Tratamento cirúrgico do mixoma odontogênico sem ressecção maxilar: relato de caso / Surgical Treatment od Odontogenic Mixoma Without Maxillary Resection: Case Report / Tratamiento Quirúrgico del Mixoma Odontogénico Sin Resección Maxilar: Informe de Caso

Mixoma Odontogênico é um tumor de origem mesenquimal raro, de desenvolvimento lento e agressivo que acomete indivíduos entre os 10 e 40 anos de idade e principalmente, do gênero feminino. Este estudo teve como principal objetivo descrever um caso clinico de tratamento cirúrgico do mixoma odontogênico sem ressecção maxilar em uma paciente do gênero feminino que compareceu ao Ambulatório de Patologia Oral e Maxilo Facial, da Faculdade de Odontologia da UNIRG, na cidade de Gurupi-TO - Brasil. A paciente foi submetida ao tratamento cirúrgico conservador, através da curetagem e enucleação total do tumor. A proservação foi realizada em períodos de 12 meses, 24 meses e 48 meses aonde pode-se observar a sequencial e completam reparação óssea, inclusive a permanência dos dentes envolvidos que foram submetidos a tratamento endodôntico com total remodelação da lâmina dura e do ligamento periodontal... (AU)

Odontogenic Myxoma (OM) is a rare tumor of mesenchymal origin, of slow and aggressive development that affects individuals between 10 and 40 years of age and mainly female. This study aimed to describe a clinical case of surgical treatment of odontogenic myxoma with out maxillary resection in a female patient who attended the Outpa tient Clinic of Oral Pathology and Facial Maxillo, of UNIRG Dental School, in the city of Gurupi-TO - Brazil. The patient underwent con servative surgical treatment through curettage and total enucleation of the tumor. Proservation was carried out in periods of 12 months, 24 months and 48 months where it was possible to observe the sequential and complete bone repair including the permanence of the involved teeth that underwent endodontic treatment with total remodeling of hard blade and of the periodontal ligament... (AU)

El mixoma odontogénico es un tumor de origen mesenquimal poco frecuente, de desarrollo lento y agresivo que afecta a individuos entre 10 y 40 años de edad y principalmente mujeres. El objetivo principal de este estudio fue describir un caso clínico de tratamiento quirúrgico de mixoma odontogénico sin resección maxilar en una paciente femenina que asistió a la Clínica Ambulatoria de Patología Oral y Maxilo Facial, de la Facultad de Odontología de UNIRG, en la ciudad de Gurupi-TO - Brasil. El paciente se sometió a tratamiento quirúrgico conservador mediante legrado y enucleación tumoral total. La conservación se realizó en periodos de 12 meses, 24 meses y 48 meses donde es posible observar reparación ósea secuencial y completa, incluyendo la permanencia de los dientes implicados que fueron sometidos a tratamiento endodóntico con remodelación total de la durancia y ligamento periodontal... (AU)

Transplantation of bone marrow mesenchymal stem cells and fibrin glue into extraction socket in maxilla promoted bone regeneration in osteoporosis rat.

AIMS: Bone defect repair in osteoporosis remains a tremendous challenge for clinicians due to increased bone metabolism resulted from estrogen deficiency. This study aims to investigate the effect of bone marrow mesenchymal stem cells (BMSCs) combined with fibrin glue (FG) in the extraction socket healing process of osteoporosis rats, as well as estimate the role of estrogen receptors (ERs) played in BMSCs differentiation in vitro and in the alveolar bone reconstruction process in vivo. MAIN METHODS: Forty rats were randomly divided into four groups, under general anesthesia, three groups underwent bilateral ovariectomy(OVX) and one group with the sham operation. Three months later, the osteogenic ability of BMSCs, isolated from healthy and osteoporosis rats, respectively, was tested. The ERα and ERß mRNA expression in BMSCs was also evaluated by RT-PCR analysis. In vivo experiment, Micro-CT detection, histological and immunofluorescent analysis, tissue PCR was conducted up to 2, 4 and 6 weeks after transplantation of BMSCs/FG to assess the newly formed bone in the extraction socket. KEY FINDINGS: The BMSCs from osteoporosis rats displayed weaker osteogenic potential and lower ERs expression compared with the BMSCs from healthy rats. Newly formed bone tissue filled the socket defect in BMSCs/FG treated VOX rats after six weeks, which was comparable to the sham group, while reduced ERs expression was found in the regenerated bone of the OVX group. SIGNIFICANCE: The BMSCs seeded within FG might provide an alternative therapeutic method for repairing the extraction socket defect in osteoporosis condition.

