Giant lipoma of the tongue: A case report and review of the literature

This report presents the case of a 49-year-old man who presented with giant masses that had recently grown on the bilateral sides of the tongue. A clinical examination revealed rubbery yellowish lesions protruding from the tongue.A panoramic radiograph showed an enlarged soft tissue shadow of the tongue. Computed tomography showed well-defined circumscribed mass exhibiting a homogeneous low density on the bilateral sides of the tongue. On magnetic resonance images, the masses showed a high signal intensity on T1-weighted images and iso-signal intensity with partially hyperintense margin on fat-suppressed T2-weighted images. Surgical excision was performed, and a histopathologic examination confirmed the diagnosis of lipoma. The patient recovered well with no sign ofrecurrence. A giant lipoma is defined as a lipoma larger than 5 cm in diameter. A literature review of giant lipomas of the tongue is also presented herein.

Radiographic study of dermal fillers in the facial area: A series of 3 cases

In recent years, as interest in maintaining beauty and a youthful appearance has grown, filler procedures such as soft tissue augmentation have become more popular. These fillers are sometimes seen as radiopaque shadows on radiographic images, either due to the fillers themselves or because of secondary reactions; such findings may present a diagnostic challenge to dentists. The present report describes 3 cases of dermal fillers observed in panoramic and cone-beam computed tomographic (CBCT) images. All 3 elderly female patients had filler injected into their cheeks and chin area for cosmetic purposes decades ago. On panoramic images, multiple symmetric radiopacities were observed in the facial area; on CBCT, these calcifications were seen in the subcutaneous tissue in various shapes and with varying density. In conclusion, dentists should be aware of the imaging characteristics of dermal filler, and should be able to differentiate dermal filler from other pathological findings.

Recurrent osteochondroma of the mandibular condyle: A case report

A 21-year-old woman presented with facial asymmetry. Crepitus and clicking of the temporomandibular joint were noted. The midline deviated 5.5 mm to the left, and secondary malocclusion was observed. Panoramic and cone-beam computed tomographic images showed an irregular and exophytic bony mass on the anteromedial surface of the right mandibular condyle. A 3-phase bone scan revealed increased tracer uptake on the affected side. The lesion was treated with excision and reshaping under the diagnosis of osteochondroma confirmed by a histopathological examination. The lesion recurred after 3 years, and the patient underwent condylectomy. Mandibular condylar osteochondroma is often resected because it causes functional and aesthetic problems, but it rarely recurs. To the best of our knowledge, only 2 cases of recurrent osteochondromas of the mandibular condyle have been reported previously. Surgical treatment of the osteochondroma should be performed considering the possibility of recurrence, and long-term follow-up is recommended.

Odontoma: a retrospective study of 73 cases

PURPOSE: The purpose of the present study was to retrospectively evaluate the clinical findings and treatment results for impacted permanent teeth associated with odontomas. MATERIALS AND METHODS: We retrospectively investigated 73 odontomas in 72 patients who visited Kyungpook National University Dental Hospital from April 2004 through November 2011. The study was performed using medical records, panoramic radiographs, and pathological reports. Data gathered included age, gender, location, chief complaints, effects on dentition, and treatment of odontoma and the impacted tooth associated with odontoma. RESULTS: Most compound odontomas (46.7%) were found in the second decade and complex odontomas were not related to age. Odontomas showed no gender predilection. Fifty-five cases (75.3%) of odontomas were detected on routine dental radiographs. Sixty percent of compound odontomas occurred in the canine area and 57.1% of complex odontomas in the molar areas. Impaction of permanent teeth (61.6%) was the most common complication on the adjacent teeth. Most odontomas (84.9%) were removed surgically and impacted permanent teeth were managed by surgical removal (53.2%), orthodontic treatment (25.5%), or surgical repositioning (6.4%). There was a statistically significant relation between age and preservation of the impacted permanent teeth associated with odontomas (p<0.01). CONCLUSION: Early detection and treatment of odontomas increase the possibility of preservation of the impacted tooth. Therefore, it would be suggested that periodic panoramic examination during the first and second decade of life might be beneficial for the early detection and better prognosis of odontomas.

