Journal of Oral and Maxillofacial Radiology

ORIGINAL ARTICLE
Year
: 2022  |  Volume : 10  |  Issue : 2  |  Page : 40--44

Diagnostic accuracy of ultrasonography verified with computed tomography for the diagnosis of maxillofacial fractures – A prospective study


Abhishek Shailesh Shah1, Tejraj Kale1, Virupaxi Hattiholi2, Husain Dhabaria3,  
1 Department of Oral and Maxillofacial Surgery, KLE Vishwanath Katti Institute of Dental Sciences, KAHER University, Belgaum, Karnataka, India
2 Department of Radiology, Jawaharlal Nehru Medical College, KAHER University, Belgaum, Karnataka, India
3 Department of Oral Surgery, Yenepoya Dental Hospital, Mangaluru, Karnataka, India

Correspondence Address:
Abhishek Shailesh Shah
Department of Oral and Maxillofacial Surgery, KLE Vishwanath Katti Institute of Dental Sciences, KAHER University, Belgaum, Karnataka
India

Abstract

Objectives: The objective of this study was to evaluate the diagnostic accuracy of ultrasonography (USG) if it can be used as a primary diagnostic method for maxillofacial trauma and to determine the sensitivity and specificity of USG verified with a computed tomography (CT) scan. Materials and Methods: This study was a comparative prospective study that consisted of a total of 32 patients. Patients reported to the Trauma Care and Emergency Center of KLES Dr. Prabhakar Kore Hospital with maxillofacial trauma during October 2018–September 2020 were included in the study. Following a CT scan, based on the inclusion criterion, the patient underwent an ultrasonographic examination of any maxillofacial fracture that had been confirmed by a CT scan to verify it. Sensitivity and specificity were calculated to establish the accuracy of USG. Results: A total of14 sites were selected in the maxillofacial region. Out of all the 14 anatomical landmarks, nine were able to detect all the fractures on USG with 100% sensitivity and specificity. Intracapsular condyle fractures were not seen on USG. The region where all the fractures were not identified on USG was medial wall and floor of the orbit, one nondisplaced ramus fracture. Conclusions: The overall sensitivity observed for the diagnosis of maxillofacial fracture was 85.21% and specificity observed was 100%. In conclusion, USG can be a handy, diagnostic, additional, noninvasive, and inexpensive tool in the detection of maxillofacial fractures when compared to CT in the primary health-care center. Furthermore, studies should be conducted with a considerable amount of sample size as the literature mentions limited work regarding USG as a primary technique in maxillofacial fractures detection.



How to cite this article:
Shah AS, Kale T, Hattiholi V, Dhabaria H. Diagnostic accuracy of ultrasonography verified with computed tomography for the diagnosis of maxillofacial fractures – A prospective study.J Oral Maxillofac Radiol 2022;10:40-44


How to cite this URL:
Shah AS, Kale T, Hattiholi V, Dhabaria H. Diagnostic accuracy of ultrasonography verified with computed tomography for the diagnosis of maxillofacial fractures – A prospective study. J Oral Maxillofac Radiol [serial online] 2022 [cited 2022 Aug 11 ];10:40-44
Available from: https://www.joomr.org/text.asp?2022/10/2/40/351668


Full Text



 Introduction



Maxillofacial injuries are quite common following road traffic accidents (RTA), fall, and assault. If a clinical examination reveals the existence of a fracture of the facial skeleton, standard evaluation in the form of imaging techniques is done for obtaining the final diagnosis.[1] For a long time, computed tomography (CT) is considered the gold standard for maxillofacial fracture diagnosis and is used as the first modality. However, it has certain limitations such as access to facilities, high cost, and radiation exposure.[2]

On the other hand, ultrasonography (USG) has been widely used in medical fields due to its remarkable features such as nonradiation, quick, and painless technique. To date, the use of ultrasound is known for its use associated with soft-tissue lesions and pathology.[3] The role of USG in maxillofacial trauma is less widely recognized. USG uses high-frequency ultrasonic waves, which are transmitted to the body and dispersed through the tissues by a transducer, and echoes are reflected on the screen for the diagnostic purpose.[2] The recent technological advancements can now transmit ultrasound waves to bony lesions and fractures of the maxillofacial region. The use of ultrasound for the assessment of maxillofacial fractures is therefore emerging.[1],[2] As ultrasound is a cost-effective, noninvasive, and easily available imaging technique, it can be used as a primary investigative imaging method. This study determined the diagnostic accuracy of ultrasound and was verified with CT for the detection of maxillofacial fractures.