Congenital Isolated Bilateral Soft Tissue Syngnathia In A 4-Day Old Baby Boy.

Congenital maxillomandibular syngnathia is characterized by fusion of jaws. Depending on the severity, it has a wide range of clinical presentations. It can be complete /incomplete and may be unilateral or bilateral. Primary concern in such patients is maintenance of airway and feeding difficulties. Therefore, early recognition and management is important to reduce nutritional, feeding, airway difficulties and growth-related problems in such new-borns. This case report presents a case of syngnathia in a 4-day infant with bilateral fusion of maxilla and mandible, leaving a small anterior portion. Early intervention was planned and the fusion was released to facilitate feeding. Good mouth opening was seen on 1week follow-up.

Correlation between the cephalometric measurements and acoustic properties of /s/ sound in Turkish.

Objectives To evaluate the acoustic properties of the /s/ sound in individuals with different occlusion types and to investigate relationships between these properties and cephalometric measurements. Methodology Sixty patients were divided into three groups based on malocclusion. Group 1 included 20 patients (mean age: 14.85±2.01 years) with Class I skeletal and dental relationships. Group 2 included 20 patients (mean age: 13.49±1.78 years) with Class II skeletal and dental relationships. Group 3 included 20 patients (mean age: 12.46±2.62 years) with Class III skeletal and dental relationships. Cephalometric tracings were obtained from cephalometric radiographs. All included patients were native speakers of Turkish. The /s/ sound was selected for center of gravity analysis. Correlations between cephalometric values and acoustic parameters were also investigated. Results The center of gravity of the /s/ sound had the lowest value in Group 2 (p<0.05). For the /s/ sound in Group 3, moderate positive correlations were found between center of gravity and Sella-Nasion to Gonion-Gnathion angle (p<0.05, r=0.444) Lower incisor to Nasion-B point (p<0.023, r=0.505), and Lower incisor to Nasion-B point angle (p<0.034; r=0.476). No correlation was found in other cephalometric measurements. Conclusions The /s/ sound was affected by malocclusion due to the changing place of articulation. Therefore, referral to an orthodontist for malocclusion treatment especially patients with class III in the early period is suggested for producing acoustically ideal sound.

Prediction of maxillary canine impaction based on panoramic radiographs.

OBJECTIVES: The objective of this article is to establish a large sample-based prediction model for maxillary canine impaction based on linear and angular measurements on panoramic radiographs and to validate this model. MATERIALS AND METHODS: All patients with at least two panoramic radiographs taken between the ages of 7 and 14 years with an interval of minimum 1 year and maximum 3 years (T1 and T2) were selected from the Department of Oral Health Sciences, University Hospital Leuven database. Linear and angular measurements were performed at T1. From 2361 records, 572 patients with unilateral or bilateral canine impaction were selected at T1. Of those, 306 patients were still untreated at T2 and were used as study sample. To construct the prediction model, logistic regression analysis was used. RESULTS: The parameters analyzed through backward selection procedure were canine to midline angle, canine to first premolar angle, canine cusp to midline distance, canine cusp to maxillary plane distance, sector, quadratic trends for continuous predictors, and all pairwise interactions. The final model was applied to calculate the likelihood of impaction and yielded an area under the curve equal to 0.783 (95% CI [0.742-0.823]). The cut-off point was fixed on 0.342 with a sensitivity of 0.800 and a specificity of 0.598. The cross-validated area under the curve was equal to 0.750 (95% CI [0.700, 0.799]). CONCLUSION: The prediction model based on the above mentioned parameters measured on panoramic radiographs is a valuable tool to decide between early intervention and regular follow-up of impacted canines.

