Department Of Oral Radiology Research Articles

Authors' response: development and validation of a questionnaire to evaluate infection control in oral radiology—consistent statistical analyses and methodology

Division of Oral Radiology Department of Oral Diagnosis Piracicaba Dental School State University of Campinas

Assessing pulp stones by cone-beam computed tomography.

The aim of this study was to evaluate the occurrence of pulp stones by cone-beam computed tomography (CBCT) and to correlate their prevalence with patient's gender, location of tooth (right or left of maxillary or mandibular arch), group of teeth, and restorations. CBCT images of 382 patients randomly selected from the database of the University Oral Radiology Department were retrospectively examined. A total of 2833 tooth images obtained using the i-CAT 3D Imaging System were evaluated. Image analysis was performed with the i-CAT software, and all teeth were evaluated in sagittal, axial, and coronal views. All the measurements were subjected to chi square test, odds ratio, and Fisher's exact tests (p<0.05). The prevalence of pulp stones was similar between patient's genders and tooth locations. Pulp stones were detected in 31.9% of patients and 9.5% of teeth. Maxillary and mandibular molars were the groups of teeth with the highest frequency of pulp stones. The presence of restorations increased the chance of occurrence of pulp stones by 2.1 times in all teeth examined (p<0.0001) and by 4.7 times in maxillary teeth (p<0.0001). Pulp stones had a high prevalence with molar teeth showing the highest prevalence. The presence of restorations increased the chance of occurrence of these calcifications, specifically in maxillary teeth. CBCT provides accurate anatomical details in three dimensions, offering the possibility to view an individual tooth in axial, sagittal, and coronal views. This study performed an investigation of the occurrence of pulp stones by CBCT.

Reliability of three-dimensional measurements of the upper airway on cone beam computed tomography images

The aim of this study was (1) to assess intra- and interobserver reliability of the localization of anatomic landmarks of the upper airway on cone beam computed tomography (CBCT) images; and (2) to assess intra- and interobserver reliability of the three-dimensional measurements of the upper airway based on these landmarks. Fifteen NewTom 5G (QR systems, Verona, Italy) CBCT data sets were randomly selected from the archives of the Department of Oral Radiology, Academic Centre for Dentistry (ACTA) at University of Amsterdam and VU University, Amsterdam, The Netherlands. Three observers localized six anatomic landmarks that are relevant for upper airway analysis twice, with a 10-day interval, using 3Diagnosys software (v5.3.1, 3diemme, Cantu, Italy). Subsequently, the observers performed upper airway volume measurement based on those landmarks twice as well, again with a 10-day interval, using Amira software (v4.1, Visage Imaging Inc., Carlsbad, CA). The upper airway measurements also included the minimum cross-sectional area (CSAmin), location of the CSAmin, and anteroposterior and lateral dimensions of the CSAmin. Both intraobserver reliability and interobserver reliability were excellent for the localization of the anatomic landmarks of the upper airway (intraclass correlation coefficients= 0.97-1.00) as well as for the three-dimensional upper airway measurements (intraclass correlation coefficients= 0.78-1.00). The methodology of landmark localization and upper airway measurements, as used in this study, showed an excellent reliability and can thus be recommended for upper airway analysis on CBCT images.

A Focus on Variation in Morphology of Soft Palate Using Cone-Beam Computed Tomography with Assessment of Need's Ratio in Central Madhya Pradesh Population.

Soft palate is an anatomical structure that helps in modifying the quality of voice and to breathe while swallowing. Through the variants and shapes of the soft palate, we can assess the age and gender of an individual. The aim of the present study was to investigate the variation in morphology of soft palate and to find its association with the Need's ratio, Velar Length (VL), Velar Width (VW) and Pharyngeal Depth (PD), in age groups and gender using CBCT in Central Madhya Pradesh population. The study sample consisted of 121 CBCT scans of individuals aged between 15 to 45 years. These scans were retrieved from the Department of Oral Radiology. The velar morphology on CBCT was examined and grouped into six types. The results obtained were subjected to a statistical analysis to find the association between variants of the soft palate with gender and different age groups. ANOVA and Z-test were used for statistical analysis. The p≤0.05 was considered as significant while p≤0.001 was considered as highly significant. The most frequent type of soft palate was rat tail shaped. The mean VL and VW values were significantly higher in males while PD and Need's ratio were higher among females, insignificantly associated with the types of soft palate. A significant association was observed between the mean VL and VW with various age groups, showing an increase in values with an increase in age. A variation in morphology of soft palate plays an important role in the assessment of velopharyngeal closure and in diagnosing obstructive sleep apnoea individuals.

