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The masticatory function of patients with skeletal anterior open bite (OPEN) is reported to be impaired compared with that of patients with normal occlusion (NORM). In this study, we compared brain blood flow (BBF) in patients with OPEN and NORM and investigated the factors related to BBF during mastication in patients with OPEN. The study included 17 individuals with NORM and 33 patients with OPEN. The following data were collected: number of occlusal contacts, jaw movement variables during mastication, and BBF measured with functional near-infrared spectroscopy during chewing. The number of occlusal contacts, maximum closing and opening speeds, closing angle, and vertical amplitude were smaller in the OPEN than in the NORM group. Interestingly, BBF increased less in the OPEN group. Correlation analysis revealed that several parameters, including number of occlusal contacts and closing angle, were correlated with changes in BBF during mastication. These results suggest that not only occlusion but also jaw movement variables and factors related to masticatory muscles contribute to the chewing-related increase in BBF. In conclusion, BBF increases less during mastication in patients with OPEN than in those with NORM. In addition, the higher increase in BBF is correlated with jaw movement. Together, we discovered that OPEN exhibits significant adverse effects not only on masticatory function but also on brain function. [ABSTRACT FROM AUTHOR]

Purpose To consider long-term postoperative stability, and its contributing factors in surgical orthodontic treatment for asymmetric mandibular prognathism by comparing a sagittal split ramus osteotomy (SSRO) and a combination of Le Fort I osteotomy and SSRO.Materials and Methods Patients with asymmetric mandibular prognathism had undergone SSRO (14 patients; one-jaw surgery group) or a combination of Le Fort I osteotomy and SSRO (15 patients; two-jaw surgery group) were enrolled. Cephalometric analyses were performed at five time points: initial visit (T0), pre-surgery (T1), several months after surgery (T2), start of retention (T3) and more than 5 years after surgery (T4). Factors were evaluated by measuring two groups at each time point, comparing changes in measurements during each time period, correlating mandibular changes between each period, and correlating changes in lower first molar and ramus inclination with T2-T4 measurements.Results The two-jaw surgery group had significantly smaller transverse changes of menton (Me) at T3–T4 and T2–T4 compared to the one-jaw surgery group. In the one-jaw surgery group, transverse changes in Me at T2–T4 were positively correlated with changes in transverse inclination of mandibular ramus at the deviated side observed at T1–T2. Vertical change of pogonion at T2–T4 was positively correlated with change in bucco-lingual inclination of lower first molar at T0–T1.Conclusions Two-jaw surgery is suggested to be more effective than one-jaw surgery in achieving long-term stability of mandibular position in the transverse and anteroposterior dimensions after surgical orthodontic treatment for asymmetric mandibular prognathism. Long-term follow-up is necessary to monitor potential mandibular relapse.

Objective To explore the method of measuring root volume with cone-beam computed tomography (CBCT) three-dimensional reconstruction technology, and to study root length and root volume of upper and lower central incisors in patients with skeletal Class Ⅲ malocclusion treated by surgical orthodontic treatment. Methods Twenty patients with skeletal Class Ⅲ malocclusion undergoing surgical orthodontic treatment were selected. CBCT data at three time points, before decompensation treatment (T0), after decompensation treatment (before orthognathic surgery, T1), and the end of post-operative orthodontic treatment (T2) were collected. Three-dimensional reconstruction technology was used to measure the root length and root volume of the upper and lower central incisors (including total root volume, cervical root and apical root), calculate the percentage of reduction volume, and measure the distance of tooth movement after orthodontic treatment. Data were statistically analyzed by SPSS 20.0 software. Least significant difference (LSD) method was used for pair comparison between the groups subject to normal distribution, and non-parametric test was used for comparison between the groups not subject to normal distribution. The differences of root length and root volume of upper and lower incisors were compared, and the characteristics of root absorption were analyzed. Results Root length and root volume of the upper and lower central incisors were reduced during the surgical orthodontic treatment (P < 0.05) in cases. Both the root volume of cervical root and apical root were significantly reduced (P < 0.05), the reduction of apical root was more significant. The percentage of root volume reduction of the upper central incisor was (30.51±23.23)%, and lower central incisor (23.24±11.96)%. Compared with the upper central incisor, the root volume reduction amount and percentage of the lower central incisor were smaller, and apical root volume reduction of the upper central incisor was greater than that of the lower central incisor, which was statistically significant (P < 0.05). During pre-surgical orthodontic treatment, maxillary central incisor palatal moving was in a controlled tipping manner, and the mandibular central incisor tipped labially. Conclusion In patients with skeletal Class Ⅲ malocclusion, root length and total root volume of upper and lower central incisors decreased during surgical orthodontic treatment. Root volume measurement indicated that the cervical root also had root resorption. The difference in root resorption of the upper and lower central incisors might be related to the distance and direction of teeth movement. CBCT three-dimensional reconstruction will compensate for the limitation of root length measurement in evaluating root resorption.