Safety and Efficacy of a New Synthetic Material Based on Monetite, Silica Gel, PS-Wallastonite, and a Hydroxyapatite Calcium Deficient: A Randomized Comparative Clinic Trial.

Background and Objectives: Maxillary bone defects related to post-extraction alveolar ridge resorption are usual. These defects may lead to failure in further surgical implant phases given the lack of bone volume to perform the dental implant. The objective of this clinical assay was to evaluate the safety and efficacy of an experimental synthetic bone substitute in the preservation of post-extraction maxillary alveoli. Materials and Methods: 33 voluntary patients who had at least one maxillary premolar tooth that was a candidate for exodontia (n = 39) and subsequent implant rehabilitation participated. The regenerated alveoli were monitored by means of periodic clinical examinations (days 9 ± 1, 21 ± 4, 42 ± 6, and 84 ± 6), measuring the height and width of the alveolar crest (days 0 and 180 ± 5), measurement of radiodensity using tomographic techniques (days 0-5 and 175 ± 5), and histological examination of biopsies collected at 180 ± 5 days. Results: No significant differences were observed during the entire follow-up period between the two groups with respect to the safety variables studied. A variation in width of -0.9 ± 1.3 mm and -0.6 ± 1.5 mm, and a variation in height of -0.1 ± 0.9 mm and -0.3 ± 0.7 mm was observed for experimental material Sil-Oss® and Bio-Oss®, respectively. The radiodensity of the alveoli regenerated with the experimental material was significantly lower than that corresponding to Bio-Oss®. However, the histological study showed greater osteoid matrix and replacement of the material with newformed bone in the implanted beds with the experimental material. Conclusions: Both materials can be used safely and proved equally effective in maintaining alveolar flange dimensions, they are also histologically biocompatible, bioactive and osteoconductive. The experimental material showed the advantage of being resorbable and replaced with newformed bone, in addition to promoting bone regeneration.

Changes of the upper airway and bone in microimplant-assisted rapid palatal expansion: A cone-beam computed tomography (CBCT) study.

OBJECTIVE: To evaluate the changes of maxillary expansion and upper airway structure after microimplant assisted rapid palatal expansion (MARPE) using cone-beam computed tomography (CBCT). METHODS: This retrospective study included 19 subjects (15 females and 4 males) aged 15-29 years old (mean, 19.95±4.39 years) with maxillary transverse deficiency treated with MARPE. CBCT was performed at the initial diagnosis and 3 months after MARPE treatment. Measurements were taken to evaluate the amount of total expansion, skeletal expansion, and dental expansion at the maxillary first premolar (P1), second premolar (P2), first molar (M1), second molar (M2) regions and upper airway changes. RESULTS: After MARPE treatment, the maxillary skeletal base expansion, skeletal expansion, alveolar expansion and dental expansion were achieved at the P1, P2, M1, M2 region. The nasopharyngeal volume significantly increased 8.48% after MARPE treatment compared with that before the treatment (P < 0.05). The change of nasal lateral width (NLW) was also significantly different before and after MARPE (P < 0.05). However, there were no statistically significant change in the oropharyngeal, palatopharyngeal, glossopharyngeal and airway total volume (all P > 0.05). CONCLUSIONS: MARPE can produce more transverse bone expansion, relieve maxillary transverse deficiency and improve upper airway ventilation.

Efficiency evaluation of rapid maxillary expansion treatment on nasal septal deviation using tortuosity ratio from cone-beam computer tomography images.

