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Objective To present the dynamical evaluation of mandible and upper airway size among Chinese infant patients following mandibular distraction osteogenesis in a short-term follow-up and compare predistraction measurements with a normal age- and sex-matched control. Methods All the patients have undergone the computed tomography (CT) scan before mandibular distraction osteogenesis (T0), at the end of the distraction phase (T1), and 3 months after the end of the distraction phase before the distractor removal (T2). A CT analyzing computer software MIMICS was utilized to analyze the anatomic variables of upper airway size and mandible size. All analysis was based on a significance level of 0.05. Results Eight patients with Pierre Robin sequence differed mainly in the mandibular body length and the minimum anteroposterior dimension of the retroglossal airway from the control. After mandibular distraction osteogenesis, the mandibular body length and the ramus height both increased significantly, the ramus height also increased after 3 months of consolidation. Only small increase in the airway dimension of the retroglossal area at T2 was observed compared with T1. Conclusion Mandibular distraction osteogenesis is an effective modality in treating Pierre Robin sequence. Compared with normal control, the main difference may be the length of mandibular body and the area of the retroglossal airway. There may not be an increase in the diameter of airway and the length of mandibular body after 3 months of growth and development in Pierre Robin sequence. Individual surgical plan should be made to gain a better prognosis.

Objective The disuse of the jaws owing to the restricted movement of the mandible in advanced cases of oral submucous fibrosis (OSMF) may have an effect on the morphologic features of the jaw bones. The purpose of the present study was to determine the jaw bone measurements in patients with OSMF and to compare the measurements in normal subjects and Caucasian norms. Methods The lateral cephalograms of 59 subjects (43 males and 16 females) with OSMF and 44 normal subjects (23 males and 21 females) in the age group of 18-45 years were collected. The jaw measurements were performed using Burstone analysis, and the relevant linear measurements of jaw sizes included were N-A, N-B, N-ANS, ANS-PNS, ANS-Gn, Ar-Go, and Pg-Go. The sex-wise comparison was performed using unpaired t-test, and measurements were compared with other studies using Z test. Results In the present study, sex-wise comparison was found to be significant with greater jaw measurements in males than in females in patients with OSMF. Overall, the measurements were less or equal in patients with OSMF than in normal subjects except for N-ANS and Pg-Go. When study measurements were compared with Burstone measurements, differences were significant with greater and less measurements. Conclusion Overall, the jaw measurements were less or equal in patients with OSMF than in normal subjects except for mandibular body length and middle third facial height that may need further evaluation.

Background: Class II malocclusion is one of the most common orthodontic problems that can be divided into class II division 1 and division 2. Considering the differences between the 2 malocclusions, the present study was designed to compare the dentoskeletal changes caused by growth modification treatment. Methods: This retrospective study included 52 patients (2 groups) with class II division 1 and 2 malocclusions, who were within the age range of 11-13 years and were treated by growth modification. Initial and final cephalograms were analyzed by Dolphin software premium 11.8. In addition, 7 cephalometric variables including SNA, SNB, ANB, SN-GOGN, inter-incisal angle, mandibular body length, and overbite were measured in traced cephalograms. Finally, treatment changes in each group were analyzed by paired t test and between-group comparison was assessed by independent t test. The significant level was considered as 0.05. Results: Based on the results of dentoskeletal changes in both groups, SNB, ANB, mandibular length, and overbite underwent significant changes during treatment in both groups. Further, the interincisal angle changed significantly in division 2 group (P

Objective: To describe the gonial angle characteristics in class III skeletal malocclusion in Javanese ethnic . Material and Methods: Pretreatment lateral cephalometric radiographs of 43 Javanese ethnic patients were measured: upper (Go1) and lower gonial angle (Go2), anterior (AFH) and posterior face height ratio (PFH), maxilla-mandibular length difference, mandibular plane angle (FMA), Y axis, ramus position, ANB angle, posterior cranial base/ramus height and mandibular body length/anterior cranial base. The relation between Go1, Go2 and other variables were analysed using correlation and regression analysis. Results: The total gonial angle is within normal range, but Go1 is below normal and Go2 is above normal. There is no difference between male and female gonial angle measurements (p=0.939 and p=0.861, respectively). Ramus position is positively correlated to Go1 (p=0.003), while AFH (p=0.000), maxilla-mandibular length difference (p=0.000), FMA (p=0.000), Y axis (p=0.000), and posterior cranial base/ramus height (p=0.018) are positively correlated to Go2. PFH is negatively correlated to Go2 (p=0.018) . Conclusion: The upper gonial angle is influenced by the position of mandibular ramus, while the lower gonial angle is affected by the posterior and anterior lower facial height and mandibular size and rotation. Javanese with class III malocclusion tends to have hypodivergent facial type, with more posteriorly located mandibular ramus and excess mandibular length.

