| Abstract|| |
Pneumatization refers to the asymptomatic development of cavities containing air within them. There is great variability in the extent of temporal bone pneumatization. Nevertheless, in a few cases it extends to the zygomatic process. Images are presented in which the panoramic radiograph and hypocycloidal tomography reveal this variation from the norm, to which professionals must be alert, since the images may simulate the presence of pathology. In this case report we describe the presence of pneumatization of the petrous and zygomatic portions of the temporal bone, demonstrating the contribution of CT to reconstruction in volumetric 2D and 3D, with the aid of image rendering protocols.
Keywords: Air cells, computed tomography, faulty zygomatic air chamber, panoramic radiograph, pneumatized articular eminence, pneumatized articular tubercle, temporal bone, temporomandibular joint
|How to cite this article:|
Romano-Sousa C M, Garritano-Papa E. Pneumatization of the temporal portion of the zygomatic arch: The contribution of computed tomography to the reconstruction in volumetric two-dimensional and three-dimensional, with the aid of image rendering protocols. Indian J Dent Res 2015;26:324-7
The diagnosis of a disease goes through several steps, such as anamnesis, physical or clinical exam, and complementary exams. Imaging exams in the complementary exam phase have been established and are widely used. Frequently, we come across radiographic findings that may be pathological alterations of what, until that time, we had no knowledge.
|How to cite this URL:|
Romano-Sousa C M, Garritano-Papa E. Pneumatization of the temporal portion of the zygomatic arch: The contribution of computed tomography to the reconstruction in volumetric two-dimensional and three-dimensional, with the aid of image rendering protocols. Indian J Dent Res [serial online] 2015 [cited 2020 Apr 2];26:324-7. Available from: http://www.ijdr.in/text.asp?2015/26/3/324/162881
The term "pneumatization of the articular tubercle (PAT) of the temporal bone" appeared with Tyndall and Matteson in 1985, to describe the accessory air cells that occur in the zygomatic arch and articular eminence of the temporal bone, which are similar to the mastoid air cells in the temporal and ethmoid bones. PAT would come from the extension of air cells from the mastoid antrum to the periphery in the regions of the zygomatic process and articular tubercle of the temporal bone. Carter et al. in 1999, re-emphasized the occurrence of this phenomenon, denominating these air cells as "defect of the zygomatic air cells." The radiographic image was defined as a revealed uni- or multilocular radiolucent image radiolucencies, which could be bilateral, however, less frequently, without the presence of symptomatology, symptoms expansion or destruction of cortical margins, with a cystic appearance, located in the temporal portion of the zygomatic arch, and could extend to the articular tubercle of the temporal bone, similar to mastoid cells, and that did not extend beyond the zygomaticotemporal suture.
Recognition of this anatomic variation, also known as aeration of the petrous portion of the temporal, is important so that it will not be confused with pathologies in the region.
The air cells in the articular eminence of the temporal bone may be visible in panoramic radiographs, and there are many case reports and prevalence studies about PAT of the temporal bone, based on the use of these radiographs.,,,
However, as computed tomography (CT) is not subject to superimpositions; it exceeds the precision of the diagnosis of panoramic radiographs in the evaluation of the temporal air spaces.
Furthermore, a region less superficially located, such as the mid-portion of the eminence, can only be visible in a CT.,,
In this case report, the aim was to relate the presence of pneumatization of the petrous and zygomatic portions of the temporal bone, demonstrating the contribution of CT to the reconstruction in volumetric two-dimensional and three-dimensional (3D), with the aid of image rendering protocols.
| Clinical Case Report|| |
The patient, a girl with a chronological age of 13 years, of Caucasian descent, sought care at the Dental Clinic at ABO-RJ (DAP), Region of Valença, Brazil, for dental evaluation. The following radiographs were requested: Panoramic and cephalometric. The presence of a multilocular, radiolucent image was found, with intra-osseous septs with defined margins, located in the temporal portion of the zygomatic arch on the left side [Figure 1].
