Differential Diagnosis of Radiolucent Lesions-1 Dental Caries PDF

9/29/2024 DIFFERENTIAL DIAGNOSIS OF RADIOLUCENT LESSIONS-1 DENTAL CARIES Radiological features Within the enamel, the early lesion presents as a relatively well defined triangular‐shaped lucency with the base at the enamel surface. This...

9/29/2024 DIFFERENTIAL DIAGNOSIS OF RADIOLUCENT LESSIONS-1 DENTAL CARIES Radiological features Within the enamel, the early lesion presents as a relatively well defined triangular‐shaped lucency with the base at the enamel surface. This triangular morphology is lost as the lesion enlarges. When the lesion reaches the dentinoenamel junction (DEJ), it spreads out along the DEJ, resulting in the appearance of a relatively ill‐defined triangular lucency within the dentin. The base of this second triangular lucency is at the DEJ with the apex directed towards the pulp. As the lesion progresses, it takes on a generally rounded morphology, usually progressing quicker within the dentin than within the enamel. Large lesions usually present with more substantial dentin involvement, undermining the overlying enamel, which may fracture. Extremely large lesions often contribute to complete or near complete loss of the entire tooth crown. 1  9/29/2024 Differential diagnosis Cervical burnout- Artefactual and seen on intraoral and panoramic radiographs. Present as lucencies in the interproximal regions but usually extends from the cementoenamel junction to the interdental alveolar crest Lucent or absent (lost) restoration- Usually more well defined and may demonstrate sharp surgically prepared angles no enamel --> no absorption of xray -- > RADIOLUCENCY --> white Interproximal caries-Originate at the mesial and distal surfaces of the crowns, usually between the contact point and the gingival margin Well-defined triangular-shaped lucency within the enamel with the apex directed towards the DEJ Lucency in the enamel Small subtle lucency 2  9/29/2024 Pit and fissure caries Root caries ▪ 2D radiographs: the dentin ▪ Seen as lucent lesions apical lucency is usually seen first, to the cementoenamel subjacent to enamel junction ▪ The enamel lesion is usually not ▪ Usually coronal to the seen unless large alveolar crest. Occasionally extend beyond the alveolar ▪ It is difficult to identify if these crest lesions are buccal, lingual RADIOLOGICAL FEATURES D/D – CERVICAL BURN OUT 3  9/29/2024 ACTIVE VS INACTIVE LESION CERVICAL BURNOUT VS CARIOUS LESION 4 9/29/2024 5  9/29/2024 Radiolucent restorations  C-1. Enamel caries less than halfway through the enamel. Also known as incipient caries.  C-2. Enamel caries penetrating at least halfway through the enamel.  C-3. Caries at the D-E junction. (moderate lesion).  C-4. Dentin caries halfway to the pulp. (severe lesion). RADIOGRAPHIC CLASSIFICATION OF CARIES. (HAUGEJORDEN & SLACK 1975) 6  9/29/2024 Progression of proximal caries: Progression of occlusal caries; (a) Incipient,(b) moderate, base of the enamel caries (c)advanced,(d) severe triangle is at theDEJ we stop till here Carious lesions are usually larger clinically than they appear radiographically and very early lesions are not seen at all Varying the tube head angulation can make a lesion confined to enamel appear to have progressed to dentine Exposure factors can have a marked effect on the overall radiographic contrast and thus affect the appearance and size of carious lesions on the radiograph Bucco-lingual extent of the lesion cannot be seen 7  9/29/2024 15 Periapical inflammatory lesions-apical periodontitis, periapical rarefying osteitis, periapical condensing or sclerosing osteitis, periapical granuloma Periradicular inflammatory lesions related to pulpal pathology are mostly seen at the apical aspect of the tooth root(s) Clinical presentation varies substantially, from an asymptomatic low‐grade chronic picture to severe infections with substantial local and systemic manifestations 16 8  9/29/2024 Periapical inflammatory lesions Radiographic features Early or lower grade lesions often present as widened apical periodontal ligament space with preservation of the lamina dura Very early or acute lesions may not demonstrate bony changes detectable with 2D radiography, CBCT ( initial phase - periapical inflammatory marrow oedema ) With some progression, it usually presents as a lucency centred at the apex of a root with effacement of the lamina dura Sometimes, these lesions are centred elsewhere on the root surface, related to accessory lateral pulp canals or root fractures. Lateral canals and root fractures may not be radiologically detectable 17 Periapical inflammatory lesions Radiographic features Margins can be ill defined or relatively well defined ❖ Many of these lesions identified radiologically are longstanding.Therefore, the margins are often relatively well defined ❖ More acute lesions tend to demonstrate less or poorly defined margins Adjacent reactive sclerosis is a common feature since many lesions demonstrated radiologically are chronic in nature ❖ The degree of sclerosis can be focal and mild or dense, extensive and diffused, related to the degree of chronicity ❖ The sclerosis can be extremely focal and dense where the widened apical periodontal ligament space or small apical lucency is not apparent. Some refer to these as periapical condensing/sclerosing osteitis 18 9  9/29/2024 Periapical