Oral Path NBDE 2

I. Cysts of the Oral Cavity Soft tissue lesions, regardless of where it is in the body. Epithelium-lined (any kind of epi, most of the ones we'll be talking about are strat. Squamous)

walls, with a cavity filled with something. Two major categories of cysts in the head/neck: odontogenic cysts, and non-odontogenic cysts

I. Odontogenic Cysts Cysts associated with tooth development After tooth development, there is often residue of epithelium left over - which becomes the source

of epithelium for the cysts later on in the mouth. These remnants are epithelial rests of Malassez - which are little clumps of epithelial cells located

in the PDL (left over from root development - Hertwig's root sheath). I. Periapical Cysts (Apical Radicular Cyst)o How does a cyst come to be? Two requirements: epithelial rests, and inflammatory stimulus.

Start with a cluster of epithelial cells within connective tissue with a blood supply These cells are activated by inflammation from the apex of the tooth, stimulates these

cells to start dividing (the source of inflammatory stimulation can be trauma, tooth decay, infection, etc. - but most often, the stimulus is pulpal in nature)

The cluster of cells becomes larger, and as time goes by, the center cells become farther and farther away from the blood supply

The cells in the center become necrotic, and eventually you end up with a cavity with epithelial cells all along the perimeter, with "garbage" inside the cavity

o If those two main ingredients are not present, it is NOT a periapical cysto The cysts are soft tissue, round-ish, usually with lots of collagen on the periphery - resembles

a tennis ballo These can range in size from less than a centimeter to several centimeterso Definition: Radiolucency at the apex of a non-vital tooth (or any tooth with some kind of

pulpal infection that requires extraction or a root canal, with some type of abnormal response)

o These are always radioclucent!! (radiolucent: a relative term, describing an area of lower density in comparison to the surrounding areas)

o The above radiograph is NOT diagnostic of a periapical cyst, it is "consistent with" a periapical cyst - you can get a radiolucency that resembles this, without and type of pulpal pathology, so technically it would not be a periapical cyst

o The only way to definitively diagnose it as a periapical cyst is a histological examinationo Treatment: you have to curette out the socket once you extract the tootho Residual cyst = periapical cyst that has not been removed from the jawbone because the

clinician did not curette out the socket In order to have a residual cyst, you must have an extraction site Typically these cysts just sit there, radiographically they have a clearly delineated

border - which indicates that it's been stable for a while, and is benigno

II. Dentigerous Cysto The source of epithelium in this cyst is the reduced enamel epithelium on the dental follicle

surrounding a developing tootho This cyst is an accumulation of fluid between the dental follicle and the crown of the tootho Diagnostic criteria: radiolucency that surrounds the crown of an unerupted toothooo Microscopically, you see a lot of connective tissue and an epithelial liningo Most frequently seen on impacted 3rd molars, and maxillary caninesoo Can vary in size, but can have the potential to get relatively largeo If it expands enough, it can enlarge the jaw and cause facial asymmetry o These can be fairly easily treated when they are small (curettage), but as they grow they can

become more difficult to remove, and you may be forced to resect the mandible and do reconstruction

o If on a pano there is a cyst around an impacted 3rd molar that is overlying the root of a posterior molar, there may be some confusion as to whether the cyst is periapical or dentigerous - to determine which, do a vitality test on the molar.

o If you were to aspirate the cyst, you would suck out a straw-colored fluid - inflammatory exudate

This can be used as a diagnostic tool - if you were to aspirate a fluid that looked different that this, especially blood, the area is not a dentigerous cyst

And if this is a tumor, you wouldn't be able to aspirate anything

o Eruption Cysto When a tooth is erupting, and a portion of the crown already broken through the bone but

has not yet broken through the soft tissue - if a dentigerous cyst forms at this time is has the freedom to expand into the mouth, in the mucosa

oo First clue to an eruption cyst is that you will see something in the moutho Can be bluish if hemorrhage is presentoo Treatment: can incise the cyst to drain it, to allow eruption - but typically nothing is done,

just observe to make sure the tooth continues to erupt normallyo These will be tender when bitingo Radiographically, you will see an erupting tooth - most likely will not see the soft tissue area

