OBJECTIVE: To evaluate the association of condylar asymmetry and chin position with different anteroposterior skeletal patterns using three-dimensional models reconstructed from cone-beam computed tomography (CBCT) images. MATERIALS AND METHODS: CBCT scans of 123 Chinese adolescents (aged 11-15 years, 68 girls and 55 boys) with 64 skeletal Class I, 46 Class II and 13 Class III were selected from scans of patients attending the orthodontic clinic. The condyles of the subjects were reconstructed bilaterally and 25 linear, angular and volumetric measurements were performed to evaluate the asymmetry of the condyles and position of the chin. The proportions of condylar asymmetry in the different skeletal groups were calculated by the absolute difference value between the left and right sides to the smaller side value. One-way analysis of variance and Pearson's correlations were used to analyse the data. RESULTS: The values for RV, RCL, LCH, RCH, LCGM, RCGM, LCo-Me and RCo-Me were significantly different among the three skeletal groups (p < 0.05). There were significant positive correlations between Pog-Ss and Co-Sh, Co-Me in the Class I and II groups (p < 0.05). Asymmetries for Co-Ss, Co-Sh, CP and SP between the left and right condyles exceeded a ratio of 20% for more than 30% of the subjects. CONCLUSION: Condylar asymmetry varied significantly among the three skeletal groups, with the vertical position of the condyle (Co-Sh) and height of the mandibular ramus (Co-Me) being significantly and positively related to the chin position.

BACKGROUND: Periodontal diseases are prevalent among adult populations. Its diagnosis depends mainly on clinical findings supported by radiographic examinations. In previous decades, cone beam computed tomography has been introduced to the dental field. The aim of this study was to address the diagnostic efficacy of cone-beam computed tomographic (CBCT) imaging in periodontics based on a systematic search and analysis of the literature using the hierarchical efficacy model. METHODS: A systematic search of electronic databases such as PubMed, Scopus, Web of Science, and Cochrane was conducted in February 2019 to identify studies addressing the efficacy of CBCT imaging in Periodontics. The identified studies were subjected to pre-identified inclusion criteria followed by an analysis using a hierarchical model of efficacy (model) designed for an appraisal of the literature on diagnostic imaging modality. Four examiners performed the eligibility and quality assessment of relevant studies and consensus was reached in cases where disagreement occurred. RESULTS: The search resulted in 64 studies. Of these, 34 publications were allocated to the relevant level of efficacy and quality assessments wherever applicable. The overall diagnostic accuracy of the included studies showed a low or moderate risk of bias and applicability concerns in the use of CBCT. In addition, CBCT is accurate in identifying periodontal defects when compared to other modalities. The studies on the level of patient outcomes agreed that CBCT is a reliable tool for the assessment of outcomes after the treatment of periodontal defects. CONCLUSION: CBCT was found to be beneficial and accurate in cases of infra-bony defects and furcation involvements.

OBJECTIVE: To compare the dimensions of the upper airway in young adults with anterior open bite versus matched individuals with an adequate overbite (control group) using different measurement approaches (linear, area, and volume measures). MATERIALS AND METHODS: The sample included 137 cone-beam computed tomographies (CBCTs) of young adults (74 men and 63 women) divided into two groups: 47 CBCTs of individuals (mean age 27.89) with open bite (overbite depth indicator (ODI) 56.84 degrees +/-9.48 degrees and Frankfort mandibular plane angle (FMA) 31.21 degrees +/-6.44 degrees ) and 90 CBCTs of individuals (mean age 26.87) without an open bite (ODI 62.24 degrees +/-9.47 degrees , FMA 26.79 degrees +/-5.81 degrees ). Two trained and calibrated orthodontists made all linear, area, and volume measurements on the CBCT records of the upper airways using Planmeca Romexis software. The Mann-Whitney U-test, chi-squared test, and multiple linear regression were applied. Significance was set at P<0.05. RESULTS: There were no differences in linear or volume measurements between groups, but there was a greater area in the open bite group (greater mean difference between groups 928.3 mm(2)) than the control group. No variable influenced nasopharyngeal airway volume, but ANB angle affected oropharyngeal airway volume (beta=-623.87) and total airway volume (beta=-651.48). CONCLUSIONS: Orthodontists should be aware that the airways diagnosis can vary depending on the measurement approach used, the volumetric method being the gold standard. The pharyngeal airway volume was similar in individuals with vs. without an open bite and is mainly influenced by ANB angle in both groups.

