Cysts of the Orofacial Region

Today we will talk about the surgical considerations in the management of jaw cysts. As you know the oral and maxillofacial cysts are divided into bone cysts and soft tissue cysts, the scope of this lecture will be about bone cysts.Now, what is the definition of a cyst? As you know we have compact bone and inside we have spongy bone so normally we dont have any cavities in the bone, but if we have a pathologic cavity which is normally not present that contains fluid or semi-fluid material or gas with epithelial lining (epithelial walling the covers the cavity) the this is called a cyst (a true/typical cyst). We have other variables of cysts like the pseudocyst which is a pathologic cavity in the bone that doesnt have epithelial lining. Im concentrating on the epithelial lining because in order to treat any cyst we have to remove the epithelial lining.

Key Features of Cysts Form sharply defined radiolucency with smooth borders Grow slowly, displacing rather than resorbing teeth If we saw on an OPG any resorbtion of teeth then we should suspect that its not a cyst, it might be an odontogenic tumor or something else) Asymptomatic unless infected Usually cysts are asymptomatic; we discover them when we take routine x-rays for a certain reason, we find the radiolucency and we start to investigate then we find that its a cyst. So infections are not associated to cysts, some people think that if they have a cyst then there is some sort of infection, but no, the presence of cysts doesnt mean the presence of an infection. But if the cyst was infected then well have pain, other than that people with uninfected cysts dont experience pain. Rarely large enough to cause pathological fractures A pathological fracture is a fracture that happens due to a minor trauma that usually doesnt cause fracture but because of the presence of pathology whether its a cyst or a tumor that has caused resorbtion of the bone which facilitated fracture.

Signs & Symptoms of Cysts None (most common presentation) Swelling Intraoral discharge (either due to the content of the cysts which is fluid or semi-fluid material, or sometimes due to an infection inside the fluid so it will drain puss) Pain ( which is unusual unless its infected) Difficulties with dentures (because there will be swelling so the denture will not be easily fitted) Movement or tilting of adjacent teeth (because it will not resorb, it will displace the teeth) Missing teeth (sometimes it obstructs the path of eruption of teeth) Lower lip anesthesia which is rare ( usually it doesnt happen due to a cyst unless its infected, sometimes because of an infection of a cyst in the lower jaw, lower lip anesthesia happens which is reversible after the resolution of the infection. But if lower lip anesthesia was present with a lesion in the mandible I have to think of 4 things, osteomyelitis., Ameloblastoma and sometimes Mets and maybe an infection of a cyst, but usually cysts dont cause lower lip anesthesia. You have to know that lower lip anesthesia is an alarming sign for any oral surgeon.*Note: Metastasis (Mets): is the spread of cancer from one organ or part to another non-adjacent organ or part. Pathological fracture (as we mentioned earlier)

Diagnosis History and examination: *inspection *palpation *percussion *auscultation -Of course we start but taking history and examination, inspection for any asymmetry, palpation because I have to feel if there is any swelling, percussion for teeth and this is very important because we have to check the vitality of teeth because it guides us towards a proper diagnosis, and finally auscultation which is the use of the stethoscope and this is very important as well in the radiolucent lesions in the mandible because some vascular lesions and hemangiomas may present as radiolucencies in the jaw so by listening to the bruit that may be caused by those vascular lesions I can exclude that this is a vascular lesion or not. There is another method other than the auscultation which is Aspiration which we will talk about shortly.*note: Abruitis an audible vascular sound associated with turbulent blood flow, usually heard with the stethoscope, also such sounds may occasionally be palpated as a thrill.

Vitality test of the teeth -As we said this is important because radicular cysts for example are associated with non-vital teeth, so this will help in the diagnosis and treatment plan. Aspiration Imaging Biopsy

Aspiration & Biopsy-Aspiration is actually considered as a type of Biopsy, what we do is we use a wide bow needle number 18 and we enter the cystic cavity and you see in the picture then we aspirate. For safety issues and this is very important, we have to exclude any vascular lesion or hemangiomas, imagine that this was a vascular lesion and we have opened into this cavity to do a biopsy or whatever, there will be massive bleeding and we wont be able to control it. Another thing is that the aspiration will help us in the diagnosis, how? If the aspirated material was: Straw-colored fluid (like apple juice) and crystalinflammatory cyst radicular cyst or dentigerous cyst Thick creamy fluidkeratocyst Blood hemorrhagic -Small amount (not a vascular lesion) this is because of the puncture of the needle itself, or a very small vessel. -Syringe filled with blood: indication for a vascular lesion. Airmaxillary sinus (in upper jaw), traumatic cyst (usually filled with gas) Nothing

