Mandibular Width Research Articles

Estudo comparativo entre medidas cefalométricas frontais delineadas manualmente e computadorizadas

From a frontal telerradiographies sample of 50 adult individuals, this work evaluated if differences exist among the rnedium values of linear and angular skeletal measurements obtained manually and through the computer programs SMTC, OrtoView, Radiocef and Orto Manager. On cach x-ray the manual Ricketts frontograrñ was accomplished and marked the points for cach one of the programs. The values obtained in each one of the five methods used were tabulated for each one of the measurements studied, and their averages compared by the Analysis of Variance (ANOVA). It was verified to the postural symetry, that there are significant statistical differences among Orto Manager and the other methods, wich do not differ significantly to each other. For the averages of the other linear and angular measurements selected: maxilo-mandibular medium line, nasal width, nasal height, maxillary width, mandibular width and facial width, was verified that there are not significant statistical differences among the studied methods.

Comparison of mandibular cross-sectional morphology between Class I and Class II subjects with different vertical patterns: based on CBCT images and statistical shape analysis

BackgroundThis study is aimed to (1) investigate the influence of sagittal and vertical patterns on mandibular cross-sectional morphology and to (2) provide visualized mandibular cross-sectional morphology in different groups with General Procrustes Analysis (GPA), canonical variance analysis (CVA) and discriminant function analysis (DFA).Methods324 cone-beam computed tomography (CBCT) images were collected to analyze mandibular cross-sectional morphology and were categorized into 12 groups according to sagittal and vertical pattern and gender. One-way analysis of variance (ANOVA) was used to compare the difference among the groups. Thirty equidistant points were marked along the contour of mandibular cross-section and GPA, CVA and DFA were applied.Results(1) Mandibular height in hyperdivergent groups was significantly higher than that in normodivergent and hypodivergent groups (P < 0.05). (2) Hypodivergent groups showed significantly wider upper third of mandibular width from symphysis to molar region than that in hyperdivergent group (P < 0.05), except for the premolar and molar regions in male groups (P > 0.05). (3) Class II hyperdivergent group showed narrowest lower third width in the molar region, with the mean value of 12.03 mm in females and 11.98 mm in males. (4) For males and females, the ratio between height and lower third width at symphysis was significantly higher in Class II hyperdivergent group than that in Class I hyperdivergent group (P < 0.05).Conclusions(1) The influence of vertical facial patterns on mandibular cross-sectional morphology is more obvious than that of sagittal skeletal pattern. (2) Subjects with increased vertical dimension presented with a remarkable “slimer” mandibular cross-sectional morphology at symphysis. (3) A deeper curve along the anterior contour of symphysis in Class II hyperdivergent group was noted with GPA.

Trabecular and cortical mandibular bone investigation in familial adenomatous polyposis patients

Mandibular cortical and trabecular bone abnormalities in patients with familial adenomatous polyposis (FAP) were evaluated using dental panoramic radiographs (DPR) radiomorphometric indices and fractal dimension (FD). Sixty DPRs from 15 FAP patients and 45 healthy controls were evaluated. FAP group was composed of 33.3% females and 66.6% males, agemean = 37.2 years (SD 15.79). The non-FAP group was paired by gender and sex. The parameters analyzed were: FD of the trabecular bone in four regions of interest (ROI), mandibular cortical index (MCI) and width (MCW). FD values were lower for the FAP group. Statistically significance differences were shown by ROI 2 and 3 anteriorly to the mental foramen bilaterally, p = 0.001, and p = 0.006. The ROI 1 and 4, at the mandibular angle trabeculae, indicated statistical significances on the right side (p = 0.036) and no differences on the left side (p = 0.091). There was no significant difference in MCI and MCW when the groups were compared, MCW (L) p = 0.247, and MCW (R) p = 0.070. Fractal values of FAP patients' mandibular trabecular bone were lower than healthy controls. The radiomorphometric indices MCI and MCW were not useful for analyzing the cortical bone pattern. Therefore, FD is a promising tool for detection of abnormal bone structure in DPRs and for supporting the appropriate referral of FAP patients.