 Materials and Methods



Patients reporting to Trauma Care and Emergency Center of KLES Dr. Prabhakar Kore Hospital with maxillofacial trauma following a RTA, fall, assault, etc., during the October 2018–September 2020 were included in the study. This study was a comparative prospective study which consisted total of 32 patients. All the patients were explained the procedure and an informed consent was signed by them. The study protocol was approved by the ethical committee board of the institution. As first-line imaging, CT of the facial skeleton was carried out and examined to establish a diagnosis. Later, the patient underwent ultrasound examination of the affected region.

Inclusion criteria

Maxillofacial injuries with bone fracturesAll age groupsBoth male and female.

Exclusion criteria

Patients with any medical or surgical emergency were excluded from the study.

Methodology

Thirty-two patients (27 males and five females) presented with clinically diagnosed injuries to the maxillofacial region were included in the study. CT of the facial skeleton with a three-dimensional reconstruction was taken and examined, to establish a diagnosis. The patients were subjected to an ultrasound examination of the affected regions using GE Voluson P8 ultrasound machine with linear probe (5-7MHz) and curvilinear probe (7-12MHz) [Figure 1]. CT scans were done with GE Voluson EVO-Germany (Assembled in India). The results of CT scans and USG were summarized by two different radiologists. The radiologist conducting the USG investigation was blinded to the findings of the CT scan examination.{Figure 1}

Patients selected were clinically examined to determine the area for carrying out the USG. The linear/curvilinear probe used for USG was cleaned and Medi gel ultrasound jelly was placed over the affected area and on the probe. The probe was applied on the affected area for the diagnosis of underlying fracture. In case of patients with contused lacerated wounds or any form of abrasion, they were given primary care before any investigation was carried out. Care was taken to ensure that no pressure was exerted, with minimum mobilization of the patient during the procedure. Absolute care was taken to perform the scan with total precautions to prevent any infection due to the scan, in the patients who had skin injuries.

 Results



A total of 32 patients were selected based on the inclusion criteria. The age group was classified into three categories: ≤30 years, 31–40 years, and ≥41 years. According to the age group, 16 of 32 (50%) were below 30 years of age. There were eight patients in the age group of 31–40 years and eight patients were above 40 years of age [Table 1]. Of the 32 patients selected, 27 were males and five were females. The majority of the patient, i.e., 27 of 32 had a history of RTA, four patients had a history of fall and one patient gave a history of assault. The mean age for selected patients was 35.78 ± 14.21 years as shown in [Table 1].{Table 1}

The sites which were fractured on CT scans and identified on USG with 100% accuracy were frontal bone, lateral wall of the orbit, anterior wall of maxillary sinus, roof of the orbit, zygomatic arch, zygomatic bone, nasal bone, symphysis/parasymphysis, and angle of mandible, respectively [Figure 2]. In this study, the sensitivity and specificity for all these sites were 100%.{Figure 2}

In this study, it was found that nine out of 14 sites taken up for the ultrasound examination were able to identify all the fractures with 100% accuracy which were verified with CT scans. Only in the cases of condylar/subcondylar region, floor of the orbit, medial wall of the orbit, and body and ramus of mandible all the fractures were not seen with the help of ultrasound. The visualization of the posterior wall of maxillary sinus was not possible with the help of linear probe in cases of midface fractures. However, fracture of the anterior wall of the maxillary sinus was easily identified using a convex probe with low resolution (2-5 MHz).

Fractures of the floor of the orbit were identified in 10 of 12 cases, respectively [Figure 3]. The sensitivity and specificity of the same were 83.33% and 100%, respectively. Fractures of the medial wall of the orbit were seen in five of seven cases. The sensitivity and specificity were 71.43% and 100%, respectively. There was no false-positive case reported. The remaining fractures could not be identified due to the poor sound wave penetration in cases of orbital fractures. Subcutaneous edema and hematoma were used as a guide to spot the fracture location.{Figure 3}

The fractures in case of the body of the mandible were identified in two of three cases with sensitivity and specificity were 66.67% and 100%, respectively. The ramus of mandible showed fracture in one of two cases with 50% sensitivity. Each fracture of the ramus and body of mandible were undisplaced fractures of mono-cortex which was diagnosed on CT scan and was not identified on USG. The fracture of the condyle/subcondyle region was identified in one of four cases which gave sensitivity and specificity of 33.33% and 100%, respectively. The negative predictive value of 93.55% indicated that three of four cases were false negative [Figure 4].{Figure 4}

 Discussion



USG is a diagnostic technique that is noninvasive and does not contain ionizing radiation. It is a quick and painless technique and has no known harmful effect on the body. When it was applied to head-and-neck medicine, it was limited to the imagery of superficial structures of the head and neck and was considered to have a limited role in bone lesions.[4] On the other hand, CT was introduced in the 1970s and it has become an important tool in medical imaging to supplement X-rays and USG.