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Background/purpose: Surgical orthodontic treatment is recommended for patients with severe dentoskeletal discrepancies, while camouflage orthodontic treatment is recommended for patients with mild to moderate discrepancies. However, the decision as to which treatment should be chosen is complicated. The purpose of this study was to determine differences in masticatory function in patients who underwent camouflage and surgical orthodontic treatment for skeletal Class III malocclusion, as well as the usefulness of Wits appraisal in treatment decision based on masticatory functional analysis. Materials and methods: The study subjects were 45 patients with skeletal Class III malocclusion (15 cases with camouflage orthodontics and 30 cases with orthognatic surgery) and 12 individuals with normal occlusion. We analyzed the pre-treatment records of electromyographic activities of masseter and temporalis muscles and jaw movements. Results: There were no significant differences in various functional measurements between the camouflage and surgery groups. However, there were significant but not strong correlations between ANB and both masseter muscle activity (r = 0.36, p

Surgical orthodontic treatment is recommended for patients with severe dentoskeletal discrepancies, while camouflage orthodontic treatment is recommended for patients with mild to moderate discrepancies. However, the decision as to which treatment should be chosen is complicated. The purpose of this study was to determine differences in masticatory function in patients who underwent camouflage and surgical orthodontic treatment for skeletal Class III malocclusion, as well as the usefulness of Wits appraisal in treatment decision based on masticatory functional analysis. The study subjects were 45 patients with skeletal Class III malocclusion (15 cases with camouflage orthodontics and 30 cases with orthognatic surgery) and 12 individuals with normal occlusion. We analyzed the pre-treatment records of electromyographic activities of masseter and temporalis muscles and jaw movements. There were no significant differences in various functional measurements between the camouflage and surgery groups. However, there were significant but not strong correlations between ANB and both masseter muscle activity (r = 0.36, p < 0.01) and expression ratio of abnormal chewing (r = −0.54, p < 0.01). Division of patients into two groups using a cutoff value of −6.0 mm for Wits appraisal showed a significant difference in masseter muscle activity between −6.0 mm or less group and the control (p < 0.01) but none between more than −6.0 mm group and the control. Camouflage orthodontic treatment is inappropriate for patients with relatively severe dentoskeletal discrepancies. Wits appraisal of −6.0 mm is a potentially useful parameter for treatment decision. [ABSTRACT FROM AUTHOR]

Background/purpose: Even after surgical orthodontic treatment, the level of masticatory function in patients with jaw deformities is still lower than that of healthy subjects. The purpose of this study was to evaluate the effects of functional training program using gum chewing exercise after orthognathic surgery on masticatory function in patients with mandibular prognathism. Materials and methods: The study subjects were 16 patients with mandibular prognathism who underwent orthognathic surgery and 8 individuals with normal occlusion. Patients were divided into two groups (training group and non-training group; n = 8 per group). Functional training included gum chewing exercise and patient-education about masticatory function. The training; gum chewing exercise of 5 min twice a day for 90 days, started at 3 months after surgery. For each subject, electromyographic activities of masseter and temporalis muscles during maximum voluntary clenching (MVC) and jaw movement during gum chewing were recorded before and after surgical orthodontic treatment. Two parameters; activity index (AI: ratio of activity of masseter and temporalis muscles) and error index (EI: ratio of the number of abnormal chewing patterns), were used. Results: In the training group, the AI value during MVC increased significantly and the EI value during gam chewing decreased significantly after surgical orthodontic treatment (AI: p