o Lateral Periodontal Cysto Cyst that occurs at the lateral aspects of a tooth, in the PDL - not at the apexo Comes from the dental lamina, NOT the epithelial rests of Malassezoo Has nothing to do with the pulp, the teeth are vitaloo To treat, curette it outo Not related to periodontal disease

o Dental Lamina Cyst (commonly referred to as gingival cysts of the newborn)o Gingival cysts of the newborn are usually seen in the perinatal periodo Usually tiny, completely within the soft tissueo No radiographic abnormalitiesoo Usually no reason to remove, no ill effectso The cyst is filled with keratin, and that's what you see as the yellowish stuff insideo Yellowish-whitish dome-shaped elevation (sessile, elevated, broad-based, will feel slightly

compressible)o Can also be found in adults - still called gingival cystsoo Usually doesn't cause any problemso To diagnose these in an adult, you must first rule out anything tooth or periodontally related

- this is not going to be the first thing you think of when you see one of theseo In an adult, you may conservatively remove this, or it can be left if it is asymptomatic.o If these are left for a long time, there is a possibility that these might cause some bone

resorption of the cortical bone - "saucerization" - you may see a vague radiolucency

o Odontogenic Keratocysto This is a fairly aggressive cysto Fairly common as well, but statistically less likely than a dentigerous cysto Hard swelling of the alveolar ridge, sessile, elevatedo These may resemble a large lateral periodontal cyst on a radiographo There is nothing diagnostic on the radiograph that tells you that this is an odontogenic

keratocyst - it may just be a generic radiolucencyo These types of cysts have a greater growth potential, so if you were shown a radiograph and

had to choose between a dentigerous cyst or a keratocyst - if it's really large, it's more likely to be an odontogenic keratocyst ----- below

oo There is no clinical association of this cyst with any of the teeth - has nothing to do with them

(unlike denitgerous cysts)oo Often, the diagnosis cannot be made until you look at it microscopically - there are subtle

differences between the epithelium of the odontogenic keratocyst and other cysts - the epithelium is unique!

oo Once this is diagnosed, these people need to be followed closely - after removal, these have

a high rate of recurrence. SYNDROME ALERT: Nevoid Basal Cell Carcinoma Syndrome

Multiple basal cell carcinomas of the skins, possibly dozens on their face Several odontogenic keratocysts of the jaws

o Calcifying Odontogenic Cysto Mixed radiolucent/radiopaque lesiono Feels bony hard on palpation - may cause migration of some teetho No particular association with a tootho The lesion has the capacity to form a hard tissue

o These can be lucent or mixed, depending on when you see ito Refer for removal after you check the vitality of the teetho This is the only CYST that looks like thisoo The larger the lesion is, if it's still lucent, then it will probably always be lucent

o Non-odontogenic Cysts These come from epithelium that is NOT odontogenic (nothing to do with teeth) - has to do with

embryologic development, fusion of growth centers, residual epithelium Nasopalatine Duct Cysto The most common of these types of cystso Found in the nasopalatine canal

o Nasopalatine canal started out as a solid cord of epithelium, then as development progresses, it gets surrounded by bone and hollowed out.

o Development of a cyst from the epithelial remnants lining the canal, in the bony canal.o As the cyst grows, bone resorbs, so the anatomy of the canal changes - will appear as a

radiolucent defect between the central incisorsoo May possibly may be completely in soft tissue, but most likely occupies an area of boneo What does it feel like? It will be variable, may feel like bone or have some compressibility

depending on how much bone has absorbed. No matter what, it will feel firm, dense - not fluctuant.

o This is often asymptomatic - but because of the location and thin layer of mucosa between the cyst and oral cavity, it has a relatively high chance of infection - because the layer of soft tissue would be easily broken.

o If it got infected, it would become very symptomatic - perfect culture medium for growth of an infection.

oo It's possible to look at a PA of the centrals and the radiograph may look like a periapical cyst

of one of the incisors due to superimposition of the teeth over the canal - do a vitality test!o Typically the fullness is seen on the palate, but it is possible to also see fullness on the facialo Treatment is to remove surgically - when you look at it histologically, you can differentiate

between other cysts by the presence of large arteries and nerves in the cyst

Nasoalveolar Cysto Also often called nasolabial cyst

o Often, these are not hugely obvious - but if you were to palpate the area, you would feel a grape-like firmness under the skin. How obvious it is depends on the size, how long it's been there.