BACKGROUND AND OBJECTIVE: This study aims to assess the effect of Rapid Maxillary Expansion (RME) on Nasal Septal Deviation (NSD) changes from three-dimensional (3D) images. METHODS: In this study, cone-beam computed tomography (CBCT) images from 15 patients with maxillary constriction (mean age 12 ± 1.6 years) were included. RME treatment with Hyrax appliance was performed in all patients. CBCT scans were taken at three different times; before appliance insertion (T0), after active expansion (T1) and 3 months after appliance insertion (T2). We developed a novel Matlab-based application to quantify NSD based on the tortuosity ratio by dividing the actual length of the septum by the ideal length in the mid-sagittal plane by using this application. RESULTS: Tortuosity ratio (TR) values were found as 1.03 ± 0.03 (T0), 1.02 ± 0.02 (T1), and 1.02 ± 0.02 (T2). Differences of TR values among these groups were evaluated using the statistical method of ANOVA (ANalysis Of VAriance) for repeated measures with the significance level of p ≤ .05. Results showed significant reductions in TR values between T0-T1 (p ≤ .05) and between T0-T2 (p ≤ .05). Nonetheless, a significant difference between T1-T2 was not determined (p > .05). CONCLUSIONS: As a result, we can conclude that the NSD degree is affected by the RME treatment. The developed application can be used for both educational and research purposes.

Correlation between the cephalometric measurements and acoustic properties of /s/ sound in Turkish

Abstract Objectives To evaluate the acoustic properties of the /s/ sound in individuals with different occlusion types and to investigate relationships between these properties and cephalometric measurements. Methodology Sixty patients were divided into three groups based on malocclusion. Group 1 included 20 patients (mean age: 14.85±2.01 years) with Class I skeletal and dental relationships. Group 2 included 20 patients (mean age: 13.49±1.78 years) with Class II skeletal and dental relationships. Group 3 included 20 patients (mean age: 12.46±2.62 years) with Class III skeletal and dental relationships. Cephalometric tracings were obtained from cephalometric radiographs. All included patients were native speakers of Turkish. The /s/ sound was selected for center of gravity analysis. Correlations between cephalometric values and acoustic parameters were also investigated. Results The center of gravity of the /s/ sound had the lowest value in Group 2 (p<0.05). For the /s/ sound in Group 3, moderate positive correlations were found between center of gravity and Sella-Nasion to Gonion-Gnathion angle (p<0.05, r=0.444) Lower incisor to Nasion-B point (p<0.023, r=0.505), and Lower incisor to Nasion-B point angle (p<0.034; r=0.476). No correlation was found in other cephalometric measurements. Conclusions The /s/ sound was affected by malocclusion due to the changing place of articulation. Therefore, referral to an orthodontist for malocclusion treatment especially patients with class III in the early period is suggested for producing acoustically ideal sound.

Evaluation of Implant Success in Patients with Dental Aplasia.

INTRODUCTION: Dental aplasia is an anomaly in which the number of teeth is reduced. It is the most commonly occurring dental anomaly during tooth development. Treatment management of patients with dental aplasia is challenging. OBJECTIVES: The aim of this retrospective clinical study was to analyze the survival and success rates of dental implants placed in hypodontic patients, rated with different criteria. METHODS: Forty-three patients were diagnosed with dental aplasia and treated with dental implants between November 2000 and February 2016. The variables assessed included the plaque level, bleeding on probing, probing depth, implant mobility, implant stability, and implant loss. To analyze the peri-implant bone level, a panoramic X-ray of each patient was taken. The results were compared with X-rays taken immediately after implantation. RESULTS: Thirty-seven patients (16 males; 21 females) participated in this study. In total, 155 implants (86 maxillary; 69 mandibular) were inserted. Two of the 155 implants failed; the in situ survival rate was 98.7%. The success rate according to the criteria of Buser et al. was 96.8%, and that according to the criteria of Albrektsson et al. was 88.4%. CONCLUSION: The survival and success rates of dental implants in patients with congenitally absent teeth were very high and did not differ significantly from results achieved in an unaffected population. Dental implants are a reliable therapy for patients with dental aplasia.

Temporomandibular joint function 10-15 years after mandibular setback surgery and six weeks of intermaxillary fixation.