Objectives: To evaluate morphometric characteristics of alveolar bone around the incisors of high-angle skeletal class III patients receiving surgical orthodontic treatment.Setting and Sample Population: Thirty high-angle skeletal class III patients (mean age, 20.94 ± 3.25 years) underwent cone-beam computed tomography before treatment (T0), after pre-surgical orthodontic treatment (T1) and after treatment (T2).Materials and Methods: The vertical bone level (VBL), alveolar bone thickness (ABT), alveolar bone area (ABA) and position of upper and lower central incisors (UCIs and LCIs) were evaluated. The ABT included five levels (4, 6, 8 mm from the cemento-enamel junction, midroot and root apex level). One-way repeated measures ANOVA with Bonferroni's multiple-comparison test and matched t test was performed to compare variables.Results: Before treatment, the average labial ABT was approximately 1 mm in UCIs and 0.38 ~ 0.79 mm in LCIs, and the VBL of the LCIs was over 2 mm. After treatment, the VBL increased by 2.19 ± 1.96 mm (P < .001) on the lingual side of UCIs and 2.78 ± 2.29 mm and 3.09 ± 2.52 mm on the labial and lingual sides of LCIs, respectively (all P < .001). ABT at every level decreased significantly, decreasing by 1.66 ± 1.93 mm at the 8 mm level of UCIs and 1.06 ± 1.01 mm at the apex of LCIs (P < .001). The lingual ABA of UCIs and LCIs decreased by over 50% (P < .001).Conclusions: In high-angle skeletal class III patients, the condition of alveolar bone around UCIs and LCIs was extremely poor before treatment. Further alveolar bone resorption occurred during surgical orthodontic treatment. More attention should be paid to the movement of anterior teeth in cases of severe alveolar bone loss. [ABSTRACT FROM AUTHOR]

Even after surgical orthodontic treatment, the level of masticatory function in patients with jaw deformities is still lower than that of healthy subjects. The purpose of this study was to evaluate the effects of functional training program using gum chewing exercise after orthognathic surgery on masticatory function in patients with mandibular prognathism. The study subjects were 16 patients with mandibular prognathism who underwent orthognathic surgery and 8 individuals with normal occlusion. Patients were divided into two groups (training group and non-training group; n = 8 per group). Functional training included gum chewing exercise and patient-education about masticatory function. The training; gum chewing exercise of 5 min twice a day for 90 days, started at 3 months after surgery. For each subject, electromyographic activities of masseter and temporalis muscles during maximum voluntary clenching (MVC) and jaw movement during gum chewing were recorded before and after surgical orthodontic treatment. Two parameters; activity index (AI: ratio of activity of masseter and temporalis muscles) and error index (EI: ratio of the number of abnormal chewing patterns), were used. In the training group, the AI value during MVC increased significantly and the EI value during gam chewing decreased significantly after surgical orthodontic treatment (AI: p < 0.01; EI: p < 0.01), indicating the improvement of activity balance of masseter and temporalis muscles and conversion of the jaw movement from abnormal to normal pattern (p < 0.01). Our findings suggested that functional training using the gum chewing and patient-education exercise improved masticatory function in patients with mandibular prognathism. [ABSTRACT FROM AUTHOR]