Background The objective of this study was to evaluate the effects of single plane and multiplane rotational errors in yaw, pitch, and roll of the head while recording the lateral cephalogram on CVM (cervical vertebrae maturity) assessment. Methods A total of 40 cone-beam computed tomography (CBCT) scans and 360 lateral cephalograms were analyzed for patients with different rotations: Controls (no rotation), Y5 (yaw 5° rotation), Y10 (yaw 10° rotation), R5 (roll 5° rotation), R10 (Roll 10° rotation), P5 (pitch 5° rotation), P10 (pitch 10° rotation), YRP5 (yaw, roll, and pitch 5° rotation), and YRP10 (yaw, roll, and pitch 10° rotation). The C2, C3, and C4 concavity and their base-anterior ratio and posterior-anterior ratio were measured. In addition, maxillomandibular linear parameters, such as effective mandibular length and height, mandibular body length, effective midface length, and maxillomandibular differential, were also evaluated. Results Y5, Y10, R5, and R10 led to overestimation of CVM in comparison with controls. Multiplane rotations (YRP5 and YRP10) led to more inaccuracies in CVM measurements than single plane rotations; 10° of rotation led to more inaccuracies than 5° of rotation while recording the lateral cephalogram, irrespective of the plane. Yaw rotational errors led to an underestimation of maxillomandibular linear measurements, whereas roll rotational errors led to an overestimation of the measurements; however, there were wide individual variations in the measurements between the different rotations and controls. Conclusions Rotational errors lead to overestimation of CVM assessment. Multiplane rotations cause higher inaccuracies than single plane rotations. Increased degree of rotations while capturing the lateral cephalograms lead to more inaccuracies in CVM assessment.

Objective To investigate the cephalometric predictors of the future need for orthognathic surgery in Korean patients with unilateral cleft lip and palate (UCLP) despite long-term use of facemask with miniplate (FMMP). Methods The sample consisted of 53 UCLP patients treated by a single orthodontist using an identical protocol. Lateral cephalograms were taken before commencement of FMMP therapy (T0; mean age, 10.45 years), after FMMP therapy (T1; mean age, 14.72 years), and at follow-up (T2; mean age, 18.68 years). Twenty-eight cephalometric variables were measured. At T2 stage, the subjects were divided into FMMP-Nonsurgery (n = 33, 62.3%) and FMMP-Surgery (n = 20, 37.7%) groups according to cephalometric criteria (point A-nasion-point B [ANB] < –3°; Wits-appraisal < –5 mm; and Harvold unit difference [HUD] > 34 mm for FMMP-Surgery group). Statistical analyses including discrimination analysis were performed. Results In FMMP-Surgery group, the forward position of the mandible at T0 stage was maintained throughout the whole stages and Class III relationship worsened with significant growth of the mandibular body and ramus and counterclockwise rotation of the maxilla and mandible at the T1 and T2 stages. Six cephalometric variables at T0 stage including ANB, anteroposterior dysplasia indicator, Wits-appraisal, mandibular body length, HUD, and overjet were selected as effective predictors of the future need for surgical intervention to correct sagittal skeletal discrepancies. Conclusions Despite long-term use of FMMP therapy, 37.7% of UCLP patients became candidates for orthognathic surgery. Therefore, differential diagnosis is necessary to predict the future need for orthognathic surgery at early age.

Background The aim of this study was to cephalometrically evaluate and compare a treatment protocol in patients with Class II Division 1 (II/1) and Class II Division 2 (II/2), and to pursue predictors of the change in chin prominence. Methods This retrospective study included 30 patients with Class II/1 and 25 patients with Class II/2 treated with the Forsus appliance, in combination with fixed appliances. Pre- and posttreatment lateral cephalometric radiographs were collected, and 28 measurements were recorded. A two-sample t test was used for the pretreatment comparison among the two Divisions. Paired t tests were used to evaluate the treatment changes within each group. Analysis of covariance was used to compare the treatment changes between the Divisions after adjusting for the baseline value, age, gender, treatment duration, and time with the Forsus appliance. The Simes multiple testing procedure permitted adjustment for multiple comparisons. Regression analysis was performed to identify predictors explaining the change in chin prominence. Results Class II correction occurred in both Divisions, mainly through dentoalveolar effects. There were no significant cephalometric differences found in the mean treatment changes between the Divisions. The pretreatment Gonial angle, molar eruption, lower incisor inclination, mandibular body length, and soft tissue chin thickness had a significant impact on the treatment changes in chin prominence. Conclusions Treatment with the Forsus in combination with preadjusted fixed appliances leads to a favorable treatment outcome and produces similar treatment changes in both Class II Divisions.