INTRODUCTION: Intermaxillary fixation (IMF) is a classic method for immobilization of the mandible after mandibular fractures and corrective surgery. However, it has been suggested that IMF may be a risk for developing temporomandibular joint (TMJ)-related symptoms, especially when applied for longer periods. OBJECTIVE: To evaluate the clinical function of TMJs and masticatory muscles 10-15 years after mandibular setback surgery and subsequent six weeks of IMF. The patients' self-reported TMJ and masticatory muscle symptoms were also addressed. METHODOLOGY: Thirty-six patients (24 women and 12 men) treated with intraoral vertical ramus osteotomies and subsequent six weeks of IMF, underwent a clinical examination of TMJs and masticatory muscles 10-15 years after surgery and completed a five-item structured questionnaire reporting subjective TMJ-related symptoms. Mean age by the time of clinical examination was 34.1 years (range 27.2-59.8 years). The clinical outcome was registered according to the Helkimo clinical dysfunction index. Descriptive and bivariate statistics were performed and level of significance was set to 5%. RESULTS: Mean maximum unassisted mouth opening 10-15 years after surgery was 50.1 mm, (range 38-70 mm, SE 1.2), statistically significantly greater in men compared to women (p=0.004). Mean Helkimo dysfunction group was 1.5 (range 1-3, SE 0.10). Eighty-one percent experienced pain on palpation in either the masseter muscle, temporal muscle or both, and 31% experienced pain when moving the mandible in one or more directions. Thirty-one percent reported pain from palpating the TMJs. In the questionnaire, none reported to have pain during chewing or mouth opening on a weekly or daily basis, but 22% reported difficulties with maximum opening of the mouth. CONCLUSION: Ten to fifteen years after mandibular setback surgery the patient's mandibular range of movement is good. Despite clinically recognizable symptoms, few patients reported having TMJ- or masticatory muscle-related symptoms in their daily life.

Functional stability analyses of maxillofacial skeleton bearing cleft deformities.

The symmetrically stable craniofacial bony structure supports the complex functions and delicate contour of the face. Congenital craniofacial deformities are often accompanied by bony defects and have been repetitively correlated with compromised dento-maxillary stability, but neither the extent nor the pattern of cleft-related maxillary instability has been explored in detail. Furthermore, it is largely unknown if the bony defect and related instability are correlated with secondary maxillary deformity common among patients with orofacial clefts. With the aid of finite element modeling, we studied the detailed relationship between cleft-related bony defect and maxillary stability under occlusal loading. Craniofacial models were generated based on cone-beam computed tomography data and loaded with mimicked bite forces along the axial axis of each tooth. Our data showed that all cleft models exhibited more asymmetrical deformations under mastication compared with the normal. Models with palatal cleft demonstrated greater asymmetry, greater dental arch contraction, and less maxillary protrusion compared to models with alveolar cleft only. For unilateral cleft models, alveolus on non-cleft side tended to be more protruded and lifted than the cleft side. For bilateral cleft models, the most prominent feature was the seriously contracted alveolar arch and curved and pitched premaxillae. These findings indicated cleft type-specific pattern of maxillary instability, which were largely in accordance with dentoalveolar morphological features among patients. Collectively, our study elucidated the detailed relationship between cleft bony defect and the pattern of maxillary instability, and suggested a prototype for studying the abnormal maxillary and dental arch growth among patients with craniofacial deformities.

Periapical Microsurgery: A 4-dimensional Analysis of Healing Patterns.

INTRODUCTION: Currently, the success of periapical microsurgery is determined by the restoration of the lamina dura and the elimination of symptoms. However, inadequate site preservation may prevent later implant placement. Although not possible before, the advent of cone-beam computed tomographic imaging and computer-aided registration allows for indirect and accurate 3-dimensional analysis of the surgical site over time. This study analyzed the volumetric healing pattern of the buccal plate after periapical microsurgery, with a specific focus on the buccolingual thickness of bone and the regression of the surface contour of the cortical plate. METHODS: Thirty-seven patients were scheduled for follow-up at least 1 year after periapical microsurgery (median = 25 months, total range = 12-31 months). Volumetric healing was analyzed by converting preoperative and postoperative cone-beam computed tomographic images into digital 3-dimensional models. The models were then registered to be able to analyze the changes in volume over time. Analysis was completed using Geomagic software (3D Systems, Rock Hill, SC), which allowed for registration of the volumes, calculation of volume change, and calculation of the margin of error. RESULTS: Twelve cases qualified for volumetric analysis. The median volumetric reduction of the cortical plate was -24.9 mm3 (interquartile range = -8.94 to -67 mm3), with an average linear error of 0.7 mm. This corresponded to an average loss in buccolingual dimension of 0.1-0.25 mm. Regression of the cortical plate was within the margin of error in all cases. CONCLUSIONS: After periapical microsurgery, and in the absence of grafting materials or membranes, healing occurs with little to no regression of the buccal cortical plate.

