Abstract
Objectives:
To assess and evaluate various jaw pathologies their nature, location, size, extent and effect on surrounding structures by CT.
Methods:
In total, 29 subjects of jaw pathologies and traumatic injuries of maxillofacial complex were subjected to CT.
Results:
showed characteristic and distinct features for various pathologies. Fisher exact test was applied to compare consistency of features like matrix, margins, density, and number.
Conclusion:
CT plays a crucial role in depicting the exact extensions of pathologies and its relation to adjacent anatomical structures in all possible directions.
KEYWORDS: Computed tomography, CT scan, cystic lesions, jaw pathology, maxillofacial complex
INTRODUCTION
The maxillofacial region is a complex structure and anatomical site for the development of various pathologies. Many lesions with a wide range of pathologic features occur in the jaws, including cysts or cyst like lesions and tumors.[1] Despite their pathologic differences these lesions cannot be differentiated solely but they require a combined assessment of clinical, radiological and microscopic features for correct diagnosis and treatment planning.[1,2]
Rapid advances in diagnostic imaging and computers have a major impact on dental radiology and dentistry and has become an integral component of dentist’s diagnostic armamentarium.[3] However, the conventional radiographic imaging techniques do not demonstrate the exact presence, size, and extent of the lesion and its spatial relationship with other anatomical structures.[2] CT aids in the elucidation of bone and surrounding soft tissue invasion with high resolution.[4,5] It completely eliminates the superimposition of images of structures outside the area of interest.[6] Thus, provides accurate information about the height, width and three-dimensional evaluation of maxilla and mandible, the location of normal anatomical structures, such as the mandibular canal, mental foramen, mandibular foramen, incisive foramen, and maxillary sinus. In addition, the relationship between lesions and anatomical landmarks, including cortical margins and roots of teeth, can be established.[7] It also helps to evaluate the extent of tumor infiltration into surrounding vascular and visceral structures.[6] CT is also used in evaluation of patients with maxillofacial trauma to identify and quantify fractures, recognize their true extent to evaluate whether bone displacements are present or not, as well as to assess soft tissue injuries.[6,7]
MATERIALS AND METHODS
In total, 29 subjects were selected from the Out Patient Department of Oral Medicine and Radiology who were suspected of having different jaw lesions. An informed written consent was obtained from all the subjects. The clinical examination with detailed case history was done and CT performed.
RESULTS
After CT evaluation, Pathologies were categorized into various diagnostic groups. Of cystic lesions, most were radicular cysts followed by keratocystic odontogenic tumors (KCEOT); residual cyst and dentigerous cyst; 9 cases had solitary cysts; 2 cases were of multiple cysts. Out of 4 cases of benign tumors, 2 had ameloblastoma (1 case of acanthomatous type and other desmoplastic type); 1 with compact osteoma and remaining one was central giant cell granuloma; 5 cases of oral malignancies (Squamous cell carcinoma) were found; 6 cases of traumatic injuries of maxillofacial region; 2 cases of jaw infections. One case of osteomyelitits and other invasive rhino-maxillary mucormycosis 1 case of fibro-osseous dysplasia in mandible [Tables 1 and 2].
Table 1.
Distribution of subjects according to AGE and SEX
| SEX | Number (n) | Percentage (%age) | Age (in years) |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Minimum | Maximum | Mean±S.D | ||||||||
| Males | 22 | 75.9 | 16 | 70 | 40.82±16.715 | |||||
| Females | 7 | 24.1 | 22 | 74 | 39.00±18.448 | |||||
| Total | 29 | 100 | 16 | 74 | 40.38±16.826 | |||||
Table 2.
Distribution of various jaw pathologies included in this study
| Various Jaw Pathologies | No of Patients | Percentage (%) | ||
|---|---|---|---|---|
| Cysts | 11 | 37.9 | ||
| Benign tumors | 4 | 13.8 | ||
| Oral malignancies | 5 | 17.2 | ||
| Traumatic injuries | 6 | 20.7 | ||
| Infections | 2 | 6.9 | ||
| Fibro-osseous lesions | 1 | 3.4 | ||
| Total | 29 | 100.0 |
All observations were recorded and statistical analysis done.
Fisher’ exact test was applied.
