PERIRADICULAR PERIRADICULAR LESIONS LESIONS of pulpal of pulpal originorigin

DefinitionDefinition

Apical periodontitis is an inflammatory Apical periodontitis is an inflammatory

disorder of the periradicular tissue caused disorder of the periradicular tissue caused

by a persistent microbial infection of the by a persistent microbial infection of the

root canal system of the affected toothroot canal system of the affected tooth

In other wordsIn other words

Apical periodontitis (AP) is a host Apical periodontitis (AP) is a host

response to infections by microbes and response to infections by microbes and

the subsequent inflammatory responsethe subsequent inflammatory response

Apical periodontitis includes the infection Apical periodontitis includes the infection

and inflammation of the lateral and furcal and inflammation of the lateral and furcal

locations.locations.

The root canal and the pulp chamber are The root canal and the pulp chamber are

niche environments for the causative niche environments for the causative

organismorganism

BiofilmsBiofilms

Bacteria form biofilms and these pathological Bacteria form biofilms and these pathological

bacteria are embedded in the biofilms bacteria are embedded in the biofilms

Biofilms protect the bacteria from antibiotic Biofilms protect the bacteria from antibiotic

attack and make them a X 1000 more resistant attack and make them a X 1000 more resistant

to the effects.to the effects.

Infection portalsInfection portals

Pulp becomes infected byPulp becomes infected by

Carious exposureCarious exposure

Leaking restorations Leaking restorations

Dentinal tubulesDentinal tubules

Fractures or cracksFractures or cracks

Inflammatory responseInflammatory response

The antigens and bacterial toxins The antigens and bacterial toxins

percolate into the surrounding tissue percolate into the surrounding tissue

Most likely anaerobic bacteria invade that Most likely anaerobic bacteria invade that

provoke an inflammatory response i.e. provoke an inflammatory response i.e.

Chemotaxis Chemotaxis

Enzymatic breakdown with the subsequent Enzymatic breakdown with the subsequent

release of antigensrelease of antigens

The host mounts a immune response The host mounts a immune response consisting of several classes consisting of several classes

intercellular messengers and antibodies.intercellular messengers and antibodies.

This response destroys much of the This response destroys much of the peripical tissueperipical tissue

This results in the formation of various This results in the formation of various types of apical periodontal lesions.types of apical periodontal lesions.

The defence reaction minimises the The defence reaction minimises the spread of infection.spread of infection.

It cannot eliminate the microbes It cannot eliminate the microbes entrenched in a necrotic root canal , and entrenched in a necrotic root canal , and

biofilm.biofilm.

Treatment is required via surgical or non Treatment is required via surgical or non

surgical endodontic therapy as biofilms surgical endodontic therapy as biofilms

protect the bacteria from the host protect the bacteria from the host

defenses.defenses.

Classification of APClassification of AP

Apical periodontitis is an inflammatory Apical periodontitis is an inflammatory

disease and classification is based on disease and classification is based on

symptoms , aetiology or histopathology.symptoms , aetiology or histopathology.

Nomenclature and ClassificationNomenclature and Classification

Numerous terms are used such as Numerous terms are used such as Apical granulomasApical granulomas Apical cystsApical cysts Periapical lesions Periapical lesions Periapical osteitis Periapical osteitis

Three main clinical groupsThree main clinical groups symptomatic(acute) apical periodontitissymptomatic(acute) apical periodontitis

asymptomatic(chronic) apical asymptomatic(chronic) apical periodontitisperiodontitis

apical abscessapical abscess

Symptomatic(acute) Symptomatic(acute) Apical PeriodontitisApical Periodontitis

The principal causes are irritants diffusing The principal causes are irritants diffusing from an inflamed or necrotic pulp.from an inflamed or necrotic pulp.

