Results 1 - 10 of 3324
Results 1 - 10 of 3324. Search took: 0.028 seconds
|Sort by: date | relevance|
[en] The mandibular canal must be considered carefully during surgical treatment, especially surgical extraction of the impacted tooth and intraosseous implant because it contains the important inferior alveolar nerve and vessel. Th e author investigated the curvature of the mandibular canal, the positional frequency of mandibular foramen to the occlusal plane and gonial angle and the positional frequency of the mental foramen to the tooth site using orthopantomorgrams. The materials considered of 295 orthopantomograms divided into seven groups ranging from the first decade to 6th decade. The results were as follows: 1. The position of mandibular foramen was most frequently below occlusal plane in Group I (78.6%) and Group II (71.2%) , above occlusal plane in Group III (63.0%), Group IV (71.1%), Group V (57.6%), Group VI (76.7%) and Group VII (70.0%). 2. The curvature of mandibular canal was 142.82 .deg. in Group I, 142.09 .deg. in Group II, 139.34 .deg. in Group III, 141.48 .deg. in Group IV, 138.45 .deg. in Group V, 140.77 .deg. in Group VI and 143.89 .deg. in Group VII. 3. The gonial angle was 125.82 .deg. in Group I, 123.18 .deg. in Group II, 124.06 .deg. in Group III, 120.45 .deg. in Group IV, 121.12 .deg. in Group V, 121.63 .deg. in Group VI and 121.24 .deg. in Group VII. 4. The position of the mental foramen was most frequently below the apex of mandibular first premolar in Group I ( 57.2%), between the apex of mandibular first and second premolar in Group II (59.6%) and Group III (48.9%), and below the apex of mandibular second premolar in Group IV (39.2%), Group V (48.5%) Group VI (46.7%) and Group VII (56.4%).
[en] To determine the effect of interpolation functions when processing the digital periapical images. The digital images were obtained by Digora and CDR system on the dry skull and human subject. 3 oral radiologists evaluated the 3 portions of each processed image using 7 interpolation methods and ROC curves were obtained by trapezoidal methods. The highest Az value(0.96) was obtained with cubic spline method and the lowest Az value(0.03) was obtained with facet model method in Digora system. The highest Az value(0.79) was obtained with gray segment expansion method and the lowest Az value(0.07) was obtained with facet model method in CDR system. There was significant difference of Az value in original image between Digora and CDR system at alpha=0.05 level. There were significant differences of Az values between Digora and CDR images with cubic spline method, facet model method, linear interpolation method and non-linear interpolation method at alpha= 0.1 level.
[en] This study was performed to determine the position of the mental foramen relative to the apices of the teeth based on panoramic radiographs in a Moroccan population. We also analyzed gender differences and the symmetry of location within individuals. Seven hundred ninety-four panoramic radiographs were evaluated with regard to the location and symmetry of the mental foramina in male and female subjects. The results were analyzed using Pearson's X2 and Fisher's exact test. Of the 794 panoramic radiographs, 377 met the inclusion criteria for at least one side. The mental foramen was located just below the apex of the second premolar in 62.7% of the patients and between the first and second premolars in 30%. It was symmetrically located in 79%. No statistically significant differences were found between males and females in the position and symmetry of the mental foramen. The most common position for the mental foramen in this sample was in line with the second premolar.
[en] The original version of this article unfortunately contained a mistake. The country was incorrect in the authors affiliations. It should read as “ROC”. The corrected affiliations are given below.
[en] Odontomas are nonaggressive, hamartomatous developmental malformations composed of mature tooth substances and may be compound or complex depending on the extent of morphodifferentiation or on their resemblance to normal teeth. Among them, complex odontomas are relatively rare tumors. They are usually asymptomatic in nature. Occasionally, these tumors become large, causing bone expansion followed by facial asymmetry. Odontoma eruptions are uncommon, and thus far, very few cases of erupted complex odontomas have been reported in the literature. Here, we report the case of an unusually large, painless, complex odontoma located in the right posterior mandible.
[en] The purpose of this study was to obtain some information for the radiographic differential diagnosis between dentigerous cysts and unicystic ameloblastomas in the mandible. The authors observed and compared the clinico-radiographic features of 38 cases of dentigerous cyst and 32 cases of unicystic ameloblastoma associated with impacted mandibular molr. The obtained results were as follows: Dentigerous cyst occurred the most frequently in the 3rd decade, but unicystic ameloblastomas in the 2nd decade, and both lesions occurred with slight predilection in males. Average of lesional size of unicystic ameloblastomas was larger than that of dentigerous cysts, and lesions of over 25 cm2 were only in unicystic ameloblastomas. Cortical thinning and expansion were more frequently observed in unicystic ameloblastomas at 72.9% than in dentigerous cysts at 15.8%. Dentigerous cysts showed smooth border at 89.5%, but unicystic ameloblastomas showed smooth border at 53.1% and scalloped border at 46.9%. Dentigerous cysts showed well-defined outline at 81.6%, but unicystic ameloblastomas showed well-defined outline at 53.1% and moderate-defined outline at 46.9%. In both lesions, the mandibular 3rd molar was the most frequent causative tooth. Average of distance between the cemento-enamel junction and lesional wall attachment of the causative tooth was longer in unicystic ameloblastomas than in dentigerous cyats. Severe displacement of causative tooth was more frequent in unicystic ameloblastomas at 62.5% than indentigerous cysts at 23.7%. Root resorption of adjacent tooth and displacement of mandibular canal were more frequent in unicystic ameloblastomas at 65.2% and 61.5% than in dentigerous cysts at 15.8% and 38.1% respectively.
[en] To assessment the angle between mandibular canal and occlusal plane at each posterior tooth region and location of mental foramen on the panoramic radiographs. This study analysed 46 half-mandibles of panoramic radiographs. Inferior border of mandibular canal was traced. Occlusal plane was drawn from lingual cusp tip of the first premolar to distolingual cusp tip of the second molar. Perpendicular line from occlusal plane was drawn at each tooth region and then tangential lines were drawn from the crossing points at canal. The angle between occlusal plane and tangential line was measured. The location of mental foramen was also studied. According to the location of mental foramen, radiographs were divided into M (mesial) group and D (distal) group on the basis of the second premolar. and then inter-group analysis about mandibular canal angle was done. The angles of mandibular canals were -17.7 .deg. C, -9.5 .deg. C, 8.2 .deg. C, 22.3 .deg. C, and 39.2 .deg. C at first premolar, second premolar, first molar, second molar, and third molar, respectively. The commonest position of the mental foramen was distal to the second premolar. Inter-group comparison showed statistically significant difference at the second premolar and the first molar (p<0.001). The acknowledgement of mandibular canal angulation and location of mental foramen can help understanding the course of mandibular canal.