Surgery-first orthognathic approach for the correction of facial asymmetry

We aimed to compare the reliability of the surgery-first approach and the traditional orthodontic-first approach for the correction of facial asymmetry based on the new classification of facial asymmetry.Patients with facial asymmetry who underwent orthognathic surgery between January 2016 and January 2019 were included. Cephalometric changes and relapse ratios were analyzed 12 months before and after surgery. Patients were divided into horizontal and vertical asymmetry groups based on the asymmetry vector, and subgroup analysis was conducted.The surgery-first approach without presurgical orthodontic treatment and the orthodontic-first approach showed a similar degree of asymmetry correction and skeletal stability. The relapse ratios of the maxilla height in the surgery-first and orthodontic-first groups were 0.25 ± 0.21 and 0.27 ± 0.25, respectively (p = 0.63), the relapse ratios of the maxilla width were 0.31 ± 0.32 and 0.21 ± 0.2, respectively (p = 0.14), the mandibular height relapse ratios were 0.34 ± 0.58 and 0.29 ± 0.36, respectively (p = 0.69), and the mandibular width relapse ratios were 0.12 ± 0.22 and 0.26 ± 0.31, respectively (p = 0.058). The treatment period of the surgery-first group (18.5 ± 5.3 months) was significantly shorter than that of the orthodontic-first group (22.9 ± 7.5 months, p = 0.024). Among the surgery-first group, patients with vertical asymmetry (15.0 ± 3.2 months) had a shorter treatment than those with horizontal asymmetry (21.6 ± 6.8 months, p = 0.006).Although contesting traditional standards is always challenging, the surgery-first orthognathic approach may lead to a new era in traditional orthognathic approaches. This new classification of facial asymmetry could be useful and practical when treating patients with facial asymmetry regardless of the etiology.

Reliability of 2 methods in maxillary transverse deficiency diagnosis

The objective of this research was to evaluate the reliability of 2 methods (Andrews' Element III analysis and Yonsei transverse analysis) in maxillary transverse deficiency diagnosis. Plaster casts and cone-beam computed tomography images of 80 outpatients with skeletal Class I malocclusion (29 males and 51 females, mean age, 20.16±8.22years) were selected. Maxillary and mandibular width were measured, respectively, and independently by 2 examiners at an interval of 2weeks, using Andrews' Element III analysis and Yonsei transverse analysis. Intraclass correlation coefficients and Bland-Altman plots of intraexaminer and interexaminer reliability were evaluated. After diagnosis, Cohen's kappa statistics were calculated to evaluate the diagnostic agreement. The intraclass correlation coefficients were all above 0.85, indicating good to excellent reliability. Compared with Andrews' Element III analysis, Yonsei transverse analysis had higher intraexaminer and interexaminer reliability in both maxillary and mandibular width measurements. Thirty-one to 42 of the patients were diagnosed with maxillary transverse deficiency by 2 examiners using 2 methods. The intraexaminer and interexaminer Cohen's kappa values of Yonsei transverse analysis were all higher than those of Andrews' Element III analysis. Both Andrews' Element III analysis and Yonsei transverse analysis had good to excellent reliability and substantial diagnostic agreement. Yonsei transverse analysis had higher reliability in maxillary and mandibular width measurements and higher diagnostic agreement, compared with Andrews' Element III analysis.

Finite Element Analysis of Two- and Three-Dimensional Fixation in Treating Mandibular Symphyseal Fracture Combined With Bilateral Condylar Intracapsular Fractures.

The aim of this study was to compare through finite element analysis two- and three-dimensional (2D and 3D) fixation in the treatment of mandibular symphyseal fracture combined with bilateral condylar intracapsular fractures. The authors created 2 fixation models for the above fracture, and analyzed the stress and displacement in the mandible and fixation materials under 3 loading conditions. The von Mises stress of the mandible and plates peaked during lateral occlusion, and was lowest during central occlusion. In all conditions, stresses in the fixation materials did not exceed the yield stress of titanium. The inferior border of the symphyseal fracture segments showed opposing displacements, and the mandible tended to widen in the 2D fixation model. However, the fracture displacement did not exceed 150 μm for either fixation method. The results suggested that after well reduction and fixation of condylar intracapsular fractures, either 2D or 3D fixation for symphyseal fracture can provide adequately strong fixation. Compared with 2D fixation, 3D fixation has more advantages in controlling the mandibular width and preventing the fixation materials from enduring excessive stress.