The prevalence of dental anomalies in a turkish population.

The aim of the present study was to investigate the prevalence of dental anomalies in a Turkish population according to the gender and age. A retrospective study was performed using panoramic radiographs of 2025 patients (885 males and 1140 females) ranging in age from 9 to 35 (mean age 25.61±10.04) years attending Department of Oral Radiology, University of Istanbul, Faculty of Dentistry. These patients were examined to determine the presence of developmental dental anomalies involving hypodontia, hyperdontia, microdontia, taurodontism and other root anomalies. The incidence of these anomalies were assessed according to the gender and age. Among the 2025 subjects, a total of 96 individuals (42 males and 54 females) showed at least one of the selected dental anomalies (4.74%). Tooth agenesis was the most common dental abnormality (1.77%) followed by taurodontism (1.18%), hyperdontia (0.79%), microdontia (0.54%) and root anomalies (0.44%), respectively. Tooth agenesis is the most common developmental dental anomaly in the studied Turkish population followed by taurodontism.

Evaluation of the mandibular canal visibility on cone-beam computed tomography images of the mandible.

The mandibular canal (MC) is an important and necessary landmark that should be considered before any surgery in the posterior region of the mandible. This study is aimed to evaluate the visibility and position of the MC in an Iranian population using cone-beam computed tomography. In this cross-sectional study, cone-beam computed tomography images of 69 patients, which were available as soft copies in the archives of the databases in the Department of Oral Radiology at Hamadan University of Medical Sciences (Hamadan, Iran), were analyzed. The visibility, corticalization, and position of the MC were assessed by 2 expert oral radiologists independently. The χ2 test, unpaired t test, and 1-way analysis of variance were used for analysis. The right and left MCs were clearly visible in 89.6% and 84.7% of the cases, respectively. Among 87.5% of cases, the MC was observed simultaneously in 2 sides. Position of the MC in relation to surrounding structures showed lowest asymmetry at the second premolar area. There were no statistically significant difference between sex and the evaluated parameters. Cone-beam computed tomography was successful in most cases in displaying the MC. The areas with most MC visibility in the right and left sides were the second and third molar regions, respectively. This visibility declined forwardly in both sides.

Analysis of imaging findings in jaw bone islands

To provide reference data on frequency and distribution of bone islands (BIs) and investigate their relationship with age, gender, and localization. A population who received a pretreatment and at least one follow-up panoramic radiograph in the Department of Oral Radiology, West China Hospital of Stomatology, Sichuan University, were selected for this retrospective study. A sample population of 29,556 patients (12,824 males and 16,732 females) with different dental complaints and ages ranging from 8 to 80 years (mean age: 23.95 years) were included. In the radiographic evaluation, BIs appeared as localized, well-defined, non-expansile, radiopaque masses which were round, elliptic, or irregular in shape. Their sizes varied from a few millimeters to about 2 cm in diameter. A total of 598 radiopacities were detected, and 545 patients of 29,556 patients (1.84%) had BIs. Among subjects with multiple lesions, 49 patients had 2 BIs and 2 patients had 3 BIs. The BIs had immense mandibular predilection, with presentation primarily in the premolar/molar region. The condition appeared to have no tendencies based on sex. Recognition of BIs variation is significant in dental examinations.

Pattern of mandibular third molar impaction: A cross-sectional study in northeast of Iran.

