Posteroanterior Cephalometric Radiographs Research Articles

The influence of orthopedic rapid maxillary expansion on the deviation of the nasal septum.

Nasal septal deviation (NSD) is one of the most common abnormalities impacting the maxillofacial development of children. Herein, we investigated the impact of orthopedic rapid maxillary expansion (RME) on the nasomaxillary complex and NSD in pediatric patients. The study sample consisted of a total of 40 patients divided into two groups. The experimental group included 26 patients (13 females and 13 males) with skeletal maxillary transversal constriction and NSD greater than 1 mm, while the control group comprised 14 patients (6 females and 8 males) with skeletal maxillary transversal constriction but no NSD. All the patients were treated for approximately 15 days with the tooth-tissue born RME device. The activation procedure was to turn the transversal Hyrax screw a quarter turn, twice a day. After that, the device was left in place for a period of five months to facilitate passive retention. Radiographic analysis was performed on posteroanterior (PA) cephalometric radiographs taken at pre-expansion (T1) and post-expansion (T2). The data were evaluated using the Mann-Whitney U and Wilcoxon Sign tests. The experimental group showed a statistically significant decrease (p < 0.05) in the distance from the axis of symmetry to middle of nasal septum (SNM-mid) and to inferior part of the nasal septum (SNI-mid) measurements, indicating a reduction in NSD. Additionally, both experimental and control groups showed a statistically significant increase (p < 0.05) in maxillofacial measurements, including the distance between the nose length (X-SNM and SNM-SNAC), width of the nasal cavity (Pir L-R), basal maxillary width (Mx L-R), vestibular cuspid of upper first molars (CVM + L-R) and lower first molars (CVM-L-R). Based on the study findings, RME was considered effective in achieving craniofacial improvement in pediatric patients with NSD, which positively impacted their healthy growth and development. The improvement in the nasomaxillary complex was similar between genders.

Cephalometric profile analysis between genders. A study protocol

Background: According to current American Association of Orthodontists guidelines, two-dimensional lateral and posteroanterior cephalometric radiographs are recognized as essential components of diagnostic imaging records in orthodontics. Cephalometry is defined as the discipline that analyzes the craniofacial complex in a segmented way, to study the interrelationships between its structures and understand how the growth or alteration of one of these structures can compromise the whole. Through cephalometry, it is possible to indicate the clinical approach for patients, involving dental therapy with intraoral appliances and physical therapy with continuous positive pressure in the upper airway. Objectives: Investigate possible differences in cephalometric anatomical patterns between genders. Methods: This study protocol follows the STROBE - Strengthening the Reporting of Observational Studies in Epidemiology guidelines. A convenience sample will be used, consisting of teleradiography (cephalograms) of adult patients of both genders, carried out in a private Dental Clinic, located in the city of São José dos Campos (SP), Brazil, by the established inclusion and exclusion criteria. Six angular and nine linear measurements will be used in the analysis of cephalometric measures according to the study protocol. The exams will be distributed into three groups and paired according to the value of the angle formed between point A nasion and point B nasion (ANB). Groups will be formed by exams with class 1 skeletal relationship (0o &lt; ANB angle ≤ 4º), group 2 with class 2 exams (ANB angle &gt; 4°), and group 3 formed by class 3 exams (ANB angle ≤ 0°). Considerations: In some cases, craniofacial changes may predict the risk of sleep-disordered breathing, such as obstructive sleep apnea (OSA). Increased length and thickness of the soft palate and hyoid bone in the mandibular plane and retrognathia are associated with the pathogenesis of OSA. Therefore, the etiology of sleep-disordered breathing may vary in patients according to gender, according to cephalometric analysis.

Treatment of Facial Asymmetry Using Distraction Osteogenesis in a Mandible First Approach.