Factors Influencing Upper Airway Dimensions in Skeletal Class Ⅱ Children and Adolescents: A CBCT Study

The purpose of this study is to investigate factors influencing the upper airway dimensions in skeletal Class Ⅱ children and adolescents. In total, 67 patients were selected. Airway volume and minimal cross-sectional area were three-dimensionally assessed. Craniofacial morphology and skeletal maturity were assessed on generated two-dimensional cephalograms. The measurements were analyzed using Mann-Whitney test, one-way ANOVA, Pearson’s correlation, and multiple regression analysis. Upper airway dimensions were significantly smaller in pre-peak stage group, and positively associated with age. Anterior facial height and age were the most relevant factors for airway volume. Mandibular width and age were the most relevant factors for minimal cross-sectional area. Upper airway dimensions were significantly associated with age, skeletal maturity and craniofacial morphology in all three planes.

Facial Contour Refining after Surgery-First SSRO with Computer-Assisted Design in East Asians.

Surgery-first sagittal split ramus osteotomies (SF-SSRO) are an effective treatment for patients with dental malocclusion. However, some patients with mandibular prognathism usually have facial deficiencies which cannot be corrected completely after orthognathic surgery. These are not accepted because the remaining facial contours are in disharmony. Twenty-five patients, who were unsatisfied with their appearances after SF-SSRO and orthodontics, were included. The preoperative CTs were used to investigate patients for facial deformity. To achieve a harmonious facial contour, mandible long-curve osteotomy/mandible U-shaped osteotomy, genioplasty or facial autologous fat grafting was selected depending on patients' contour deformities with the assistance of CAD. Among the patients who underwent osteotomy, the gonial angle was improved from 111.16° ± 9 to 111.58° ± 9.06 after SF-SSRO because of distal fragment setback and rotation. After facial refine surgery, the gonial angle was significantly increased to 121.69°±2.41 (p < 0.05). And the mandibular width was decreased from 11.29 cm ± 0.44 to 10.45 cm ± 0.39 (p < 0.05) after mandibular outer plate griding. All patients were shown no signs of infection, massive bleeding, and osteonecrosis in the early stage. After follow-up time, they were all satisfied with their results and most of them recovered from lip numbness. This study indicated the clinical feasibility of two-stage orthognathic and facial bone contouring surgery for the treatment of dentofacial deformities. Two-stage facial contouring surgery can provide esthetic improvement for more accuracy in refining the facial contour. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Clinical and ultrasonographic evaluation of ultrasound-guided single puncture temporomandibular joint arthrocentesis

ABSTRACT Objective To evaluate the effects of successful TMJ treatment on relief of pain, improvement of mandibular movement and capsular width with clinical and ultrasonography (US) findings. In this study, TMJ changes were evaluated by clinical and US examination after US-guided single-puncture arthrocentesis, which represents a novel approach. Methods Clinical measurements were obtained before each procedure and at 1 day, 7 days, and 3 months thereafter. Capsular width was measured via the US at the 3-month follow-up. Results Significant improvements were evident at the short term of 3 months post-arthrocentesis with supportive treatment, including splint therapy and jaw exercises. Conclusion Arthrocentesis in conjunction with splint therapy and jaw exercises demonstrated significant clinical improvement at the short-term follow-up of 3 months. US imaging can be helpful for follow-up evaluation of the pre- and post-treatment capsule width. Longer follow-up studies are necessary to validate the effectiveness of this treatment protocol.

Evaluation of Change In Mandibular Width During Maximum Mouth Opening and Protrusion

Evaluation of Change In Mandibular Width During Maximum Mouth Opening and Protrusion

Evaluation of mandibular indices in panoramic radiography

Aim of the study was to evaluate mandibular indices on a panoramic radiograph. A number of mandibular cortical indices, including the mandibular cortical index (MCI), mandibular cortical width (MCW) and panoramic mandibular index (PMI), AI (Antegonial index)was evaluated on Panoramic radiograph. Correlation between the indices were also done in our study and we found that PMI with MI and MI with AI were highly significant and showed similar results whereas MCI was non significamt with the other indices. Keywords: Mandibular Cortical Index (MCI), Mandibular Cortical Width (MCW), Panoramic.