Many literature studies have already identified the possibility of ultrasonographic fracture visualization in the maxillofacial region.[5] USG has its own set of advantages when compared to CT scans such as no exposure to radiation, painless technique and inexpensive. and easy availability, patient cooperation required is less and there is no requirement of patient positioning.[4] Second, USG is portable which makes it available intraoperatively to check the reduction of the fracture in cases of isolated zygomatic arch fractures and nasal bone fractures. However, ultrasound cannot penetrate deeper bony structures, and thus its use is only restricted to superficial facial landmarks.[3]

Ord et al. used ultrasound for the first time in 1981 to detect orbital wall fractures.[6] In that study, USG showed 95% sensitivity to screen all the fractures.[2] In the literature, the lowest sensitivity found for the identification of medial and lateral wall fractures in the literature was 56% and 88%, respectively, while the lowest specificity was 90% and 87%, respectively. The precision for detecting orbital wall fractures typically varies from 90% to 100%.[4] In the present study, medial orbital wall fracture showed the values for sensitivity and specificity of 71.43% and 100%, respectively. For the lateral orbital wall, the sensitivity and specificity were 100%, i.e., all fractures were identified.

The orbital floor fracture has their sensitivity and specificity varying from 85% to 100% and 57% to 100%, respectively, and accuracy varies from 86% to 98%.[1],[7],[8],[9] It was repeatedly found out that orbital floor fractures beyond 4 cm to the orbital margin which is present posteriorly, are poorly identified by ultrasound.[1] The current study showed us the sensitivity and specificity of 83.33% and 100%, respectively, for orbital floor fracture. Using a curved array transducer, recently published results demonstrated good to excellent reliability in the diagnosis of orbital fractures involving the infraorbital rim and the orbital floor.[10] The literature mentioned little work on orbital roof fractures. The present study showed a sensitivity and specificity of 100% for the diagnosis of orbital roof fracture. The overall diagnostic accuracy for all orbital wall fractures was seen ranging from 90% to 100% which shows a good reliability.[7],[8],[10],[11] In patients with only minor clinical symptoms, ultrasound could be used to rule out a fracture. USG of the medial orbital wall and floor of orbit fracture requires highly experienced investigators.

Nasal bone, frontal bone, and zygomatic arch fractures have 100% precision in the ultrasound detection of fractures shown in the literature.[6] In 2019, Rajeev et al. conducted an analysis in which ultrasound identified all the fractures at some anatomical landmarks, i.e., the zygomatic arch, the frontal sinus (anterior wall), infraorbital margin, roof of the orbit, and mandibular symphysis/parasymphysis and mandibular angle.[3] The current study showed a similar result in diagnosing fractures with 100% accuracy at all these sites.

In this contemporary study, fractures of the anterolateral wall of the maxillary sinus and zygoma (malar bone) were detected easily by ultrasound with a sensitivity and specificity of 100%. This is in agreement with a study conducted by McCann et al.[1] who concluded that ultrasound as an initial examination is a valuable method in imaging facial injuries, which may help to cut down on the total number of radiographs required for the detection of zygomatic-orbital complex fractures.

Kleinheinz et al.[12] and Friedrich et al.[13] reported ultrasonographic sensitivity and specificity of 100% and 100%, respectively, and 66% and 52%, respectively, in the detection of mandibular subcondylar/ramus fractures. In our study, the mandibular ramus and condylar/subcondylar region showed the sensitivity of 50% and 33.33%, respectively, while it showed the specificity of 100%. Only in one case of the subcondylar fracture, it was identified on ultrasound because there was subluxation of temporomandibular joint. Other fractures seen on CT scan were condylar head and intracapsular fracture of condyles. Friedrich et al.[13] highlighted the shortcomings of ultrasound to detect intracapsular condylar fractures due to its overlap by the zygomatic arch.

A systematic review conducted by Adeyemo and Akadiri has mentioned the factors affecting the credibility of USG in maxillofacial trauma:[4]

Expertise of sonographerTransducer's type and its resolutionLack of a traditional facial skeleton scanning techniqueVisualization in real-time is better than hard copy interpretationUltrasound evaluation from the time of injury.

