CCOAK cheat sheet

Angle Class I: mesiobuccal cusp of the maxillary first molar occludes in the buccal groove of the mandibular first molar; Class II: cusp mesial to the groove; Class III: cusp distal to the groove.

Overjet is horizontal distance from the labial incisal edge of the maxillary incisor to the labial surface of the mandibular incisor; normal is about 2 mm. Overbite is vertical overlap, normally 2-3 mm (about 20-30%).

Leeway space (difference between primary canine+molars and permanent canine+premolars) averages about 1.5 mm per side in the maxilla and 2.5 mm per side in the mandible.

Tooth movement types: tipping (single force, rotation about a center), translation/bodily movement (equal and opposite couple, center of rotation at infinity), torque (pure couple), and intrusion/extrusion.

Optimal continuous orthodontic force is roughly 50-150 g for most tooth movement; heavy forces exceed capillary pressure (~20-25 g/cm2), causing hyalinization and undermining resorption.

Center of resistance for a single-rooted tooth lies roughly at one-third to one-half of root length apical to the alveolar crest; for a multirooted molar it is near the furcation.

Anchorage classifications: maximum, moderate, minimum; reciprocal movement occurs when both units move equally; anchorage loss shows as mesial molar drift during anterior retraction.

Crowding is measured as arch length discrepancy (arch perimeter minus sum of tooth widths); a negative value indicates crowding, positive indicates spacing.

Cephalometric landmarks include Sella, Nasion, A-point, B-point, and the Frankfort horizontal; SNA, SNB, and ANB describe anteroposterior jaw relationships (ANB normal about 2-4 degrees).

Critical items (penetrate mucosa or contact bone, e.g., surgical burs, extraction forceps) require sterilization; semicritical items (contact intact mucosa, e.g., mirrors, impression trays) require sterilization or high-level disinfection; noncritical items require low-level disinfection.

Spaulding classification drives reprocessing decisions; orthodontic pliers and band-seating instruments that contact saliva and blood are treated as semicritical to critical and are steam sterilized between patients.

Standard autoclave cycle for wrapped instruments: 121 degrees C (250 degrees F) at 15 psi for 15-30 minutes, or 132 degrees C (270 degrees F) at 30 psi for 4-6 minutes; follow manufacturer instructions.

Biological monitoring (spore test with Geobacillus stearothermophilus) is performed at least weekly for steam sterilizers; positive results require recall of loads since the last negative test and equipment evaluation.

Chemical indicators (internal and external) verify exposure to sterilant parameters but do not prove sterility; only biological indicators confirm lethality.

Hand hygiene with alcohol-based rub or soap and water is required before and after glove use; gloves are single-use and not washed or disinfected for reuse.

Heat-sensitive items such as some elastomeric or plastic components are processed by chemical sterilants (e.g., glutaraldehyde) or ethylene oxide per manufacturer instructions.

Surface barriers (plastic wrap, bags) are used on handles, light handles, and control panels; barriers are removed and surfaces disinfected between patients with an EPA-registered hospital disinfectant.

Four-handed dentistry pairs an operator and an assistant working simultaneously; the assistant anticipates and delivers instruments into the operator's palm in the transfer zone near the patient's chin.

Transfer zone is the area over the patient's chest, below the chin, where instruments are exchanged; instruments are passed so the working end points toward the operator and the handle is presented first.

Palm-to-palm transfer: assistant places instrument handle into operator's palm while retrieving the used instrument with the other hand, minimizing finger movement and injury risk.

Instrument grasps: pen grasp for precision (explorer, scaler), palm-thumb grasp for force (extraction forceps), and modified pen grasp for hand instruments.

Ergonomic positioning: operator at 9-12 o'clock, assistant at 2-4 o'clock; patient's head positioned so the oral cavity is at the operator's elbow level to reduce fatigue.

Suction and retraction are coordinated with irrigation; high-volume evacuation is placed near the working area to control aerosol and moisture during bonding and banding.