Negative vitality test not always accurate Negative vitality test not always accurate

Pain!!!(WHY?)Pain!!!(WHY?)

user

Radiographic appearance of SAP because of a high filling note the widened PDL extreme pain to percussion Vital TOOTh

Asymptomatic(chronic) Apical Asymptomatic(chronic) Apical PeriodontitisPeriodontitis

Preceded by an acute episodePreceded by an acute episode lesion frequently develops and enlarges lesion frequently develops and enlarges

without any subjective signs and symptomswithout any subjective signs and symptoms

Causes Causes

1.1. Inadequate endodontic procedureInadequate endodontic procedure

2.2. Low grade pathogenicity/ irritantLow grade pathogenicity/ irritant

3.3. Pathosis is a long-standing “smoldering” Pathosis is a long-standing “smoldering” lesionlesion

Asymptomatic(chronic) Apical Asymptomatic(chronic) Apical Periodontitis(Cont)Periodontitis(Cont)

Non vital respnseNon vital respnse Radiographic evidence is the keyRadiographic evidence is the key Called a peri radicular granuloma or Called a peri radicular granuloma or

periradicular cyst.periradicular cyst. Periradicular Granuloma. Nobuhara and del Periradicular Granuloma. Nobuhara and del

Rio(JOE1993;19:315)Rio(JOE1993;19:315) showed that 59.3% showed that 59.3% of the periradicular lesions were of the periradicular lesions were granulomas, 22% cysts, 12% apical scars, granulomas, 22% cysts, 12% apical scars, and 6.7% other pathoses and 6.7% other pathoses

Histologically, the periradicular granuloma Histologically, the periradicular granuloma consists predominantly of granulation consists predominantly of granulation inflammatory tissue with many small inflammatory tissue with many small capillaries, fibroblasts, numerous capillaries, fibroblasts, numerous connective tissue fibers, inflammatory connective tissue fibers, inflammatory infiltrate, and usually a connective tissue infiltrate, and usually a connective tissue capsulecapsule

Apical periodontitis (granuloma) with containedApical periodontitis (granuloma) with containedepithelium. Epithelial cells of periodontal ligament have proliferatedepithelium. Epithelial cells of periodontal ligament have proliferatedwithin new inflammatory tissue. The epithelium tends to ramify in awithin new inflammatory tissue. The epithelium tends to ramify in a

reticular pattern reticular pattern (straight arrow) toward receding bone. It also may,(straight arrow) toward receding bone. It also may,as in this case, apply itself widely to the root surface as in this case, apply itself widely to the root surface (curved arrow).(curved arrow).

Infiltration of epithelium by round cells is everywhere apparent.Infiltration of epithelium by round cells is everywhere apparent.Human tooth. Reproduced with permission from Matsumiya S.AtlasHuman tooth. Reproduced with permission from Matsumiya S.Atlas

of oral pathology. Tokyo: Tokyo Dental College Press; 1955.of oral pathology. Tokyo: Tokyo Dental College Press; 1955.

Periradicular Cyst.Periradicular Cyst.

Periradicular cyst shows a central cavity Periradicular cyst shows a central cavity lined by stratified squamous epitheliumlined by stratified squamous epithelium

This lining is usually incomplete and This lining is usually incomplete and ulceratedulcerated

The lumen contains a pale eosinophilic The lumen contains a pale eosinophilic fluid and occasionally some cellular debrisfluid and occasionally some cellular debris

Apical cyst with marked inflammatory overlay. RoundApical cyst with marked inflammatory overlay. Roundcells permeate both the epithelium and the connective tissue immediatelycells permeate both the epithelium and the connective tissue immediately

deep to it. Spaces indicate where crystalline cholesterol hasdeep to it. Spaces indicate where crystalline cholesterol hasformed within the cyst. Bone formation is evident formed within the cyst. Bone formation is evident (arrow). This(arrow). This

may reflect narrowing of the width of the connective tissue zone, asmay reflect narrowing of the width of the connective tissue zone, asoccurs in some apical cysts. Human tooth. Reproduced with permissionoccurs in some apical cysts. Human tooth. Reproduced with permission

from Matsumiya S. Atlas of oral pathology. Tokyo: Tokyofrom Matsumiya S. Atlas of oral pathology. Tokyo: TokyoDental College Press; 1955.Dental College Press; 1955.

Condensing OsteitisCondensing Osteitis

Inflammation of periradicular tissues of Inflammation of periradicular tissues of teeth usually stimulates concurrent teeth usually stimulates concurrent osteoclastic and osteoblastic activities.osteoclastic and osteoblastic activities.