Facial asymmetry includes several etiologies, among them trauma to the condylar area during early childhood and congenital malformations such as hemifacial microsomia. This article describes the management of facial asymmetry in adolescents and young adults using a mandible first approach by distraction osteogenesis, followed by maxillary Le-Fort I as a second stage. Eighteen patients 14-25 years of age presented with unilateral hypoplasia of the jaws which manifested clinically by deviation of the chin and canting of the occlusal plane. Etiology included hemifacial microsomia and trauma injuries at early childhood.All patients underwent orthodontic treatment and two phases of surgical treatment. Surgical treatment included unilateral mandibular distraction followed by Le-Fort I osteotomy for alignment of the maxilla. Additional bone graft in the affected side and sliding genioplasty were done as required. Marked ramal elongation of 18.94 mm concomitant with mandibular forward traction of 12.5 mm was noted while achieving symmetry. In all cases, the maxilla was centered to the midline in proper occlusion. Post distraction, posteroanterior cephalometric radiographs demonstrated elongation of the affected ramus, improvement in facial symmetry, and correction of the occlusal canting. Relapse was minimal based on long-term follow-ups of 47.4 months. The two-stage surgical approach that includes elongation of the mandible as a first stage followed by adaptation of the maxilla is useful in correcting facial asymmetry. Using this protocol at the correct age (14-18) is very stable, as demonstrated by our results, yet one should always remember the transverse deficiency in the gonial angle requires additional bone grafting or patient specific implants.

Association between the Temporomandibular Joint Morphology and Chewing Pattern.

This study aimed to investigate whether the morphology of the temporomandibular joint (TMJ) is associated with chewing patterns while considering skeletal morphology, sex, age, and symptoms of temporomandibular disorder (TMD). A cross-sectional observational study of 102 TMJs of 80 patients (age 16-40 years) was performed using pretreatment records of cone-beam computed tomography imaging of the TMJ, mandibular kinesiographic records of gum chewing, lateral and posteroanterior cephalometric radiographs, patient history, and pretreatment questionnaires. To select appropriate TMJ measurements, linear regression analyses were performed using TMJ measurements as dependent variables and chewing patterns as the independent variable with adjustment for other covariates, including Nasion-B plane (SNB) angle, Frankfort-mandibular plane angle (FMA), amount of lateral mandibular shift, sex, age, and symptoms of TMD. In multiple linear regression models adjusted for other covariates, the length of the horizontal short axis of the condyle and radius of the condyle at 135° from the medial pole were significantly (p < 0.05) associated with the chewing patterns in the frontal plane on the working side. "Non-bilateral grinding" displayed a more rounded shape of the mandibular condyle. Conversely, "bilateral grinding" exhibited a flatter shape in the anteroposterior aspect. These findings suggest that the mandibular condyle morphology might be related to skeletal and masticatory function, including chewing patterns.

Using of panoramic and posteroanterior cephalometric radiographs to identify the optimal nasal passage for nasotracheal intubation.

Selecting the optimum nasal passage for nasotracheal intubation is quite important in the maxillofacial surgeries for the success of intubation and the reduction of potential complications such as nasal mucosal laceration, epistaxis, avulsion of the inferior and middle turbinates, and septal laceration. The present study evaluates standard panoramic radiographs (PR) and posteroanterior cephalometric radiographs (PACR) to determine the optimal nasal passage for nasotracheal intubation and compares the results with those of routine anesthesiological occlusion and spatula tests (ST). The results of occlusion tests (OT), ST, and radiological assessments of 60 patients prior to nasotracheal intubation were compared with the nasal endoscopic assessment results, and complications were evaluated. There was no significant association between the OT and nasal endoscopy results (P = 0.075). A significant association was found between the ST and nasal endoscopy results (P = 0.000), and between the radiological assessments and the nasal endoscopy results (P = 0.000). Compatibility with nasal endoscopy was 54% when the occlusion and ST were evaluated together, 75% when the OT and radiological assessments were evaluated together, and 86% when the ST and radiological assessments were evaluated together. The highest level of compatibility was 92% when all the tests were evaluated together. The simple tests alone were found to be inadequate for the selection of the optimal nasal passage. Evaluation of PR and PACR, which are commonly used in maxillofacial surgeries, together with simple anesthesiological examination tests would increase nasotracheal intubation success and decrease complications.