inflammatory lesions Radiographic features Apical root resorption may be seen with chronic lesions The pulp chamber and root canals of the involved tooth may appear larger Larger lesions may efface the jaw cortices. There may be periosteal response (periosteal new bone formation) Lesions approximating the maxillary antral bases : ❖ Commonly stimulate variable reactive mucosal thickening at the antral floor ❖ There may be focal effacement of the antral cortical floor 19 Periapical inflammatory lesions Differential/Diagnosis Periapical osseous dysplasia Radicular cyst Bone island Fibrous healing Malignant lesions Osteomyelitis 20 10  9/29/2024 21 Round to ovoid radiolucency Non-vital tooth > 1.5 cm 22 11  9/29/2024 Radiological features Corticated lucent lesion centred at the Displacement and resorption of tooth roots apical foramen of a tooth root Expansion with thinning of the jaw cortices Often demonstrates a periapical Elevation of the maxillary sinus and nasal ‘tear‐drop’ morphology in relation to cortical floors the offending tooth root apex Displacement and compression/flattening The border can be more sclerotic if of the mandibular canal chronic in nature Post treatment, radicular cysts often However, in acute secondary infection, demonstrate new bone formation beginning there may be focal regions of absent at the periphery cortical borders. Occasionally, this bony infill of the cystic Longstanding lesions may defect may be incomplete, demonstrating a demonstrate internal dystrophic residual lucency related to fibrous healing, calcifications more commonly seen with large lesions 23 Differential diagnosis Keratocystic odontogenic tumour Postendodontic therapy apical fibrous (KCOT)-Rarely centred at the root healing - Can be difficult to apex. However, it can be difficult to differentiate as fibrous healing often identify the site of origin with larger demonstrates a corticated border. cysts However, a radicular cyst tends to demonstrate a more full spherical Relative lack of expansion is a morphology and the border of fibrous feature of the KCOT in the body of healing is usually thick and denser, mandible sometimes with some irregularity Lateral periodontal cyst - Can be Periapical osseous (cemental) difficult to differentiate from the dysplasia-Immature lesions are radicular cyst related to the lateral essentially lucent but the borders are canal usually sclerotic rather than corticated. These lesions are often multiple, affecting more than one tooth 24 12  9/29/2024 25 26 13  9/29/2024 Well-defined radiolucency within the alveolar ridge at the site of a previous tooth extraction 27 Residual cyst -Radiological features Essentially the same as the radicular cyst, but with absent tooth The borders may appear thicker or slightly more sclerotic than those of the radicular cyst 28 14  9/29/2024 Well-defined corticated lucent lesion 29 Unilocular radiolucency associated with the crown of an unerupted tooth 30 15  9/29/2024 Dentigerous cyst ; Follicular cyst A pericoronal cyst associated with an unerupted tooth Second most common jaw cyst Most commonly associated with the third molars Often asymptomatic until it causes swelling or is secondarily infected 31 Dentigerous cyst- Radiological features Presents as a corticated pericoronal lucent lesion or appearance of an enlarged follicular space of a tooth crown (5 mm or more ) This pericoronal lucency may evenly surround the entire crown or may be more focal, centred at one region or limited to one side of the crown ❖ The border typically extends to the cementoenamel junction (CEJ) ❖ This border can be sclerotic ; When acutely secondarily infected, there may be focal regions of effacement of this corticated border Displacement of teeth. The offending tooth can be displaced substantially, depending on the size of the cyst, e.g. a maxillary third molar can be displaced to the orbital floor Resorption of adjacent tooth roots Expansion with thinning of the jaw cortices Elevation of the maxillary sinus and nasal cortical floors Displacement and compression/flattening of the mandibular canal 32 16  9/29/2024 Dentigerous cyst - Differential diagnosis Normal follicular space - Can be difficult to differentiate as an early developing dentigerous cyst appears similar. As a rule of thumb, a distance of 5 mm or more from the follicular cortex to the crown surface is considered to be more likely a cyst. Other features, such as slight displacement of the affected tooth, may be helpful Keratocystic odontogenic tumour -Usually non‐expansile in the mandible. Likely to be attached 3 mm or more from the CEJ. Less displacement and/or resorption of tooth roots Unicystic ameloblastoma -Can appear very similar but this is a rare cyst and is usually substantially expansile (more than most dentigerous cysts) Ameloblastic fibroma - Can be difficult to differentiate. Rare 33 34 17  9/29/2024 35 36 18  9/29/2024 Buccal bifurcation cyst Cyst arising from the buccal furcation of mandibular first or second molars, most frequently the first molars Similar lesions associated with the mandibular third molars are usually referred to as paradental cysts Can be bilateral Usually seen in the younger age Clinically presents with swelling and/or delayed/non‐eruption of the molar Can be secondarily infected 37 Buccal bifurcation cyst- Radiological features A well‐defined expansile