Location of the mandibular canal: comparison of macroscopic findings, conventional radiography, and computed tomography

Four mandibular specimens were radiographically examined bilaterally to locate the mandibular canal. The following radiographic techniques were used: periapical and panoramic radiography, hypocycloidal tomography, and computed tomography (CT). The distance from the crest of the alveolar process to the superior border of the mandibular canal was measured in millimeters on all radiographs. The specimens were then sectioned, and the location of the mandibular canal (as measured on contact radiographs of the sections) was compared with measurements made on the other radiographs. The results showed that CT gave the most accurate position of the mandibular canal and is therefore probably the best method for preoperative planning of the implant surgery involving the area close to the mandibular canal.     

The evaluation of vertical heights of maxillary and mandibular bones and the location of anatomic landmarks in panoramic radiographs of edentulous patients for implant dentistry

The purpose of this study was to determine variations in the vertical height measurements in the edentulous maxilla and mandible, and to assess positions of the maxillary sinus, mandibular foramen, and the mandibular canal, which are important for implant length selection and planning using panoramic radiographs. The study sample included 346 edentulous alveolar ridges of 90 men and 83 women. Sixty-three dentate patients' panoramic radiographs were used for location of the first premolar and molar area. Panoramic radiographs were made with a Siemens Orthophos panoramic machine which had been standardized previously. All radiographs were made using a standardized manner by the same technician. Fourteen sites were measured on every panoramic radiograph whenever possible, eight sites in the maxilla and six sites in the mandible. Correlation analyses were performed between age groups and all measurements to determine if age is significant as a covariate. In order to examine the effect of gender the statistical analysis of differences between men and women was performed with Student t-test. The 5% significance level was used for statistical significancy. The height of the maxilla and the mandible in the anterior, first premolar, and first molar regions were significantly greater in men than in women. A majority of the most inferior border of the maxillary sinuses was located anterior to the first molar area (premolar regions) both in men (48.9%) and women (55.4%). Although, there was no statistically significant difference between edentulous men and women for the vertical distances from the mental foramen to the alveolar crest, and horizontal distances from mental foramen to midline, there were statistically significant differences between edentulous men and edentulous women for the vertical distances from the upper border of the mandibular canal to the alveolar crest in the first molar area. Mental foramens were located at the crest of the ridge in 7.2% of the edentulous women, and 6.7% of the edentulous men. The results of this study may guide clinicians to make primer decision of implant insertion area for implant supported prosthesis in edentulous patients.     

下磨牙区种植体尖端与下颌管间安全距离的探讨

目的:探讨下颌磨牙区植入的种植体尖端与下牙槽神经管上缘之间的安全距离。方法:用游标卡尺测量23例患者全景片中的30颗下颌磨牙区种植体长度,除以对应的种植体实际长度,计算全景片中下颌磨牙区垂直放大率(vertical magnification factor,MF);选择种植体尖端至下牙槽神经管上缘间距离小于2mm的8例患者的全景片,测量片中12颗种植体尖端至下牙槽神经管上缘间的距离,除以对应种植体的垂直放大率,计算其实际距离;记录该8例患者有无下唇和(或)颏部感觉异常。结果:①全景片中下颌磨牙区垂直放大率为1.27±0.02;②12颗种植体尖端距下牙槽神经管上缘之间的距离为(1.19±0.33)mm(0.69～1.89mm);③8例接受种植体植入的患者,无一例出现下唇或颏部感觉异常。结论:下颌磨牙区植入种植体的尖端与下颌管上缘之间保存完整的骨壁,是防止损伤下牙槽神经的最关键因素之一。     

Comparison of three radiographic methods used to locate the mandibular canal in the buccolingual direction before bilateral sagittal split osteotomy

OBJECTIVE: Panoramic radiographs, computerized tomography (CT), and conventional spiral tomographic (Scanora, Soredex, Helsinki, Finland) radiographs were compared for their ability to locate the mandibular canal in the buccolingual direction. Furthermore, the relationship between the cortication of the mandibular canal in panoramic radiographs and the location of the canal in both computerized and conventional tomographic radiographs was assessed. STUDY DESIGN: The buccolingual location of the mandibular canal was determined bilaterally in twenty consecutive patients scheduled for bilateral sagittal split osteotomy. The position of the mandibular canal was evaluated by means of panoramic radiography, Scanora, and CT. The three imaging methods were compared for their ability to locate the mandibular canal in the buccolingual direction. The subjective neurosensory deficit of the lower lip and chin on both sides was registered preoperatively and at 4 days, 3 weeks, and 3 months after surgery, and the operative outcome was analyzed in relation to the distance from the mandibular canal to the buccal cortex of the mandible. RESULTS: CT gave better visualization of the mandibular canal than Scanora imaging. Cortication of the mandibular canal on the panoramic radiograph did not serve as a predictor of the proximity of the mandibular canal to the cortices of the mandible. At 3-month follow-up, there were only eight operated sides with abnormal sensation of the lower lip and chin. In seven of these sides, the distance from the mandibular canal to the buccal cortex was less than 2 mm. CONCLUSION: The buccolingual location of the mandibular canal is visualized better with CT than with Scanora or panoramic radiographs.     