Background Mandibular premolar extraction of Class III patients needing orthognathic surgery might adversely affect their final profile. Methods This case report describes the successful application of mandibular symphyseal distraction osteogenesis (MSDO) followed by combination of nonextraction orthodontic therapy and orthognathic surgery to treat an 18-year-old man with severe skeletal Class III malocclusion with severe crowding in both dentition arch and unilateral crossbite. Results The mandibular arch expanded dentally and skeletally by MSDO without periodontal problem. By orthodontic therapy, the mandibular incisors were proclinated 10° and the maxillary incisors were retroclinated 6°, resulting in correction of anteroposterior dental compensation. Skeletal Class III tendency Class I jaw relationship with improved facial profile was achieved by impacted maxilla and mandibular setback. Conclusion Our case report suggests that use of MSDO expands the possibility of the presurgical orthodontic treatment with nonextraction for skeletal Class III orthognathic surgery case with crowding in mandibular dentition. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The purpose of this study was to determine the incidence of temporomandibular joint (TMJ) signs and symptoms in patients with dentofacial deformities and to assess longitudinally the changes in TMJ signs and symptoms after surgical orthodontic treatment. Materials and methods: The subjects consisted of 170 patients with dentofacial deformities. A combination of Le Fort I osteotomy and bilateral sagittal split osteotomies was used in 112 patients, bilateral sagittal split osteotomies were performed in 58 patients. The joints were examined clinically and by computed tomography. Results: TMJ signs and symptoms were recognized in 29.5% of the patients, and disk displacements and condylar bone changes were recognized in 22.1% and 13.4% of the joints, respectively. More patients with mandibular retrusion and asymmetry had TMJ signs and symptoms, disk displacements and condylar bone changes than those with mandibular prognathism. The incidence of TMJ signs and symptoms had significantly decreased to 12.1% at one year after orthognathic surgery, and there were no significant differences in the incidences of TMJ signs and symptoms among the types of dentofacial deformity. Conclusion: Surgical orthodontic treatment has a beneficial effect on TMJ signs and symptoms in most patients with dentofacial deformities. However, there is a risk of TMJ symptoms and signs developing in preoperative asymptomatic patients after orthognathic surgery though the risk is low. [Copyright &y& Elsevier]

Abstract: When it is difficult to treat impacted teeth with orthodontic traction, surgical techniques including intentional luxation, autografts and distraction osteogenesis may be performed. However, these techniques are associated with problems such as root resorption, gingival recession and pulp circulatory disorders after extrusion. Single tooth dento-osseous osteotomy is considered to be a surgical technique with minimal effect on the pulp and periodontium. We used this method to treat a patient with impacted permanent canine teeth. After concomitant single tooth dento-osseous osteotomy and orthodontic treatment, root resorption of the bilateral canines was kept to a minimum and pulp vitality was confirmed. This method may be effective in patients in whom ordinary traction is difficult. [Copyright &y& Elsevier]

Copyright of Mondo Ortodontico is the property of Masson SPA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Preoperative and postoperative temporomandibular disorders (TMDs) were observed in 72 patients before surgical-orthodontic treatment and about 2 years after bilateral sagittal split osteotomy. Prevalence and degree of TMD were assessed using the modified clinical dysfunction index of Helkimo. A total of 49 women and 23 men (mean age 32 years) were included in the study. To find out which patients benefit most from the treatment, the sample was classified into subgroups--myogenous, arthrogenous, or both components of TMD. The prevalence of clicking and headache decreased significantly with the treatment, while the incidence of crepitation increased. In general, severity of the dysfunction was greatly reduced. Furthermore, multiple regression analysis showed that patients with excessive overjet and previous occlusal splint therapy benefit most from orthognathic treatment. In addition, patients with signs of mainly myogenous origin got more relief from their dysfunction than patients with mainly arthrogenous components of TMD. The results suggest that in patients with severe maxillomandibular discrepancy surgical-orthodontic therapy is a good choice of treatment for reducing myogenous TMD pain and discomfort. [ABSTRACT FROM AUTHOR]

This research aimed to evaluate the effects of presurgical mandibular incisor decompensation on long-term outcomes of Class III surgical orthodontic treatment. Thirty-five patients with skeletal Class III malocclusion who received conventional surgical orthodontic treatment were included. Mandibular incisor brackets with −6° of inclination were placed normally in 18 patients (NB group) and inversely in 17 patients (RB group). Between-group differences and relationships between incisal and skeletal variables were analyzed based on lateral cephalograms at pretreatment, presurgery, postsurgery, posttreatment, and retention. Mandibular incisors were more labially inclined in the RB group than in the NB group from presurgery to retention. No significant between-group differences were observed in presurgical and postsurgical skeletal relationships. The NB group exhibited a larger overjet with deficient interincisal contact at postsurgery than the RB group. Skeletal Class III relationship was also more severe in the NB group at retention. More lingually inclined mandibular incisors at presurgery and larger overjet at postsurgery were correlated with a more severe skeletal Class III relationship at retention. Thus, establishing appropriate postsurgical overjet by sufficient presurgical mandibular incisor decompensation may play a significant role in postsurgical stability of Class III surgical orthodontic treatment. [ABSTRACT FROM AUTHOR]