Clinical evaluation of an automated virtual surgical planning platform for mandibular reconstruction.

Virtual surgical planning (VSP), via commercial services or developed in-house, has been applied to facilitate head and neck reconstruction. We evaluate a custom, automated planning software. Prospectively, VSP of 25 consecutive patients undergoing segmental mandibular reconstruction was performed. Postoperative CT was used to assess structural accuracy of VSP. Operative time, length of stay, and complication rate of the prospective cohort were compared with those of 25 consecutive retrospective historical cases. The deviations between the plan and execution in mandibular width, projection, and volumetric overlap were 2.32 ± 3.91, 2.39 ± 1.72, and 0.59 ± 0.51 mm respectively. Compared with historical data, there was a significant reduction in operative time and length of stay, and no significant difference in complication rates. This is the largest prospective series evaluating an in-house VSP workflow for mandibular reconstruction and the first clinical evaluation of an automated planning platform.

Evaluation of Mandibular Arch Width Changes following Fixed Retention in Post Orthodontic Patients - a Randomized Clinical Trial

Background: Retention is an integral phase in which teeth are maintained in their newly adapted position for which retainers are inserted. Retainers are generally of two types: removable and fixed. Fixed retainers are indicated in the mandibular arch for an indefinite period specifically in the non-extraction cases. Changes in intercanine and intermolar widths are valuable parameters to evaluate the stability. The objectives of this study were to assess and compare the mandibular intercanine and intermolar width changes following orthodontic treatment after insertion of two types of fixed lingual retainers for one year. Methods: Total 54 subjects were recruited in which two types of fixed lingual retainers were inserted in the mandibular arch randomly. Intercanine and intermolar arch widths were measured by digital caliper of 0.01 mm accuracy. Data was analyzed by using Statistical Package of Social Sciences (SPSS V-21). Chi-square and independent t tests were used to compare baseline characteristics. Intercanine and intermolar widths were assessed and compared using independent t test, p-value ≤ 0.05 is considered as statistically significant. Results: Intercanine width increased from baseline to T4 in both retainers. When mean differences of intercanine width were compared between two retainers significant differences were observed at T1, T2, T3 and T4 with significant p-values (&lt; 0.05) and increased intercanine width with multistranded stainless steel wire (MSW) retainers. Conclusion: Mandibular intercanine width increases significantly in post retention phase with multistranded stainless steel retainers. Thus, fiber reinforced composite retainers are more effective in preserving the arch width changes.

3D Analysis of Facial Morphology of a Colombian Population Compared to Adult Caucasians.

Objective: The purpose of this study involves describing the facial morphology of a Colombian population with three-dimensional (3D) imaging, and comparing their facial morphology with the Caucasian to create a database for this ethnicity. Materials and Methods: The study, which included 135 subjects selected from the Valle University in Cali, Colombia, and 535 Caucasian subjects selected from the FaceBase–Data (1U01DE024449–01), was funded by the National Institute of Dental and Craniofacial Research. All images were taken in the natural head position (NHP) and captured using a stereo-photogrammetric camera system (3dMDface) to obtain a 3D image of each patient. The subjects were between 19 to 31 years of age, with a normal body mass index (BMI), and no craniofacial deformities. All images were plotted and analyzed using the 3dMDVultus software to calculate linear and angular measurements. Standard deviation (SD) and means were calculated for each measurement and analyzed using t -test for different samples. Results: The Hispanic population had wider eyes, more protruded upper and lower lips, wider face, and greater mandibular width. Caucasian females had a more acute full profile, larger middle third, and less protrusive lips. Understanding the facial morphology of different populations would help to establish a better diagnosis and treatment planning for each ethnicity. Conclusions: From this study, the following conclusions may be drawn: 1. The mean values of Colombian males showed greater measurements than females in the majority of measurements.2. Caucasian females had a more acute full profile, larger middle and lower third, and less protrusive lips.3. This study showed significant ethnic differences in the linear and angular measurements, showing us the importance of considering these findings in the diagnosis and treatment planning when a Hispanic population is involved. Soft tissue values should reflect the norms according to each ethnic population in order to achieve treatment goals.