Temporomandibular joint function 10-15 years after mandibular setback surgery and six weeks of intermaxillary fixation

Abstract Intermaxillary fixation (IMF) is a classic method for immobilization of the mandible after mandibular fractures and corrective surgery. However, it has been suggested that IMF may be a risk for developing temporomandibular joint (TMJ)-related symptoms, especially when applied for longer periods. Objective: To evaluate the clinical function of TMJs and masticatory muscles 10-15 years after mandibular setback surgery and subsequent six weeks of IMF. The patients' self-reported TMJ and masticatory muscle symptoms were also addressed. Methodology: Thirty-six patients (24 women and 12 men) treated with intraoral vertical ramus osteotomies and subsequent six weeks of IMF, underwent a clinical examination of TMJs and masticatory muscles 10-15 years after surgery and completed a five-item structured questionnaire reporting subjective TMJ-related symptoms. Mean age by the time of clinical examination was 34.1 years (range 27.2-59.8 years). The clinical outcome was registered according to the Helkimo clinical dysfunction index. Descriptive and bivariate statistics were performed and level of significance was set to 5%. Results: Mean maximum unassisted mouth opening 10-15 years after surgery was 50.1 mm, (range 38-70 mm, SE 1.2), statistically significantly greater in men compared to women (p=0.004). Mean Helkimo dysfunction group was 1.5 (range 1-3, SE 0.10). Eighty-one percent experienced pain on palpation in either the masseter muscle, temporal muscle or both, and 31% experienced pain when moving the mandible in one or more directions. Thirty-one percent reported pain from palpating the TMJs. In the questionnaire, none reported to have pain during chewing or mouth opening on a weekly or daily basis, but 22% reported difficulties with maximum opening of the mouth. Conclusion: Ten to fifteen years after mandibular setback surgery the patient's mandibular range of movement is good. Despite clinically recognizable symptoms, few patients reported having TMJ- or masticatory muscle-related symptoms in their daily life.

Efficacy of Alveolar Ridge Preservation after Maxillary Molar Extraction in Reducing Crestal Bone Resorption and Sinus Pneumatization: A Multicenter Prospective Case-Control Study.

AIM: To evaluate, with three-dimensional analysis, the effectiveness of alveolar ridge preservation (ARP) after maxillary molar extraction in reducing alveolar bone resorption and maxillary sinus pneumatization when compared to unassisted socket healing. METHODS: Patients were included in the study following inclusion criteria and underwent minimally traumatic maxillary molar extraction followed by ARP using synthetic nanohydroxyapatite (Fisiograft Bone, Ghimas, Italy) (test group) or unassisted socket healing (control group). Cone-beam computerized tomographies (CBCT) were performed immediately after tooth extraction (T0) and 6 months postoperatively (T1). CBCTs were superimposed by using a specific software (Amira, Thermo Fisher Scientific, USA) and the following items were analyzed in both groups: (i) postextractive maxillary sinus floor expansion in coronal direction and (ii) postextractive alveolar bone dimensional changes (both vertical and horizontal). All data were tested for normality and equality of variance and subsequently analyzed by independent samples T-test and Mann-Whitney test. RESULTS: Thirty patients were treated by three centers and twenty-six (test n=13; control n=13) were included in the final analysis. Mean sinus pneumatization at T1 was 0.69±0.48 mm in the test group and 1.04±0.67 mm in the control group (p=0.15). Mean vertical reduction of the alveolar bone at T1 was 1.62±0.49 mm in the test group and 2.01±0.84 mm in the control group (p=0.08). Mean horizontal resorption of crestal bone at T1 was 2.73±1.68 mm in test group and 3.63±2.24 mm in control group (p=0.24). CONCLUSIONS: It could be suggested that ARP performed after maxillary molar extraction may reduce the entity of sinus pneumatization and alveolar bone resorption, compared to unassisted socket healing. This technique could decrease the necessity of advanced regenerative procedures prior to dental implant placement in posterior maxilla.