Impacted teeth, if left untreated, have a potential to induce various complications. The aim of the current study was to determine the prevalence and pattern of impacted mandibular third molar in the Iranian population. This cross-sectional study was performed in patients who were referred to the Department of Oral Radiology between July 2009 and October 2010 to obtain an orthopantomogram (OPG). Data were collected regarding age and gender, prevalence of impacted mandibular third molars, angulation of impacted teeth (Winter's classification), level of impaction (Pell and Gregory classification), and relationship of the mandibular third molar with the ramus (Pell and Gregory classification). The collected data were analyzed using SPSS software version 11.0 with a confidence interval of 95%. Among the 1433 patients included in the study, 489 (34.12%) patients were male and 944 (65.88%) were female. Of the total OPGs performed, 871 (60.78%) OPGs demonstrated at least one impacted mandibular third molar. In addition, of the 2866 mandibular third molars investigated, 1397 (48.74%) were found to be impacted. A significant association was observed between gender and the number of impacted teeth or the presence of impaction of any mandibular tooth (or teeth) (P < 0.05). The most common type of tooth angulation was mesioangular (48.67%). In addition, the most prevalent type of impaction level and ramus relationship was level B (63.85%) and Class II (48.46%), respectively. There were no significant differences between the two sides of the mandible for the prevalence of impacted third molar (P > 0.05). The pattern of mandibular third molars in the Northeast region of Iran revealed a high prevalence of impaction, which was mostly mesioangular, level B, and Class II with a gender predilection for females.

Intraosseous mucoepidermoid carcinoma: a review of the diagnostic imaging features of four jaw cases

The purpose of this case series is to present the common features of intraosseous mucoepidermoid carcinoma (IMC) of the jaws in plain film and CT imaging. Two oral and maxillofacial radiologists reviewed and characterized the common features of four biopsy-proven cases of IMC in the jaws in plain film and CT imaging obtained from the files of the Department of Oral Radiology, Faculty of Dentistry, University of Toronto, Toronto, Canada. The common features are a well-defined sclerotic periphery, the presence of internal amorphous sclerotic bone and numerous small loculations, lack of septae bordering many of the loculations, and expansion and perforation of the outer cortical plate with extension into surrounding soft tissue. Other characteristics include tooth displacement and root resorption. The four cases of IMC reviewed have common imaging characteristics. All cases share some diagnostic imaging features with other multilocular-appearing entities of the jaws. However, the presence of amorphous sclerotic bone and malignant characteristics can be useful in the differential diagnosis.

Bone islands of the craniomaxillofacial region

Objectives: To present and discuss the demographic and radiographic aspects of craniomaxillofacial bone islands (BIs) in the population of china. Materials and Methods: A retrospective chart review was performed of all cases of BIs diagnosed in the Department of Oral Radiology in West China College of Stomatology, Sichuan University. The data collected included age at diagnosis, gender, race, location, presenting symptoms, type of BIs. Results: In radiographic evaluation, BIs appear as localized, well-defined, non-expansile, radiopaque masses, which are round, elliptic or irregular in shape and are of variable size, ranging from a few millimetres to about 2 cm in diameter. The results of this study generally supported previous findings that BIs have an overwhelming mandibular predilection, especially, in the pre-molar/molar region, no sex predilection. Conclusions: The presumptive diagnosis of a BI can easily be made if the individual clinical and radiologic findings, together with follow-up examinations, are taken into account. In addition, it is important to recognize this anomaly, evaluate radiographies carefully and distinguish it from other bone variations such as primary or metastatic tumours, which is much more significant clinically in dental examinations.

Utility of thyroid collars in cephalometric radiography

A study was carried out to investigate the rationale that use of a thyroid collar (TC) in cephalometric radiography hampers the diagnostic and descriptive quality of lateral cephalogram. A randomized observer blinded study was designed. The study consisted of two groups. The first group data were retrieved from the oral radiology archival system having lateral cephalogram without a TC. The second group was selected from the oral radiology department of patients where lateral cephalogram was taken using a TC. Lateral cephalogram was taken on direct digital system, the Kodak 9000 unit (Eastman Kodak, Rochester, NY). 2 observers blinded about the aim of the study were appointed to identify 15 sets of landmarks on the lateral cephalogram. Interobserver variance was also analysed for the study. 50 lateral cephalograms in each group were studied. Out of 15 sets of landmarks, 12 were identified consistent with the TC group. Three landmarks, namely the hyoid bone, second cervical vertebra and third cervical vertebra could not be identified on the TC group. There was no significant difference in the interobserver markings on lateral cephalogram. TCs do mask a few landmarks on the lateral cephalogram. These landmarks are mainly used for analysis of skeletal maturity index (SMI). Lead TCs are probably the most convenient and easily available means to protect the thyroid from unwanted radiation while taking lateral cephalogram. It is therefore encouraged to use a TC during routine cephalometric radiography where SMI information is not needed.