The purpose of this study was to clarify differences in skeletal morphologies between male and female orthodontic patients with and without agenesis of all four third molars. A total of 64 patients (32 males and 32 females) with agenesis of all four third molars without agenesis of other teeth were selected as the third molars agenesis group (group 1). In addition, 64 patients (32 males and 32 females) with all these teeth were selected as controls (group 2). Lateral cephalograms taken between the ages of 14 and 30 years were used to compare skeletal morphology between groups 1 and 2 and between sexes. Maxillary length (P

Objective: This study aimed to determine the cephalometric association of mandibular size/length to the surface area and dimensions of the frontal and maxillary sinuses. Materials and Methods: This descriptive study was conducted on 116 digital lateral cephalograms of 38 patients with skeletal Class I malocclusion (normal), 40 patients with skeletal Class II malocclusion with mandibular deficiency, and 38 patients with skeletal Class III malocclusion with mandibular excess. Both male and female patients were included. Using AutoCAD 2016 software, the anteroposterior dimension, height and surface area of the frontal and maxillary sinuses, mandibular body length and cephalometric indices including anterior and posterior cranial bases, and growth pattern indices were measured on lateral cephalograms. Results: Dimensions and surface area of the frontal and maxillary sinuses in skeletal Class III malocclusion were greater than those in other groups. These variables were significantly correlated with the mandibular body length. The coefficient for the correlation of height, width, and surface area of the frontal sinus with mandibular body length was 0.253, 0.284, and 0.490, respectively. The coefficient for the correlation of height, length, and surface area of the maxillary sinus with mandibular body length was 0.346, 0.657, and 0.661, respectively. These variables (except for the frontal sinus width) had a significant correlation with the anterior and posterior cranial bases. The frontal sinus width had a significant correlation with the anterior cranial base. These variables in males were greater than those in females. Conclusion: The dimensions and surface area of the frontal and maxillary sinuses in skeletal Class III malocclusion were greater than those in other groups. These variables (except for the frontal sinus width) had a significant correlation with the anterior and posterior cranial bases and mandibular body length.

Background The purpose of this study was to elucidate the factors that cause facial asymmetry by comparing the characteristics of the mandibular morphology in patients with mandibular prognathism with or without facial asymmetry using three-dimensional computed tomography (3D-CT). Methods We studied 28 mandibular prognathism patients whose menton deviated by ≥ 4 mm from the midline (FA group, n = 14) and those with a

Background: Hormone deficiency could affect craniofacial complex during esqueletal growth and development. Objective: Determine whether there is scientific evidence of the association between hormonal treatment and craniofacial growth measured by cephalometry films, in subjects of 10 to 18 years with hormonaltreatment. Materials and Methods: A systematic review. For the articles published in PubMed, Google Scholar, Lilacs, Embase and Science Direct databases, without restriction of publication year was performed. Clinicaltrials, case control studies, cohort, systematic reviews and meta analysis studies were included. Reading f the abstracts and the complete articles were made by two researchers. Results: Among 1085 articles found, 1074 were excluded because did not meet the inclusion criteria. After complete reading of the articles, five were excluded because they were cross-sectional studies and one was not recovered in the full text. In total, 6 articles were included. These studies report that patients who were treated with hormone substitution therapy showed favorable changes in their craniofacial structures, especially in mandibular total length, ramus length and mandibular body length. These positive changes led to an improvement in profile, inter-maxillary relations, and other osseous body structures. Conclusions: Despite the heterogeneity of the studies it was found that early replacement with hormone treatment, regardless of the dose and long-term treatment, accelerates the development of craniofacial structures, mainly the mandible, to reach the skeletal patterns genetically established. Studies are required to evaluate replacehormone treatment in patients without additional systemic compromises.

Facial asymmetries (FAs) have been classified according to the mandibular morphological differences to obtain better diagnostic and treatment decisions. The purpose of the present study was to establish diagnostic differentiation among FAs using computed tomography (CT) and 3-dimensional (3D) reconstruction.We performed a cross-sectional study of patients with a diagnosis of FA, who had been evaluated by CT and 3D reconstruction in the same clinical center from 2015 to 2018. The following mandibular anatomic characteristics were compared between the 2 sides (deviated side vs contralateral side) and type of FA: condylar length, mandibular ramus length and width, mandibular body length, and symphysis deviation.The 53 patients included 23 men and 30 women (age range, 16 to 25 years). Six categories of FA were identified: hemimandibular elongation (n = 25), hemimandibular hyperplasia (n = 2), hybrid hyperplasia (n = 3), asymmetric mandibular prognathism (n = 14), asymmetry of the glenoid fossa (n = 2), and functional laterognathism (n = 7). The condylar length and mandibular ramus width were greater in the displaced side than in the contralateral side, with differences of -2.0 ± 2.8 mm (P .001) and -0.5 ± 1.7 mm (P = .009), respectively. The mandibular body length was greater on the contralateral side (mean difference, 2.1 ± 3.5 mm; P .001). The symphysis deviation was 5.0 ± 3.4 mm, and those with a hybrid form presented with a greater deviation, with values greater than 10 mm, followed by those with hemimandibular elongation.The evaluation of the CT images and 3D reconstructions in patients with FA provided detailed information of the mandibular structure that is useful to compare the differences between sides and to classify the entities associated with FA.