OBJECTIVE: The purpose of this study was to evaluate the morphology of mandibular condyle using cone-beam computed tomography (CBCT) on coronal sections in a South-Eastern Anatolian population. METHODS: A total of 1820 joints in 910 subjects with age range of 18 to 86 years were examined retrospectively on CBCT images. The mandibular condylar morphology was examined in right and left sides on coronal sections and classified as convex, round, flat, and angled. In addition, condyle morphology was assessed according to age, gender, edentulism, Angle's classification. RESULTS: The study sample contained CBCT scans of 910 patients (50.3% female, 49.7% male) with a mean age of 42.31 +/- 15.74. Condylar morphologies were analyzed as convex in 40.5%, angled in 34.3%, flat in 15.5%, round in 9.6% of the cases. Condyle shape was found statistically related to group age, gender, edentulism (P <0.05). CONCLUSION: The findings suggest that mandibular condyle shape is associated with age, gender, and edentulism. CBCT may be considered as an appropriate imaging method for detection of condyle alterations of temporomandibular joints and it could provide early diagnosis of temporomandibular joint disorder.

BACKGROUND: The correlation between individuals' condylar morphology and their skeletal pattern is of great interest for treatment strategies ranging from orthodontic orthopaedics to orthognathic surgery. The objective of the present study was to investigate this relationship three-dimensionally. METHODS: A total of 111 adult patients (mean age = 27.0 +/- 10.2 years) who underwent head computed tomography or cone beam computed tomography scans were included. Based on these data, 3D models of the skull and the condyles were calculated. The craniofacial skeleton was evaluated (1) transversally regarding skeletal symmetry (menton deviation), (2) sagittally regarding skeletal classes (Wits appraisal) and vertically regarding the inclination of the jaws (maxillomandibular plane angle). The condylar morphology was assessed (a) linearly by the condylar width, height and depth; (b) angularly by the antero-posterior and medio-lateral condylar inclination; and (c) volumetrically by the ratio of the condylar volume/mandibular volume (C/Mand). RESULTS: (1) Transversal: Asymmetric patients showed significantly higher discrepancies in the volumetric ratio C/Mand on the deviation and non-deviation side compared to symmetric patients. (2) Sagittal: Class III subjects demonstrated longer, more voluminous condyles with higher antero-posterior and medio-lateral inclination angles compared to Class II participants. (3) Vertical: Hyperdivergent subjects had smaller condyles with higher antero-posterior inclination angles than those of hypodivergent subjects. No interactions of skeletal class and vertical relationships regarding condylar morphology were observed. CONCLUSIONS: This study demonstrates a clear correlation between pronounced skeletal patterns and condylar morphology in an adult population. The description of radiographic condyle characteristics in relation to the craniofacial morphology improves orthodontic treatment planning and could be helpful in the diagnosis of temporomandibular joint pathologies.

OBJECTIVES: This study sought to investigate the three-dimensional (3D) changes in anteroposterior, vertical and mediolateral positions and orientations of the mandibular condyle as well as joint space parameters following maxillary first premolar extraction and incisor retraction in skeletal Class II patients. SETTING AND SAMPLE POPULATION: Thirty patients were treated by orthodontic maxillary first premolar extraction at the Faculty of Oral and Dental Medicine, Cairo University, Egypt. MATERIALS AND METHODS: Cone beam computed tomography (CBCT) analysis was performed in patients pre- and post-treatment. Sixty joints were evaluated based on the volumetric images, and the following 3D measurements were evaluated: (i) mandibular condylar position relative to the cranial base and the joint itself, (ii) condylar inclination and (iii) anterior, posterior, superior and medial joint spaces. RESULTS: There was a statistically significant (P