week nine/ten - occlusal radiography, perio dx Flashcards
list the two types of occlusal radiography and their indications
- upper/lower standard 90 degree occlusal
- PA area eval of ant. teeth in pt who can’t tolerate PA film holder/technique
- eval of size/extent of lesions eg cysts, tumours in ant region
- assessment of fractures of ant teeth and alveolar bone due to easier film
- detection of presence of position of radiopaque calculi in submand salivary glands - upper/lower oblique 45 degree occlusal
- PA assessment of teeth, esp in pts unable to tolerate PA film holders
- eval of size/extent of cysts, tumours
- assessment of displaced fractures
describe PAs and indications
- usually shows 2-4 teeth including root structure and surrounding alveolar bone
indications
- detection of apical infection and inflammation
- assessment of periodontal status
- presence, absence or position of unerupted tooth
- assessment of root morpho
- apical cysts
- post op evaluation of implant
- post-trauma to teeth and assoc alveolar bone
describe the PA ideal positioning requirements and the paralleling technique + adv/disadv
- tooth and film parallel, film positioned w long axis of tooth = vert for ant.teeth, horz for post.teeth
- 2mm beyond apices should be visible
- dot to occlusal/incisal aspect of tooth
- xray cone positioned so beam meets film at right angles to vert/horz plane
paralleling technique
- always use when possible
- film parallel to tooth long axis
adv
- v low chance of cone cut
- bone lvl well represented
- PA tx shown accurately
disadv
- film positioning can be uncomfortable - may cause gagging
- may be difficult for inexperienced operator
- mouth anatomy sometimes makes technique impossible [shallow palate]
describe the clinical and histological presentation of the peridontium in health
clinical
- pink, resilient consistency gingiva
- scalloped gingival margins
- knife-edged interdental papilla
- no bleeding/ < 10%
- sulcus = 1-3mm probing depth
histological
- JE attached at CEJ
- gingival fibres = intact
- alveolar bone = intact - 1-3mm apical to CEJ
- PDL = intact
- cementum = intact
describe the bisecting PA technique + adv/disadv
same indications as PA paralleling technique
+ indicated for low palatal height
technique
- film placed as close to tooth w/o bending
- xray tube positioned at right angle to bisecting line
adv
- positioning of film = reasonably comfortable, simple, quick
disadv
- many variables = high chance of image distortion
- incorrect angulation - foreshortening/elongation [vert angulation] or horz teeth overlapped [horz angulation]
- not reproducible
- may cone cut
outline how gingival health on reduced periodontium is characterised
gingival health
- < 10% bleeding sites w 3mm or less probing depth
- clinical gingival health can be found on both an intact/reduced periodontium
reduced periodontium
- absence of BOP, erythema, edema, pt symptoms in presence of reduced clinical attachment and bone levels
stable periodontitis pt
- successful tx = control of local/systemic risk factors, minimal [< 10% BOP], no probing depth > 4mm that BOP, improvement in other clinical areas and lack of progressive perio destruction
- successfully treated and stable perio pts = remains at higher risk of recurrent progression of periodontitis, compared to gingivitis or healthy pt = require ongoing managment and risk assessment
non-periodontitis pt
- recession/crown lengthening
describe the clinical and histological presentations of gingivitis
inflammation of periodontium confined to gingiva
reversible damages
clinical
- red, reddish-blue
- swollen gingival margin
- bulbous, erythematous, edematous gingiva
- bleeding
- probing depths 1-3mm but can be more due to pseudopocketing
histological
- JE attached at CEJ, some coronal attachment may be present
- gingival fibres can be damaged but reversible
- alveolar bone, PDL, cementum = intact
describe dental biofilm induced gingivitis which is assoc w dental biofilm alone
- inflammation consistent w amt plaque present
- 10% or more bleeding sites w probing depths 3mm or less
- localised gingivitis = 10-30% bleeding sites
- generalised gingivitis = > 30% bleeding sites
- no other local or systemic factors present that could modify host response
describe dental biofilm induced gingivitis which is mediated by local/systemic factors
local/systemic factors predispose pt to plaque accumulation and induces gingivitis as result
local risk factors = encourage plaque accumulation
- overhangs
- crowding
- appliances
- hyposalivation = reduced cleansing/biofilm removal
systemic factors incl
- smoking
- nutrition
- metabolic factors
- pharmacological
- elevation in sex steroid hormone
- haematological conditions
describe dental biofilm induced gingivitis assoc w drug-induced gingival enlargement
plaque bacteria in conjunction w any of below
anti-epileptic drugs : phenytoin
immunoregulating drugs : cyclosprine
Ca channel blockers
high dose oral contraceptives
usually occurs during first 3 mths of use, in younger age groups and observed in anterior region first
describe non dental biofilm induced gingivitis
- less common than plaque induced
- not directly caused by plaque but can be exacerbated by presence of plaque and gingival inflammation
eg
- fungal infections
- allergic reactions
- vitamin C deficiencies
- tooth brushing trauma
describe FOUR types of errors in radiography
- technique
pt prep
- radiopaque object superimposition eg jewellry not removed
blurred image
- cone/pt movement during exposure
film placement
- incorrect vert dimensions - foreshorted/elongated
- beam centering error - cone cutting
- exposure
double exposure
film orientation
density errors
- phosphor plate under/over exposed = impacts the image’s degree of darkness
exposure to light
- processing
- film handling
describe the ICCMS radiography classifications
International Caries Classification and Management System [ICCMS]
RA = initial stages
RA1 = radiolucency in outer 1/2 enamel
RA2 = radiolucency in inner 1/2 enamel ~ DEJ
RA3 = radiolucency limited to outer 1/3 dentin
RB = moderate stage
RB4 = radiolucency reaching middle 1/3 dentin
RC = extensive stage
RC5 = radiolucency reaching inner 1/3 dentin, clinically cavitated
RC6 = radiolucency into pulp, clinically cavitated