Objective: To evaluate the skeletal variations amongst individuals and to compare the measurements with the standardized linear and angular values of Bjork Jarabak’s analysis. Methods: This study was conducted at POS Department, King Khalid University on 100 adult Saudi patients recruited through convenience sampling. It was conducted between April to September 2017, had inclusion criteria of patients between the age group 17 to 22 years showing normal occlusion. After history and examinations, lateral cephalographs were taken, scanned and traced using Dolphin Imaging Software and Cephalometric points were recognized. Linear and angular dimensions were calculated according to Bjork-Jarabak’s method. Results: Analysis and assessment of Saudi male and female values revealed considerable variation in the anterior and posterior cranial base lengths (p

Edentulism can negatively affect both masticatory performance and dietary intake by altering the patterns of biomechanical stress and strain, which in turn modifies the morphology of the different regions of the mandible. The morphological changes in the mandible caused by these stressors are unknown when comparing mandibles across varying dentition states. This study investigated differences in the morphology of human mandibles across various states of the dentition. In total, 498 mandibles of individuals between 20 and 80 yr of age at death were sourced from the Raymond A. Dart Collection of Human Skeletons. These included fully dentate (n = 95), partially edentulous (n = 333), and fully edentulous (n = 70) mandibles. Twelve linear anthropometric measurements of the mandible were derived from digitized landmarks located on its external surface. Data analysis included geometric morphometrics and multivariate analyses. Compared with dentate and partially edentulous mandibles, fully edentulous mandibles showed a shorter alveolar height (-0.4 mm), a shorter mandibular body length (-4 mm), a larger gonial angle (+4°), a more obtuse mental angle (+4.7°), a broader bicondylar width (+3.8 mm), and a taller ramus height (+1.6 mm). Thus, edentulous states are associated with an altered mandibular morphology, which may result from a reduction in jaw function.

The aim of this study was to evaluate corrective outcome and transverse stability after orthognathic surgery via a surgery-first approach (SFA) in mandibular prognathism with and without facial asymmetry using 3-dimensional analysis.Twenty-nine patients who received mandibular setback surgery using SFA were divided into 2 groups according to the menton deviation (4 mm): symmetry group (n = 17) and asymmetry group (n = 12). Using computed tomography images obtained before (T0), immediately after (T1), and 6 months after (T2) surgery, time-dependent changes in variables related to facial asymmetry, including maxillary height, ramal length, frontal and lateral ramal inclination, mandibular body length, and mandibular body height, were evaluated.Immediately after surgery, the asymmetry group showed significantly decreased discrepancies between the longer and non-longer sides for all variables (P .05); there were no significant differences in discrepancies between the 2 groups. During the postoperative period, no significant changes in discrepancies were found in any variable in either group. Compared with T0, the asymmetry group showed significantly decreased discrepancies in ramal length, frontal and lateral ramal inclination, and mandibular body length at T2.Variables related to facial asymmetry showed significant improvement after surgical-orthodontic treatment using SFA, and corrected outcomes showed good postoperative stability in both the symmetry and asymmetry groups.

Introduction: Bones often survive the process of decay and therefore provide the major evidence of human age and sex after death. The identification of human skeletal remains is a critical problem and is very important in medico-legal and anthropological works. The determination of sex of an individual is important and necessary both in the living and dead for medico-legal purposes. The aim of this study is to measure and analyze the various parameters of the mandible and to assess the reliability of the above parameters in terms of percentage accuracy in sex determination. Material and Methods: A total of 106 whole-adult human mandibles of unknown sex, between the age group of 18–60 years, were collected and studied at the Department of Anatomy and Forensic Medicine, Guntur Medical College, Guntur from 2014 to 2015. The following parameters studied were symphyseal height, mandibular body length, bicondylar diameter, bigonial diameter, inter incisor width, and mandibular angle. Results: Of the six parameters studied, highly significant (statistically) difference in sex was observed in bigonial diameter (82.15% accuracy) and mandibular angle (81.5% accuracy). Discussion and Conclusion: The inference of the study is that no single parameter gives 100% accuracy in the determination of the sex of the individual. Hence, a judicious consideration of the highly significant parameters of the mandible may be taken into account in the determination of the sex of the individual.