Osteoclastic (resorptive) activities are Osteoclastic (resorptive) activities are usually more prominent than osteoblastic usually more prominent than osteoblastic (formative)(formative)

Condensing osteitis is associated with Condensing osteitis is associated with predominant osteoblastic activitypredominant osteoblastic activity

Condensing Osteitis Condensing Osteitis (CONT)(CONT)

attributable to a special balance between host attributable to a special balance between host tissues and the root canal irritants.tissues and the root canal irritants.

Condensing osteitis, or chronic focal sclerosing Condensing osteitis, or chronic focal sclerosing osteomyelitisosteomyelitis, , is a radiographic variation of AAP is a radiographic variation of AAP and is characterized as a localized and is characterized as a localized overproduction of apical bone.overproduction of apical bone.

usually observed around the apices of usually observed around the apices of mandibular posterior teeth with pulp necrosis or mandibular posterior teeth with pulp necrosis or chronic pulpitischronic pulpitis

Condensing Osteitis Condensing Osteitis (CONT)(CONT)

The tooth associated with condensing osteitis The tooth associated with condensing osteitis may be asymptomatic or sensitive to stimuli.may be asymptomatic or sensitive to stimuli.

Apical condensing osteitis that developed in response toApical condensing osteitis that developed in response tochronic pulpitis. Additional bony trabeculae have been formed andchronic pulpitis. Additional bony trabeculae have been formed and

marrow spaces have been reduced to a minimum. The periodontal ligamentmarrow spaces have been reduced to a minimum. The periodontal ligamentspace is visible, despite increased radiopacity of nearby bone.space is visible, despite increased radiopacity of nearby bone.

APICAL ABSCESSESAPICAL ABSCESSES

An abscess is a localized collection of pus An abscess is a localized collection of pus in a cavity formed by the disintegration of in a cavity formed by the disintegration of tissuetissue

Apical abscesses can be divided into Apical abscesses can be divided into symptomatic or asymptomatic conditionssymptomatic or asymptomatic conditions

APICAL ABSCESSESAPICAL ABSCESSES Symptomatic Apical Abscess A sudden egress of Symptomatic Apical Abscess A sudden egress of

bacterial irritants into the periradicular tissues bacterial irritants into the periradicular tissues severe sequelae, acute osteitis and cellulitis.severe sequelae, acute osteitis and cellulitis. Accompanied by exudate formation within the Accompanied by exudate formation within the

lesionlesion May occur without any obvious radiographic signsMay occur without any obvious radiographic signs infection and rapid tissue destruction arising from infection and rapid tissue destruction arising from

within AAP( Phoenix abcess)within AAP( Phoenix abcess)

APICAL ABSCESSES/clinicalAPICAL ABSCESSES/clinical

May or may not have swellingMay or may not have swelling Swelling may be localized or diffuseSwelling may be localized or diffuse Varying degrees of sensitivity to percussion and Varying degrees of sensitivity to percussion and

palpationpalpation No pulp reaction to cold, heat, or electrical No pulp reaction to cold, heat, or electrical

stimuli as the involved tooth has a necrotic pulpstimuli as the involved tooth has a necrotic pulp Radiographic features of the SAA vary from a Radiographic features of the SAA vary from a

thickening of the periodontal ligament space to thickening of the periodontal ligament space to the presence of a frank periradicular lesionthe presence of a frank periradicular lesion

Radiographic features of symptomatic apical abscess.Radiographic features of symptomatic apical abscess.The patient developed sudden symptoms of pain and facialThe patient developed sudden symptoms of pain and facial

swelling. Radiographically, a lesion is apparent apically to the maxillaryswelling. Radiographically, a lesion is apparent apically to the maxillaryleft lateral incisor, that did not respond to vitality tests, confirmingleft lateral incisor, that did not respond to vitality tests, confirming

pulpal diagnosis of necrosis.pulpal diagnosis of necrosis.

Asymptomatic Apical AbscessAsymptomatic Apical Abscess

Asymptomatic apical abscess (AAA), also referred to asAsymptomatic apical abscess (AAA), also referred to as

suppurative apical periodontitis, is associated with asuppurative apical periodontitis, is associated with a

gradual egress of irritants from the root canal systemgradual egress of irritants from the root canal system

into the periradicular tissues and formation of an exudate.into the periradicular tissues and formation of an exudate.