Significance of Clinical Signs in Diagnosing Each Variant of Periapical Pathology: A Random Population Study in 1000 Patients

Objectives: To find out the accurate prevalence of periapical pathology and to see the significance of the clinical signs in diagnosing each variant of periapical pathology. Methods: A study of 1000 patients chosen consecutively, who visited the department of oral radiology, for intraoral periapical radiographs. The clinical data of all the variants of periapical pathology were registered in a specific clinical form followed by intraoral periapical radiographs of the same site All the data were entered into Microsoft Excel and analyzed using Chi-square test setting a value of p < 0.05 for the prevalence and distribution of periapical pathology and Z-test setting a value of p < 0.05 to see the significance of the clinical signs in diagnosing each variant of periapical pathology. Results: A total of 584 radiographs were diagnosed with periapical pathology- Periapical rarefying osteitis was present in almost every second radiograph (4127%) and the less common were periapical cysts and infected periapical cysts (6.3% each). No sex predilection in distribution of periapical pathology (p = 0415) and the majority of the patients (36.30%) belonged to 25 to 36 years age group (p = 0.000). Mandibular molars (512%) were the most common and mandibular canines (0.51 %) were the least common sites to involve with periapical pathology (p=0-000). Overall significance of the clinical signs in diagnosing each variant of periapical pathology was observed (p = 0-000). Conclusion: Our results suggested high prevalence rate of periapical pathology. This study also elaborated all the clinical signs of periapical pathology and their statistical significance in diagnosing each variant of periapical pathology.

Osteochondromas of the mandibular condyle: variance in radiographic appearance on panoramic radiographs

Osteochondromas are frequently found in the general skeleton, but are rare in the mandibular condyle. Radiographically, most reports describe osteochondromas as a mushroom-shaped bony enlargement capped with cartilage on the condylar surface. However, the radiographic appearance of this lesion on the panoramic radiograph has rarely been studied. The purpose of this article is to increase the radiographic knowledge of mandibular condylar osteochondroma and facilitate making an exact diagnosis through observing the lesional appearance on panoramic radiograph. The panoramic radiographs of 12 cases of mandibular condylar osteochondromas were reviewed. All cases were obtained from the Department of Oral Radiology, West China College of Stomatology, Sichuan University, between 1988 and 2006. The final diagnoses of all cases were based on pathology. Osteochondromas may arise on different areas around the mandibular condyle and present diverse appearances on panoramic radiograph. The mandibular condylar osteochondromas may show different growth positions encircling the condyle and exhibit varying shapes on panoramic radiograph. These features will help us to increase cognition of the lesion and make an exact diagnosis.

Radiographic examination of 41 cases of odontogenic myxomas on the basis of conventional radiographs

There are some different radiographic appearances of odontogenic myxoma that have not been reported in the published literature. The purpose of this article is to offer rare views of odontogenic myxomas and analyse the characteristics of the radiographic appearances. We reviewed the radiographic appearances of 41 cases of odontogenic myxomas on conventional radiographs, recruited from patients who visited the Department of Oral Radiology, West China College of Stomatology, Sichuan University between 1964 and 2005. The diagnoses of the cases were verified by histopathology. On conventional radiographs, odontogenic myxomas presented varying radiographic appearances, which could be divided into six types as follows: Type I-unilocular; Type II-multilocular (including honeycomb, soap bubble and tennis racquet patterns); Type III-involvement of local alveolar bone; Type IV-involvement of the maxillary sinus; Type V-osteolytic destruction and Type VI-a mix of osteolytic destruction and osteogenesis. Odontogenic myxoma has variable radiographic appearances on conventional radiographs. This classification system helps us better understand the radiographic appearances of odontogenic myxoma on conventional radiographs.