Purpose The purpose of this study was to investigate the relationship between changes in three-dimensional (3D) facial morphology and mandibular movement after orthognathic surgery. We hypothesized that facial morphology changes after orthognathic surgery exert effects on 3D mandibular movement. Materials and methods We conducted a prospective follow-up study of patients who had undergone orthognathic surgical procedures. Three-dimensional facial morphological values were measured from facial CT images before and three months after orthognathic surgery. Three-dimensional maximum mandibular opening (MMO) values of four points (bilateral condylions, infradentale, and pogonion) were also measured using a mandibular movement tracking and simulation system. The predictor variables were changes in morphological parameters divided into two groups (deviated side (DS) or contralateral side (CS) groups), and the outcome variables were changes in the MMO at four points. Results We evaluated 21 subjects who had undergone orthognathic surgical procedures. Alterations in the TFH (total facial height), LFH (lower facial height), CS MBL (mandibular body length), and DS RL (ramus length) were negatively correlated with changes in bilateral condylar movement. The UFH, DS MBL and CS ML (mandibular length) showed correlations with infradentale movement. The CS ML, DS ML, MBL, UFH, and SNB were correlated with pogonion movement. Conclusion The height of the face is most likely to affect post-operative mandibular movement, and is negatively correlated with movement changes in the condyles, infradentale and pogonion. The changes in CS morphological parameters are more correlated with mandibular movement changes than the DS. The changes in CS MBL and bilateral RL were negatively correlated with condylar movement changes, while the bilateral MBL and CS ML were positively correlated with changes in infradentale and pogonion.

Objective: In this study, we aimed to examine the relationship between chin deviation and the positional and morphological features of the mandible and to determine the factors that contributed to chin deviation in individuals with a unilateral cleft lip and palate (UCLP). Methods: Cone-beam computed tomography (CBCT) images of 28 adults with UCLP were analyzed in this study. Segmented three-dimensional temporomandibular fossa and mandible images were reconstructed, and angular, linear, and volumetric parameters were measured. Results: For all 28 individuals, the chin was found to deviate to the cleft side by 1.59 mm. Moreover, among these 28 individuals, only 7 showed distinct (more than 4 mm) chin deviation, which was toward the cleft side. Compared to the non-cleft side, the mandibular body length, frontal ramal incli nation, and vertical position of the condyle were lower and inclination of the temporomandibular fossa was steeper on the cleft side. Furthermore, the dif ferences in inclination of the temporomandibular fossa, mandibular body length, ramus length, and condylar volume ratio (non-deviated/deviated) were po sitively correlated with chin deviation. Conclusions: UCLP individuals show mild chin deviation to the cleft side. Statistical differences were noted in the parameters that represented positional and morphological asymmetries of the mandible and temporomandibular fossa; however, these differences were too small to indicate clinical significance. [Korean J Orthod 2013;43(4):168-177]

Introduction: Raising the knowledge of skeletal and soft tissue changes with aging has been highly essential due to an increasing demand for aesthetic facial surgery following aging. The aim of this study is to evaluate the three dimensional computed tomographic images and process of changes in mandible with aging. Materials and Methods: In this descriptive study, the facial CT scans were obtained from 124 subjects (70 men and 54 women). The population of the study was categorized in three ages (21 to 30, 31 to 40, 41 to 50). Each CT image was reinforced under volume rendering threedimensional reconstruction by using the three dimensional analysis software volume viewer. The specific parts of mandible consisting of bigonial width, mandibular body height, ramus breadth, ramus height, mandibular body length and mandibular angle were measured and the data were analyzed employing two-ways analysis of variance.

Purpose The present study was designed to analyze the skeletal differences in patients with temporomandibular joint (TMJ) disc displacement (DD), according to the sagittal jaw relationship. Materials and Methods We implemented a cross-sectional study design and enrolled a sample of Korean women older than age 17 years. The subjects were classified into 3 groups according to the magnetic resonance images of the bilateral TMJs: bilateral normal disc position (BN), bilateral disc displacement with reduction, and bilateral disc displacement without reduction. Each group was subdivided into 2 groups using the mandibular body length to anterior cranial base ratio as a sagittal jaw parameter: normal-size mandible (NM) and oversized mandible (OM). Seventeen variables from the lateral cephalograms were analyzed using 2-way analysis of variance to analyze the differences in skeletal characteristics with respect to the mandible size and TMJ DD status. Results The subjects with TMJ DD generally had a short ramus height and clockwise rotation of the ramus and mandible compared with those with BN in both OM and NM groups. However, significant differences were present in the skeletal characteristics of the TMJ DD patients between the NM and OM groups. Significant backward positioning and rotation of the ramus and mandible were found between BN and bilateral disc displacement with reduction or bilateral disc displacement without reduction in the OM group, while those of the ramus and mandible were found between BN and bilateral disc displacement with reduction or bilateral disc displacement without reduction in the NM group. Conclusions The results of our study suggest that the skeletal characteristics associated with TMJ DD are differently represented according to the sagittal jaw relationship.

