Occlusal Radiographs in a Turkish Pediatric Subpopulation

Abstract

Objectives

Dental radiographs are a useful diagnostic aid in the oral health care and dental treatment of children. The most commonly used radiographs are periapical and panoramic radiographs. Occlusal radiographs are preferred in more specific cases. The aim of this study was to retrospectively evaluate the reasons for obtaining occlusal radiographs in pediatric patients.

Material and methods

Occlusal radiographs of patients aged 1-13 years who attended the Pediatric Dentistry Clinic of Ondokuz Mayıs University Faculty of Dentistry between 01 August 2015 and 01 August 2020 were retrospectively evaluated. Patients with syndromes and diseases that could cause cleft lip and palate and dental anomalies were not included in the study. The medical history of the 354 patients who were included in the study was provided by the automated system.

Results

A total of 359 occlusal radiographs from these patients were analysed. The number of male patients included in the study was 208 and the number of female patients was 146. Occlusal radiographs of the maxilla of 312 patients were taken, of the mandible of 37 patients, and both the upper and lower jaws of 5 patients. It was found that occlusal radiographs were taken mostly for dental trauma in the permanent dentition (156), injuries in the primary dentition (68) and for the diagnosis of dental anomalies (57).

Conclusions

Occlusal radiographs are taken for specific situations in pediatric dentistry and are particularly useful in the detection and diagnosis of primary and permanent tooth injuries.

Introduction

Radiographic techniques in dental practice are based on the principles of ionizing radiation, which requires controlled use (1). Following both extra-oral and intra-oral examinations, specific radiographic studies are performed when deemed necessary to obtain more detailed information, all in accordance with the As Low As Reasonably Practicable (ALARP) principle. This principle has been modified to As Low As Diagnostically Acceptable (ALADA), which emphasizes the trade-off between image quality and radiation dose. It focuses on minimizing radiation exposure to levels that are both safe and reasonably achievable (2). Recently, the new ALADAIP principle has been introduced. This means that As Low As Diagnostically Achievable principle is indication-based and patient-specific. The main idea is that each exposure should be justified and tailored to the individual patient and circumstances (2, 3).

In pediatric dentistry, radiographic imaging techniques are mainly needed to diagnose caries lesions, assess dental injuries, detect developmental abnormalities in teeth, determine the presence of pathological conditions and estimate dental age (4-7). The 2-dimensional radiographic imaging techniques commonly used in pediatric dentistry can be listed as periapical, bitewing, occlusal, lateral oblique, cephalometric, skull and panoramic. Other imaging modalities rarely used by dentists include radioisotope imaging, multidetector computed tomography (MSCT), cone beam computed tomography (CBCT), ultrasound and magnetic resonance imaging (MRI), which are occasionally used in pediatric dentistry (1, 8). Panoramic radiographs are often used to view all of the teeth, jaws, maxillary region up to 1/3 upper part of the eye sockets, maxillary sinuses and the temporomandibular joint. Periapical and bite-wing radiographs are also frequently preferred in general and pediatric dental practice. Periapical radiographs show the entire tooth in detail, including the surrounding bone. Bite-wing images show crowns of teeth and adjacent alveolar crests. Occlusal radiographs are preferred in more specific situations in both adult and pediatric patients (9, 10). Occlusal images show a larger area of ​​teeth and bone than periapical images. Thanks to occlusal radiography, which is one of the guiding methods especially for orthodontics and maxillofacial surgery, the development of bone structure and healthy development of teeth can be examined together with the position of the jaw. Occlusal radiographs can give a diagnostically important third dimension that is not usually available with periapical radiographs or standard panoramic imaging. An occlusal radiograph is indicated for painless examination of the region following an accident or injury in the anterior region, especially in children. Large size image receptors are needed to obtain occlusal radiographs. The size is 7.7cm x 5.8cm. The size of image receptor number 2 is 3.1cm x 4.1mm. Occlusal receptors consist only of conventional film and phosphor plates. CCD and CMOS sensors do not have this dimension. Occlusal radiography is divided into maxillary and mandibular radiography according to the area to be imaged. The maxillary occlusal projection shows the anterior maxilla and the teeth, the zygomatic processes of the maxilla, the anteroinferior surfaces of each antrum, the nasolacrimal ducts, the nasal septum, and the intermolar teeth (8). The mandibular occlusal projection shows the anterior part of the mandible and the soft tissue of the floor of the mouth (11).

The indications for occlusal radiography include antero-posterior and buccolingual/buco-palatinal widths of pathologies that may be encountered in the upper and lower jaw, localization of impacted teeth, residual roots, foreign bodies, periapical images for localization of supernumerary teeth, visualization of sublingual and submandibular salivary stone, detection of fractures in the mandible or maxilla, a complete examination of the maxillary sinus, and it is used in patients with trismus who cannot open their mouth (8, 12).