The quantity of irritants, their potency, and theirThe quantity of irritants, their potency, and their

host resistance are all important factors in determininghost resistance are all important factors in determining

the quantity of exudate formation and the clinical signsthe quantity of exudate formation and the clinical signs

and symptoms of the lesion. Asymptomatic apicaland symptoms of the lesion. Asymptomatic apical

abscess is associated with either a continuously orabscess is associated with either a continuously or

intermittently draining sinus tractintermittently draining sinus tract..

WHO uses a symptomatic classification WHO uses a symptomatic classification based on clinical signs based on clinical signs Acute apical periodontitis Acute apical periodontitis Chronic apical periodontitisChronic apical periodontitis Periapical abscess with sinus Periapical abscess with sinus Periapical abscess without sinus Periapical abscess without sinus Radicular cystRadicular cyst

Histopathological classificationHistopathological classification(Nair PNR: Pathology of Apical Periodontitis)(Nair PNR: Pathology of Apical Periodontitis)

In order to understand the disease In order to understand the disease process a histopathological classification process a histopathological classification is used:is used:

1.1. The distribution of pathological cells in the The distribution of pathological cells in the lesionlesion

2.2. Presence or absence of epithelial cellsPresence or absence of epithelial cells

3.3. Transformation of a lesion into a cystTransformation of a lesion into a cyst

4.4. The relationship of the cyst cavity to the The relationship of the cyst cavity to the affected rootaffected root

Histopathological classificationHistopathological classification

Acute apical periodontitisAcute apical periodontitis - an acute - an acute inflammation of endodontic origin . A inflammation of endodontic origin . A distinct focus of neutrophils have to be distinct focus of neutrophils have to be presentpresent Primary or initial short lived inflammation in a Primary or initial short lived inflammation in a

healthy periodontium.healthy periodontium. secondary or exacerbating when an acute secondary or exacerbating when an acute

episode occurs on a preexisting chronic episode occurs on a preexisting chronic lesion *also called a phoenix abcesslesion *also called a phoenix abcess

Histopathological classificationHistopathological classification

Established Established chronic apical periodontitischronic apical periodontitis Long standing inflammationLong standing inflammation presence of granulomatous tissuepresence of granulomatous tissue Cells are lymphocytes , plasma cells and Cells are lymphocytes , plasma cells and

macrophagesmacrophages Lesion may be epithelialised or non-Lesion may be epithelialised or non-

epithelialisedepithelialised

Histopathological classificationHistopathological classification

Periapical true cystPeriapical true cyst is an apical is an apical

inflammatory cyst with a distinct inflammatory cyst with a distinct

pathological cavity completely enclosed in pathological cavity completely enclosed in

an epithelial lining so that NO an epithelial lining so that NO

communication to the root canal existscommunication to the root canal exists

Histopathological classificationHistopathological classification

A periapical pocket cystA periapical pocket cyst is an apical is an apical

inflammatory cyst containing a saclike inflammatory cyst containing a saclike

epithelium lined cavity that is open and epithelium lined cavity that is open and

continuous with the root canalcontinuous with the root canal

Histopathologically the lesions of AP can be classified as acute, chronic ,or cystic .AAP may be (A.) Histopathologically the lesions of AP can be classified as acute, chronic ,or cystic .AAP may be (A.) primary or secondary(B) and is characterized by a focus of PMN, (C) major component are primary or secondary(B) and is characterized by a focus of PMN, (C) major component are

lymphocytes plasma cells and macrophages, (D) true cysts enclosing the lumina and pocket cysts lymphocytes plasma cells and macrophages, (D) true cysts enclosing the lumina and pocket cysts (E)cavity is open to the root canal. Arrows indicate the direction of in which the lesion can change.(E)cavity is open to the root canal. Arrows indicate the direction of in which the lesion can change.

Important pointsImportant points

Bacteria are anaerobesBacteria are anaerobes Bacteria have to be presentBacteria have to be present There has to be a portal for infection to There has to be a portal for infection to

occur i.e.occur i.e. Caries Caries Clinical proceduresClinical procedures FracturesFractures Dentinal tubulesDentinal tubules

To treat or not to treat?To treat or not to treat?