Sharp instruments (explorers, scalers, wire cutters) are counted and accounted for; needles and blades are placed in sharps containers immediately after use.

Moisture control during bonding uses cheek retractors, cotton rolls, and saliva ejector; contamination of the etched field requires re-etching and re-isolation.

Enamel bonding sequence: clean/pumice, isolate, acid-etch with 35-37% phosphoric acid for 15-30 seconds, rinse and dry to a frosty white appearance, apply primer, then adhesive and bracket.

Bond strength depends on enamel etch pattern and moisture control; contamination with saliva or water after etching reduces bond strength and requires re-etching.

Light-cured adhesives require adequate light intensity (typically 400-1000 mW/cm2) and curing times per manufacturer; excess adhesive around the bracket base is removed before curing to reduce plaque retention.

Band cementation: bands are fitted, checked for fit, then cemented with glass ionomer or resin-modified glass ionomer; excess cement is cleaned before it sets.

Molar bands are selected by trial fitting; band should seat fully with contact points and not impinge on gingiva; separators may be placed 1-2 days before banding to create space.

Direct bonding places brackets directly on teeth; indirect bonding uses a transfer tray made from a model, improving accuracy and reducing chair time.

Bracket failure is more common on posterior teeth and with moisture contamination, high bond stress, or heavy occlusal forces; rebonding requires removal of residual adhesive and re-etching.

Fluoride-releasing materials (glass ionomer, compomer) may be used for band cementation and are useful in patients at high caries risk.

Archwire sequence typically progresses from light round nickel-titanium (NiTi) for alignment (e.g., 0.014, 0.016) to rectangular NiTi or stainless steel for space closure and finishing (e.g., 0.016x0.022, 0.019x0.025).

NiTi wires provide superelasticity and shape memory, delivering light continuous force over a wide range; stainless steel is stiffer and used for sliding mechanics and finishing.

Archwire sizes are given in inches (thousandths); a 0.016 NiTi round wire fits a 0.018 slot loosely, while a 0.016x0.022 rectangular wire fills a 0.018 slot in the second order.

Wire insertion: engage the archwire into the slot, secure with ligatures or self-ligating clips, and check for full engagement and patient comfort; cut distal ends with wire cutters and smooth with a polishing disc.

Archwire adjustments include bends (first order for in-out, second order for angulation, third order for torque) and use of a three-prong plier or torquing plier.

Excessive force from heavy archwires can cause root resorption, pain, and anchorage loss; lighter forces are preferred for initial alignment.

Archwire removal: use a ligature cutter or plier to remove elastomeric or wire ligatures; protect the airway and eyes, and use a gauze to catch small pieces.

Wire ends that irritate mucosa are managed with wax, bending the end, or trimming; distal ends should be checked at each visit.

Elastomeric ligatures (O-rings) secure archwires to brackets; they lose force over time (force decay) and are replaced at each adjustment visit.

Elastomeric chains and threads are used for space closure and rotation correction; they exhibit force decay of up to 50% within 24 hours and should be replaced or reactivated at intervals.

Separators (elastomeric or metal) are placed interproximally to create space for bands; they are typically placed 1-2 days before banding and removed before band cementation.

Headgear and elastics apply extraoral or intermaxillary forces; patient compliance is essential, and instructions include wear time (e.g., 12-14 hours/day) and replacement schedule.

Hooks, buttons, and cleats are auxiliary attachments used to engage elastics or chains; they must be checked for looseness and re-bonded if debonded.

Elastomeric materials are latex-containing in some products; latex allergy screening is required, and latex-free alternatives (silicone, non-latex elastomers) are available.

Auxiliary appliances include palatal expanders, lingual arches, and transpalatal arches; these require periodic activation and checking for tissue irritation.

Elastomeric force is affected by oral environment (temperature, saliva); patients should avoid excessive heat and sticky foods that dislodge appliances.