The role of fluoride on eruption of mandibular molar of albino rats

Eruption of the tooth is a complex and highly regulated process which can be influenced by genetic, environmental and systemic factors. Fluoride is found naturally in water as well as in foods and dental products. The first mandibular molar is the first molar to erupt and it is essential for mastication of food. We studied the effect of fluoride on the eruption of the first mandibular molar in albino rats. Fluoride at different concentrations was added to the water of pregnant albino rats while sterile water without fluoride was given to the control pregnant dams. The pregnant dams were allowed to deliver, and the heads of their pups carefully decapitated, and mandibles dissected out on days 10, 12, 15 and 18 for assessment of eruption pattern of the first molar while also measuring the mandibular length and breadth. The mandibles were then processed for hematoxylin and eosin staining. On gross examination, some of the teeth developed intraosseously while others were located mucosally, pre-occlusally or occlusally. There was significant reduction in both the birth weight and mandibular length as the fluoride concentration increased compared to the control but a significant increment in the mandibular breadth between the experimental groups in comparison with the control group on day 15 (p value &lt;0.05). These findings suggest that high concentrations of fluoride could delay mandibular molars’ eruption and also cause low birth weight.&#x0D; Key Words: fluoride, mandibular molar, tooth eruption

Evaluation of Mandibular First Molars' Axial Inclination and Alveolar Morphology in Different Facial Patterns: A CBCT Study.

Objective The purpose of this study was to evaluate and compare the axial inclination of the mandibular first molars and their respective bone morphology among individuals with different facial patterns. Materials and Methods The sample comprised the cone beam computed tomographies (CBCTs) of 58 subjects divided into three groups according to the facial patterns: 18 brachyfacial (Group 1), with a mean age of 21.58 years; 23 mesofacial (Group 2), with a mean age of 19.14 years; and 17 dolichofacial subjects (Group 3), with a mean age of 19.09 years. Eight variables were evaluated on CBCT scans of each subject: buccal and lingual mandibular height, cervical and middle mandibular width, inclination of mandibular body, inclination of the mandibular molar buccal surface, molar width, molar angulation and tooth/bone angle. Intergroup comparisons were performed with one-way analysis of variance followed by Tukey tests. Results Buccal mandibular height presented statistically significant difference in the three facial patterns. Lingual mandibular height and mandibular inclination showed to be statistically and significantly smaller in brachyfacial subjects than in the other two groups. Mandibular width presented a statistically significant difference between brachyfacial and mesofacial groups. Negative correlations could be observed between the facial pattern and the buccal and lingual mandibular heights and inclination of the mandibular body. Conclusion Buccal mandibular height was significantly and progressively larger in brachyfacial, mesofacial, and dolichofacial subjects. Lingual mandibular height was significantly smaller in brachyfacial than in mesofacial and dolichofacial subjects. Mandibular width was significantly thicker in brachyfacial than in mesofacial subjects. Brachyfacial subjects had smaller mandibular inclination than mesofacial and dolichofacial subjects.

A Modified Method Using Double Computed Tomography Scan Procedure to Maintain Mandibular Width in Mandibular Reconstruction.

The purpose of this study was to evaluate the use of a modified template system and double computed tomography scan procedure to maintain mandibular width in cases of mandibular reconstruction. Ten patients who underwent mandibular reconstruction with a fibular flap were enrolled. The surgeries were planned with a computer-aided surgical simulation (CASS) planning method. Following double computed tomography scan procedure, the template system was designed in a computer and was fabricated using a three-dimensional printing technique. The cutting guides were designed with the holes of the conventional reconstruction plate on the remnant mandibular segments. After surgery, the outcome evaluation was compared by first superimposing the post-operative computed tomography model onto the planned model and then measuring the differences between the planned and actual outcomes. All surgeries were completed successfully using the template system. With the use of the templates, the largest linear root-mean-square deviation (RMSD) between the planned and post-operative remnant segments was 1.01 mm, and the largest angular RMSD was 4.05°. The authors conclude that this template system and double computed tomography scan procedure provides a reliable method to maintain mandibular width in mandibular reconstruction using a fibular flap.