Comparison of mini-screw-assisted rapid maxillary expansion in adolescents with different body mass indices: a prospective clinical study

Abstract Objectives The objective of the present study was to compare the dentoskeletal effects of mini-screw-assisted rapid maxillary expansion (RME) in children with different body mass index (BMI) percentiles. Study design The study was performed on 20 patients who were divided into two groups based on their BMI percentiles as normal-weight (n = 10) and overweight-obese (n = 10). The linear, angular and area analyses were performed on lateral and postero-anterior cephalometric radiographs and three-dimensional dental models before and after RME therapy. Results A statistically significant increase was observed in maxillary intermolar and intercanine distances and palatal area measurements in both groups (P &lt; 0.05). There was no significant difference between the two groups when dental RME changes were measured on 3D models. A significant difference was observed in latero-nasal and maxillo-mandibular width as well as postero-anterior cephalometric parameters between the groups (P &lt; 0.05). While a significant change was observed in the SN-GoMe, FMA, Z angle, Wits appraisal, total anterior facial height and lower anterior facial height parameters in the normal-weight group (P &lt; 0.05), a statistically significant change was observed in the gonial and nasolabial angles in the overweight-obese group. Conclusions Mini-screw-assisted RME treatment significantly increased maxillary intermolar and intercanine width, and the palatal area in both groups; however, there was no significant difference between the BMI groups.

Effect of septal deviation on nasomaxillary shape: A geometric morphometric study.

Nasal cavities in their primitive stage communicate with the oral cavity until the 8th week of intrauterine life where the posterior palate initiates its development. Hence, starting from the initial growth phases, a significant connection lays between the nasal structures and the maxillary bone and witnessing key functional roles, among which the respiration. Proper nasal breathing has been proven to be a crucial factor for the maturity of the craniofacial complex, and obstruction of the respiratory airway due to nasal septum deviation can generate clinically significant reduction of the nasal airflow. This situation will imply irreversible repercussions that hinders the harmonious development of the craniofacial complex. In order to understand such potential impacts of septal deviation, our first objective was to materialize the relation between septum deviation, and both nasal cavity and maxillary structures. For the second objective, we used Procrustes analysis to assess the shape variation of these two anatomical regions, the bivariate plots of Principal Components to evaluate their shape space, and a two-block Partial Least Square (PLS) to explore their covariation. We analysed, in this cross-sectional study, 62 posteroanterior cephalometric radiographs of adult subjects from both sexes (23males, 39 females; mean age 25.3years) collected from the database of the Department of Orthodontics at Lebanese University. Landmarks were plotted and variables were calculated and divided into nasal septum, nasal cavity and maxillary ones. The sample was further divided into two groups based on septal deviation severity (a septal deviation is considered minor if <6). The results suggested that nasal septum deviation was correlated to reduced nasal cavity area and a reduced maxillary area. Moreover, the comparison of the two groups concluded that the difference between all variables was statistically significant with higher scores in the minor septal deviation group. These findings were corroborated with the shape analysis where the mean centroid size of nasal cavity and that of the maxilla in the group of reduced septal deviation were significantly greater than those of the group with increased angle of deviation. Results of PLS analysis concluded to a strong covariation between nasal septum and nasomaxillary complex. These conclusions support the early septoplasty in growing patients as a solution to redirect the normal course of growth and re-establish a good function of the nasomaxillary complex.

Comparison of the dento-skeletal effects produced by Leaf expander versus rapid maxillary expander in prepubertal patients: a two-center randomized controlled trial.