Effect of Age and Sex: Antegonial and Gonial Notch of Mandible

The morphological change in the antegonial region has received little attention in literature. A few studies focused on the mandibular angle, its alternations throughout aging, and changing relation to dental status. Their results were variable and inconsistent1,2, even using similar methodologies. Casey and Emrich3 compared the changes in genial angle in patients who were edentulous on one side of the arch and dentate on the other side of arch. They found no statistically significant differences between the edentulous and dentate sides. They also compared dentulous and edentulous men using panoramic radiographs. Their results suggested a slight widening of the mandibular angle in the edentulous patients. The aim of this study was to evaluate the changes in the antegonial angle, antegonial depth and gonial angle in 10 to 45 years old age groups and between genders. Panoramic radiographs of patients (M:F, 52:57), aged 10 years to 45 years from Oral Radiology Department of Government Dental College associated with Pt. B.D. Sharma Post Graduate Institute of Medical Sciences, Rohtak (Haryana) India, were examined. Only radiographs with good quality were used. Patient with fractures, post surgical and with any skeletal deformities were excluded from study. The examiner performed all measurements (in centigrade) with digital angle measurement instrument after tracing of parameter's. The following measurements were made:

Oral radiology in Bangladesh today: a brief review

P.C. Mallick (*) Department of Oral and Maxillofacial Radiology, Division of Medical Intelligence and Informatics, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan Tel. 81-82-257-5691; Fax 81-82-257-5692 e-mail: mallick@hiroshima-u.ac.jp The country Bangladesh, which gained its independence in December 1971, is cramped into an area of only 144000km on the delta formed by the three great rivers of South Asia. The Brahamaputra, Meghna, and Ganga rivers all discharge into the Bay of Bengal through Bangladesh. The country is therefore frequently affected by floods, cyclones, river-bank erosion, and tornadoes, and such natural disasters have several times caused significant damage to the national economy. Moreover, the population density of Bangladesh is likely to increase in all parts of the country. Nearly half of the people of Bangladesh still live in poverty, more than 60% are illiterate, and barely 20% are truly functionally literate. These conditions pose obstacles not just for the field of oral radiology but for the entire academic community. There have nevertheless been some notable achievements, although a need for faster technological development is increasingly felt in Bangladesh today. Development plans emphasize the scientific and technological sectors and specifically call for the development of medical science technologies through the adoption of imported technologies because Bangladesh is heavily dependent on imported technologies and specialized information from countries around the world. In particular, the technological advancement of dentistry in Bangladesh has been dependent primarily on Japan, the United States, and the United Kingdom. In Bangladesh, three government-run dental colleges at three universities offer courses leading to a bachelor in dental surgery (BDS) degree. Surprisingly, none of these colleges have oral radiology departments or faculty members specializing in this area. The subject of oral radiology properly belongs to operative dentistry, and the curriculum currently available is not sufficient to train students in proper diagnostic procedures. The World Health Organization, however, has suggested that the success rate of medical procedures depends on the use of imaging to make accurate diagnosis possible. Nevertheless, although BDS courses are offered by nearly ten private dental colleges in Bangladesh, none of these colleges have departments of oral radiology, and neither do they offer courses solely on oral radiology. Many institutions, including the government-run dental colleges, do not even have panoramic X-ray machines with which to perform demonstrations for students. Although some private diagnostic centers have adequate facilities to take panoramic X-rays of their patients, differential diagnoses cannot be made owing to the lack of specialists in oral radiology. As a result, oral surgeons and practitioners cannot even discuss their diagnoses with an oral radiologist. The people of Bangladesh, therefore, do not have the advantage of modern oral imaging technologies. Very recently, Bangabondhu Sheikh Mujib Medical University in Bangladesh has begun offering postgraduate programs of education in oral surgery, prosthetic dentistry, and operative dentistry, but these programs have no instructor of oral radiology, since currently no specialist in this field is available. In Bangladesh today, teachers from other departments have full responsibility for handling the subject matter of oral radiology. To demonstrate the usefulness of oral radiology among Bangladeshi academics and practitioners, the following basic points should be considered:

Annual report of limited cone beam computed tomography (3D Accu-I-Tomo) from 3000 cases at Nihon University dental hospital in 2003

Purpose: The purpose of this paper is to demonstrate the effectiveness of three-dimensional (3D) Accu-I-Tomo computed tomography (CT) for clinical applications in dentistry and to present sample cases. Materials and methods: Between January and December 2003, about 21,000 examinations were conducted in our Department of Oral Radiology. Two 3D Accu-I-Tomo CT were running in the dental hospital. Of the 21,000 examinations, 2887 were performed using 3D Accu-I-Tomo CT. These cases were investigated about classification of a disease by the database. Results: About 50% of 3D Accu-I-Tomo cases were related to dental implant planning and follow-up, while temporomandibular joint disease (TMD) accounted for about 20%. Other cases included apical disease and treatment, impacted teeth, mesiodens, cysts, and removal of foreign bodies. Conclusion: Examination using 3D Accu-I-Tomo proved integral to clinical applications in dentistry, as the resulting xyz sectional images were very clear. This device will be widely used in the near future.