Proximity of Impacted Mandibular Third Molars to the Inferior Alveolar Canal and Its Radiographic Predictors: A Panoramic Radiographic Study

Purpose

To assess the radiographic proximity of impacted mandibular third molars to the inferior alveolar canal on panoramic radiographs. The radiographic distance between the impacted mandibular third molars and inferior alveolar canal and the reliable radiographic risk predictor signs that indicate close proximity between these two structures were evaluated.

Methods

The study comprised of 64 subjects with 68 symptomatic impacted mandibular third molars for whom panoramic radiographs were made. The radiographs were interpreted for type of impaction, radiographic distance between impacted mandibular third molars to inferior alveolar canal and presence of one or more of the seven radiographic risk predictor signs. Further, these teeth were surgically removed and the proximity was assessed based on the exposure of inferior alveolar canal/nerve which was considered as Gold standard.

Results

The overall mean distance from the impacted mandibular third molars to inferior alveolar canal was −0.50 mm. Most of the samples (61.8 %) extended beyond the superior border of the inferior alveolar canal with a mean distance of −1.40 mm. Mesioangular impactions were found to be in the close proximity (−1.14 mm) to inferior alveolar canal than any other type. Interruption of the white line was the only statistically significant radiographic risk predictor sign p = 0.006 (< 0.05) that indicated close proximity of impacted mandibular third molars to inferior alveolar canal.

Conclusion

It can be concluded that panoramic radiographs are reliable in assessing the proximity of impacted mandibular third molars to inferior alveolar canal. Mesioangular impactions are more closely placed to inferior alveolar canal and interruption of the white line is the most reliable risk predictor sign on the panoramic radiographs.     

Evaluation of volumetric measurements on CBCT images using stafne bone cavities as an example

Background

The aim of the present study is to evaluate the efficacy of CBCT in volume measuring using Stafne Bone Cavities (SBC) as an example.

Material and Methods

The study was conducted with 14 subjects with SBC detected on panoramic radiographs. In order to evaluate lesions volumetric dimensions, CBCT images for each patient were captured. Files in Digital Imaging and Communications in Medicine (DICOM) format were transferred into a medical image processing program (ITK-SNAP 2.4.0) and volume in mm3 of the cavities were measured using semi-automatic segmentation procedure by 2 observers blinded to each other over a one-month period. Inter-reliability of volumetric measurements between observers was compared. SBCs relation to mandibular canal was also examined and three types of relation were observed; type 1: mandibular canal is separated from the SBC, type 2: mandibular canal is in contact with SBC, type 3: mandibular canal goes through the SBC.

Results

There were 12 males and 2 females who had SBC in this study (age range: 37-73, mean age: 55.3 years). The total volume of SBC in patients ranged from 160 mm3 to 520 mm3 (mean: 361.7 mm3). There was no significant difference between observers for volume measurements (p>0.05). According to relationship of SBC with mandibular canal, most SBCs were Type 1 (64.3 %) followed by type 3 (21.4 %) and type 2 (14.3 %). Pearson correlation coefficient shows a positive correlation between lesions volumetric size and relation with mandibular canal (pearson correlation = 0.54, sig < 0.05).

Conclusions

Based on the results of this preliminary study, CBCT was considered to be an effective radiographic technic for measuring volumetric sizes of SBCs. However further studies with larger sample sizes are needed to prove the usefulness of CBCT in volume measurements. Key words:Stafne bone cavity, CBCT, volumetric measurements, image segmentation.     

Comparison between panoramic radiography and cone-beam computed tomography findings for assessment of the relationship between impacted mandibular third molars and the mandibular canal

Objectives

The aim of this study was to assess the relationship between the mandibular canal and impacted mandibular third molars using cone-beam computed tomography (CBCT) and to compare the CBCT findings with panoramic radiographic signs.