This study aimed to compare the skeletal and dentoalveolar effects produced by slow maxillary expansion (SME) with the Leaf expander versus the conventional rapid maxillary expansion (RME) on digital dental casts, lateral and postero-anterior cephalometric radiographs. This is a superiority, two-center, two arms parallel balanced randomization trial. Patients in the mixed dentition were included with a transverse interarch discrepancy of at least 3 mm. An expansion screw using moderate continuous forces (Leaf group) was compared to a conventional RME screw (RME group). The primary response variable was the difference in maxillary intermolar width (U6-U6) measured at baseline (T0) and one-year follow-up (T1) on the digital dental casts. Other dento-skeletal variables were also measured on digital dental casts and cephalograms. Computer-generated block randomization was used with allocation concealed in sequentially numbered opaque sealed envelopes. The examiner was blinded on the type of expander used. Linear models were used for statistical analysis. Twenty-eight patients in the Leaf group and 28 patients in the RME group were randomized and included in the study. There were no dropouts. U6-U6 did not show a statistically significant difference between the two groups (-0.4 mm in favor of the RME group, 95% CI from -1.2 to 0.5, P = 0.365). As for the other secondary variables no statistically significant differences were found between the two groups except maxillary intercanine width (U3-U3, -0.9 mm in favor of the RME group, 95%CI from -1.5 to -0.3, P = 0.005) and maxillary skeletal width (Mx-Mx, -1.4 mm in favor of the RME group, 95%CI from -2.4 to -0.3, P = 0.013). No significant differences between the RME and Leaf groups were detected for any of the analyzed dento-skeletal variables except the T1-T0 differences in U3-U3 and Mx-Mx that were significantly greater in the RME group. The study was registered in the ISRCTN register on 08/11/2016 with the number ISRCTN18263886. No funding or conflict of interest to be declared.

A postero-anterior cephalometric evaluation of different rapid maxillary expansion appliances

The purpose of the study was to evaluate dental and skeletal changes induced by tooth-bone-borne, tooth-tissue-borne, and tooth-borne rapid maxillary expansion (RME) appliances using postero-anterior (PA) cephalometric radiographs. A total of 54 patients' (25 boys, 29 girls) PA cephalometric radiographs who had bilateral posterior crossbite and RME treatment were included and divided into three groups according to the type of appliance used during treatment: tooth-bone-borne RME appliance (hybrid Hyrax) (7 boys, 11 girls, mean age 13.28 ± 1.20 years), tooth-tissue-borne RME appliance (TTB) (8 boys, 10 girls, mean age 13.08 ± 1.06 years) and tooth-borne RME appliance (Hyrax) (10 boys, 8 girls, mean age 12.05 ± 1.35 years). Pretreatment (T0) and posttreatment (T1) PA cephalometric radiographs were analyzed with Dolphin software v. 11.7 (Chatsworth, CA). The comparisons of the groups were performed with Two-way analysis of variance. P < 0.05 was considered statistically significant. Significant and equal increase of right molar relationship and upper intermolar molar widths occurred in all groups. Dental midline discrepancy showed significant increase in only hybrid Hyrax group between T0 and T1. Significant increases were reported for lateronasal width in hybrid Hyrax and tooth-tissue-borne groups (P < 0.05). Both skeletal and dental changes were observed after RME in all groups. However, the greatest skeletal changes were seen in hybrid Hyrax and tooth-tissue-borne groups.

The effect of TMJ disk repositioning by suturing through open incision on adolescent mandibular asymmetry with and without a functional orthodontic appliance