Simple bone cysts of two brothers / 대한구강악안면방사선학회지

17-year-old and 14-year-old brothers were referred for evaluation of the cystic lesions on the mandibular anterior area with no symptoms. Neither their mother nor the brothers could recall any past trauma to those areas. Panoramic and intraoral radiographs revealed moderately defined cystic lesions on their mandibular anterior areas. Biopsies on both lesions revealed simple bone cysts. Hereditary cause or familial history of simple bone cysts could not be found in literature review. This case may have been a coincidence. However, further investigation is needed to find the cause of simple bone cysts occurring in patients those are closely related.

Efficacy of panoramic radiography as a screening procedure in dental examination compared with clinical evaluation / 대한구강악안면방사선학회지

PURPOSE: To evaluate the efficacy of panoramic radiography by comparing the results of clinical examination with radiographic findings. MATERIALS AND METHODS: We studied 190 patients (20 men and 170 women; mean age, 40 years; range, 22 to 68 years) who visited the health promotion center of Korea Medical Science Institute and were examined both clinically and by panoramic radiography. We compared results from both examinations. Treatment options by clinical examination were described as "no treatment indicated", "treatment of dental caries", "removal of calculus", "treatment of periodontal disease", "prothodontic treatment" and "extraction of the third molar". Findings taken from the panoramic radiography were: dental caries, periapical lesion, alveolar bone loss, calculus deposition, retained root, impaction of the third molar, disease of maxillary sinus, bony change of mandibular condyle, etc. RESULTS: The prevalence of panoramic findings were: 37.9% of dental caries, 17.4% of periapical lesions, 44.7% of alveolar bone losses, 62.6% of calculi deposition, 7.9% of retained roots, 26.8% of third molar impactions, 6.3% of diseases of maxillary sinus, 2.1% of bony changes of mandibular condlye and 35.8% of miscellaneous lesions. Abnormal conditions revealed by panoramic radiography which had not been discovered on clinical examination were: 24.2% of the patients had dental caries, 17.4% had periapical lesions, 7.4% had calculi deposition, 5.3% had retained roots, 15.3% had third molar impactions. The opposite cases were: 5.2% had dental caries, 12.6% had calculi deposition, and 9.5% had third molar impactions. CONCLUSION: The use of panoramic radiography as a supplement to the clinical examination might be a valuable screening technique.

Efficacy of panoramic radiography as a screening procedure in dental examination compared with clinical evaluation / 대한구강악안면방사선학회지

PURPOSE: To evaluate the efficacy of panoramic radiography by comparing the results of clinical examination with radiographic findings. MATERIALS AND METHODS: We studied 190 patients (20 men and 170 women; mean age, 40 years; range, 22 to 68 years) who visited the health promotion center of Korea Medical Science Institute and were examined both clinically and by panoramic radiography. We compared results from both examinations. Treatment options by clinical examination were described as "no treatment indicated", "treatment of dental caries", "removal of calculus", "treatment of periodontal disease", "prothodontic treatment" and "extraction of the third molar". Findings taken from the panoramic radiography were: dental caries, periapical lesion, alveolar bone loss, calculus deposition, retained root, impaction of the third molar, disease of maxillary sinus, bony change of mandibular condyle, etc. RESULTS: The prevalence of panoramic findings were: 37.9% of dental caries, 17.4% of periapical lesions, 44.7% of alveolar bone losses, 62.6% of calculi deposition, 7.9% of retained roots, 26.8% of third molar impactions, 6.3% of diseases of maxillary sinus, 2.1% of bony changes of mandibular condlye and 35.8% of miscellaneous lesions. Abnormal conditions revealed by panoramic radiography which had not been discovered on clinical examination were: 24.2% of the patients had dental caries, 17.4% had periapical lesions, 7.4% had calculi deposition, 5.3% had retained roots, 15.3% had third molar impactions. The opposite cases were: 5.2% had dental caries, 12.6% had calculi deposition, and 9.5% had third molar impactions. CONCLUSION: The use of panoramic radiography as a supplement to the clinical examination might be a valuable screening technique.

Giant osteoma of the mandible causing breathing problem / 대한구강악안면방사선학회지

The review of the literature determines that large osteomas of the mandible are relatively rare. We present a case of a 60-year-old man with painless swelling of the left submandibular area and mild difficulty in breathing. The patient complained that the mass have been progressing slowly for at least 20 years. Radiographic studies showed a giant osteoma that attached to the lingual surface of the left mandibular angle and extended from submandibular space to infratemporal space. After the excision of the tumor the patient made a full recovery.