Evaluation of Long-term Stability of Vertical Control in Hyperdivergent Patients Treated with Temporary Anchorage Devices.

This study aims to evaluate the long-term stability of vertical control in hyperdivergent patients treated with temporary anchorage devices. The sample included 20 hyperdivergent patients without anterior open bite. The temporary anchorage devices were used to intrude the upper incisor and molars for vertical control. Lateral cephalograms were established prior to treatment, immediately after treatment, and during retention. The upper molars and incisors were intruded by 1.33 mm and 1.41 mm after treatment (P<0.05). U6-PP increased by 0.11 mm and 0.23 mm during the first and second stages of retention (P>0.05). U1-PP was found to possess a significant extrusion of 1.2 mm during the first stage (P<0.05), which increased by 0.68 mm during the second stage (P>0.05). The mandibular plane angle (MP-SN) decreased by 2.58 degrees following treatment, and underwent a relapse of 0.51 degree and 0.42 degree during the first and second stages of retention respectively (P>0.05). No significant soft tissue changes occurred, with the exception of increased upper lip length during the second stage (P<0.05). Maxillary anterior and posterior intrusions, counter clockwise rotation of the mandibular plane, and improved profiles can be successfully achieved following treatment with vertical control. During the first stage of retention (less than three years), intruded molars and incisors both exhibited some extrusion, and molars had better long-term stability than incisors. During the second stage of retention (three to six years), the therapeutic effects appeared stable, with the exception of some increase in upper lip length. Rotated mandibular plane remained stable during the entire retention period.

Clinical evaluation of modified transalveolar sinus floor elevation and osteotome sinus floor elevation in posterior maxillae: study protocol for a randomized controlled trial.

BACKGROUND: Implant placement in the posterior maxilla is often complicated by the insufficient bone volume. While transalveolar sinus floor elevation (TSFE) has been proven as a predictable surgical procedure to increase the bone height in the posterior maxilla, questions in regard to the necessity of the bone grafting during the sinus lift and the question of whether TSFE could be performed when the residual bone height is below 5 mm are still debated. Furthermore, high-quality evidence comparing the clinical outcome of transalveolar sinus floor elevation with osteotome and modified sinus floor elevation with crestal non-cutting drills is limited. METHODS/DESIGN: One hundred twenty adult patients who fit the inclusion criteria are being recruited from the Peking University Hospital of Stomatology First Clinical Division (Beijing, China). All patients are assigned to one of four groups according to a table of random numbers. Participants will receive (1) TSFE using osteotomes with bone grafting, (2) TSFE using osteotomes without bone grafting, (3) modified TSFE with bone grafting, or (4) modified TSFE without bone grafting. In a one-year follow-up period, implant survival rates, complications, implant stability, bone remodeling around the implant, and patient-reported outcome (visual analog scale for intraoperative discomfort and postoperative pain) will be observed and documented. The implant stability will be gauged by the resonance frequency analysis six times (at baseline and weeks 6, 8, 12, 16, and 26), and the bone remodeling will be observed and compared via radiographic examinations. DISCUSSION: The result of the trial will potentially contribute to better decision making in atrophic posterior maxilla when implant placement is needed. Therefore, if the outcome is deemed favorable, the use of the modified TSFE would achieve an outcome equivalent to that of the traditional TSFE while introducing less trauma and postoperative discomforts. Separately, whether the bone graft procedure is necessary for the TSFE will also be discussed. TRIAL REGISTRATION: The study has been registered in ClinicalTrials.gov under the identifier number NCT03445039 . Registered on 26 February 2018.

