[Assessment of visibility and extension rate of incisive branch of the inferior alveolar nerve in cone beam computed tomography imagings]

Background and Objective: Many surgeries are performed on anterior region of mandible. Incisive branch of the inferior alveolar nerve is located in the anterior region of mandible. The identification of various form of nerve is important for diagnosis and treatment plan. This study was carried out to the assessment of visibility and extension rate of incisive branch of the inferior alveolar nerve in cone beam computed tomography [CBCT] imagings

Methods: This descriptive - analytic study was performed on 105 CBCT images. The presences or absence of incisive branch of the inferior alveolar nerve and assessment of visibility and extension rate of mandibular incisive canal were studied

Results: In 79% extension of the incisive branch of the inferior alveolar nerve were observed. 18.07% of extensions were observed in one-side and 78.31% were bilateral. Extension of the incisive branch of the inferior alveolar nerve was observed to central, lateral and canine tooth in 59%, 26.5% and 14.5% respectively. There was no significant relation beween gender and age of subjects with extension of the incisive branch of the inferior alveolar nerve

Conclusion: Regarding the high visibility of the incisive nerve branches in the lower dental CBCT images this method can be used to evaluate the anterior region of mandible

[Estimation of mandibular premolar teeth length and mesiodistal width based on panoramic radiograph]

Statement of Problem: In diagnostic studies of dentistry, estimation of the mesiodistal width of the unerupted teeth and the required space for their eruption in relation to the space analysis and evaluation of the root-crow ratio is of great importance

Purpose: This study aimed to evaluate the ratio between the real and radiographic length and mesiodistal width of mandibular premolars and provide a formula for prediction of the teeth length and mesiodistal width

Materials and Method: Fifty six extracted teeth of mandibular first and second premolars of patients and their panoramic radiographs with good quality were collected. The extracted teeth were divided into four groups: T34 [lower left first premolar], T44 [lower right first premolar], T35 [lower left second premolar], and T45 [lower right second premolar]. Then the length and mesiodistal width of both the panoramic images and the extracted teeth were measured. All of the obtained data were analyzed through t-test, two tailed student and linear regression model

Results: It was shown that the vertical magnification of the mandibular first premolars was almost 11.4%-12.1% and that of the mandibular second premolar was almost 16%. The horizontal magnification of the mandibular first premolar was almost 15% and that of the mandibular second premolar was almost 26%. No statistically significant differences were found between the true and radiographic length and mesiodistal width and the magnifications of the left side premolars compared with right side premolars. To determine the real mesiodistal width and length size, some equations are introduced

Conclusion: The panoramic radiographs taken in this research by X-ray imaging machine are feasible and reliable for estimating the actual premolar teeth length and mesiodistal width using specific equations for each teeth in the lower jaw

[Accuracy of Bitewing radiography in posterior teeth Interdental bone resorption]

Alveolar bone level is changed due to the balance between bone formation and resorption. Precise examination of alveolar bone is done by clinical and radiographic methods. Radiographic examination has an important role in diagnosis and treatment of periodontal patients, so this study was performed to determine the accuracy of bitewing radiography in alveolar bone resorption. This analytical and cross-sectional study was performed in 37 interdental osseous wall of patients who referred to the periodontology department of Babol dental faculty for periodontal surgery in 2004. Vertical bitewing radiography was done in premolar and molar region by use of Snap-A-Ray film holder. A caliper with accuracy of 0.05 mm was used for measuring the level of interdental bone resorption on cliche. During periodontal surgery the amount of bone resorption was measured by Williams probe. Then datas were analyzed by paired-t-test and Pearson correlation coefficient and linear regression. The mean value of alveolar bone resorption with Williams probe and bitewing radiography was 2.66 +/- 1.2 and 2.81 +/- 1.06 in maxillary molars, 2.31 +/- 0.75 and 2.5 +/- 1.6 in mandibular molars, 1.73 +/- 1.03 and 1.93 +/- 0.97 in maxillary premolar and 1.91 +/- 1.11 and 2.25 +/- 1.59 in mandibular premolars respectively. According to the results, bite wing radiography had high accuracy in measuring the amount of alveolar bone resorption. So, this method can help to diagnose and determine treatment plan of periodontal disease

Accuracy evaluation of panoramic radiography in detecting the position of third molar roots

Correct radiographic interpretation, especially for root morphology is a useful way to choose open or close surgery and to avoid root fracture during tooth extraction. Since, the third molar has the most irregular and unpredictable root position between all teeth, this study was performed to evaluate the accuracy of panoramic radiography in detecting the position of third molar roots. This cross-sectional and analytical study was performed on 38 patients [49 third molar teeth] who referred to Babol dental school during 2003-2005. Panoramic radiographs were taken from patients in the standard condition and two specialists of oral and maxillofacial radiology and surgery were asked to complete the questionnaire about radiographic interpretation of third molar before surgery. The questionnaire contained the number of tooth roots, relation between roots and relation between root angle and crown. After surgery tooth position was evaluated again. Presurgical and post-surgical radiographic findings were compared and then data were analyzed using paired t-test, X [2], Linear regression and Pearson correlation coefficient. In this study, the accuracy of interpretation of panoramic radiographs in evaluation of number of third molar roots and relation between roots [fused or non fused] was 64.3% and 63.3%, respectively. For the root angle to crown, the radiographic interpretation significantly estimated accurate angle [p<0.0001]. According to the results, panoramic radiography is a useful method for evaluation of the third molar position. Nevertheless, we must be aware of its high diagnostic error rate in evaluation of morphological details of root [number of roots and relation between roots]