CHRISMED Journal of Health and Research

ORIGINAL ARTICLE
Year
: 2019  |  Volume : 6  |  Issue : 2  |  Page : 102--107

Spectrum of mandibular and maxillary pathologies as assessed with dentascan: A pictorial essay


Gurleen Kaur1, Uttam B George2, Subhash Singla2, Sumir Gandhi3, Shubhra Rathore2,  
1 Department of Radiodiagnosis, St. Stephen's Hospital, New Delhi, India
2 Department of Radiodiagnosis, Christian Medical College, Ludhiana, Punjab, India
3 Department of Oral and Maxillofacial Surgery, Christian Dental College, Ludhiana, Punjab, India

Correspondence Address:
Shubhra Rathore
Department of Radiodiagnosis, Christian Medical College, Ludhiana - 141 008, Punjab
India

Abstract

Introduction: Dentascan is a CT imaging software that provides three dimensional display and high resolution panoramic views of the jaw. It has become an important aspect of evaluation of mandibular and maxillary pathologies due to its advantages over two dimensional techniques and conventional CT. Materials and Methods: 60 patients presenting with jaw lesions, were studied using Dentascan software. The aim of the study was to explore the spectrum of findings in various mandibular and maxillary pathologies as well as define their extent and involvement using DentaScan. Results: Impacted mandibular molars constituted 45% of cases followed by tumors and inflammatory lesions (36.6 %). Of the 22 tumors and inflammatory lesions, giant cell granulomas and radicular cysts, accounted for 22.7% each while osteomyelitis constituted 18%. Other lesions included osteosarcoma, buccal space infection, ameloblastoma, adenomatoid odontogenic tumor, dentigerous cysts and carcinoma alveolus. Trauma leading to facial fractures and TMJ pathologies constituted 8.3% and 10% of cases respectively. Conclusion: DentaScan is a valuable tool in evaluation of maxillary and mandibular pathologies including tumors/cysts, inflammatory /infectious lesions, TMJ ankylosis and facial fractures. By providing information superior to radiographs and conventional computed tomography, it plays a valuable role in pre-operative assessment of various pathologies.



How to cite this article:
Kaur G, George UB, Singla S, Gandhi S, Rathore S. Spectrum of mandibular and maxillary pathologies as assessed with dentascan: A pictorial essay.CHRISMED J Health Res 2019;6:102-107


How to cite this URL:
Kaur G, George UB, Singla S, Gandhi S, Rathore S. Spectrum of mandibular and maxillary pathologies as assessed with dentascan: A pictorial essay. CHRISMED J Health Res [serial online] 2019 [cited 2022 Jul 6 ];6:102-107
Available from: https://www.cjhr.org/text.asp?2019/6/2/102/258978


Full Text



 Introduction



DentaScan was introduced to overcome limitations of conventional imaging of diseases affecting the mandible and maxilla. It uses a computed tomography (CT) software/protocol allowing high resolution, multiplanar imaging of the mandible and maxilla in three different planes of reference: axial, panoramic, and oblique sagittal 1 with reconstruction. In recent times, its usefulness has extended to evaluation of mandibular and maxillary lesions including cysts, tumors, and fractures in addition to pre-operative assessment of implant surgery.

Aims and objectives

This study was carried out to assess the spectrum of findings in various mandibular and maxillary pathologies using DentaScan.

 Materials and Methods



This study was conducted in the Department of Radiodiagnosis, at our institute from December 1, 2014, to November 30, 2015. It was approved by the Institute Ethics Committee. This was a descriptive study where patients with maxillary and mandibular pathologies were assessed with DentaScan using a 128 slice Philips Ingenuity CT scanner. A total of 60 patients were included in the study. Descriptive statistics was used to analyze data and report findings. Patients with dentures or implants and those with prior surgery or radiation in the jaw on the same side of present pathology were excluded from the study. Imaging protocol included collimation 16 mm × 0.75 mm, slice thickness 0.9 mm, increment-overlapping with 120 kv, 150–200 mAs with pitch of 0.75 and rotation time 0.5 s. Source images were processed using DentaScan (dental planning) software on the “Extended Brilliance Workplace Version 4.5” Workstation. Spectrum of imaging findings were assessed, characterized, and documented as per the reporting protocol.

 Results



Of a total of 60 cases, 45% were impacted mandibular molars followed by tumors and inflammatory lesions (36.6%). Traumatic and temporomandibular joint (TMJ) pathologies constituted 8.3% and 10%, respectively.