Background: This study was undertaken to investigate the facial skeletal features associated with chin deviation. Methods: Twenty-five patients (14 males and 11 females) diagnosed with chin deviations of more than 2 mm were recruited. Fifteen skeletal landmarks, including median and lateral points, were located on posteroanterior cephalograms. The CG–ANS (crista-galli of the ethmoid–anterior nasal spine) line and the perpendicular line through the CG were used as references. The differences between the distances from paired lateral points to reference lines were examined with intraclass correlation coefficients to analyze the symmetry of facial skeletal tissue. The factors associated with the amount or direction of chin deviation were analyzed by multiple regression analysis or by logistic regression analysis. Results: Seventeen subjects (68%) showed chin deviation to the left side and 8 subjects (32%) to the right side. Sixtyeight percent of subjects presented with Angle Class III malocclusion. Horizontal distances of all paired lateral points to the y-axis, in mandibular body length and effective length, showed a low grade of symmetry. Only vertical distances of paired zygomaticofrontal sutures and zygonion points to the x-axis were asymmetric. However, there were no significant asymmetries of the gonial angle, ramus height, and vertical distances from other paired lateral points to the x-axis. The amount of chin deviation was associated with the absolute differences of the left and right antegonion to the y-axis and zygomaticofrontal suture to the x-axis. The direction of chin deviation was significantly associated with the difference in the effective length of bilateral mandibular halves. Conclusion: Facial skeletal asymmetry exists in patients with chin deviation. This should be considered when planning treatment for both the nonsurgical and surgico-orthodontic cases with chin deviation. [J Chin Med Assoc 2010;73(1):29–34]

Summary Background This study was to evaluate the stability of the bioabsorbable plate used in the orthognathic surgery for patients with prognathic mandibles and to evaluate the relapse tendency after surgery and the factors affecting the relapse. Materials and methods The sample consisted of 30 subjects (14 males and 16 females) who underwent bilateral sagittal split ramus osteotomy (BSSRO) for mandibular setback using the poly-l/dl-lactide plate system (Biosorb FX ® , Linvatec Biomaterials Ltd., Tampere, Finland). The lateral cephalometric radiographs of each subject were taken pre-operatively within 1 month (T0), post-operatively within 1 month (T1), and post-operatively between 4 and 10 months (T2) and skeletal changes were analyzed with V-Ceph (CyberMed ® , Seoul, Korea) software. The changes between T1 and T2 were evaluated with a paired t -test to estimate the stability of the surgery. The post-operative changes of mandibular body length and ramus height were used for a K-means clustering analysis to separate subjects into either the less changed (LC), or the more changed (MC) group. The two groups were compared with T0 and the surgical changes (T1−T0) using the t -test. Results Significant relapse after surgery was shown in vertical measurements but not in the horizontal plane measurements. The MC group showed significantly more vertical operative changes than the LC group independent of horizontal measurements. Conclusions Usage of a bioabsorbable plate in mandibular setback surgery could provide stable fixation in the horizontal dimension, but also may allow an increase of vertical relapse due to the increase in vertical dimension post-operatively.

The purpose of this retrospective case-control study was to compare the cephalometric features of parents of children with cleft anomalies to those of parents of normal children in the hope of finding potential markers of predisposition for this condition. There were 22 sets of parents of cleft children (study group) and 22 sets of parents of normal children (control group). A total of 88 lateral cephalograms were traced twice by two observers separately and analyzed using Student's t-test. Seven linear, two angular and five triangular cephalometric variables were measured. Mandibular body length (Go-Gn) in mothers was larger in the study than the control group, posterior cranial base (S-Ba) in fathers was shorter in the study than the control group, anterior maxillary triangle (S.N.A) in parents in the study group was larger than in the control group and posterior maxillary triangle (S.N.Pns) in study group mothers was larger than in control group mothers. In conclusion, the craniofacial morphology of the parents of children with cleft anomalies differs from that of parents of normal children and may have some predictive value.

The purpose of this study was to investigate the morphological changes of the inharmonious growth of mandible in rats.We investigated a rat (6-week-old, male) mandibular asymmetry model to assess the growth changes in morphological study after removal of lateral guide plane. A mandibular lateral guide plane (shift to the left side) was applied to the upper incisors of rats for 8 weeks (0, 1, 2, 4, 8 weeks after removal of lateral guide plane). After mandibular asymmetry was recongnized, the mandible was observed.In morphological measurement, there were no diferences in mandibular height and mandibular body length until the 8th week between left and right sides after removal of the lateral guide plane. However, the mandibular length of the left side was significantly shorter than that of the right side. After 4 weeks there was no difference between the left and right sides. Moreover, the deformity of condyle in the left side recovered after removal of the lateral guide plane. These results suggested that the early treatment of mandibular shift is necessary to treat mandibular asymmetry.