EFFECT OF HYPERBARIC OXYGEN THERAPY ON THE OSSEOINTEGRATION AROUND IMPLANTS AFTER MANDIBULAR RECONSTRUCTION BY DESTRACTION OSTEOGENESIS

Increases in mandibular width by distraction osteogenesis have recently been shown to be an acceptable and stable treatment option for deficiencies, and also, in the oral rehabilitation, where one of the major problems is the alveolar bone loss, and adjacent soft tissues.Aim: The aim of this study is to evaluate the influence of hyperbaric oxygen therapy (HBOT), on the osseointegration of implants retained partial mandibular overdenture after reconstruction of mandibular deficiency by distraction osteogenesis. Methods: This study was conducted on eight male patients with a lack of the anterior mandibular jaw bone due to anterior marginal mandibulectomy, and partially edentulous maxillary arch (different classes), selected from the maxillofacial outpatient clinic, Faculty of Dentistry, Misr University for Science and Technology, (mean age 43 years, minimum 35 years and maximum 51 years). For all patient, distraction the insufficient alveolar ridge by using an Extraosseous Track Alveolar Distractor (KLS Martin, Germany), after consolidation period, patients received maxillary and mandibular conventional acrylic partial dentures prior to implant insertion. Then, each patient received two endoosseous implants in the mandibular interforaminal region, (following two stage surgical protocols), to retain partial mandibular overdentures. Patients were randomly divided by closed envelops, into two equal groups. Group I; Patients were received hyperbaric oxygen therapy (HBOT), on a protocol of five sequential sessions (study group), while Group II; Patients were received no hyperbaric oxygen therapy (HBOT), as a control group. Ball attachments were screwed to the implants, after four months of surgery. All patients received new mandibular removable partial overdentures were retained by two implants, and designed as Kennedy class IV partial overdentures, to fitted partial mandibular overdentures. Marginal bone height changes and bone density were assessed using cone beam computed tomography(CBCT); at time of prosthetic loading, then after six, and twelve months.Results: Decrease in marginal bone height and increase in bone density through a follow-up period (one year) were observed in both groups , however; group I; that received HBOT revealed less marginal bone resorption and more increase in bone density than group II. Conclusion: After mandibular reconstruction by distraction osteogenesis, hyperbaric oxygen therapy effective treatment, and improve osseointegration around implants retained partial ovedentures, as it associated with increased bone density and reduced marginal bone loss after one year follow up.

EXPERIMENTAL RESPONSE TO DENSITY LEVELS IN THE DEVELOPMENT OF TADPOLES AND FROGLETS OF Boana pulchella (ANURA: HYLIDAE)

Density has been proposed as a factor that could determinate larval growth in anurans. We studied such effects on Boana pulchella. After hatching, we reared the tadpoles during 90 days and 93 tadpoles with similar size and developmental stages were chosen. We placed them in 800 cm3 cans with declorified water at five densities (1, 2, 4, 8 and 16 individuals/can) with three replicates for each treatment. In all the cans the feeding was ad libitum, and they were maintained until the end of the Gosner’s developmental stage 41. Each time that a tadpole was extracted, a proportional water volume was too, in order to maintain constant densities. We found significant differences among treatments for froglets’ length, mandibular width and mass, while these differences were not significant for metamorphic time. Since the tadpoles were feeding ad libitum an explanation by competitive trophic interactions for that significant differences could be discarded. These differences could be evidence that density has significant effects.

Changes of mandibular dental arch shape during adolescence and its influence on late mandibular incisor crowding.

The aim was to analyze the changes in mandibular dental arch shape during adolescence and assess its relation to late mandibular incisor crowding. Longitudinal study included 68 orthodontically untreated subjects (49% female) and analyzed their data for the ages of 12, 15, 18 and 21 years. Measurements included anterior arch depth, intercanine, interpremolar/anterior and intermolar/posterior width, Little's Irregularity and Bolton's index and the ratio between anterior arch depth and width. Males had significantly greater posterior widths than females at any age (p < 0.05). The anterior arch depth continuously decreased (p < 0.05), while width increased after the age of 18 years. Mandibular incisor crowding increased during all investigated periods (p < 0.05). The increase of intercanine width at 12-21 years of age reduced the risk for mandibular incisor crowding in the same period by 74% (OR: 0.265: 95% CI 0.076-0.931; p = 0.045). The shape of mandibular dental arch continues to change during adolescence becoming more squared while mandibular incisor crowding increases. The increase in mandibular intercanine width reduces the risk of crowding.