Radiographic study of the unicystic ameloblastoma / 대한구강악안면방사선학회지

PURPOSE: To acquire the useful diagnostic information through the analysis of the clinical and radiological characteristics of mandibular unicystic ameloblastoma. MATERIALS AND METHODS: The researchers compared and analysed the clinical and radiological features of 79 cases of mandibular unicystic ameloblastoma confirmed by histopathlogic examination. RESULTS: The results of our research showed that unicystic ameloblastomas occurred more frequently in males than in females and the incidence is the highest in the 2nd and 3rd decades. These lesions occurred most frequently in angle-ramus area, mandibular molar area, and anterior area in descending order respectively 68.4%, 24%, and 7.6%. These lesions had smooth (54.4%) rather than undulating (45.6%) borders. These lesions showed welldefined borders in 59.5% among all the cases. Root resorption and loss of lamina dura were observed as 55.7% and 58.5% respectively. Displacement of mandibular canal was observed in 55.9% among all the related cases. Internal pattern of lesional radiolucency was observed as even (49.4%) or uneven (50.6%). CONCLUSION: These results would be helpful in diagnosing of mandibular unicystic ameloblastoma.

Radiographic study of the odontogenic keratocyst / 대한구강악안면방사선학회지

PURPOSE: To acquire the useful diagnostic information through the analysis of the clinical and radiological characteristics of mandibular odontogenic keratocyst. MATERIALS AND METHODS: The researchers compared and analysed the clinical and radiological features of 112 cases of mandibular odontogenic keratocyst confirmed by histopathlogic examination. RESULTS: Mandibular odontogenic keratocysts occurred more frequently in males than in females and the incidence is the highest in the 2nd and 3rd decades. These cysts occurred in the mandibular posterior area, angle-ramus area and anterior area 51.8%, 31.2% and 17.0% respectively. These cysts had undulating border (69.6%) rather than smooth border (30.4%). Most of these cysts had well-defined hyperostotic border (94.6%). These cysts caused cortical thinning or expansion (78.6%) rather than no cortical reaction (21.4%). Loss of lamina dura was observed in 72.3%, displacement of tooth appeared in 35.7% and root resorption appeared in 12.5% of cases. In 71% of cases, displacement of mandibular canal was observed. Internal patterns of lesional radiolucency were even (61.6%) or uneven (38.4%). CONCLUSION: These results would be helpful in diagnosing of mandibular odontogenic keratocyst.

Processing Mechanism of Sensory Information Originated from the Oral Cavity in the Trigeminal Nucleus Oralis / 대한해부학회지

To analyze the synaptic characteristics of axon terminals originated from the tooth pulp in the trigeminal nucleus oralis, labeling of tooth pulp afferents with wheat-germ agglutinin conjugated horseradish peroxidase and morphometric analysis with electron microscopic photographs were performed. The results obtained from 23 labeled endings were as follows. All of the labeled boutons contained clear and round synaptic vesicles (dia. 45~55 nm). 3 (13.64%) out of 23 labeled endings have 20~105 dense cored vesicles and do not make synaptic contacts with p-endings. But remaining 20 labeled endings (86.36%) almost do not have dense cored vesicles and 12 of them make synaptic contacts with p-endings. The mean number of synaptic contacts was 2.61+/-2.06 and the postsynaptic profiles were usually middle or distal dendrite and dendritic spine (1.74+/-1.36) rather than soma or proximal dendrite. The mean number of synaptic contacts with pendings was 0.87+/-1.01. And the frequency of the synaptic triads were 0.39+/-0.58. The vesicle density was 993.23+/-267.41/mum(2). The volume of labeled bouton was 3.54+/-2.20 mum(3) and highly correlated (P < 0.01) with surface area (11.78+/-4.92 mum(2), r = 0.95), total apposed surface area (2.90+/-1.56 mum(2), r=0.72), total active zone area (0.61+/-0.37 mum(2), r = 0.82), mitochondrial volume (0.75+/-0.53 mum(3), r = 0.94), the number of synaptic vesicles (2621.30+/-1473.61, r= 0.91) and the number of synaptic contacts (r = 0.76). These results suggest that there are two groups of tooth pulp afferent terminals according to the presence of dense cored vesicles in the trigeminal nucleus oralis. And the sensory processing mechanism of each groups may be different. And the "size principle" of Pierce & Mendell (1993) is also applicable to these terminals.