o This is not in the alveolar process - it is ENTIRELY in soft tissue - causes alar-labial fullnesso Remnant of the nasolacrimal duct - source of epitheliumo

o Treatment is to anucleate the cyst, from the oral cavity side, so you don't have to cut the skin - easiest way to remove is in one piece

oo These may be squamous epitehlium, or respiratory epithelium, or a combination of both

o Lymphoepithelial Cysto Arise because during embryologic development sometimes epithelial tissue gets

incorporated into the lymph nodes - and these epithelial rests can develop into cystso These are entirely soft tissue lesionso Two groups:

Oral lymphoepithelial cysts - they occur in a particular region = the ventral surface of the tongue, floor of the mouth, anterior region of the oral cavity

They tend to remain small, and they just sit there The texture of this is important - it will be compressible, you may feel rebound in

a larger cyst - it will NOT feel like a solid knot/piece of tissue/submucosal nodule - it is fluid filled

They may be yellow-ish due to straw colored fluid inside Histologically, the tissue will have lymphoid tissue in the wall of the cyst, as well

as the normal epithelium If it is asymptomatic and it's growth is arrested (not very large) - measure if with

your probe, check it out again in 6 months - if nothing has changed, leave it alone. If it's grown or has become symptomatic, remove it.

Either way, tell the patient about this! Lymphoepithelial cyst of the neck - occur in the lateral neck, and they usually in line

with and medial to the sternocleidomastoid muscle How does it feel? What are the symptoms? Is there any infection present? There has to be nothing else going on - the absence of important clinical

information is just as critical as the presence of clinical information Record that everything on the clinical exam is normal, the radiographs are

normal, record the texture of the area

This presentation could also be consistent with a hair follicle cyst, any cyst of skin origin - have to rule other things out

All you have to do is verify that it is NOT of dental origin - then refer it out These used to be called branchial cleft cysts

o Thyroglossal Duct Cysto It's in the neck, forms along the thyroglossal tracto The tract starts at the foramen cecum (where the thyroid gland begins development), then

descends down into the neck through an epithelium lined tract (the thyroglossal tract in embryologic development) - this tract disintegrates as you develop, but can leave remnants

o Found on the midlineo Texture of this is hugely important - should be compressibleoo When the patient sticks their tongue out, the cyst may have some upward movemento

o When these are removed, the whole neck is dissected and all remnant of this tract are removed to prevent recurrency

o Epidermal Cysto Can be seen ANYWHERE - in the mouth or on the skino Cyst that forms from squamous epithelium that has been left in the connective tissue, or

implanted into connective tissue via trauma, etc.o Has all the characteristics of a cyst - nothing else is unique to ito If these are located in or near the oral cavity, check the teeth first for signs of abscess, other

symptomatologyo Feel it, make sure it's compressible/fluctuant

o Dermoid Cysto Most common in the floor of the mouth - very characteristicoo Can have significant growth potential, if it gets large enough it can interfere with

eating/breathingo Will have a very similar appearance to a ranula in the floor of the moutho Epithelial lining and filled with skin adnexal structures such as hair, sweat glands, - so the

filling becomes thick/doughy/cheesyo When you feel this, it feels doughy - not fluctuant, more denseo Fairly uncommono This does NOT fluctuate in size, is usually NOT painful, and is dense, non-fluctuant (unlike a

ranula)o Can be tricky to remove because there are a lot of important anatomic structures in the area

o Aneurysmal Bone "Cyst"o Radiographically, it has a cystic appearance but is NOT a cysto Has nothing to do with blood vessels, so it's not an aneurysm eithero But it does have something to do with bloodoo Pathogenesis not known, the people that get these are usually youngo Multiloculated radiolucent lesion - multiple cavities, with thin bony septaoo When you see this, you should know it's most likely benign - has well-defined borders, slow

growth o A lot of things will have a very similar radiographic appearance - and these aren't always so

large, they've got to start somewhere. May appear as a small radiolucency.o When you treat these, you typically resect the area - degree of surgery is proportionate to

size of the lesionoo Think of a sponge - that's what these are like - collagen forms the sponge, and blood fills all