Orthodontic records include extraoral and intraoral photographs, radiographs (panoramic, cephalometric, periapical), study models or digital scans, and a medical/dental history.

Alginate impressions: mix powder and water per manufacturer ratio, load into tray, seat over teeth, and allow set (typically 1-2 minutes); pour with stone within a short time to avoid distortion.

Digital intraoral scanning captures 3D surface data; the scanner tip is moved systematically across the arch, and the scan is checked for completeness before export.

Cephalometric radiographs are used for skeletal and dental measurements; the patient is positioned with the Frankfort horizontal parallel to the floor and teeth in centric occlusion.

Panoramic radiographs show the entire dentition, jaws, and TMJ; they are used to assess eruption, impaction, and pathology.

Photographic records include frontal, profile, and intraoral views; consistent lighting and retraction improve comparability over time.

Informed consent for records and treatment is documented; records are stored securely and released per privacy regulations.

Digital models allow measurement of arch length discrepancy, Bolton analysis, and treatment simulation.

Oral hygiene with braces requires brushing after every meal, flossing with a floss threader or interdental brush, and using fluoride toothpaste; plaque retention increases caries and gingivitis risk.

White spot lesions (demineralization) appear as chalky white areas around brackets; prevention includes fluoride varnish, high-fluoride toothpaste, and dietary counseling.

Patients should avoid hard, sticky, and sugary foods that can dislodge appliances or increase caries risk; examples include ice, hard candy, and chewing gum with sugar.

Compliance with elastics and headgear is monitored by wear time and clinical response; missed wear leads to prolonged treatment and anchorage loss.

Patients are instructed to report loose brackets, broken wires, and irritation; temporary management includes orthodontic wax and soft diet.

Smoking and vaping increase periodontal risk and impair healing; cessation counseling is part of orthodontic care.

Regular recall visits (typically every 4-8 weeks) allow adjustment and monitoring of hygiene and appliance integrity.

Patient education includes explaining treatment goals, expected discomfort, and the importance of attending appointments.

Trauma with avulsed tooth: handle by crown, do not scrub, replant immediately if possible, or store in milk/saline and seek emergency dental care within 60 minutes.

Loose or debonded bracket: remove the bracket if it is a swallowing risk, or cover with wax; schedule repair; do not attempt to re-bond at home.

Broken archwire with a sharp end: cover with wax, bend the wire away from tissue with a plier if possible, or cut the wire; refer for repair.

Ingested or aspirated appliance: assess airway, refer for medical evaluation and radiograph; prevention includes checking appliance security and using floss ties.

Soft tissue irritation from appliances: apply orthodontic wax, rinse with warm salt water, and adjust the appliance at the next visit.

Anaphylaxis or allergic reaction to latex or materials: remove the offending material, assess airway, and follow emergency protocol (epinephrine if indicated).

Pain after adjustment is common and managed with analgesics (e.g., ibuprofen) and soft diet; severe or persistent pain requires evaluation for root resorption or infection.

Infection control during emergency repair includes gloves, barriers, and sterilization of instruments used.

Scope of practice: orthodontic assistants perform duties delegated by the supervising dentist according to state law; tasks such as diagnosis, treatment planning, and prescribing are reserved for licensed dentists.

Informed consent requires disclosure of risks, benefits, alternatives, and the right to refuse; documentation in the record is essential.

Patient confidentiality is protected by privacy laws (e.g., HIPAA in the US); records are shared only with consent or as required by law.

Professional ethics include honesty, competence, and avoiding conflicts of interest; assistants must not misrepresent credentials or qualifications.

Patient safety includes proper infection control, radiation safety (ALARA principle), and prevention of aspiration or ingestion of appliances.

Reporting obligations: suspected abuse, impaired colleagues, and adverse events are reported per legal and institutional requirements.

Continuing education and competency maintenance are required to remain current with materials and techniques.

Documentation should be accurate, timely, and objective; alterations to records must be clearly identified and dated.