Methods

This study involved a retrospective radiographic review of 781 impacted third molars in 500 patients who showed a close relationship between the mandibular canal and the third molars on panoramic radiographs. Panoramic radiographic images were evaluated for interruption of the white line, darkening of the roots, diversion of the mandibular canal/roots, and narrowing of the mandibular canal/roots. The authors evaluated CBCT images to determine the course of each canal and its proximity to the roots. The statistical correlations between the panoramic radiography and CBCT findings were examined using the Chi-square test and Fisher’s exact test.

Results

Cone-beam computed tomography examination showed that darkening of the roots and deviation of the canal associated with the absence of corticalization between the mandibular third molar and the mandibular canal on panoramic radiographs were statistically significant, both as isolated findings and in association. No significant associations were observed for the other panoramic radiographic findings, either individually or in association.

Conclusions

The results of this study suggest that darkening of the roots, deviation of the mandibular canal, and interruption of the white line observed on panoramic radiographs, both as isolated findings and in association, were effective for determining the risk relationship between the roots and the mandibular canal, requiring three-dimensional evaluation of such cases.     

Visualisation of the mandibular canal by different radiographic techniques

6 mandibles were radiographically examined bilaterally to visualise the mandibular canal. 5 imaging techniques were used: periapical radiography, panoramic radiography, hypocycloidal tomography, spiral tomography and computed tomography (CT). Panoramic radiographs were obtained with 2 different X-ray machines. The CT-examinations comprised direct images and standard reconstructions based on axial slices. The specimens were subsequently sectioned for contact radiography. The visibility of the mandibular canal was estimated by 3 observers at special reference points on all radiographs and classified as clearly visible, questionable visibility or not visible. The contact radiographs served as the "gold standard". The inter-observer and the intra-observer agreement were assessed by calculating the overall agreement and the x value. Direct coronal computed tomography, as well as spiral and hypocycloidal tomography, gave better visualisation of the mandibular canal than periapical and panoramic radiography.     

Third molar position: reliability of panoramic radiography.

PURPOSE: The purpose of the present study was to determine whether panoramic radiographs could predict physical contact between the mandibular third molar and the mandibular canal on limited cone-beam computed tomography, known as dental 3D-CT (3-dimensional computed tomography [3D-CT]). PATIENTS AND METHODS: The association of images between the panoramic radiograph and the dental 3D-CT was investigated in a cross-sectional study. Seventy-three lower third molars in 65 patients were examined. Findings of absence or presence of the white line of the mandibular canal wall on panoramic radiographs and contact or separation between the tooth and the mandibular canal on dental 3D-CT were compared. RESULTS: Absence of a superior white line on panoramic radiography was associated with an increased risk of contact between the third molar and the mandibular canal on dental 3D-CT, even when the effects of tooth position, age, and gender were taken into account. The multivariate adjusted odds ratio was 10.79. Women were more likely to have contact between the 2 structures on dental 3D-CT when their panoramic radiograph showed absence of the white line. CONCLUSIONS: Panoramic radiography is useful for predicting to a limited extent physical contact between the mandibular third molar and the mandibular canal on dental 3D-CT.     

A comparison of conventional panoramic radiographs with volumetric computed tomography images in the preoperative assessment of impacted mandibular third molars.

PURPOSE: In the present study, we evaluated the geometric, topographic, and anatomic reliability of volumetric computed tomography (VCT) images by comparing conventional panoramic radiographs with reconstructed VCT panoramic and paraxial images before performing third molar surgery. PATIENTS AND METHODS: A total of 6 anatomic sites on 10 patients who showed a topographic relationship between the apices of the third molar root and the mandibular canal were preoperatively assessed by 5 oral surgeons using conventional panoramic radiographs; these were complemented and compared with secondary reconstructed paraxial and panoramic VCT images. RESULTS: The position of the apices in relation to the mandibular canal could be revealed on 94% of VCT reconstructed paraxial images. Assessment of VCT paraxial images could be facilitated by using a toolbar marker in 70% of the paraxial images. In 90% of the paraxial images, it was possible to assess the relationship of the mandibular canal and its adjacent anatomy. The visual grading scores for conventional panoramic images were significantly better on all 7 assessed anatomic sites compared with the reconstructed VCT panoramic images. CONCLUSION: The results showed that the VCT paraxial images gave a significantly clearer perception of the mandibular nerve than conventional panoramic radiographs. However, conventional panoramic radiographs were shown to be better than the VCT reconstructed panoramic images and were therefore an invaluable tool in the "expert-derived" assessment and posed the potential for identifying the need for further VCT diagnostic procedures.     