Anatomic considerationsAnatomic considerations Root shapes? Root shapes? Can you remove infected hard and soft tissue Can you remove infected hard and soft tissue Give disinfecting agents access to the apical Give disinfecting agents access to the apical

canal spacecanal space Create space for the delivery of medicaments Create space for the delivery of medicaments

and subsequent obturationand subsequent obturation Retain the integrity of the radicular structuresRetain the integrity of the radicular structures

To treat or not to treat?To treat or not to treat?

Is the tooth restorable?Is the tooth restorable? Is there an adequate ferule, the amount of Is there an adequate ferule, the amount of

remaining tooth structureremaining tooth structure Is root decay presentIs root decay present Vertical fracturesVertical fractures Post preparations in teethPost preparations in teeth Anatomical positions of the toothAnatomical positions of the tooth Occlusal forces on the toothOcclusal forces on the tooth

To treat or not to treat?To treat or not to treat?

Restorative requirements of the toothRestorative requirements of the tooth Aesthetic requirementsAesthetic requirements

Sclerotic canals Sclerotic canals

Surgical Surgical

Posterior part of mandible Posterior part of mandible Inferior dental nerveInferior dental nerve Thickness of mandibleThickness of mandible Mental foramenMental foramen Facial arteryFacial artery PDLPDL Consider alternativeConsider alternative

SurgicalSurgical

Posterior part of MaxillaPosterior part of Maxilla Sinus perforation with infected root fragmentsSinus perforation with infected root fragments Palatal accessPalatal access

Anterior maxilla / mandible Anterior maxilla / mandible Long rootsLong roots Inclinations (mandible) and mental Inclinations (mandible) and mental

protuberanceprotuberance

Prepared teeth are anatomically more Prepared teeth are anatomically more difficult to treatdifficult to treat

Endodontic and Endodontic and periodontal relationshipsperiodontal relationships

Vascular connections exist between the Vascular connections exist between the pulp and periodontal ligament.pulp and periodontal ligament.

Pulp and periodontal problems are Pulp and periodontal problems are responsible for more than 50% of tooth responsible for more than 50% of tooth mortality.mortality.

There is no doubt that an interrelationship There is no doubt that an interrelationship exists in diseases that affect both the pulp exists in diseases that affect both the pulp and periodontiumand periodontium

When the pulp necroses for whatever When the pulp necroses for whatever reason products from pulp degeneration reason products from pulp degeneration reach the supporting periodontium. This is reach the supporting periodontium. This is characterised by bone loss, tooth mobility , characterised by bone loss, tooth mobility , and sometimes sinus tract formation.and sometimes sinus tract formation.

Apically if this occurs , a periradicular Apically if this occurs , a periradicular lesion forms which can extend crestally lesion forms which can extend crestally (Reverse pocket is formed)(Reverse pocket is formed)

Periodontal disease may have a Periodontal disease may have a gradual , atrophic effect on the gradual , atrophic effect on the

pulp.pulp.

Periodontal treatments such as Periodontal treatments such as deep root planing or curettage, or deep root planing or curettage, or localized irritants e.g. acids may localized irritants e.g. acids may

cause pulpal irritation.iscause pulpal irritation.is

Apical foramina have been shown to be the Apical foramina have been shown to be the most direct root of communication to the most direct root of communication to the

periodontium.periodontium.

In addition lateral or accessory canals with In addition lateral or accessory canals with 28% at the furcation. 28% at the furcation.

Periradicular periodontitisPeriradicular periodontitis

Acute, painful to biting or percussion, the Acute, painful to biting or percussion, the vitality may or may not be positive. No vitality may or may not be positive. No periradicular radiolucency and widened periradicular radiolucency and widened PDL, Apical 1/3 of rootPDL, Apical 1/3 of root

Chronic , no clinical symptoms, negative Chronic , no clinical symptoms, negative vitality test , periapical radiolucency , vitality test , periapical radiolucency , altered patient sensationaltered patient sensation

Periradicular abcessPeriradicular abcess

Acute, sensitive to pressure and Acute, sensitive to pressure and palpation, palpation, negativenegative vitality test , increased vitality test , increased mobility , increased pdl space, associated mobility , increased pdl space, associated temperaturetemperature

Chronic, no clinical symptoms, no vitality Chronic, no clinical symptoms, no vitality response periradicular radiolucency on response periradicular radiolucency on radiograph, suppurative lesion(pus radiograph, suppurative lesion(pus drainage )drainage )