Quantitative and Ultrastructural Analysis of Afferent Terminals from Tooth Pulp in the Trigeminal Principal Sensory Nucleus / 대한해부학회지

To analyze the synaptic characteristics of axon terminals originated from tooth pulp in the trigeminal principal sensory nucleus, and find morphological evidence that p-endings on these terminals use GABA as neurotransmitter, labeling of tooth pulp afferents with wheat -germ agglutinin conjugated horseradish peroxidase, postembedding immunocytochemistry and morphometric analysis were performed. The results obtained were as follows. The labeled boutons contained clear and round synaptic vesicles, and the mean number of synaptic contacts was 4.21 +/- 2.58. The postsynaptic profiles were usually middle or distal dendrites and dendritic spines rather than soma or proximal dendrites. The mean number of synaptic contacts with p -endings was 2.62 +/- 2.01. The volume of labeled bouton was 4.39 +/- 3.08 micro meter 3 and highly correlated (P<.01) with surface area (r = 0.96), total apposed surface area (r = 0.84), total active zone area (r = 0.84), mitochondrial volume (r = 0.95), the number of synaptic vesicles (r = 0.92), the number of synaptic profiles (r = 0.76) and the number of synaptic p -endings (r = 0.67). The p -endings contained pleomorphic synaptic vesicles. The volume of p -ending was 0.91 +/- 0.47 micro meter 3 and highly correlated (P<.01) with surface area (r = 0.94), total apposed surface area (r = 0.76), total active zone area (r = 0.62), mitochondrial volume (r = 0.70) and the number of synaptic vesicles (r = 0.94). P -endings were GABA immunoreactive. These results suggest that tooth pulp afferent terminals in trigeminal principal sensory nucleus may be related to complex processing of sensory information and presynaptic p -endings using GABA as neurotransmitter, are important in this sensory processing. The "size principle" of Pierce and Mendel (1993) is also applicable to tooth pulp afferent terminals and presynaptic p -endings.

Radiographic evaluation of the zygomatic air cell defect / 대한구강악안면방사선학회지

PURPOSE: The purpose of this study was to determine the prevalence, radiographic appearance, and characteristics of patients with zygomatic air cell defect (ZACD), and to give recommendations concerning radiographic evaluation and surgery. MATERIALS AND METHODS: Routine panoramic radiographs of 1,400 patients admitted to the Kyungpook National University Hospital Dental Clinic, were retrospectively examined for the clinical and radiographic features of ZACD. RESULTS: ZACD was found in 31 cases, representing a prevalence of 2.2%. Patients with ZACD had a mean age of 27.5 years and a range of 9-52 years. Most ZACD cases were in their thirties. ZACD showed a strong male prediliction, 22 of the 31 subjects were males and 9 were females. Twenty-four cases of ZACD (77.4%) were unilateral, with the half occurring on the right side. In seven cases (22.6%), ZACD was bilateral. Twenty-six (68.4%) of the defects were of unilocular, while twelve (31.6%) of the defects were multilocular. CONCLUSION: Knowledge of ZACD may be helpful in interpreting images, including panoramic radiographs, in planning surgical treatment of the TMJ and in understanding the spread of pathological processes into the joint.

Radioprotective effects of dimethyl sulfoxide in the artificial skin reconstructed with cultured human cells / 대한구강악안면방사선학회지

PURPOSE: To evaluate cultured human artificial skin as an experimental model for studying radiation effects in vitro. MATERIALS AND METHODS: The skin was constructed by culturing keratinocytes over collagen lattice which made by culturing fibroblasts. Two groups were irradiated to gamma rays at single dose of 25 Gy with or without 3.5% of DMSO. Ultrastructures were investigated by electron microscopy after irradiation. The number of epidermal layers and expression of cytokeratin (CK) 14 and 10 were also seem by light microscopy. RESULTS: At 2 days after irradiation in experimental group without DMSO, necrotic cells were rarely found in the spinosal layer and undercornified cells were visible in the horney layer. Similar findings were also found in experimental group with DMSO but in mild form. The number of epidermal layers in experimental group without DMSO were significantly fewer than other group. CK 14 expressed in all the layer excluding horney layer but CK 10 expressed over 3~4 basal layers. Such patterns of CK expression were similar to all groups. It is suggested that structures of the keratinocytes and epidermal formation could be disturbed by irradiation in artificial skin and that DMSO can protect these damages. CONCLUSION: Therefore this work could be used as an organotypic experimental model in vitro using human cells for studying radiation effect in skin. Furthermore structural findings provided in this study could be used as useful basic data in further study using this model.