A novel soft tissue prediction methodology for orthognathic surgery based on probabilistic finite element modelling.

Repositioning of the maxilla in orthognathic surgery is carried out for functional and aesthetic purposes. Pre-surgical planning tools can predict 3D facial appearance by computing the response of the soft tissue to the changes to the underlying skeleton. The clinical use of commercial prediction software remains controversial, likely due to the deterministic nature of these computational predictions. A novel probabilistic finite element model (FEM) for the prediction of postoperative facial soft tissues is proposed in this paper. A probabilistic FEM was developed and validated on a cohort of eight patients who underwent maxillary repositioning and had pre- and postoperative cone beam computed tomography (CBCT) scans taken. Firstly, a variables correlation assessed various modelling parameters. Secondly, a design of experiments (DOE) provided a range of potential outcomes based on uniformly distributed input parameters, followed by an optimisation. Lastly, the second DOE iteration provided optimised predictions with a probability range. A range of 3D predictions was obtained using the probabilistic FEM and validated using reconstructed soft tissue surfaces from the postoperative CBCT data. The predictions in the nose and upper lip areas accurately include the true postoperative position, whereas the prediction under-estimates the position of the cheeks and lower lip. A probabilistic FEM has been developed and validated for the prediction of the facial appearance following orthognathic surgery. This method shows how inaccuracies in the modelling and uncertainties in executing surgical planning influence the soft tissue prediction and it provides a range of predictions including a minimum and maximum, which may be helpful for patients in understanding the impact of surgery on the face.

Novel Method for Superposing 3D Digital Models for Monitoring Orthodontic Tooth Movement.

Quantitative three-dimensional analysis of orthodontic tooth movement (OTM) is possible by superposition of digital jaw models made at different times during treatment. Conventional methods rely on surface alignment at palatal soft-tissue areas, which is applicable to the maxilla only. We introduce two novel numerical methods applicable to both maxilla and mandible. The OTM from the initial phase of multi-bracket appliance treatment of ten pairs of maxillary models were evaluated and compared with four conventional methods. The median range of deviation of OTM for three users was 13-72% smaller for the novel methods than for the conventional methods, indicating greater inter-observer agreement. Total tooth translation and rotation were significantly different (ANOVA, p < 0.01) for OTM determined by use of the two numerical and four conventional methods. Directional decomposition of OTM from the novel methods showed clinically acceptable agreement with reference results except for vertical translations (deviations of medians greater than 0.6 mm). The difference in vertical translational OTM can be explained by maxillary vertical growth during the observation period, which is additionally recorded by conventional methods. The novel approaches are, thus, particularly suitable for evaluation of pure treatment effects, because growth-related changes are ignored.

Model Analysis of Digital Models in Moderate to Severe Crowding: In Vivo Validation and Clinical Application.

OBJECTIVE: We investigated the suitability of intraoral-scan models for measuring tooth dimensions and the amount of crowding in patients with severe tooth crowding. MATERIALS AND METHODS: Fifty-eight patients who had undergone intraoral scans for diagnosis were included. Cast models were divided into two groups depending on the amount of crowding, as determined by initial caliper-based measurements (mild crowding [MC] group: <3.0 mm; severe crowding [SC] group: >4.5 mm). Twenty maxillary models and 20 mandibular models were used in this study. For the three types of models (i.e., IS digital model, C cast model, and CS digital model), the reproducibility and the precision of linear measurements were evaluated. RESULTS: We found that linear measurements made using digital calipers on a plaster model and on the relevant software were reproducible. There was no significant difference in most linear measurements between digital models and the C model. There were differences in the amount of crowding (p < .05), although these were not clinically significant. There was no relationship between the precision of crowding in the three types of models and the severity of crowding. CONCLUSIONS: Digital models can be used for measuring crowding in both mild and severe crowding cases. However, crowding measured by digital models tends to be lesser than that measured by cast models, and this should be considered during clinical application.