Mandibular Incisive Canal: Cone Beam Computed Tomography

Purpose: Panoramic radiography is often used to analyze the anatomical structure of the teeth, jaws, and temporomandibular joints. Cone beam computed tomography (CBCT) imaging allows multiple axial slices of the image to be obtained through these anatomical structures. The aim of this study was to assess CBCT compared with panoramic radiography to verify the presence, location, and dimensions of the mandibular incisive canal. Materials and Methods: CBCT scan images and panoramic radiographs of 89 subjects were compared for the presence of the mandibular incisive canal, its location, size, and anterior‐posterior length. The distance between the incisive canal and the buccal and lingual plate of the alveolar bone, and the distance from the canal to the inferior border of the mandible and the tooth apex were also measured. A paired t‐test was used to calculate any significant difference between the two imaging techniques. Results: Eighty‐three percent of the CBCT scans showed the presence of the incisive canal, as did 11% of the panoramic radiographs. The range of the incisive canal diameter, as seen in the CBCT scans, was from 0.4 × 0.4 mm to 4.6 × 3.2 mm. The mean length of the canal was 7 ± 3.8 mm. The distance from the inferior border of the mandible to the canal was 10.2 ± 2.4 mm, and the mean distance to the buccal plate was 2.4 mm. The apex–canal distance (in dentate subjects) was 5.3 mm. Conclusion: The presence, location, and dimensions of the mandibular incisive canal are better determined by CBCT imaging than by panoramic radiography.     

Panoramic radiographs: determination of mandibular steepness

The aim of this study was to evaluate the potential of panoramic radiographs to measure mandibular inclination and steepness. Standardized panoramic and lateral cephalometric radiographs were taken for 95 subjects (46 females, mean age 12.4 +/- 1.2 years; 49 males, mean age 12.1 +/- 1.3 years). Mandibular inclination from panoramic radiograph was measured using gonial angle formed by the tangents of the lower border of the mandible and the distal border of the ascending ramus and the condyle. A correlation test was performed to check for similarity between the measurements. The mean values for the gonial angle were 127.3 +/- 6.2 and 125.7 +/- 6.5 degrees measured from the panoramic and cephalometric radiographs respectively. A high correlation between the measurements taken from both radiographs was found (r = 0.83, P < 0.001). Panoramic radiographs are a useful tool for the measurement of gonial angle, which is an indicator of manibular steepness and subsequently mandibular growth direction. The ability to determine growth direction from the orthopantomogram will be useful because majority of dentists request an OPG for patients during routine dental examination. This will enable the dental professional to spot vertical growth problems using a readily available tool.     

曲面断层片在评价下颌骨生长发育时下颌骨线性指标的作用

目的 研究在X线全颌曲面断层片和头颅后前位片上下颌骨线距测量项目的相关性,探讨曲面断层片定量分析评价下颌骨发育的应用价值.方法 选取同一技师同时期拍摄的52例患者的全颌曲面断层片和头颅后前位X片,分别测量左右侧下颌骨升支高度、下颌体长度、下颌综合长度,对测量结果进行统计分析.结果 下颌骨升支高度和下颌综合长度在X线全颌曲面断层片和头颅后前位片上测量值间有明显相关性,而下颌体长度两测量值间尚未见明显相关性.结论 在严格控制拍摄条件下,曲面断层片可以进行下颌骨线性指标的测量来评价下颌骨生长发育.     

Clinical bone densitometric evaluation of the mandible in removable denture wearers dependent on the morphology of the mandibular cortex

STATEMENT OF PROBLEM: Wide normal variations have been found in the structure and density of the human skeleton, as well as of the mandible. PURPOSE: The objective of this study was to determine whether the mandibular bone mineral density is correlated with the classification of the structure of the inferior cortex on panoramic radiographs in complete and removable partial denture wearers. MATERIALS AND METHODS: The mandibular cortical index of 136 randomly selected complete and removable partial denture wearers was evaluated via panoramic radiographs. The criteria for the mandibular cortical index were as follow: category 1, sharp endosteal margin of the inferior cortex; category 2, semilunar defects; and category 3, thick cortical residues on endosteal margin. Forty male patients (mean age 72.7; range 56 to 84 years) and 96 female patients (mean age 69.7; range 48 to 86 years) participated. With a copper stepwedge and DenEx 2001 computer program, the mandibular bone mineral density was investigated densitometrically on dental panoramic radiographs. Four experienced observers and 6 general dental practitioners made the observations on all panoramic radiographs. All bone mineral density values were expressed in equivalents of the actual stepwedge thickness. An independent t test (alpha =.05) was used. RESULTS: The severity of changes in the mandibular cortex was significantly related to all measured mandibular bone mineral density values (t test: P<.01). Mandibular cortical index category 3 had significantly lower bone mineral density values in all measured regions of interest. Interobserver and intraobserver agreement in mandibular cortical index assessment was excellent. CONCLUSION: Patients having lower bone mineral density values in the mandible have much more porous cortical layer of the inferior border of the mandible.     