the spaces in the connective tissue matrixo Has nothing to do with blood vessels, is NOT endothelium linedo Not very common, but is significant because it has a high growth potential

o The potential for bleeding is significant - can't apply pressure to the wound to stop the bleeding - so oral surgeons will often aspirate large radiolucencies to get a better handle on what it is, so they'll be more prepared to treat it (i.e. removing it in the OR)

o Once it's removed, it behaves well

o Traumatic Bone Cavity ("Cyst")o NOT a cysto Also called "solitary bone cavity/defect"oo There was something that occurred that caused bleeding in the jaw, and as that bleeding

occurs, it caused resorption in the bone. The blood clot that forms will normally act as scaffolding for new bone formation, but sometimes the clot just breaks down ---> an empty hole in the bone. Not lined with anything, not filled with exudate.

o Usually in younger people, usually in the posterior mandible, always radiolucent, generally they are asymptomatic, usually found when they're getting a pano for some other reason (accidentally on a routine radiograph).

o Usually have cavitation of bone with little or no expansiono Typically does not cause tooth migrationo Diagnosed when the oral surgeon goes into it to remove the tissue, and all they find is an

open cavity in the bone - diagnosis is based on the fact that there's nothing inside ito Typically not treated

o Lingual Mandibular Salivary Gland Defect (Stafne Bone "cyst")oo During development a portion of the submandibular gland became incorporated into the

lingual inferior border (below the mandibular canal) of the mandible - get a discrete, well-defined radiolucency

o If you see this on the pano, get a good PA! You will see a very clear intact PDL and lamina dura - eliminates the possibility of a periapical cyst. (Still, first thing you would do is pulp test the teeth if you can)

o Osteoporotic Bone Marrow Defectoo May resemble a residual cysto Just areas filled with bone marrowoo Sometimes these create diagnostic problems, treatment problems

o Inflammation Disorders

1. Pulpitis Inflammation of the pulp Can be chronic or acute

o Acute will have more severe paino Pathologically, you get a lot of exudate with acute inflammationo In a chronic process, it's lower grade, so you have less symptomatology

Different than most types of inflammation because it is incased within hard structure, so the outcomes are different

Can get to a non-viable situation very quickly because the inflammation has no place to go, and constricts the contents of the pulp

Causes: trauma, of any variety - baseball to the face, large restoration, deep carious lesion What is the one question that you really need to answer? Is it reversible or irreversible? Need to make that assessment, decide if it's salvageable - have to assess the degree of

inflammation. Will see nothing abnormal on the radiograph - there's not been enough time to resorb the bone

around the tooth If it's acute (reversible), it's usually a small insult - high restoration, minor trauma What would you be doing chairside?

o Endo ice - length of the response, and intensity, and how long it takes to get a response - all can tell you whether it's reversible or irreversible

o If the pain doesn't linger, it's most likely reversibleo Most of the time, it's going to be irreversible, and will have an obvious causeo Does the pain wake the patient up at night? Spontaneous pain? Indications of irreversible

pulpitis. In inflamed pulp is still viable If the pulpitis persists, when pressure builds up enough in the pulp, it can cause the pulp to

become necrotic Symptomatology may be all over the board - depending on degree of inflammation, age of the

patient, health of the patient, etc

2. Periapical Granuloma Most common periapical pathology Generic inflammation at the periapical region of a tooth of a sick or nonvital tooth - NOT a cyst Type of inflammation and contents of the granuloma can be variable - no one, particular histologic

appearance Will see a radiolucency at the apex of the tooth on a radiograph This is NOT granulomatous inflammation (like TB) If you were to dissect a periapical granuloma, it would be solid - just a mass of fibrous connective

tissue - that was once granulation tissue Will continue to proliferate because the presence of necrotic tissue continues to stimulate the

inflammatory response Symptomatology depends on the degree of inflammation - sensitive to percussion, no response

from the pulp When you have drainage, you have an abscess - will also affect the symptomatology Treatment options are the same as a periapical cyst "Radicular cyst" is the same thing

Periapical Scar Sometimes the way the bone fills in around the tooth is not completely sufficient The periapical area will still look slightly radiolucent If that's still there, how do you know that the RCT was successful?