Periodontal considerations Periodontal considerations Channels exist between pulp and periodontal Channels exist between pulp and periodontal

tissue tissue These include neural pathways, lateral canals These include neural pathways, lateral canals

dentinal tubules, palato-gingival grooves dentinal tubules, palato-gingival grooves periodontal ligament alveolar bone , apical periodontal ligament alveolar bone , apical foramina and vascular and lymphatic foramina and vascular and lymphatic pathwayspathways

Endodontic / Periodontic Endodontic / Periodontic RelationshipsRelationships

Primary endodontic -lesions lateral Primary endodontic -lesions lateral aspects of the root sinus tract along the aspects of the root sinus tract along the root – gutta-percha traceroot – gutta-percha trace

Primary endodontic with secondary Primary endodontic with secondary periodontal involvement –accumulation of periodontal involvement –accumulation of plaque / calculus apical migration of tissueplaque / calculus apical migration of tissue

Endodontic / Periodontic Endodontic / Periodontic RelationshipsRelationships

Primary periodontal lesions -deposit in Primary periodontal lesions -deposit in sulcus migrates apically. Vital pulp got to sulcus migrates apically. Vital pulp got to distinguish this from previous both look distinguish this from previous both look the same.the same.

Primary periodontal secondary endodontic Primary periodontal secondary endodontic involvement-accentuated pain from lesion. involvement-accentuated pain from lesion. Hard to separate from endo perioHard to separate from endo perio

Endodontic / Periodontic Endodontic / Periodontic RelationshipsRelationships

True combined lesion- damage to pulp True combined lesion- damage to pulp and periodontium at the same time that and periodontium at the same time that may coalesce classic ‘J’- lesionmay coalesce classic ‘J’- lesion

Treatment can include the resection of Treatment can include the resection of roots (multirooted) , but lesions associated roots (multirooted) , but lesions associated with cracked roots , older patients and with cracked roots , older patients and posts. Regeneration procedures.posts. Regeneration procedures.

NONENDODONTIC NONENDODONTIC PERIRADICULAR LESIONSPERIRADICULAR LESIONS

Got to differentiate between pulpal pathology and non-Got to differentiate between pulpal pathology and non-

endodontic origins of alterations in bone morphologyendodontic origins of alterations in bone morphology.. 38 radiolucent lesions and other abnormalities of the 38 radiolucent lesions and other abnormalities of the

jaws.Three of these lesions, dental granuloma, radicular jaws.Three of these lesions, dental granuloma, radicular cyst, and abscess, are categorized as being related to cyst, and abscess, are categorized as being related to necrotic pulps. In addition,16 radiopaque lesions of the necrotic pulps. In addition,16 radiopaque lesions of the jaws, 3 of which, condensing osteitis, sclerosing jaws, 3 of which, condensing osteitis, sclerosing osteomyelitis, and Garré’s osteomyelitis, are also related osteomyelitis, and Garré’s osteomyelitis, are also related to pulpal pathosisto pulpal pathosis

Never assume a radiolucency is pulpal pathology.Never assume a radiolucency is pulpal pathology.

NONENDODONTIC NONENDODONTIC PERIRADICULAR LESIONSPERIRADICULAR LESIONS

Lesions of the jaws categorized as odontogenic or Lesions of the jaws categorized as odontogenic or nonodontogenic in originnonodontogenic in origin

OdontogenicOdontogenic lesions arise from remnants of lesions arise from remnants of odontogenesis (or the tooth-forming organ), either odontogenesis (or the tooth-forming organ), either mesenchymal or ectodermal in origin.mesenchymal or ectodermal in origin.

Nonodontogenic lesions trace their origins to a variety of Nonodontogenic lesions trace their origins to a variety of precursors and therefore are not as easily classified.precursors and therefore are not as easily classified.

Differentiating between lesions of endodontic and nonendodontic origin is usually not difficult. Pulp vitality testing, when done with accuracy, is the primary method of determination; nearly all nonendodontic lesions are in the region of vital teeth, whereas endodontic lesions are usually associated with pulp necrosis, giving negative vitality responses. Except by coincidence, nonendodontic lesions are rarely associated with pulpless teeth..