Radiographic Differential Diagnosis Between The Fibrous Dysplasia And The Ossifying Fibroma / 대한구강악안면방사선학회지

The author observed and compared the radiographic features of 49 cases of the fibrous dysplasia and 14 cases of the ossifying fibroma in the osteoblastic or mature stage radiologically and histopathologically. The obtained results were as follows: 1. Fibrous dysplasia occurred most frequently in the 2nd decade, but ossifying fibroma in the 3rd and 4th decades, and both lesions occurred with slight predilection in females. 2. In most cases, chief complaints were painless facial swelling. And 61.1% of fibrous dysplasia occurred in the maxilla, 92.9% of ossifying fibroma in the mandible, and most of these lesions occurred in the premolar-molar region. 3. In the mandibular lesions, ossifying fibroma was shown more oval and round shape, but fibrous dysplasia was shown fusiform shape. 4. Fibrous dysplasia was shown homogeneously distributed, complete radiopaque shadow at 63%, and ossifying fibroma was shown concentric, mixed appearance of radiolucent and radiopaque shadow at 92.9%. 5. Fibrous dysplasia was entirely shown poorly outlined and blended to normal surrounding bone, but ossifying fibroma was shown well-defined border. 6. Cortical thinning and expansion were observed in these lesions, but degree of cortical expansion was more severe in ossifying fibroma than fibrous dysplasia. 7. Loss of lamina dura, tooth displacement, and displacement of mandibular canal were observed in both lesions, but root resorption was observed in ossifying fibroma only.

Desmoplastic Fibroma Of The Mandible / 대한구강악안면방사선학회지

Desmoplastic fibroma is a rare, benign intraosseous fibroblastic tumor, which is locally aggressive. It is osseous counterpart of soft tissue fibromatosis. The authors experienced the patient who complained persistent mouth opening limitation with mild swelling on the left mandibular angle area. After careful analysis of clinical, radiological and histopathological findings, we diagnosed as desmoplastic fibroma of the mandible. The results were as follows: 1. Main clinical symptoms were mouth opening limitation which had been persistent for 9 months and mild swelling on the left mandibular angle area. 2. Radiographs showed the radiolucent lesion and expansion of lingual cortex. CT finding is homogeneous soft tissue mass with expansion of left mandibularramus. Destruction of medial wall of ramus and invasion to adjacent soft tissue is also seen. 3. Histopathologically, plump spindle shaped fibroblasts arranged in bundles or fascicles are observed. The cells of tumor are infiltrating into muscle fiber with destruction of bony trabeculae and merged with surrounding salivary gland.

Desmoplastic Fibroma Of The Mandible / 대한구강악안면방사선학회지

Desmoplastic fibroma is a rare, benign intraosseous fibroblastic tumor, which is locally aggressive. It is osseous counterpart of soft tissue fibromatosis. The authors experienced the patient who complained persistent mouth opening limitation with mild swelling on the left mandibular angle area. After careful analysis of clinical, radiological and histopathological findings, we diagnosed as desmoplastic fibroma of the mandible. The results were as follows: 1. Main clinical symptoms were mouth opening limitation which had been persistent for 9 months and mild swelling on the left mandibular angle area. 2. Radiographs showed the radiolucent lesion and expansion of lingual cortex. CT finding is homogeneous soft tissue mass with expansion of left mandibularramus. Destruction of medial wall of ramus and invasion to adjacent soft tissue is also seen. 3. Histopathologically, plump spindle shaped fibroblasts arranged in bundles or fascicles are observed. The cells of tumor are infiltrating into muscle fiber with destruction of bony trabeculae and merged with surrounding salivary gland.