o Examine all other features - absence of symptoms

o Percussion tests, no paino Not all root canals are successful

Periapical Abscess (Dento-Alveolar Abscess)(Parulis) Pus formation that builds up under pressure in the bone, and will go the route of least resistance -

and drain somewhere But you will NOT always see drainage - but there will be pus somewhere! This can be really bad for a patient - pain can be very severe due to the pressure ---------^ This is caused by fluid under pressure, coming from the bone to beneath the periosteum -

not draining yet Sometimes these are very hard to detect When these abscesses break open and drain, these typically become asymptomatic - no pain The clinical term for where the drainage comes from is a sinus tract - NOT a fistula! The radiographs might look perfectly normal - there may not have been sufficient time for the

bone to resorb - radiographs are irrelevant to the diagnosis of a periapical abscesso BUT - you can have a chronic lesion that becomes secondarily infected, so you will see a

periapical radiolucency, as well as pus production - called a "phoenix abscess" because it rises from a preexisting periapical lesion

The only way you definitively diagnose is to actually see the presence of pus, or the presence of a draining sinus tract

Treatment is RCT If not treated, what could happen?

o Sinus tract may close ---> build up of inflammatory exudate at the apex, so biting would be painful

o Severity of the inflammation can become more significant ---> symptoms When you have fairly intense inflammatory problems, it is a bone-destructive process - but, when you get further away from the epicenter of inflammation (or you have a chronic low-grade inflammatory process), you can get bone formation - can stimulate osteoblasts to form more bone

Osteomyelitis Osteitis - more localized, low-grade, confined Osteomyelitis - implies something much more significant than osteitis - much larger, more intense

bone-destructive/formative process Irregular area of radiolucency, not well-defined, not a discrete lesion - malignant bone lesions can

present in a similar way (so it's NOT diagnostic to see it on the xray - just consistent with) Nothing to hold this together as a mass, just fluid under pressure These patients typically have some symptoms - they're all over the board Does not have to come from pre-existing bad teeth - the source of the infection/inflammation can

come from anywhere What are the implications?

o Always significant - even in healthy peopleo Treated very aggressively, sometimes use hyperbaric oxygen chamberso In older people, with significant medical histories - may take long-term IV antibioticso In some instances, it is not curable

o Typically in the mandible, because it is not as well vascularized as the maxilla - and as the process continues, the vascularity becomes even more compromised

o Sometimes surgery is indicatedo There is no golden rule when is comes to prescribing systemic antibiotics - one good

indicator is if the patient has a fevero You can have areas of bone that become completely surrounded by exudate - cut off from

any vascular supply - so the bone then becomes necrotic, which perpetuates the inflammatory response

oo Sometimes the necrotic bone comes through the mucosa o Sequestrum = piece of non-vital bone that becomes separated from the rest of the viable

bone - sometimes requires surgery to remove this - or else the wound will never heal If on the radiograph the lesion is a mixed lesion, or more radiopaque - then it is termed a sclerosing

osteomyelitis - bone deposition and destruction are occurring at the same timeo Typically occurs when the osteomyelitis is chronic, more low-grade

Osteoradionecrosis Occurs in bone following radiation therapy Presentation is exactly the same as osteomyelitis Radiation therapy decreases vascularity of bone, which increases the vulnerability of the bone to

develop these types of infections Treatment can be just as difficult, if not more so because of the reduced vascularity

Condensing Osteitis Nothing more than bone that is very dense in a localized area Has nothing to do with the tooth, can clearly see the PDL So why did it happen?

o Theoretically, there was some very low-grade inflammatory process that stimulated bone formation

o The source of the problem is often not obvious Diagnostic criteria:

o Discrete, well-defined, uniform opacification o No symptoms, shouldn't be hearing that there's anything else wrong

Sometimes also called "bone scars"

Osteomyelitis with Proliferative Periostitis (Garre's osteomyelitis) In children Causes proliferation of the periosteum surrounding bone Bone enlargement Variation of osteomyelitis unique to children, and the perisoteal tissues surrounding bone becomes

involved in the inflammation, and lays down successive layers of bone over time which leads to jaw enlargement

Symptomatology is usually low Presentation can mimic aplasia/tumor May resemble "onion skin" on the radiograph - layers of bone formation

Get rid of the source of the infection, and over time, it tends to remodel itself<-------- Residual Cyst