The objective of this study was to evaluate the effect of combined temporomandibular joint (TMJ) disk repositioning by suturing through open incision and orthodontic functional appliance (OFA) treatment for adolescents with mandibular asymmetry. Adolescent patients (12-20 years old) with mandibular asymmetry combined with unilateral TMJ disk displacement without reduction were treated with disk repositioning by suturing through open incision with and without postoperative OFA. Magnetic resonance imaging and posteroanterior cephalometric radiographs (PA) were used to measure and compare the changes in condylar height, joint space, and menton deviation pre- and postoperatively. Twenty-six patients were included in the study. Joint space was significantly increased postoperatively and new bone mostly formed at the superior or posterior superior part of the condyle after 6 to 18 months in all surgically treated joints. Fourteen patients with OFA had a significant increase in condylar height and menton deviation compared to 12 patients without OFA (2.29 ± 0.91 mm vs 1.22 ± 0.69 mm, P=.003; 4.56 ± 1.48 mm vs 2.01 ± 0.74 mm, P=.000). Combined treatment with TMJ disk repositioning by suturing through open incision and OFA can promote condylar growth and correct mandibular deviation in adolescent patients. Postoperative OFA can maintain the increased joint space created by disk repositioning and promote new bone formation at the superior and posterior parts of the condyle.

The effect of arthroscopic disc repositioning on facial growth in juvenile patients with unilateral anterior disc displacement

ObjectiveTo investigate the effect of arthroscopic disc repositioning on condylar development and mandibular asymmetry in juvenile patients with unilateral temporomandibular joint (TMJ) anterior disc displacement (ADD). Patients and methodsA retrospective cohort study was conducted on unilateral juvenile anterior disc displacement (UJADD) patients of 10–20 years of age treated in Shanghai Ninth People's Hospital from 2010 to 2017. The primary predictor was TMJ arthroscopic disc repositioning surgery, according to which patients were divided into a surgery group and a control group. Initial and re-examined (with at least 6-month interval) magnetic resonance imaging (MRI) and posteroanterior cephalometric radiographs (PA) were collected. The condylar heights on both sides of the TMJ were measured by MRI and the difference between them was calculated. Menton (Me) deviation was measured based on PA. Changes in condylar height difference and Me deviation were compared between the two groups. ResultsA total of 108 UJADD patients were collected in this study, including 55 patients in the surgery group and 53 patients in the control group. There were no significant differences in age, sex and follow-up time between the two groups. The condylar height difference was (−0.61 ± 2.02) mm in surgery group and (1.68 ± 1.73) mm in control group (P < 0.0001); while the Me deviation was (−1.00 ± 1.15) mm in surgery group and (1.81 ± 1.96) mm in control group (P < 0.0001), indicating that TMJ arthroscopic disc repositioning surgery could significantly improve condylar height difference and Me deviation. ConclusionsUJADD should be treated as early as possible, especially in juvenile patients, in order to improve condylar development and avoid jaw deformities.

Comparison of Transverse Craniofacial Dimensions Between Growing Individuals With Unilateral Cleft Lip and Palate and Age-and Sex-Matched Noncleft Controls.

The study aimed to assess the transverse craniofacial dimensions of patients (age, 7-14 years) with unilateral cleft lip and palate (UCLP), compare these dimensions with those of noncleft individuals, and identify the correlations between the nasal and maxillary transverse widths of patients with UCLP. A cross-sectional study. Eighty patients operated on for complete UCLP (UCLP group; 35 girls, 45 boys; median age: 10.7 [7.9-14] years) and 80 age- and sex-matched noncleft individuals (control group; 35 girls, 45 boys; median age: 10.7 [7.3-14] years). Interorbital, bizygomatic, nasal, maxillary skeletal, maxillary molar, mandibular molar, and antegonial width measurements were performed using posteroanterior cephalometric radiographs. Intergroup comparisons were conducted by using the independent samples t-test and Mann-Whitney U test. Correlation between the variables was examined using Pearson correlation analysis. The bizygomatic, maxillary skeletal and molar, mandibular molar, and antegonial widths in the UCLP group were significantly less than those in the control group (P < .05). A positive correlation was found between the maxillary skeletal and nasal widths (r = 0.550, P < .001) and between the maxillary molar and nasal widths (r = 0.560, P < .001). In individuals with UCLP, the bizygomatic, maxillary skeletal and molar, mandibular molar, and antegonial widths were significantly less than those in noncleft individuals. As the maxillary skeletal and dental widths presented a positive correlation with the nasal width, a decrease in nasal width must be considered when maxillary constriction is noted.