DISCUSSION
Diverse disease entities with a wide range of pathologic features may occur in the jaws and maxillofacial complex region and might present a great challenge even for experienced radiologists.[6] Patient’s age at manifestation, prevalence, location, cystic or solid appearance, border contour, the effect of the lesion on adjacent anatomic structures, tooth vitality and radiographic features. are all considerations in making final diagnosis.[1,7] 3-D (CT scan) radiography helps in evaluating the exact extent and nature of lesion in all the three dimensions and provides superior delineation of osseous anatomy and is sensitive to mineralization.[6] Though high radiation dose in CT being a disadvantage it’s advantages in assessing the contours of the lesion, its contents and extension into the soft tissues, makes it preferable for diagnosis.[5,7] First, cystic lesions in jaws can be of odontogenic and non-odontogenic origin. Such as radicular cysts, dentigerous cysts and Keratocystic odontogenic tumor. These lesions mostly have a cyst like appearance both on radiographs and on CT images. Most of them are non-invasive though a few may have different degree of destructive potential locally.[5,6] Radicular cysts varied from small to large. Maxillary radicular cysts caused the elevation of floor of maxillary sinus, deviation of nasal septum. Residual cyst in maxilla showed solitary oval-shaped lesion of medullary origin with well-defined expansion of buccal cortical plate with persistence of corticated margins, elevation of floor of maxillary sinus growing into the maxillary sinus occupying most of its lumen. CT of dentigerous cyst showed, a solitary cystic lesion with well-defined margins associated wrt embedded third molar, homogeneous matrix, caused expansion of palatal cortical plate and embedded tooth was directed posteriorly and buccally encircling the crown of embedded tooth and grew mostly on its lateral aspect. KCEOT; showed involvement of body of mandible; involvement of ramus; some showed an unusual involvement of whole of mandible with expansion, thinning and resorption of buccal and lingual cortical plates at different locations. The common CT findings of KCEOT were solitary as well as multiple lesions with lytic and cystic density; expansion and thinning of cortical plates with well-defined corticated margins. One case involving whole of the mandible with an impacted tooth showed calcified material within the lumen of cystic lesion. KCEOT showed propensity to grow in an antero-posterior direction within medullary cavity of bone causing minimal expansion, but the case where whole mandible was involved, grew antero-posteriorly and also caused expansion, thinning and resorption of cortical plates bucco-lingually.[5,6]
Ameloblastomas are an enigmatic group of oral tumors. Usually benign in growth pattern invading locally and occasionally can metastasize.[4,6] Ameloblastoma involving mandible i.e. acanthomatous and desmoplastic type, revealed mixed lytic and sclerotic density, heterogenous matrix with well-defined margins and presence of calcifications with no association with unerupted tooth.
Expansion and thinning of buccal and lingual cortical plates with perforation was observed in acanthomatous type whereas only expansion and thinning of both the cortical plates in desmoplastic ameloblastoma. KCEOT and ameloblastoma are have multilocular lesions on CT, to differentiate between them, ameloblastomas show knife-edge resorption of the roots of teeth with marked expansion of buccolingual cortical bone, whereas KCEOT shows relatively less resorption of roots of teeth with no buccolingual expansion of cortical plate. Osteoma was located in the mandibular posterior region ovoid with lobulated and well-defined margins, a sessile base and dense sclerotic matrix which was cortical in origin (buccal cortex) with expansion of buccal cortical plate. CT of Central Giant Cell Granuloma (CGCG) revealed ovoid shaped cystic density, homogenous matrix, expansion and thinning of cortical plates with well-defined margins and calcifications.
Third, malignant tumors also invade the maxilla and mandible and shows erosive changes[2,3,4] were histologically diagnosed as squamous cell carcinoma and extended to involve the bone. CT revealed heterogenous matrixes with ill-defined margins, mixed lytic and sclerotic density while 2 had lytic density. A breach in continuity of adjacent structures; resorption of alveolar bone and perforation of lower border of mandible were also seen. Hyperdense, in-homogenous destructive soft tissue masses, breach in the continuity of adjacent structure, extending into the adjacent fascial space and planes and mild to moderate enhancement. Lymph node involvement was also seen.
Traumatic injuries to maxillofacial complex. CT helped in eliciting the exact extent and localization of the fractured segments, multiple fractures displaced fractured segments, and perforations of maxillary sinus.
CT of Osteomyelitis of mandible involving body, ramus, coronoid, and condylar process. Revealed altered trabecular bone pattern, heterogenous matrix, mixed lytic and sclerotic appearance with ill defined margins with erosion and perforation of medial, lateral, posterior, and lower border of mandible with involvement of surrounding normal landmarks. CT of invasive rhinomaxillary mucormycosis revealed altered trabecular bone pattern, heterogenous matrix, mixed lytic and sclerotic appearance with ill defined margins. Perforation of maxillary sinus, right orbit and frontal sinus, exophthalmoses and deviated nasal septum. CT of Fibroosseous dysplasia revealed heterogeneous matrix, presence of dense sclerotic mass in the center associated with the root of the tooth and surrounded by hypodense halo creating mixed lytic and sclerotic density, ill defined margins; altered trabecular pattern bone, expansion and thinning of buccal cortical plate, showing homogeneously low attenuation with frequent remodeling of bony walls.
CONCLUSION
CT scan played a crucial role in depicting the exact extensions of the various lesions, fractured segments and its relation to adjacent anatomical structures in all possible directions. CT is an important diagnostic tool that helps in better treatment planning and management and reducing complications.
Conflicts of interest
There are no conflicts of interest.
Funding Statement
Nil.
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