Diagnostic agreement of conventional and inverted scanned panoramic radiographs in the detection of the mandibular canal and the mental foramen

The aim of this study was to evaluate the diagnostic agreement of conventional panoramic radiographs and their inverted scanned images in the detection of the mandibular canal and mental foramen. A total of 77 panoramic radiographs obtained from the files of totally edentulous patients were used. Digitization was done by means of a scanner with brightness and contrast adjustment, as well as image inversion. The extension of mandibular canal was divided into anterior, middle, and posterior regions, and the presence of a radiopaque line that characterized the mandibular canal was classified according to a 5-point confidence scale. The mental foramen was classified in 4 types: continuous, separated, diffuse, and unidentified. Both conventional and inverted scanned panoramic radiographs were evaluated by 3 calibrated implantologists at 2 distinct moments with a minimum interval of 10 days between them. Intraexaminer agreement was evaluated by Kappa statistics by point and by 95% confidence interval. Because the intraexaminer level of agreement was low, interexaminer agreements could not be carried out. The results showed a substantial (in 2 situations), moderate (in 16 situations), and fair (in 18 situations) intraexaminer agreement for mandibular canal and a substantial (in 1 situation), fair (in 1 situation), and moderate (in 10 situations) intraeaminer agreement for mental foramen. There were no statistically significant differences in most instances. In conclusion, the diagnostic agreement of conventional and inverted scanned panoramic radiographs for detection of mandibular canal and mental foramen was low.     

Panoramic radiography: effects of head alignment on the vertical dimension of the mandibular ramus and condyle region

The aim of this study was to assess whether it is possible to derive accurate vertical measurements of the mandibular ramus and condyle from panoramic radiographs. A human dry skull was positioned in a panoramic machine. The skull was displaced along the sagittal and transverse plane and rotated around the vertical and transverse axes. A set of 252 digital radiographs with defined positioning errors was compared with a set of 42 radiographs in the 'ideal' position. The distances between the metal markers that had been attached at the angle of the mandible at a distance of 60 mm in the condyle region to produce fixed reference points on the radiographs were measured. Statistical differences were investigated using Friedman repeated measures analysis of variance on ranks followed by the Dunnett's test for the comparison against the control group in the ideal position (α = 0.05). Vertical measurements were significantly affected when the skull was rotated around the vertical (P < 0.001) or shifted along the transverse axis (P < 0.001). Misalignment of the head affected the vertical measurement of the mandibular ramus and condyle. However, asymmetries of more than 6 per cent are probably not due to patient positioning in the panoramic machine.     

下颌阻生第三磨牙与下颌管位置的曲面体层X线片和锥形束CT观察

目的 观察分析在曲面体层x线片上人群中下颌阻生第三磨牙(impacted mandibular third molar,IMTM)与下颌管位置关系的类型,并对二者关系密切的病例行锥形柬CT(conc beam computed tomography,CBCT)检查,了解二者实际位置关系.为临床制定IMTM拔除手术方案提供参考.方法 观察390例(645侧)曲面体层X线片,将IMTM与下颌管的位置关系的影像分为3种类型:①无接触类,二者影像无任何重叠或接触;②点状接触类,二者之间影像仅为点状接触;③部分重叠类,二者影像部分重叠或有较大范围接触.统计3种类型的构成比.曲面体层X线片显示IMTM与下颌管影像呈部分重叠或较大范围接触的部分病例行CBCT检查,观察曲面体层X线片IMTM与下颌管关系密切者中,IMTM实际突破下颌管壁所占的比例.结果 390例(645侧)IMTM的曲面体层X线片影像中,无接触类441侧(68.4%);点状接触类149侧(23.1%);部分重叠类55侧(8.5%).对31例(50侧)曲面体层X线片上显示IMTM与下颌管呈部分重叠或较大范围接触的CBCT检查发现,25侧(50%)IMTM突破下颌管壁.结论 ①曲面体层X线片可以排除90%以上IMTM与下颌管关系不密切的病例;②曲面体层X线片IMTM与下颌管影像呈部分重叠或较大范围接触表现的病例有必要行CBCT进一步检查.     