The systematic review also mentioned limitations of ultrasound imaging in maxillofacial fractures which included;[4]

Inability to represent multiple facial fractures that are complex in nature. In this study, all the fractures were identified even in patients with pan facial fracturesDifficulty in detecting undisplaced fractures. In the present study, all the fractures were identified by USG except in the case of one ramus fracture which was undisplacedNot able to investigate posterior orbital floor ≥4 cm. Orbital floor fractures were not seen in some cases as they were present posteriorly in the current studyInability to detect the intracapsular fracture of condyles due to the overlapping of the zygomatic arch.

 Conclusions



In this study, the overall sensitivity observed for diagnosis of maxillofacial fracture was 85.21% and the specificity observed was 100%. Fractures of the nasal bone, uncomplicated orbital wall fractures, anterior maxillary wall of maxillary sinus, zygomatic arch fractures, mandibular fractures of symphysis/parasymphysis, and body and angle were readily detected on ultrasound. USG shows favorable results in the detection of extracapsular subcondylar fractures, but maxillofacial surgeons must know its shortcomings in undisplaced fractures, complex maxillofacial fractures, posterior orbital floor fractures, and intracapsular mandibular condyle fractures. The sonographic techniques need to be upgraded and special transducer probes should be made for certain regions to detect fractures without any difficulty. The maxillofacial surgeons should be trained for the use of ultrasound so that intraoperative and postoperative reduction of fractures can be checked and radiation exposure can be avoided. USG gives a good utility in the diagnosis and treatment of maxillofacial trauma. If properly developed and implemented, the relative advantages of USG over CT could minimize the use of CT scans for exclusive circumstances and thus revolutionize maxillofacial imaging in trauma care.

Furthermore, studies should be conducted with a considerable amount of sample size as the literature mentions limited work regarding USG as a primary technique in maxillofacial fractures detection. Furthermore, it should be validated as a procedure along with CT scans and conventional radiographs in medicolegal cases for detection of fractures.

In conclusion, USG can be a handy, diagnostic, additional, noninvasive, and inexpensive tool in the detection of maxillofacial fractures when compared to CT in primary health-care centers.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1McCann PJ, Brocklebank LM, Ayoub AF. Assessment of zygomatico-orbital complex fractures using ultrasonography. Br J Oral Maxillofac Surg 2000;38:525-9.
2Sreeram MP, Mandava R, Ravindran C, Elengkumaran S. Use of ultrasound as a screening tool in the maxillofacial fractures. Int Med J 2016;3:573-7.
3Rajeev A, Pai KM, Smriti K, Kadavigere R, Kamath AT, Gadicherla S, et al. Diagnostic accuracy of ultrasonography in the assessment of facial fractures. Pesqui Bras Odontopediatria Clín Integr 2019;19:e4832.
4Adeyemo WL, Akadiri OA. A systematic review of the diagnostic role of ultrasonography in maxillofacial fractures. Int J Oral Maxillofac Surg 2011;40:655-61.
5Reddy VK, Shaik M, Sasthrulu G. Ultra sonography in zygomatic arch fractures. Int J Recent Sci Res 2016;7:12102-5.
6Ord RA, Le May M, Duncan JG, Moos KF. Computerized tomography and B-scan ultrasonography in the diagnosis of fractures of the medial orbital wall. Plast Reconstr Surg 1981;67:281-8.
7Jank S, Emshoff R, Etzelsdorfer M, Strobl H, Nicasi A, Norer B. The diagnostic value of ultrasonography in the detection of orbital floor fractures with a curved array transducer. Int J Oral Maxillofac Surg 2004;33:13-8.
8Jank S, Deibl M, Strobl H, Oberrauch A, Nicasi A, Missmann M, et al. Interrater reliability of sonographic examinations of orbital fractures. Eur J Radiol 2005;54:344-51.
9Jenkins CN, Thuau H. Ultrasound imaging in assessment of fractures of the orbital floor. Clin Radiol 1997;52:708-11.
10Jank S, Deibl M, Strobl H, Oberrauch A, Nicasi A, Missmann M, et al. Interrater reliability in the ultrasound diagnosis of medial and lateral orbital wall fractures with a curved array transducer. J Oral Maxillofac Surg 2006;64:68-73.
11Forrest CR, Lata AC, Marcuzzi DW, Bailey MH. The role of orbital ultrasound in the diagnosis of orbital fractures. Plast Reconstr Surg 1993;92:28-34.
12Kleinheinz J, Anastassov GE, Joos U. Ultrasonographic versus conventional diagnostic procedures in dislocated subcondylar mandibular fractures. J Craniomaxillofac Trauma 1997;3:40-2.
13Friedrich RE, Plambeck K, Bartel-Friedrich S, Giese M, Schmelzle R. Limitations of B-scan ultrasound for diagnosing fractures of the mandibular condyle and ramus. Clin Oral Investig 2001;5:11-6.