So as we said we first have to exclude any vascular lesion and then from the color or nature of the aspirated material itself I can determine the type of cyst present, in addition to that, I can also send the aspirated material to the chemistry lab and from the level of the protein inside this aspirate we can know what type of cyst is present so it will help in the diagnosis. Soluble protein (albumins and globulins) determination of the aspirate (electrophoresis) 5-10g/dl: inflammatory cyst radicular (range of serum soluble protein) 7 mm heart shaped radiolucency between the maxillary centrals Soft swelling behind the upper anterior teeth Enucleation + curettage

**not any radiolucency between the two maxillary central incisors is a nasopalatine duct cyst, because theres a normal structure that exists between the two centrals which is the incisive foramen also called nasopalatine or anterior palatine foramen, it lies in the midline of the palate behind the central incisors at the junction of the median palatine and incisive sutures.

We mentioned that we have a true cyst which is with an epithelial lining, and we have a pseudocyst which is without any epithelial lining, and It includes 3 cysts: traumatic solitary, simple, aneurysmal and stafnes bony cavity and well talk about each one.

7- TRAUMATIC BONE /SOLITARY/SIMPLE CYST

Pseudocyst Post mandible (premolar and molar) Well defined radiolucency with scalloped borders (for example a 25 year old male comes to the clinic with a history of trauma, he takes an x-ray and there appears to be radiolucency inside the bone which doesnt resorb, so its like a soft tissue mass inside the bone which is scalloped its alongside the roots Biopsy is curative (when we enter the cyst and do a biopsy we will induce bleeding, and then healing and replacement by bone, of course you have to follow up the patient as well).

8-Aneurysmal Bone CystRemember when we talked about the keratocyst we said that it goes through anterioposterior growth, but the aneurysmal is the opposite, it goes through buccal expansion and makes balloons severe expansion, so its an expansile lesion. Pseudocyst Posterior mandible (body and angle) Well circumscribed soap bubble type lesion Expansile with ballooning -this is associated with another type of category, meaning that even if its categorized between cysts as a pseudocyst, it also follows another category which is giant cell lesions, ((which include : aneurysmal bone cyst, central giant cell granuloma, giant cell tumor, brown tumor of Hyperparathyroidism, cherubism)) so if we send it to the histopathology lab it will appear to have giant cells, this is important in the management of the cyst, because theres one of the giant cell lesions which is the brown tumor of hyperparathyroidism and its the only one that doesnt need surgical treatment , even if there appears to be radiolucency in the x-ray but the problems lies in the parathyroid so if we correct the problem in the parathyroid, the lesion will heal spontaneously.

Enucleation and aggressive curettage Here in the picture you can notice that there is expansion in the lower border of the mandible.

9- Stafnes Idiopathic Bone Cavity

Its a pseudocyst, it doesnt need treatment because its an ectopic salivary tissue in continuity with the submandibular salivary gland and has caused resorbtion to the lingual plate below the ID canal as you seen in the picture, heres the canal, and right below it theres a radiolocency, so what happened here is that lingualy the submandibular gland caused some pressure over the bone so theres a little bit of soft tissue that entered the bone and it appears as a radiolucency so thats why it doesnt need treatment. Pseudocyst Symptomless Round at oval, well-demarcated radiolucency between premolar region & angle of jaw Usually beneath inferior dental canal Bilateral anomaly Saucer-shaped depression at lingual bone defect Contain ectopic salivary tissue in continuity with submandibular salivary gland Sialography identify salivary inclusions No treatment required *Apical Radicular Cyst Images

*Residual Radicular Cyst images

*Dentigerous Cyst Images

*Keratocyst Images

*Lateral Periodontal Cyst images

*Nasopalatine Duct Cyst

I tried to include everything in the scriptSorry for any mistakesDone by: Ruby Daoud