To analyze changes in mandibular form associated with an inverted-L osteotomy and autogenous bone graft, preoperative, early postoperative (EPO), and late postoperative (LPO) lateral cephalographs of 14 children (mean age approximately 9 years) with unilateral craniofacial microsomia (CFM) were scanned and nine mandibular landmarks digitized. Average mandibular geometries, scaled to an equivalent size, were generated using Procrustes superimposition. Cephalometry, Euclidean distance matrix analysis (EDMA), and thin-plate spline (TPS) analyses were carried out on mean mandibular configurations. Cephalometric results showed increases in oblique mandibular length (approximately 9% on average, P < 0.05) and increased ramus height (P < 0.05). Similarly, using EDMA there were also significant differences (P < 0.05) between the mean preoperative, EPO, and LPO configurations. The most demonstrable EPO change in the mandibular configuration using EDMA was increased oblique length (approximately 11%). This improvement depended on ramus oblique lengths increasing by approximately 26%, ramus height increasing by approximately 25%, and mandibular body length increasing by approximately 5%. For TPS analysis, affine and nonaffine changes contributed to the total spline. In all three comparisons the affine transformation showed an antero-inferior rotation of the mandibular configuration. For nonaffine changes the EPO configuration indicated a supero-inferior stretch of the mandibular configuration. The nonaffine LPO changes maintained the supero-inferior stretch of the mandibular configuration. It is concluded that improvements in the lateral facial profile of CFM patients can be achieved using an inverted-L osteotomy, with little relapse approximately 2 years postoperatively.

This study aimed at determining the relative genetic and environmental impact on a number of well-known cephalometric variables in twins. In order to find a clue in the heritability pattern of some dentofacial characteristics and on the expected limits of the therapeutic impact on the dentofacial subparts they are representing. Cephalograms were collected from 33 monozygotic and 46 dizygotic twins, who did not undergo any orthodontic treatment. Nineteen linear and four angular variables were selected all representing a different definite subpart of the dentofacial complex. The reproducibility of the measurement of most of the linear variables was very high. A genetic analysis using model fitting and path analysis was carried out. First, data were checked on the fulfilment of the conditions for genetic analysis in twins reared together. The results show that the genetic determination is significantly higher for vertical (72%) than for horizontal (61%) variables. As far as the genetic component is concerned, all variables selected seem to be inherited by additive genes, except for mandibular body length, which was determined by dominant alleles. Sex differences in genetic determination were found for the anterior face height, showing a significantly higher genetic component for boys (91%) than for girls (68%). For the angular measurements, no genetic influence was found: only environmental influences common to both members of each pair could be demonstrated.

The role of the mandible in sex determination is still poorly defined because of the plasticity of this bone. We carried out a teleradiographic study of the mandibles of 63 living white subjects, measuring bigonial breadth, bicondylar breadth (anterior radiographs), mandibular symphysis height, mandibular length, articulare-gonion height, mandibular ramus height and mandibular body length (lateral radiographs). All these paramters showed significant sexual dimorphism (p

No current age- and gender-related normative data exist for the dimensions of facial structures in Northern Sudanese subjects. In the current study information about normal sex- and age-related linear distances is provided. The three-dimensional coordinates of 14 landmarks on the facial soft tissues were obtained using a hand-held laser scanner in 653 healthy Northern Sudanese subjects (326 males and 327 females) aged 4-30 years. From the landmarks, 13 linear distances were calculated, and averaged for age and sex. Comparisons were performed by factorial analysis of variance. All analyzed linear soft tissue facial dimensions were significantly larger in men than in women (p 0.01), except mouth width (ch-ch), upper facial height (n-sn), mandibular body length (pg-go) and width (go-go). All measurements underwent significant modifications as a function of age (p 0.01), with significant age × sex interactions (p 0.01) for all linear dimensions except lower face height (sn-pg). Overall, when compared to literature data for African and Caucasoid subjects, several differences were found, pointing to the necessity of ethnic-specific data. Data collected in the present investigation could serve as a database for the quantitative description of human facial morphology during normal growth and development.