The relationship between frontal sinus morphology and skeletal maturation.

The aim of this study is to evaluate the relationship between frontal sinus morphology and hand-wrist bone maturation by using postero-anterior (PA) cephalometric radiographs. The study sample consisted of 220 patients divided into 11 groups based on the hand-wrist radiographs. The right and left maximum height, width and area of the frontal sinus parameters were measured in PA cephalometric radiographs of 220 subjects aged 8-18 years. The hand-wrist skeletal maturation stages were evaluated on the hand-wrist radiographs using the method of Fishman. The Kendall tau-b values were analysed to evaluate the correlation between the hand-wrist skeletal maturation stages and the frontal sinus parameters. The right and left frontal sinus areas and widths were found to be larger in males than in females (p < 0.05). In males, a significant difference was observed in all frontal sinus parameters in different maturation stages (p < 0.001), while a statistically significant correlation was found in females between the left frontal sinus area, right frontal sinus height, right frontal sinus width and different maturation stages (p < 0.05). The relationship between frontal sinus dimensions obtained from PA cephalometric radiographs and hand-wrist maturation stages suggests that frontal sinuses can be used in determining growth and development.

&lt;b&gt;Morphometric analysis of three normal facial types in mixed dentition using posteroanterior cephalometric radiographs: preliminary results

The aim of the present investigation was to evaluate the craniofacial features of subjects with normal occlusion with different vertical patterns in the mixed dentition using morphometric analysis (Thin-Plate Spline analysis - TPS) applied to posteroanterior (PA) films. The sample comprised 39 individuals (18 females and 21 males), all in mixed dentition, aged from 8.4 to 10 years with satisfactory occlusion and balanced profile and with no history of orthodontic or facial orthopedic treatment. The sample was divided into three groups (mesofacial, brachyfacial and dolichofacial) according to the facial types proposed by Ricketts (1989). The average craniofacial configurations of each study group were obtained by orthogonal superimposition of Procrustes, thereby eliminating size differences and allowing only shape differences between groups to be analyzed by viewing the TPS deformation grid. Significant differences were found among the three facial types but were more remarkable between mesofacials and dolichofacials than between mesofacials and brachyfacials. TPS morphometric analysis proved efficient for accurate visualization of transverse and vertical differences among facial types even before pubertal growth spurt. These differences cannot be easily detected by traditional posteroanterior cephalometry.

Evaluation of the skeletal and dental effects in orthodontic patients with maxillary lateral incisor agenesis.

The purpose of this study was to evaluate the transverse dimension of the dentoalveolar and skeletal widths in both unilateral (UMLIA) and bilateral (BMLIA) maxillary lateral incisor agenesis groups. The study sample consisted of 59 patients (34 females and 25 males) divided into three groups as UMLIA group (16 patients; 14.94 ± 1.37 years), BMLIA group (21 patients; 14.46 ± 1.53 years) and control group (22 patients; 15.28 ± 1.70 years) without tooth agenesis. Transversal measurements (maxillary and mandibular intercanine, interpremolar, intermolar, intercanine alveolar, interpremolar alveolar, intermolar alveolar widths) were done on dental casts. Craniofacial skeletal measurements were done with posteroanterior cephalometric radiographs. Statistical testing was performed with the one-way variance analysis, Kruskal-Wallis and post hoc tests. UMLIA and BMLIA groups had statistically significantly narrower skeletal apical base of the maxilla, maxillary intercanine and intercanine alveolar widths compared with the control group (P < .05). Moreover, UMLIA and BMLIA groups had statistically significantly similar dental, alveolar and skeletal features (P > .05). The UMLIA and BMLIA groups showed statistically significantly smaller values for maxillary intercanine, maxillary intercanine alveolar and skeletal maxillary widths compared with the control group. This study provides information the transverse dimension of the dental, alveolar and skeletal widths with maxillary lateral incisor agenesis patients. Knowledge of transverse dimension of the dental, alveolar and skeletal widths with maxillary lateral incisor agenesis patients is important for diagnosis and treatment planning.