corticated lucent lesion centred at the buccal furcation of a mandibular molar. There is often a tendency for this lesion to extend posteriorly from the bifurcation The root is usually displaced lingually, with the occlusal surface of the tooth directed superobuccally. Root resorption is not a feature If secondarily infected, periosteal new bone formation may be evident 38 19  9/29/2024 Buccal bifurcation cyst- Differential diagnosis Dentigerous cyst -The buccal bifurcation cyst is centred at the buccal furcation 39 40 20  9/29/2024 Keratocystic odontogenic tumour- Odontogenic keratocyst, OKC Most commonly seen in the posterior mandible Usually asymptomatic unless large or secondarily infected 41 Odontogenic keratocyst- Radiological features Well‐defined corticated border which may demonstrate a scalloped appearance Most often unicystic and internally completely lucent Larger lesions may demonstrate internal septa, usually one or a few, which are quite prominent Within the body of the mandible, it classically demonstrates little or no expansion, relative to the size of the lesion There is often variable thinning of the jaw cortices, where there may be regions of cortical effacement 42 21  9/29/2024 Odontogenic keratocyst- Radiological features This lesion may displace teeth and contribute to root resorption, this occurs to a lesser degree than that usually seen with dentigerous cysts May displace or compress the mandibular canal When involving the posterior maxilla, evaluation of the integrity of the posterior wall of the sinus and possible extension of the lesion into the pterygopalatine fossa is important 43 Odontogenic keratocyst- Differential diagnosis Dentigerous cyst - A pericoronal cystic lesion with borders which are not at the CEJ or within 2–3 mm of the CEJ is more likely a KCOT than a dentigerous cyst Dentigerous cysts are expansile, KCOTs are more likely to demonstrate scalloped borders Simple bone cyst (SBC) - SBCs usually demonstrate a much thinner and delicate corticated border than KCOTs. May also be scalloped. Effacement of lamina dura and root resorption is less often seen with SBCs. SBCs essentially do not directly displace teeth 44 22  9/29/2024 Odontogenic keratocyst- Differential diagnosis Odontogenic myxoma- Can appear similar in the posterior body of the mandible, as both are often not expansile and KCOTs occasionally demonstrate internal septa Radicular cyst- The borders of a radicular cyst demonstrate a more acute angle to the root surface of the offending tooth, usually a ‘tear‐drop’ appearance. KCOT borders are usually at right angles or demonstrate obtuse angles in relation to the root surfaces of the apical aspect of involved roots. Radicular cysts are expansile and KCOTs are usually not expansile or minimally expansile within the body of mandible 45 Odontogenic keratocyst- Differential diagnosis Ameloblastoma- The scalloped margins of KCOTs, when present, can be mistaken for a multilocular lesion. Ameloblastomas are expansile lesions, unless quite small 46 23  9/29/2024 47 48 24  9/29/2024 49 Well-defined corticated largely lucent lesion with two relatively prominent internal septa 50 25  9/29/2024 Basal cell naevus syndrome- Gorlin–Goltz syndrome An inherited syndrome demonstrating abnormalities which include multiple skin naevoid basal cell carcinomas, skeletal, central nervous system and eye abnormalities as well as multiple KCOTs of the jaws 51 Basal cell naevus syndrome Radiological features Differential diagnosis Multiple KCOTs Buccal bifurcation cysts Often Early calcification of the falx present bilaterally in a relatively cerebri symmetric pattern, unlike the basal cell naevus syndrome Radicular, residual, dentigerous cysts 52 26  9/29/2024 Absence of the tuberosity and maxillary sinus Corticated border cortical floor confirms the presence of a lesion Effacement of the lamina dura originating from the alveolar process Calcification of the falx cerebri 53 Lateral periodontal cyst Cyst arising from the odontogenic epithelium of the lateral surface(not at the apex) of the root, unrelated to the pulp status/ vitality of the tooth Most often involving mandibular premolars, canines and lateral incisors. Also seen in the anterior maxilla, especially the canines and lateral incisors 54 27  9/29/2024 Lateral periodontal cyst-Radiological features Well‐defined corticated unicystic lucent lesion centred upon the lateral (not at the apex) surface of a root surface Botyroid odontogenic cyst –Multiple Effacement of the lamina dura of involved teeth is common. Large lesions demonstrate expansion and displacement of teeth 55 Lateral periodontal cyst-D/D Radicular cyst - Radicular cysts related to lateral canals can appear similar. However, there is often evidence to suggest a compromised/non‐vital pulp and there may be periapical inflammatory disease Keratocystic odontogenic tumour -KCOTs are relatively non‐expansile. 56 28  9/29/2024 57 58 29  9/29/2024 Glandular odontogenic cyst Mandible (87%), usually anterior Very slow progressive growth (CC: swelling, pain 40%) 59 Glandular odontogenic cyst Radiological features Differential diagnosis Unilocular or multilocular Ameloblastoma well‐defined lesion with Keratocystic odontogenic tumour corticated borders Expansile, with effacement of maxillary/mandibular cortices Displaces teeth 60 30  9/29/2024 61 To be continued 31