Short-term and long-term alterations of condylar position after bilateral sagittal split ramus osteotomy for mandibular setback: A preliminary before-after clinical trial.

Background: Because of the importance of the condyle, it is crucial to document all changes in its position after orthognathic surgery. Since previous studies in this regard are mostly controversial and limited by two-dimensional radiography technique, this study was conducted. Materials and Methods: This prospective clinical trial was performed on 102 measurements (17 patients, 2 condyles each, and 3 time points). Cone-beam computerized tomography imaging was done for 17 skeletal Class-III patients (10 females and 7 males, mean age, 24.05 ± 4.78 years) undergoing fixed orthodontic treatment, at three time points T0 (before surgery), T1 (immediately after surgery), and T2 (8 months after surgery). Condylar positions were measured. Position changes were evaluated during the course of the study. They were also compared between right/left sides and between men and women. Tests in use were repeated-measures one- and two-way analysis of variance and paired t-tests (α =0.05, α =0.017). Results: Alterations in various anatomical condyle parameters over the 8-month course of the study did not reach the level of significance (P ≥ 0.078). At all intervals, mean anterior-posterior index (API) remained between -12 and +12 (indicative of central position of the condyle in the glenoid fossa). Between men and women, left superior joint space, left anterior joint space, and left API differed (P ≤ 0.05). Left condyle mean superior joint space and anterior joint space were greater in men compared to women in all the three intervals; left condyle mean API was greater in women compared to men (more posterior in men, P ≤ 0.05). Conclusion: Condyles might not change significantly after 8 months post-surgery. However, small changes might be observed, and these changes might differ between the left and right sides and between males and females.

Correlations among chronological age, cervical vertebral maturation index, and Demirjian developmental stage of the maxillary and mandibular canines and second molars.

PURPOSE: Estimation of growth spurt from chronological age or dental development is of clinical interest to orthodontists. Since results in this regard are highly controversial and limited, this study was conducted to investigate associations among chronological age, skeletal development (cervical vertebral maturity [CVM]), and dental calcification (Demirjian) in girls and boys, independently. METHODS: Panoramic radiographs and lateral cephalographs of 112 boys and 112 girls were evaluated. Demirjian stages of dental development of the bimaxillary canines and second molars were determined. CVM stages of skeletal growth were as well estimated. Correlations among these were assessed. Differences between sexes and between maxilla/mandible arches were assessed. Cutoff points in Demirjian and chronological age reflecting skeletal growth spurt were found using receiver operator characteristic curve (α = 0.05, ß = 0.9 separately for girls and boys). RESULTS AND CONCLUSIONS: Sex dimorphism existed both in CVM index and in Demirjian indexes. Compared to dental development and calcification, chronological age was the best predictor of skeletal growth and maturation. In estimating chronological age by radiography means, in girls, Demirjian method was better than CVM. In boys, Demirjian was better than CVM in the case of the molars but not canines. The cutoff points estimated for chronological age and dental calcification that can reflect skeletal growth spurt (between CS-3-and-CS-4) were as follows: in boys, age of 12 years; in girls, age between 11 and 12 years; the upper and lower canines: between G and H; the maxillary and mandibular second molars: between F and G; in the case of all teeth: between F and G.

Relationship between bridging and dimensions of sella turcica with classification of craniofacial skeleton.

PURPOSE: In orthodontics, it is essential to determine the craniofacial skeleton pattern (class I, II, III) for planning treatment. Sella turcica bridging that is seen on lateral cephalometric radiographs is considered as a normal finding. This study aimed to compare sella turcica bridging and its dimensions in patients with various craniofacial patterns. MATERIAL AND METHODS: A total of 105 lateral cephalometric radiographs (53 men and 52 women), aged 14-26 years, were randomly and equally assigned to three groups of class I, II, and III, respectively. The length, diameter, and depth of the sella turcica as well as sella turcica bridging were determined on radiographs. The chi-squared test was used for assessing the relationship between sella turcica bridging and craniofacial skeleton classification. ANOVA was used for assessing the relationship between the dimensions of the sella turcica and craniofacial skeleton classification. The Pearson's correlation coefficient was used for assessing the relationship between age and the dimensions of the sella turcica. RESULTS: The sella turcica had a normal shape in 64.76% of patients, whereas 35.33% of patients had sella turcica bridging. In total, 11.42% of patients belonged to class I, 34.28% to class II, and 66.62% to class III. The diameter of the sella turcica had a significant relationship with age; the diameter of the sella turcica increased with age (p < 0.001). CONCLUSIONS: There is a significant relationship between craniofacial skeleton patterns and sella turcica bridging, i.e., the incidence of sella turcica bridging is higher in class III patients. The sella turcica had a greater diameter in older patients.

Dosimetry of Three Cone Beam Computerized Tomography Scanners at Different Fields of View in Terms of Various Head and Neck Organs.

