DANB COA cheat sheet

Angle classification is based on the mesiodistal relationship of the first molars: Class I has the mesiobuccal cusp of the maxillary first molar in the buccal groove of the mandibular first molar; Class II has it mesial to the groove; Class III has it distal to the groove.

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

Arch length discrepancy = arch length available minus the sum of mesiodistal tooth widths; a positive value indicates space excess, a negative value indicates crowding.

Leeway space is the difference in mesiodistal width between the primary canine and molars (C, D, E) and their permanent successors (canine, two premolars); it is larger in the mandible than the maxilla.

E-space (Lee way space plus the primary second molar width) is used to estimate arch length in the mixed dentition and to judge whether space maintenance or serial extraction is appropriate.

Incisor inclination is described by crown torque: labial (proclined) versus lingual (retroclined) crown movement. Root torque moves the root apex and is independent of the crown's labial-lingual position.

Anchorage is classified as maximum, moderate, or minimum; intraoral sources include teeth, palate, and cortical bone, while extraoral sources include headgear and facebow. Anchorage loss shows as mesial drift of posterior teeth.

Cephalometric landmarks include Sella (center of the sella turcica), Nasion (frontonasal suture), A-point (deepest point of the maxillary anterior alveolar curve), B-point (deepest point of the mandibular anterior alveolar curve), and Pogonion (most anterior point of the bony chin).

Common cephalometric angles: SNA (normal about 82°), SNB (about 80°), ANB (about 2°); ANB > 4° suggests a skeletal Class II tendency, ANB < 0° suggests Class III.

Dental age assessment uses tooth emergence and root development; mixed dentition typically spans ages 6-12, with the permanent first molars and incisors erupting first and the premolars and canines later.

Bonding protocol for brackets: isolate and dry, etch enamel 15-30 s, rinse thoroughly, dry to a frosty white appearance, apply primer, then place adhesive and bracket; avoid saliva contamination after etching.

Light-cure adhesives require the curing light tip to be held close to the bracket for the manufacturer's specified time (commonly 10-20 s per surface); a light-curing unit should be tested periodically for output.

Etch should be limited to the enamel surface; avoid etching near gingival margins or onto dentin, and protect the eyes of the patient and operator from phosphoric acid splash.

Band fitting requires trying the band, checking the fit at the contact points, and confirming that the band seats fully; separators (elastomeric or metal) are placed 1-2 days before banding to create space.

Archwire sequence typically progresses from a light round wire (e.g., 0.014 or 0.016 NiTi) for alignment to progressively stiffer wires for leveling and space closure; wire size and material are selected by the orthodontist.

Ligature placement: elastomeric ligatures are stretched over the bracket tie wings; wire ligatures are tied with a hemostat and tucked so the ends do not irritate the mucosa.

Removing brackets requires debonding pliers and careful force; residual adhesive is removed with a polishing bur or finishing bur, and enamel is polished to restore smoothness.

Impressions for study models or appliances use alginate mixed to a smooth consistency (typically in a 1:1 or manufacturer-specified ratio) and poured promptly; distortion increases if the impression dries out.

Retainer and appliance delivery includes checking fit, instructing the patient on insertion and removal, and documenting the instructions in the chart; retainers should be cleaned with a soft brush and cool water, not hot water.

Hand hygiene is the single most important infection control measure; use alcohol-based hand rub when hands are not visibly soiled and soap and water when soiled or after contact with body fluids.

Personal protective equipment includes gloves, masks, protective eyewear or face shields, and gowns; gloves are changed between patients and after any contamination, and hand hygiene follows glove removal.

Critical items (e.g., surgical instruments, scalers) must be sterilized; semicritical items (e.g., mouth mirrors, some impression trays) require sterilization or high-level disinfection; noncritical items require low-level disinfection.

Sterilization monitoring includes mechanical (temperature/pressure), chemical (indicator strips or autoclave tape), and biological (spore) indicators; biological indicators are the most reliable and should be run at the frequency required by the practice's policy.

Clean and disinfect surfaces between patients; use an EPA-registered hospital-grade disinfectant with the manufacturer's contact time, and cover items that are difficult to clean.

Sharps safety: never recap needles by hand; use the one-handed scoop method or a recapping device, and place sharps in a puncture-resistant container immediately after use.

The OSHA Bloodborne Pathogens Standard requires an exposure control plan, hepatitis B vaccination offered to at-risk employees, and post-exposure evaluation and follow-up after an exposure incident.

Radiographic safety: use the ALARA principle (as low as reasonably achievable), provide lead aprons and thyroid collars, and use the fastest film or digital sensors consistent with diagnostic quality.

Medical emergencies: know the location of the emergency kit and oxygen, and recognize signs of syncope, hypoglycemia, and anaphylaxis; syncope management includes positioning the patient supine with legs elevated.

The patient record is a legal document; entries should be accurate, dated, timed, and signed, with no blank lines and no alterations that obscure prior text.

Informed consent for orthodontic treatment should document the diagnosis, proposed treatment, alternatives, risks (e.g., root resorption, decalcification, relapse), and the patient's or guardian's signature.

Health history should capture systemic conditions relevant to orthodontics (e.g., diabetes, bleeding disorders, cardiac conditions requiring antibiotic prophylaxis per current guidance) and medications.

HIPAA protects individually identifiable health information; disclosures require authorization or a permitted exception, and the minimum necessary standard applies to uses and disclosures.

Records typically include diagnostic models, intraoral and extraoral photographs, radiographs (panoramic, cephalometric, periapical), and treatment notes; retention periods are set by state law and practice policy.

Recall and appointment scheduling should account for the typical 4-6 week adjustment interval; broken appliances and poor oral hygiene may require shorter intervals.

Communication with patients and parents should be documented, including instructions given, compliance discussions, and any refusal of recommended care.

Financial records, insurance claims, and treatment estimates should be kept separate from the clinical chart but remain part of the patient record system and be retained per applicable rules.