Quality assessment of lateral cephalograms amongst radiologists and orthodontists.

This study investigated technical errors in the production of lateral cephalograms necessitating a retake and the extent to which the retake, as ordered by the radiologist, actually produced a gain in quality as assessed by the orthodontist. All the rejected lateral cephalograms taken at the Department of Oral Radiology over a period of 1 year were saved, and 20 such radiographs and their approved counterparts were then studied. Ten orthodontists were asked to decide whether the radiographs were acceptable or not and to provide reasons for those judged unacceptable. Considerable variation was found between the 10 orthodontists in the rate of acceptance of the radiographs. One orthodontist accepted only 13, while another accepted 37 out of the 40 radiographs. The main cause for rejection by the orthodontists of the radiologically approved films was: patients positioning error, and for the rejected: poor (or no) intercuspation. The results show large discrepancies between the radiologists and the orthodontists in quality criteria for cephalometric radiographs, as well as large interindividual variations among the orthodontists. In half of the cases, the radiologists ordered retakes that, according to the orthodontists, were not necessary.

Radiographic study of periosteal new bone formation in osteomyelitis of the mandible

A total of 1008 cases with osteomyelitis of the mandible underwent radiological examinations at the department of Oral Radiology, Osaka Dental University Hospital from 1979 to 1988. Osteomyelitis with periosteal new bone formation was observed in 114 out of the 1008 cases (11.3%). The radiographic patterns of the periosteal new bone formation were grouped into 3 types: solid, laminated and one-layer. Sixty-seven of the 114 cases (58.8%) were of the solid type, 23 cases (20.2%) were the laminated type and 24 cases (21.0%) were the one-layer type. The average age in the solid type was 30.8 years, 23.8 years in the laminated type and 38.0 years in the one-layer type.

Clinical observations on the development of third molars.

In order to investigate the developmental conditions of third molars in Japanese, we studied the panoramic radiographs taken during dental treatment at the Pediatric Outpatient Section of Osaka Dental University Hospital of 9,111 children (4,646 boys and 4,465 girls) between the ages of 7 years 0 months and 16 years 11 months, in addition to 2,769 panoramic radiographs of students of this university (2,312 men 457 women) kept by the Department of Oral Radiology. The following results were obtained. 1. Calcification of the third molars in both boys and girls began as early as 7 years 6 months in the maxilla and 7 years 0 months in the mandible. The average age for initiation of calcification in the maxilla was 9 years 4 months for boys, and 9 years 2 months for girls, while the ages in the mandible were 9 years 1 month and 8 years 9 months, respectively. 2. The average age for completion of the third molar crowns in the maxilla was 11 years 8 months for boys and 11 years 5 months for girls, while in the mandible it was 12 years 4 months and 12 years 3 months, respectively. 3. At greater than 13 years of age, the tooth germ could be found in boys about 70% of the time in the maxilla and 75% of the time in the mandible, while these figures for girls were 65 and 80%, respectively. 4. All four third molars were present in 52.3% of the males and 45.5% of the females, while 9.5% of the males and 12.0% of the females had no third molars at all. 5. The direction of eruption was classified as either vertical, mesial, horizontal, distal, or buccal/lingual type. The rate for the vertical type in males was 70% in the maxilla and 45% in the mandible, while these figures for females were 50 and 40%, respectively. 6. Microdontia of the third molars appeared only in the maxilla. 7. Congenital absence of the third molars was more common in females than males, and occurred more frequently in the maxilla than in the mandible. The results of this study allow a better understanding of the third molars of Japanese and provide an aid to planning in such areas of clinical pediatric practice as guiding occlusal development.