BACKGROUND: Marketing new radiography devices necessitates documenting their absorbed X-ray doses. Since the current literature lacks studies on new devices, we assessed the doses of two new devices that had not previously been assessed. OBJECTIVES: The new devices were compared to the Promax three dimensional (3D) scanner at two fields of view (FOV) in nine critical head and neck tissues and organs. MATERIALS AND METHODS: Seventeen thermoluminescence dosimeters positioned in an average-sized male RANDO phantom were used to determine the dosimetry of the three cone beam computerized tomography devices (NewTom VGi, NewTom 5G, and Promax 3D) at two field of views (FOVs), one small and one large. The exposure by each device per FOV was performed five times (30 exposures). The absorbed and effective doses were calculated for the thyroid, parotid, submandibular gland, sublingual gland, calvarium, cervical vertebra, trunk of the mandible, and mandibular ramus. The doses pertaining to the different devices, the FOVs, and the tissues were compared using the Kruskal-Wallis, Mann-Whitney U, and Wilcoxon tests. RESULTS: The average absorbed doses, respectively, for the large and small FOVs were 17.19 and 28.89 mGy in the Promax 3D, 19.25 and 35.46 mGy in the NewTom VGi, and 18.85 and 30.63 mGy in the NewTom 5G. The absorbed doses related to the FOVs were not significantly different (P value = 0.1930). However, the effective doses were significantly greater at the smaller FOVs / higher resolutions (P = 0.0039). The doses of the three devices were not significantly different (P = 0.8944). The difference among the nine organs/tissues was significant (Kruskal-Wallis P=0.0000). CONCLUSION: The absorbed doses pertaining to the devices and the FOVs were not significantly different, although the organs/tissues absorbed considerably different doses.

The Effect of Emboss Enhancement on Reliability of Landmark Identification in Digital Lateral Cephalometric Images.

BACKGROUND: Evaluation of the craniofacial bones is the oldest method to measure the facial proportion ratio in orthodontics. OBJECTIVES: The purpose of this study was to evaluate the effect of emboss enhancement on the reliability of landmark identification in digital lateral cephalometric images. MATERIALS AND METHODS: Ten digital lateral cephalograms were selected from the archive of an oral and maxillofacial radiology center. Using DIGORA software, these images were saved in two formats; common images and 3D emboss images. On these images, 32 skeletal, dental, and soft tissue landmarks were marked at least twice with a 2-week interval by four observers (two radiologists and two orthodontists). In order to determine the position of the marked landmarks (in x and y coordinates), a software was designed. The statistical analysis was performed in SPSS software and the reliability of each observer was obtained by means of intraclass correlation coefficient (ICC). RESULTS: In three skeletal landmarks [Orbit (Or), condyl top (Cond), and pogonion (Pog)], the enhancement caused significant reduction in the reliability, and in four skeletal [Anterior Nasal Spine (ANS), B, A, and Basion (Ba)], two dental (U1 root, L1 incisal), and one soft tissue landmark (Menton soft tissue), the enhancement increased the reliability of landmark detection between the two phases of the study. Totally, ICC of embossed images in both x and y coordinates were greater than the typical images, but the difference was not statistically significant. However, the effect of enhancement on the improvement of the reliability of landmark identification was higher in the x-axis than the y-axis. CONCLUSIONS: Using embossed images is only effective in increasing the reliability of detection in a few numbers of cephalometric landmarks.

Relationship between carotid artery calcification detected in dental panoramic images and hypertension and myocardial infarction.

BACKGROUND: Carotid artery calcification may be related to cerebrovascular accident, which may result in death or physical and mental disabilities in survivors. OBJECTIVES: Our purpose is to study the association of carotid artery calcification (CAC) on dental panoramic radiographs and two risk factors of cerebrovascular accident (CVA) including hypertension and myocardial infarction (MI). PATIENTS AND METHODS: Panoramic images of 200 patients that were all women above 50 years of age (a population suffering from vascular diseases) were investigated. All panoramic images were provided under similar conditions in terms of the type of panoramic radiograph equipment, type of applied films and the automatic film processor. Then, the patients answered questions about MI history and taking antihypertensive drugs. We also measured the blood pressure of patients in two separate surveys. Data analysis was performed by SPSS statistical program. We used Exact Fisher test and Chi-Square test at a significant level of less than 0.05 to study the effect of these variables on the occurrence of carotid artery calcification. RESULTS: Among 200 studied samples, 22 of the patients (11%) had carotid artery calcification on the dental panoramic radiograph. In total, 52 patients (26%) had hypertension and four people (2%) had a history of MI. Eleven individuals among patients suffering from hypertension (21.2%) and three individuals among patients with a history of MI (75%) demonstrated CAC on dental panoramic images . CONCLUSIONS: The relationship between CAC found on dental panoramic radiographs and two CVA risk factors--hypertension and MI-- was significant. Therefore, it seems that detection of CAC on panoramic images of dental patients must be considered by dentists.

Validity and reliability of the Persian version of the oral health impact profile (OHIP)-14.

BACKGROUND: The need for assessment of oral health related quality of life has been increased over the last decades. The aim of this study was to develop a Persian version of the Oral Health Impact Profile (OHIP)-14 and to evaluate its reliability and validity for its use in Persian-speaking communities. METHODS: The original version of the OHIP-14 was translated into the Persian language using the back-translation technique. To establish the reliability of the translated instrument, internal consistency and test-retest reliability trials were performed on 20 subjects (at 4-week intervals); Cronbach's alpha was used. One hundred sixty adults over 50 years of age who attended Health Care Centers in Sari and Babol were recruited to fill out the questionnaires and received a clinical examination by a single dentist. The socio-demographic and oral health information was also collected. RESULTS: The test-retest reliability was excellent (Cronbach's alpha = 0.095). In the main study, Cronbach's reliability coefficient for all 14 questions in each dimension was more than 70%. The individuals in need of dental treatment showed significantly higher OHIP scores than the individuals not requiring treatment. The individuals with hopeless teeth, negative self-perceived oral had significantly higher OHIP scores. CONCLUSION: The Persian version of the OHIP-14 is a comprehensive and accurate instrument with acceptable reliability and validity for measuring oral health-related quality of life.