Spectrum of findings

There were a total of 22 cases of tumors and inflammatory lesions. Among these, the maximum numbers of cases were giant-cell granulomas and radicular cysts, accounting for 22.7% of cases each. Osteomyelitis constituted 18% of the cases. Rest of the lesions included osteosarcoma, buccal space infection, ameloblastoma, adenomatoid odontogenic tumor, dentigerous cysts, and carcinoma alveolus [Figure 1].{Figure 1}

 Discussion



DentaScan is a CT protocol/software that allows high resolution, multiplanar assessment of the jaw. Although initially confined to pre-implant assessment, it is increasingly used for evaluation of mandibular and maxillary pathologies. By clearly depicting lesion characteristics and extent, without magnification, geometric distortion or superimposition, it aids diagnosis and surgical planning of jaw lesions.[1] We assessed a wide spectrum of disease entities using DentaScan with features described below, confirming its usefulness in assessing benign, malignant or infectious diseases.

Osteosarcoma

We observed a right hemimandibular primary bone tumor in our study with ill-defined margins and foci of calcification. Chandel et al.[2] observed that the commonly encountered findings in osteosarcoma were soft-tissue mass, mineralization, bone destruction, periosteal reaction, floating teeth, and sunburst appearance. In our study, DentaScan not only provided these imaging characteristics, including the typical “sunburst periosteal pattern” [Figure 2] but also provided accurate depiction of its relation to the mandibular canal and the presence of root resorption in the adjacent tooth.{Figure 2}

Osteomyelitis

Schulze et al.[3] highlighted the use of three-dimensional imaging for osteomyelitis in assessing soft tissue involvement, extent of involved bone, relation to adjacent structures, and periosteal reaction. We had four cases of osteomyelitis, three involving the maxilla and one the mandible. Variable radiographic appearances ranging from acute or chronic suppurative to sclerosing osteomyelitis have been reported.[4] The first case showed diffuse osteopenia of left hemimandible. The second case revealed multiple erosions involving the left maxillary sinus, left zygomaticomaxillary complex, and superior alveolar ridge [Figure 3] while the third case revealed thinning and rarefaction of right superior alveolar ridge at site of previous extraction. These features, in addition to clinical presentation suggested an underlying acute osteomyelitis. The fourth case of a patient presenting with purulent discharge postdental procedure showed multiple erosions involving hard palate, superior alveolar ridge, and floor of right maxillary sinus. In addition, there was sclerosis of right maxillary sinus wall, extending caudally to superior orbital ridge, and ipsilateral hard palate suggesting a diagnosis of chronic osteomyelitis. Dentascan with its superior imaging allowed better evaluation of disease extent and detection of osseous erosions.{Figure 3}

Radicular cysts

There were seven cases of radicular cysts in this study most with well-defined margins. Erosion of buccal cortex was seen in two of these cases. The imaging features were similar to those observed by Dunfee et al.[4] including radiolucent, rounded, well-defined lesions with sclerotic borders. Abrahams and Oliverio[5] suggested also that proximity to the root apex may help differentiate it from other cystic lesions [Figure 4]. Dentascan panoramic views allowed better depiction and relations of lesions with adjacent structures.{Figure 4}

Giant cell granulomas

These are uncommon, benign, proliferative lesions of unknown etiology.[6],[7] Two types, central and peripheral have been described. In this study, out of a total of five cases, four were central, and one was peripheral. Two cases involved the maxilla and mandible [Figure 5] each and one involved the nasal cavity [Figure 6]. Consistency was solid in three lesions and mixed in two. Dentascan 3D imaging display and high-resolution imaging allowed assessment of the buccal and lingual cortex which in one case each was expanded. There was calcification in one case and root resorption of adjacent teeth in two.{Figure 5}{Figure 6}

Adenomatoid odontogenic tumor

It is a benign, noninvasive odontogenic epithelial tumor with slow progressive growth. One case was seen in our study, appearing as a well-defined, unilocular, low attenuation lesion involving the right maxilla [Figure 7]. There was no calcification, necrosis, or root resorption. Mishra et al.[8] suggested that adenomatoid odontogenic tumor may commonly be associated with an unerupted tooth thus mimicking a dentigerous cyst. Radiolucency and the presence of fine calcifications may aid differentiating it from a dentigerous cyst.[9]{Figure 7}

Dentigerous cyst

A case of the dentigerous cyst was observed in our study which is a type of odontogenic cyst usually occurring around the crown of an impacted tooth. DentaScan effectively displayed it as a well-defined expansile cystic lesion with sclerotic margins, involving the left superior alveolar ridge corresponding to the 1st, 2nd, and 3rd molars and encasing the unerupted 3rd molar [Figure 8].{Figure 8}

Ameloblastoma

These are odontogenic tumors composed of epithelial elements. It may be of variable consistency: Cystic, solid or mixed, and are usually well encapsulated. Two cases were observed in our study. On imaging, one appeared as a well-defined unilocular cystic lesion involving the body of left hemi-mandible with no buccal or lingual cortical erosion but in proximity to the mandibular canal. On DentaScan the other lesion appeared well-defined, multiloculated cystic with irregular walls involving the body of left hemi-mandible. Proximity to mandibular canal and lingual and buccal cortical erosion of both was also seen. Both cases revealed root resorption of adjacent teeth.