The patient was asked to undergo a computerized tomographic exam in axial [Figure 2] and coronal [Figure 3] slice, and in volumetric 3D, for accurate analysis of its extent and observation as regarding expansion, thinning, and cortical bone destruction [Figure 4] and [Figure 5].
| Discussion|| |
The incidence and characteristics of PAT of the temporal bone was demonstrated in the study by Carter et al., using panoramic radiographs, observing a nonexpansive, nondestructive, asymptomatic radiolucency with a cystic appearance, present in the zygomatic arch, similar to the mastoid air cells, and which did not extend beyond the zygomaticotemporal suture.
The dental surgeon must recognize this variation from normality and be capable of making a differential diagnosis. PAT must be differentiated from other radiolucent images within the zygomatic arch, including the aneurismatic bone cyst, hemangioma, giant cell tumor, eosinophilia granuloma, mixoma, fibrous dysplasia, and metastatic tumor, observed radiologically as expansive, destructive lesions. When there are suspected cases for differential diagnosis, the use of CT images may be considered.
Through the study of a group of children evaluated by Orhan et al. with regard to the age group in which pneumatization of the mastoid process is defined, they concluded that pneumatization of the air cells begins before puberty, contrary to the opinion and affirmations in general.,,
After exam of the CT, Stoopler et al. related the case of a woman with a chronological age of 53 years, Caucasian, with orofacial pain, who, in the panoramic radiograph, had presented an extensive multilocular radiolucent area in the articular tubercle of the temporal bone on the right side, and concluded that the radiolucency was PAT, and that this could cause inadequate interpretations because it presented an imaging pattern compatible with that of a lesion.
The use of Cone Beam CT to detect the prevalence and characteristics of PATs in the study by Miloglu et al. showed the pneumatization better than it was shown using the conventional technique. The majority of the PATs were found in female individuals while the multilocular variant was the most common (around 58%). They concluded that PATs are more common than was previously thought, and for cases of suspected evaluation, a supplementary exam should be performed.
Panoramic radiographs of routine ambulatory clinic patients with ages between 19 years and 91 years, were concomitantly evaluated by four investigators in the study by Patil et al., and observed a prevalence of 1.82% of unilateral and multilocular photoacoustic cystography with a preponderance in males.
In our study, CT with volumetric 3D reconstruction, aided by image rendering protocols, was the method of choice for the evaluation of bone structures and air spaces at the base of the skull, should doubts still persist with regard to the analysis of details such as expansion and destruction of the cortical bone.
| Conclusion|| |
Panoramic radiographs allow us to observe the presents of help visualize pneumatization of the temporal portion of the zygomatic arch. Recognition of this anatomic variation is important so that it is not confused with pathologies of the region. CT with volumetric 3D reconstruction, with the aid of image rendering protocols, is the method of choice for arriving at a differential diagnosis. Further research with additional variables may provide new perspectives for this little-known entity.
| Resumo|| |
Pneumatização refere-se ao desenvolvimento assintomático de cavidades contendo ar em seu interior. Existe uma grande variabilidade na extensão da pneumatização do osso temporal. Contudo, em poucos casos ela atinge o processo zigomático. São apresentadas imagens em que a radiografia panorâmica e a tomografia hipocicloidal revelam esta variação da normalidade para a qual os profissionais devem estar atentos, já que as imagens podem simular a presença de patologia. Neste relato de caso descrevemos a presença de pneumatização das porções petrosa e zigomática do temporal demonstrando a contribuição da TC com reconstrução em 2D e 3D volumétrica, com auxílio de protocolos de renderização da imagem.
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There are no conflicts of interest.
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Department of Clinical Dentistry, Faculty of Dentistry, University Federal Fluminense, UFF, Rio de Janeiro
Source of Support: Nil, Conflict of Interest: None
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]