Introduction Compression on the midface with nasal mask-delivered positive airway pressure (PAP) therapy in growing patients might contribute to midface retrusion. The objective of this study was to investigate the association between long-term PAP use and craniofacial morphologic pattern in children with persistent obstructive sleep apnea. Methods Images generated with cone-beam volumetric imaging were used to complete lateral cephalometric analyses of anteroposterior projection of the midface region. The study group included 12 subjects (10 boys, 2 girls; mean age, 9.0 years) who used PAP therapy for at least 6 months and at least 6 hours per night. Measurements from this group were compared with those of a control group of 11 subjects (5 boys, 6 girls; mean age, 9.6 years) with obstructive sleep apnea who did not have PAP. Measurements were taken at 1 time point. Results No significant differences were identified between the groups for any cephalometric variable. Multivariate linear regression analysis also did not identify a significant association between the number of months of PAP therapy and the cephalometric variables. Cephalometric data for both groups were pooled for comparison with appropriate published normative values for age and sex. Anterior cranial base length, overall anteroposterior length of the maxillary base, and mandibular body length were significantly shorter than normal in the subjects compared with published normative values. Conclusions No association was demonstrated between midface projection and PAP use in growing patients. When compared with normative data for anterior cranial base, children with obstructive sleep apnea had shorter maxillary and mandibular lengths.

Mandibular morphology and position were evaluated in a group of 50 patients with juvenile rheumatoid arthritis (JRA), and in a matched control group, by means of two different postero-anterior radiographs. In the 50 matched pairs, the mean age of the patients was 10.7 years and 10.8 for the controls. Female/male ratio was 2.1/1. The patients showed a statistically significant reduction in maximum mandibular length, in vertical height in the ramus region, in total face height, and in the inclination angle of the mandibular body, as compared to the controls. Both groups showed a systematic, statistically significant right-sided dominance in mandibular breadth and projected mandibular body length. In addition, the patients demonstrated asymmetry tendencies in overall length of the mandible and in vertical height in the ramus region. The differences between patients and controls indicated a failure of increase in vertical dimensions among the patients.

Legitimate questions exist concerning the degree to which routine orthodontic treatment alters face form. To the extent that such alterations do occur, the delivery of different vectors should result in different sorts of skeletal change. In this study, we have attempted to discern and quantify differences in the rates of change of nine linear measures of mandibular and facial proportions during the course of Phase 1 treatment for the correction of Class II mixed-dentition malocclusion. The analysis took the form of a series of computer-conducted tests performed upon a previously reported tape-stored numerical data base which had been constructed earlier by digitizing pre- and posttreatment lateral cephalograms for a large group of Class II subjects. Rates of change for the nine linear measures were computed separately for samples of subjects treated with cervical face-bow, high-pull face-bow, and activator type intraoral appliances as well as for a control group of untreated Class II subjects. Statistically significant between-treatment differences which we believe are large enough to be of clinical importance were detected for several measures. As compared to the control group, a statistically significant rate of increase in condyle-pogonion distance was found in the intraoral group. Such an observation is consistent with the hypothesis of treatment-associated alteration of growth pattern in the region of the condyle. To our considerable surprise, the cervical group exhibited a similar statistically significant rate of increase in condyle-pogonion distance which is as yet unexplained. In general, rates of increase in measures of anterior face height had higher values in the cervical group than in the control group, implying that consideration should be given to avoiding the use of this treatment modality in patients for whom facial elongation during treatment would be undesirable. The cervical group also exhibited a statistically significant rate of increase in ramus height. Such an effect would tend to keep mandibular plane orientation relatively unchanged in the presence of increase in anterior face height, helping to explain our previously reported findings as to the relative constancy of mandibular plane angle. In the high-pull-treatment group, rates of increase in ramus height and condyle-pogonion distance were significantly lower than those in the control group and rates of increase in lower face height and anterior face height were significantly lower than those in the cervical group. In all three treatment groups, the rate of increase in mandibular body length was less than in the untreated control group, though only in the cervical group was this effect large enough to be statistically significant.

Relative mandibular prognathism is an observed finding in Apert and Crouzon syndromes. This imbalance in the facial profile is generally attributed to the diminished growth of the maxilla, thereby increasing the disparity between maxilla and mandible with increasing age. What is not known is whether the mandible is, indeed, normal. Previous work by Kreiborg1 with Crouzon syndrome led to the conclusion that the mandible, although somewhat smaller, grew in a “normal” pattern. Our own observations, which used a greater variety of mandibular measurements on patients with both Apert and Crouzon syndromes, corroborated Kreiborg's1 conclusions but go further to suggest a syndrome-specific mandibular malformation. Ramal height was found equal to the norm and sometimes greater. Mandibular body length was significantly shorter, thereby producing a distinctly different ramus/body length ratio, particularly in older patients. These findings become significant in the planning of reconstructive procedures. They also raise the question as to whether the shape of the mandible is genetic in origin or is an adaptation to the increasing derangements of the cranial base, maxilla, and occlusion observed with maturation in these patients. The possibility of interactive genetic and environmental factors affecting growth of the mandible emerges from the data.