Association between frontal sinus morphology and craniofacial parameters: A forensic view

The aim of this study was to evaluate the morphologic structure of the frontal sinuses with postero-anterior cephalometric radiographs in Turkish adolescents and to compare the findings between genders. The study sample consisted of 148 subjects divided into two groups (74 male subjects; mean age: 14.55 ± 1.42 years-74 female subjects; mean age: 14.95 ± 1.80 years). The right and left maximum height and width of the frontal sinus, maxillary width, nasal width, cranial width, antegonial width parameters were measured in 148 postero-anterior cephalometric radiographs. The data were analyzed using independent t and Mann Whitney U test. Spearman correlation analyses were used to evaluate the relationships of the frontal sinus measurements and transversal cephalometric parameters. The mean values of the right and left frontal sinus width, maxillary width, antegonial width, and cranial width were larger in males than females (P < 0.05). The right frontal sinus height were positively correlated with antegonial width (r = 0.243; P < 0.05) and the right frontal sinus width were positively correlated with antegonial width (r = 0.327; P < 0.01) in males. The right frontal sinus width were positively correlated with nasal width (r = 0.244; P < 0.05) and the left frontal sinus width were positively correlated with nasal width (r = 0.231; P < 0.05) in females. Frontal sinuses were unique to each individual due to their morphological structures, and in forensic science, taking advantage of these features was very important for personal identification.

Mandibular symmetry in participants with a unilateral cleft lip and palate

Context: Facial asymmetry has been reported to be a typical morphological characteristic of unilateral cleft lip and palate (UCLP). Posteroanterior cephalometric radiographs have shown that in addition to an asymmetrically developed nasomaxillary complex, children with UCLP may also have distorted mandibles. Aims: The aim of this retrospective study was to evaluate mandibular symmetry in participants with a complete unilateral left cleft lip and palate (ULCLP) using panoramic radiographs. Subjects and Methods: Pretreatment records of 163 participants (84 ULCLP, 79 Angle Class I without a cleft; mean age: 12.9 ± 3.5 years) were retrieved from the orthodontic department archives. A total of ten anatomic landmarks were marked on panoramic radiographs, and measurements were performed using the PORDIOS software. Statistical Analysis Used: Intra- and inter-group differences were analyzed using Student's t-test. Results: Mandibular right and left ramus, total ramus, condylar, and mandibular molar alveolar heights were significantly shorter in the ULCLP group when compared to controls (P < 0.05 to P< 0.001). In the ULCLP group, mandibular and corpus lengths were shorter on the left side (P < 0.05), whereas in the control group, mandibular and corpus lengths and ramal, condylar, and molar alveolar heights were shorter on the right side when compared to the left side. In addition, ramus/corpus angles were significantly larger in the ULCLP group when compared to the control group (P < 0.001). Conclusions: Mandibular asymmetry exists to varying extents in ULCLP patients and is characterized mainly by smaller cleft-side dimensions. Discrepancies in left-right mandibular dimensions also occur in normal participants.

A Comparison between 2D and 3D Images to Study Maxillary and Mandibular Widths: A Pilot Study

The objective of this study is to compare the transverse dimensions of the jaws, obtained from traditional posteroanterior (PA) cephalometric radiographs, and with the similar respective measurements obtained by means of cone beam computed tomography (CBCT). Data of twelve subjects were selected from the clinical records of Orthodontic Department. All of the subjects had their permanent teeth in occlusion and had good quality regular (2D), and CBCT (3D) images as part of their initial records. Subjects were divided to a posterior cross-bite and non-cross bite groups. The ratio of the maxillary, to mandibular transverse widths was calculated for the sample. In subjects without dental cross-bites the average ratio of the maxillary, to mandibular jaw widths was 0.75 on the standard radiographs and 1.04 on the CBCT scans. In subjects with dental cross-bites the average ratio of these widths was 0.70 on the standard radiographs and 0.9 on the CBCT scans. The ratios of the maxillary, to mandibular widths differ when obtained from conventional cephalometric radiographs as compared to the respective ratios obtained from CBCT scans. Maxillary, to mandibular width ratio is in the order of 1:1 as determined by means of CBCT scans.