Buccal space infection

DentaScan has utility in diagnosing cases of odontogenic infections leading to space infections. We evaluated a case of buccal space infection using DentaScan in a patient presenting with boggy swelling of the face posttooth extraction. DentaScan showed multiple, loculated, peripherally enhancing subgaleal collections along the left fronto-parieto-temporal region, extending into left infra-temporal fossa and further down along ramus until the angle of left mandible [Figure 9]. Few air pockets were also seen within this collection.{Figure 9}

Sinusitis

One of the patients in our study presented with pain and swelling in right upper posterior aspect of oral cavity. OPG showed a cystic lesion in the right maxillary region. Assessment with DentaScan revealed polypoidal mucosal thickening involving right maxillary sinus without air-fluid level, bony erosions, or calcifications [Figure 10]. No cystic lesion was seen on DentaScan, incorrectly inferred from the panoramic radiograph.{Figure 10}

Carcinoma alveolus

A case of carcinoma alveolus was also observed in our study presenting with pus discharge from the right upper alveolus. DentaScan showed a soft-tissue density mass completely opacifying the right maxillary sinus with extension into retromalar space [Figure 11]. The right pterygopalatine fossa, inferior orbital fissure, and foramen rotundum were expanded by the mas. Osseous erosions involving roof, medial, and posterolateral walls of right maxillary sinus, hard palate, and the superior alveolar process of maxilla were noted. Osseous erosions were also seen involving floor of right orbit with intraorbital extension. Enlargement of the foramen rotundum signified perineural spread. Here too, Dentascan provided valuable information about disease extent and osseous erosions.{Figure 11}

Facial fractures

These constituted five cases in our study [Figure 12] and [Figure 13]. Literature suggests that three-dimensional imaging is particularly useful for the evaluation of mandibular fractures, especially complex fractures including condylar fractures.[10] Tanrikulu and Erol[11] reported CT to be superior to conventional radiographs for the assessment of orbital as well as complex midface fractures. Dentascan with both three-dimensional capabilities and enhanced resolution depicted all fractures effectively in our study.{Figure 12}{Figure 13}

Temporomandibular joint ankylosis

TMJ ankylosis constituted six cases in our study [Figure 14] and [Figure 15]. TMJ ankylosis occurs due to the intra-capsular union of the disc-condyle complex with the temporal articular surface resulting in restricted mandibular movements. Bilateral involvement was seen in all the cases with varying degree of the severity. Bony ankylosis was seen in most cases, with only one case revealing fibrous ankylosis. Associated fracture or dislocation was seen in none of the cases. Sawhney classified TMJ ankylosis into four types.[12] There were 50% of cases of type IV ankylosis, 25% of cases of type I ankylosis and 8.3% of cases of type III ankylosis.{Figure 14}{Figure 15}

Impacted mandibular molars

Mandibular molars are the most common impacted teeth. The third mandibular molar's proximity to important anatomical structures including inferior alveolar nerve and lingual cortex makes surgical removal challenging. This, in turn, necessitates its careful pre-operative evaluation to avoid injury to the inferior alveolar nerve, fracture of lingual cortex, and injury to adjacent second molar. DentaScan aids in assessing the proximity of the mandibular canal to the impacted molar and lingual cortex. Twenty cases of impacted mandibular molars were seen in our study. The majority were impacted # 38. Others had an impacted # 48. Majority of the impacted mandibular molars had a horizontal alignment (55.5%). Other alignments seen included mesioangular (25.9%), distoangular (7.4%), and vertical (11.1%). Contact with mandibular canal was noted in 51% of cases [Figure 16].{Figure 16}

 Conclusion



Thus, DentaScan, although originally designed for pre-operative assessment of implants, has proven, as in our study, to be useful in the evaluation of other maxillary and mandibular pathologies including tumors, cysts, inflammatory, and infectious lesions, TMJ ankylosis, and facial fractures. By providing high resolution, multiplanar imaging and three-dimensional as well as panoramic display it plays a vital role in the pre-operative assessment of all such lesions and provides an accurate roadmap for safe surgical management.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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