There is limited information in the literature on occlusal radiographs. The aim of this study was to retrospectively evaluate digital occlusal radiographs which were taken from pediatric patients.

Materials and methods

In this retrospective study, patients aged 1-13 years, who attended the Ondokuz Mayıs University, Faculty of Dentistry, Department of Pedodontics between August 1, 2015 and August 1, 2020 were included.

Inclusion criteria in the study were as follows: No systemic disease or syndrome; High quality of occlusal radiographs.

Exclusion criteria: Presence of a systemic disease and syndrome; Cleft lip and cleft palate; Radiotherapy and chemotherapy in head and neck; Radiographs of low quality.

Occlusal radiographs were taken using a digital x-ray unit (Sirona Dental systems heliodent plus D3507 intraoral x-ray, Sirona Dental Company, Germany) at 70 kVp, 7 mA, and 0.25 second exposure time. Occlusal radiographs of 354 patients (208 boys, 146 girls) who met the inclusion criteria were evaluated on digital film. Occlusal radiographs were analyzed for jaw fractures, dental trauma, dental anomalies (number, size, shape, position, eruption), odontogenic cysts, tumors and infections, and control. When the study groups were formed, if there were fewer than about ten reasons for taking occlusal radiographs, the groups were combined.

This study was based on retrospectively evaluating radiographs. The parents of the patients had given informed consent before the radiographs were taken. The authors conducted the study in accordance with the principles of the Declaration of Helsinki, including all modifications and revisions.

The Chi-square test (χ2) was used to analyze the data. P<.05 was accepted as the level of significance. All statistical calculations were performed using the statistical package program SPSS 17.0 V.

Results

Patients aged 1-13 years who had occlusal radiographs were included in this study. The mean age of the patients was 7.48 ± 2.59 years for females and 7.76 ± 2.41 years for males. It was determined that 359 occlusal radiographs were taken from 354 patients included in the study. These occlusal radiographs were taken from the upper jaw of 312, the lower jaw of 37, and both the lower and upper jaws of 5 patients. The number of male patients was 208, and the number of female patients was 146. It was found that more occlusal radiographs were taken in male patients, but according to the results of the chi-squared test, no statistical difference was observed between the genders in terms of the reasons for taking occlusal radiographs (χ2 (5) = 3,123; p> 0.05), and occlusal radiographs were mostly taken in eight-year-old patients, in both females and males.

The reasons for taking occlusal radiographs from the patients and their distribution by age are shown in Table 1. It was found that the most common reason for taking occlusal films was permanent tooth trauma (156), followed by primary tooth trauma (68). Number anomaly was the most common dental anomaly (57). Jaw fracture was noted in only one patient, talon tubercle in two patients, and dens in dente in two patients. Occlusal radiographs were taken for control in 35 patients. (Figures 1a-f)

Table 1. Reasons for occlusal radiography and age distribution.

Reasons	Total	Male	Female	Lower	Upper	Both upper and lower	1y	2y	3y	4y	5y	6y	7y	8y	9y	10y	11y	12y	13y
Jaw fracture Talon cusp Gemination Dens in dente Crown malformation Ectopic eruption Odontogenic cyst, tumor, infection	1 (0.28%)	1 (0.48%)		1 (2.7%)		-	-	-	-	-	-	1	-	-	-	-	-	-	-
	2 (0.56%)	1 (0.48%)	1 (0.68%)		2 (0.64%)	-	-	-	-	-	-	-	1	-	-	1	-	-	-
	1 (0.28%)	1 (0.48%)			1 (0.32%)	-	-	-	-	-	-	-	-	1	-	-	-	-
	2 (0.56%)	2 (0.96%)	-	1 (2.7%)	1 (0.32%)	-	-	-	-	-	-	-	-	-	1	1	-	-
	3 (0.85%)	2 (0.96%)	1 (0.68%)		3 (0.96%)	-	-	-	-	-	-	-	-	1	-	1	1	-
	5 (1.41%)	3 (1.44%)	2 (1.37%)	-	5 (1.6%)	-	-	-	-	1	-	-	1	1	1	1	-	-	-
	9 (2.54%)	5 (2.40%)	4 (2.74%)	2 (5.41%)	7 (2.24%)	-	-	-	-	-	2	3	1	-	-	2	-	1	-
Trauma in primary dentition	68 (19.2%)	35 (16.8%)	33 (22.6%)	4 (10.8%)	62 (19.9%)	2 (40%)	1	10	11	12	14	16	4	-	-	-	-	-	-
Trauma in permanent dentition	156 (44.1%)	93 (44.7%)	63 (43.1%)	19 (51.4%)	137 (43.9%)	-	-	-	-	-	-	5	19	38	39	29	18	6	2
Anomalies of number (Supernumerary tooth)	57 (16.1%)	37 (17.8%)	20 (13.7%)	1 (2.7%)	56 (17.9%)	-	-	1	2	1	2	5	12	14	9	7	3	2	-
Delay in tooth eruption	15 (4.24%)	9 (4.33%)	6 (4.11%)		15 (4.81%)	-	-	-	-	-	-	-	6	5	1	2	-	1	-
Diagnosis and control	35 (9.89%)	19 (9.13%)	16 (11%)	9 (24.3%)	23 (7.37%)	3 (60%)	-	1	1	-	5	6	5	4	4	5	2	-	1
	354 (100%)	208 (100%)	146 (100%)	37 (100%)	312 (100%)	5 (100%)	1	12	14	14	23	36	49	64	55	49	24	10	3

y: year

Figure 1.

