual cement
with minimal damage to the tooth surface.
• Bands: Breaking seal of cement and lifting band off.
• Brackets: Creating a fracture within the cement.
- post debonding: fluoride tx, √ for perio, dental caries
Debonding – read: Wilkins chpt 28
Retention Phase
– Control of tooth position and occlusal relationship.
1. Ortho positioner
3. Lingual retainer
2. Hawley retainer
Specialized appliances:
• Palatal expander – 2 styles:
- correction of crossbite and expands the maxilla
N.Y.S. Statutory Duties for RDH – July 10, 2003
Under the personal supervision of DDS regarding ortho:
• Take impression for space maintainers, orthodontic
appliances, and occlusal guards
• Place and remove temporary separating devices
• Place and remove orthodontic ligatures
• Prefit and place orthodontic bands
• Remove orthodontic arch wires
New York State licensed dental hygienists must be able to perform these new
supportive services and all other professional duties competently. Additional
education and training may be required to competently provide these services.
A dental hygienist attempting to perform these functions without training may be
held liable to discipline. “Performing professional responsibilities” which the
licensee knows or has reason to know that he/she is not competent to perform”
is unprofessional conduct, according to Section 29.1 of the Rules of the Board
of Regents.
Any Questions?