A Radiographic study of Fibro-osseous lesions of the jaw bones / 대한구강악안면방사선학회지

The purpose of the study was to obtain information on the clinical and radiographic features of the fibro-osseous lesions in the jaws. For this study, the author examined and analysed the clinical records and radiographs of 71 cases of 68 patients in fibrous dysplasia diagnosed by clinical and radiographic or histopathological examinations. The obtained results were as followings : 1. Fibrous dysplasia occured most frequently in the 2nd decade(30.0%), ossifying fibroma in the 3rd-4th decades, periapical cemental dysplasia in the 4th decade, and all of three lesions showed slight predilection in females. In most cases, chief complaints were painless facial swelling in fibous dysplasia and ossifying fibroma, and periapical cemental dyplasia was found accidentally in radiographs. 2. Fibrous dysplasia was occured more frequently in maxilla, ossifying fibroma in mandible and both lesions in premolar-molar area. Periapical cemental dysplasia was larger than that of ossifyng fibroma, and the shape of ossifying fibroma was more round and elliptical than fibrous dysplasia whose was fusiform. 3. Fibrous dysplasia was shown homogeneous radiopaque shadow of 57.6% and ossifying fibtoma & periapical cemental dysplasia were shown mixed appearance of radiolucency and radiopacity shadows at 74.2%, 60.0%, respectively. 4. Fibrous dysplasia was entirely shown poorly defined at 87.7%, but ossifying fibroma & periapical cemental dysplasia were shown well outlined at 60.0%, 70.0%, repectively. 5. Cortical thinning and expasion were observed in fibrous dysplasia and ossifying fibroma, and severe in ossifying fibroma than fibrous dysplasia, and those signs were not seen in periapical cemental dysplasia. Loss of lamina dura was dominant in fibrous dysplasia and root resorption was dominant in ossifyingfibroma. Displacement of mandibular canal and the degree of the increase of vertical dimension were alike in both lesions. Displacement of maxillary sinus or nasal cavity, thinning & expansion of the maxiilary sinus were dominant in fibrous dysplasia. 6. Polyostotic fibrous dysplasia was occured at 5.9%, Multiple periapical cemental dysplasia at 43.7%. Occurrence rate in the edentulous area of fibrous dysplasia and ossifying fibroma were 7.0%, 8.6%, respectively.

A Radiographic Study of Odontoma / 대한구강악안면방사선학회지

The purpose of this study was to obtain information on the clinical and radiographic features of the odontomas in the jaws. For this study, the authors examined and analyzed the clinical records and radiographs of 119 patients who had lesion of odontoma diagnosed by clinical and radiographic examinations. The obtained results were as follows ; 1. Odontoma occurred the most frequently in the 2nd decade(45.4%) and occurred more frequently in males(60.5%) than in females(39.5%). 2. The most common clinical symptom was the delayed eruption of the teeth(34.2%). 3. The type of lesions was mainly observed as compound odontoma(80.8%), and internal pattern of the complex odontoma was unevenly radiopaque(73.9%). 4. The compound odontoma frequently occurred in anterior portion of the maxilla(57.7%) and mandible(30.9%), and complex odontoma frequently occurred in anterior portion of maxilla(34.8%) and posterior portion of mandible(30.5%). 5. The effects on adjacent teeth were impaction of teeth(71.7%) and prolonged retention of deciduous teeth(31.7%). 6. The impaction of the teeth occurred in anterior portion of maxilla(44.2%) amd mandible(19.2%), but root resorption of the adjacent teeth were not seen. 7. The boundary to adjacent structure was well-defined, the lesions appear as radiopaque mass with radiolucent rim.

A radiographic study of the position and shape of mental foramen in panoramic radiographs / 대한구강악안면방사선학회지

The purpose of this study was to evaluate the position and shape of mental foramen in panoramic radiographs. For t his study, panoramic radiographs were obtained from the 200 adults and evaluated the position and shape of mental foramen. According to various positional changes in panoramic radiographs of the patients, the author also obtained panoramic radiographs from the 100 adults and then evaluated the positional and shape changes of mental foramen. The following results were obtained: 1. Shapes of mental foramen were observed elliptical(43.3%), round or oval(42.5%), unidentified(7.5%) and diffuse(6.7%) type in descending order of frequency. 2. Horizontal position of mental foramen were most frequently observed at the 2nd premolar area(54.2%), and area between the 1st premolar and 2nd premolar(43.1%), area between the 2nd premolar and 1st molar(2.7%), and at apex(9.7%), overlap with apex(1.9%), superior of apex(0.2%) in descending order of frequency. 4. According to various positional changes in panoramic radiographs of the patients, shape changes of mental foramen we re more obviously observed at the forward 10mm and chin down 10degrees positioned panoramic radiographs, And changes of horizo ntal and vertical position were observed in similar to compared with normal positioned panoramic radiographs.