The relationship between lateral displacement of the mandible and scoliosis.

Idiopathic scoliosis is an orthopaedic disease of childhood, with onset and progress occurring until adolescence. Here, the relationship between lateral displacement of the mandible and scoliosis was analysed quantitatively. Seventy-nine non-syndromic Japanese patients (18 men, 61 women), who were diagnosed with jaw deformities and underwent surgical orthognathic treatment at Kyushu University Hospital from January 2011 to August 2014, were enrolled. Their mean age at the time of radiography was 25.3±8.7years. Postero-anterior cephalometric radiographs and chest radiographs were examined. In postero-anterior cephalometric radiographs, a horizontal baseline (X-axis) was drawn as a straight line that intersects both the zygomatic bases, and a vertical line (Y-axis) was marked perpendicular to the X-axis, with an intersection at the anterior nasal spine (ANS). Point A was defined as the intersection of the X- and Y-axes, and line A was defined as the line connecting point A to the menton. The angle made by the X-axis and line A (i.e., lateral displacement of the mandible) was measured. We designated an absolute value even if the mandibular menton was located on the right or left side. In chest radiographs, Cobb's method was used to measure scoliosis curves; the direction of the curve was designated similarly. Nine (11.4%) individuals had a Cobb angle >10°. There was a positive correlation between the Cobb angle and the degree of mandibular deviation (p<0.05). Lateral displacement of the mandible and scoliosis are related.

Will unilateral temporomandibular joint anterior disc displacement in teenagers lead to asymmetry of condyle and mandible? A longitudinal study.

To evaluate the change of morphological symmetry of the temporomandibular joints (TMJ) during natural course of unilateral juvenile anterior disc displacement (UJADD) by comparing the ipsilateral joint with the contralateral side; and to analyse its effect over mandibular asymmetry (MA). This study is a self-control longitudinal study. Consecutive UJADD cases with no history of TMJ infection, injuries to the jaws, or congenital, developmental and systematic disorders that may affect the craniofacial growth were collected and followed for at least 6 months. Patients' age at both first visit and revisit was recorded. Pictures of magnetic resonance imaging (MRI) were selected to measure the differences between bilateral condylar height, disc length and condyle-disc distance, and comparison of the measurements before and after follow-up were made. Meanwhile, posteroanterior cephalometric radiographs (PA) were taken and deviation of menton from facial midline was measured before and after follow-up. Severity of MA was divided into 4 stages according to menton deviation: Non-MA (<2mm), Minor-MA (≥2mm, <4mm), Medium-MA (≥4mm, <6mm), and Major-MA (≥6mm). The constituent ratio of MA was evaluated and correlation between TMJ morphological change and asymmetry of the mandible was analysed. Forty four patients were included, with a mean follow-up of 12.22 months. The average age was 16.31 years old (range, 10-20 years) at first visit. Significant progression of disc displacement was found: condyle-disc distance increased, disc shortened and difference between bilateral condylar heights increased. Along with this, occurrence of MA increased from 86.36% to 93.18%, and average menton deviation increased from 5.58mm to 7.74mm after follow-up. The correlation coefficient (CC) of increase of condylar height difference and development of MA was 0.681 (p<0.05). Also, increase of menton deviation was significantly related to age of the patients (CC=-0.760, p<0.05). The results show that UJADD result in asymmetric growth bilateral TMJs, especially condylar height, which was much shorter on the ipsilateral side. In the same time, MA got worse during the natural course of UJADD. It is concluded that UJADD was one of the major causative factors of MA.