a Talon cusp in a tooth #22, 1b Dental trauma in two permanent teeth # 11, 21, 1c Dental trauma in two primary teeth #51, 61, 1d Supernumerary teeth in the upper jaw, 1e Lesion in the right maxillary canine tooth region, 1f Eruption disorder in a tooth #21.

Discussion

Radiology in dentistry is an integral part of a holistic approach to diagnosis and treatment. Although the oral clinical examination and the patient's medical history bring the clinician closer to the treatment, a comprehensive view cannot be provided without any radiological support. Occlusal projection, which is one of the radiographic techniques, is also a special technique that is needed in many cases. However, there has been no study in the Turkish population on the purpose of using occlusal radiographs in children. This study attempted to fill the gap in this area to some extent.

Tooth and jaw development, as an integral part of body integrity, is affected by systemic diseases and syndromes (13, 14). Therefore, the patients with such syndromes were not included in the study. Since radiation and chemotherapy treatments received during childhood affect the bony structures, the patients undergoing such treatments were also excluded from the study (15) In terms of standardization; all digital occlusal radiographs in the study were taken with a single X-ray unit.

Post-traumatic occlusal radiographs are as effective as periapical radiographs and allow a wider area to be examined. They are particularly efficient and effective in imaging foreign bodies embedded in soft tissue (16). Occlusal radiographs were taken following dental trauma in 63.3% of cases. 44.1% of these radiographs were taken after permanent dental trauma. Consistent with a study by Schüler et al. on the frequency of intraoral radiographs, the most common indication for intraoral radiographs was trauma (28.7%), followed by caries (22.7%) and apical diagnosis (17). Although the results of our study are valid for occlusal radiographs, it can be concluded that trauma is the most common indication for all types of intraoral radiographs. Injuries due to trauma to permanent teeth increase between the ages of 8-10 years (18). Consistent with this, it was found that most occlusal radiographs were taken at the age of 9 years in children, the age group in which most injuries occur. Approximately 3/5 of the patients are male, while the remaining 2/5 are female. Maxillary central teeth are the most commonly injured teeth due to trauma (18, 19). This is supported by the fact that 89.5% of the occlusal radiographs taken due to permanent tooth trauma were taken from the maxilla.

The rate of occlusal radiographs taken for primary dental trauma was 19.2%. Occlusal radiography, which is often used because of its ease of use and acceptability, especially in the evaluation of tight contacts and trauma in young children, is more tolerable and provides a wider view in children aged 0-7 years compared to periapical radiography (20). It was found that approximately 61.8% of patients undergoing radiography for primary tooth trauma were aged 4-6 years.

This study found that another reason for taking occlusal radiographs in pediatric patients was the number anomalies in the teeth with a rate of 16.1%. The reason for using occlusal radiographs, especially in the presence of supernumerary teeth, is the 3rd dimensional data that allows us to understand the exact position of the supernumerary tooth. 98% of the radiographs taken for the detection of supernumerary teeth were taken from the maxilla. This correlates with the information that supernumerary teeth are approximately 10 times more common in the upper jaw (21).

It is likely that occlusal radiographs taken due to odontogenic cysts, tumors and similar lesions can be clearly visualized by providing the third dimension of pathological lesions that expand spatially or extend beyond anatomical boundaries (11).

Delayed eruption can be caused by many reasons (22). In this study, regardless of the cause, the rate of occlusal radiographs taken to detect dental eruption delay was 4%. Occlusal radiographs, which provide a wide-area assessment of the level of development of the teeth, their roots and their supporting tissues, are a good alternative when local factors need to be investigated after systemic factors have been eliminated.

There are some limitations of our study. The first limitation is that the study was conducted at one location and the patient population consisted only of patients who attended the Ondokuz Mayıs University Faculty of Dentistry, Pediatric Dentistry Clinic. Since the study population consisted of patients who presented to the clinic, it does not fully reflect the general population. Furthermore, all data were taken from the digital system, and there were no manual data to analyze.

Conclusion

Occlusal radiographs are used for specific conditions in pediatric patients. Occlusal radiographs in pediatric dental practice are most frequently used in cases of dental trauma and are mostly taken from the upper jaw. There is a need for more comprehensive studies including adult patients with occlusal radiography of the lower or upper jaw.