Odontogenic CystsOdontogenic Cysts

Dentigerous CystDentigerous Cyst Lateral Periodontal CystLateral Periodontal Cyst Odontogenic KeratocystOdontogenic Keratocyst Residual Apical Cyst.Residual Apical Cyst.

Lateral periodontal cyst.Well-circumscribed radiolucentLateral periodontal cyst.Well-circumscribed radiolucentarea in apposition to the lateral surfaces of the lower premolarsarea in apposition to the lateral surfaces of the lower premolars

((black arrows demarcate the extent of lesions). No clinical signs orblack arrows demarcate the extent of lesions). No clinical signs orsymptoms were noted. Pulps tested vital.symptoms were noted. Pulps tested vital.

Bone Pathology: Fibro-osseous LesionsBone Pathology: Fibro-osseous Lesions

Periradicular Cemental DysplasiaPeriradicular Cemental Dysplasia Osteoblastoma and CementoblastomaOsteoblastoma and Cementoblastoma Cementifying and Ossifying Fibroma.Cementifying and Ossifying Fibroma.

A, Periradicular cemental dysplasia (osteofibrosis), initial stage. Pulps in both teeth are vital. B,Transition to the second stage is developing. C, Biopsy of periradicular osteofibrosis, initial stage. Fibrous connectivetissue lesion has replaced cancellous bone.

Cementoblastoma. The lesion is a fairly well-definedCementoblastoma. The lesion is a fairly well-definedradiopaque mass surrounded by a thin radiolucent line. It has alsoradiopaque mass surrounded by a thin radiolucent line. It has also

replaced the apical portions of the distal root of the first molarreplaced the apical portions of the distal root of the first molar

Ossifying fibroma. The patient presented with pain.Ossifying fibroma. The patient presented with pain.The pulp was vital, indicating that this was not an endodonticThe pulp was vital, indicating that this was not an endodontic

pathosis. Root canal treatment was followed by root end removalpathosis. Root canal treatment was followed by root end removaland excision of the lesion. Biopsy confirmed the diagnosisand excision of the lesion. Biopsy confirmed the diagnosis

Odontogenic TumorsOdontogenic Tumors

Ameloblastoma.Ameloblastoma.

Two examples of ameloblastoma. Two examples of ameloblastoma. A, Surgical specimenA, Surgical specimenof infiltrating ameloblastoma of mandible. of infiltrating ameloblastoma of mandible. B, “Unicystic” ameloblastoma.B, “Unicystic” ameloblastoma.

This solitary lesion has displaced teeth much as an apical cystThis solitary lesion has displaced teeth much as an apical cystwould do. The teeth are vital.would do. The teeth are vital.

Nonodontogenic LesionsNonodontogenic Lesions

Central Giant Cell Granuloma.Central Giant Cell Granuloma. Nasopalatine Duct CystNasopalatine Duct Cyst Simple Bone Cyst.Simple Bone Cyst. Globulomaxillary CystGlobulomaxillary Cyst Enostosis.Enostosis.

MalignanciesMalignancies

Carcinomas or sarcomas of various types are found in the jaws, Carcinomas or sarcomas of various types are found in the jaws, rarely as primary but usually as metastatic lesionsrarely as primary but usually as metastatic lesions

Carcinoma. Generally found in older patients, involvement of the Carcinoma. Generally found in older patients, involvement of the jaws (usually the mandible) is by metastasis from a primary lesion jaws (usually the mandible) is by metastasis from a primary lesion elsewhereelsewhere

Carcinoma lesions of the jaw may also manifest pain and swelling, Carcinoma lesions of the jaw may also manifest pain and swelling, loosening of teeth, or paresthesia, similar to endodontic pathosisloosening of teeth, or paresthesia, similar to endodontic pathosis

Radiolucent jaw malignancies have been mistaken for periradicular Radiolucent jaw malignancies have been mistaken for periradicular lesions.lesions.

Radicular cyst Radicular cyst  Residual cyst Residual cyst  Paradental and mandibular infected Paradental and mandibular infected

buccal cystsbuccal cysts Mandibular Infected Buccal Cyst   Mandibular Infected Buccal Cyst    Lateral periodontal cystLateral periodontal cyst Glandular odontogenic cystGlandular odontogenic cyst Odontogenic keratocystOdontogenic keratocyst Gorlin syndromeGorlin syndrome