Accuracy of linear measurements before and after digitizing periapical and panoramic radiography images

The aim of this study was to evaluate the accuracy of linear measurements made on conventional and digitized periapical and panoramic radiographic images of dry human hemi-mandibles. Images from the posterior region of 22 dry human hemi-mandibles were obtained by conventional panoramic and periapical radiography technique. Using a digital caliper, 3 vertical measurements were marked directly on the dry hemi-mandibles (reference measurements) as well as on the tracing from the conventional radiographic images of the specimens made onto acetate paper sheet: Distance 1: between the upper limit of the alveolar ridge and the lower limit at the mandible base; Distance 2: between the upper limit of the alveolar ridge and the upper limit of the mandibular canal; Distance 3: between the lower limit of the mandibular canal and the lower limit of the mandible base. Next, the radiographs were digitized and the three measurements were made on the digital images using UTHSCSA Image Tool software. Data were analyzed statistically by one-way ANOVA (α=0.05). There was no statistically significant differences (p>0.05) between periapical and panoramic radiographs or between the measurements recorded using the digital caliper and UTHSCSA software compared with dry mandible specimens for Distances 1 (p=0.783), 2 (p=0.986) and 3 (p=0.129). In conclusion, the radiographic techniques evaluated in this study are reliable for vertical bone measurements on selected areas and the UTHSCA Image Tool software is an appropriate measurement method.     

Comparison of periapical radiography and limited cone-beam computed tomography in mandibular molars for analysis of anatomical landmarks before apical surgery

Introduction

The purpose of the present study was to evaluate the detectability and dimensions of periapical lesions, the relationship of the mandibular canal to the roots of the respective teeth, and the dimension of the buccal bone by using limited cone-beam computed tomography (CBCT) in comparison to conventional periapical (PA) radiographs for evaluation of mandibular molars before apical surgery.

Methods

The study comprised 38 molars with 75 roots. The type of PA lesion as diagnosed on PA radiographs was compared with the type of lesion seen on sagittal and coronal CBCT sections. The distances of the apices of the first mandibular molars and basal border of the PA lesion to the coronal lining of the mandibular canal were assessed with PA radiographs and corresponding sagittal and coronal CBCT images. Furthermore, coronal CBCT images were used to measure the distance from the apices to the buccal bone surface and the corresponding width of the cortical bone plate.

Results

Of 58 detected PA lesions, 15 (25.9%) lesions diagnosed with sagittal CBCT slices were missed with PA radiography. The distance between the apices and the upper border of the mandibular canal was only measurable in 24 of 68 radiographs (35.3%) by using PA images. The cortical bone wall had a mean thickness of 1.7 mm, whereas the total buccal bone wall (cortical and spongious) measured 5.3 mm on average.

Conclusions

The present study highlights the advantages of using limited CBCT for treatment planning in mandibular molars before apical surgery.     

The effects of compression on the image quality of digital panoramic radiographs

Size reduction through compression is an important issue that needs to be investigated for possible effects on image quality. The aim of the present study was to evaluate the subjective image quality of digital panoramic radiographs which were lossless and lossy compressed for the visualization of various anatomical structures. Fifty-five digital panoramic radiographs in Tagged Image File Format (Tiff) were used in the study. Two types of lossy (Joint Photographic Experts Group (Jpeg)) and one type of lossless (Lempel?CZiv?CWelch) compression were applied to the original radiographs. These radiographs were evaluated by two observers separately for the visibility of some anatomical structures with visual grading. Mean quality number for each radiograph was obtained. The differences between the mean quality numbers in each compression and original image mode were evaluated with Friedman test. Pair-wise comparisons revealed that there were statistically significant differences between all groups (p?=?0.000) for all comparisons except for Jpeg_1 and Jpeg_2 groups. Kappa statistics was used to evaluate inter- and intra-observer agreements. Intra-observer agreements were ranging from 0.229 to 1.000 and inter-observer agreements were ranging from 0.154 to 1.000. The observers had better inter- and intra-observer agreements in highly compressed Jpeg_1 images. The anatomical structures evaluated in this study had better visibility in Tiff images than Jpeg images except for mandibular canal and mental foramen. While Jpeg compressed images offer high inter- and intra-observer agreements, the visibility of anatomical structures are better in Tiff images except for mandibular canal and mental foramen.