Role of Whey Protein in the Treatment Outcome of Maxillofacial Trauma Patients: An Interventional Study.

Introduction: Maxillofacial fracture severely affects the diet of the patients leading to reduction of body weight. Facial trauma affects the muscles of mastication and the bones of face leading to reduction in bite force. The purpose of our study was to investigate the effect of whey protein supplement in the postoperative period of maxillofacial trauma patients with respect to body weight, bite force and callus formation. Methodology: Patients were divided into control group and study group having 20 patients each. The control group received usual modified diet for maxillofacial fracture and study group received same diet along with whey protein for 6 weeks. Results: There was mean weight loss of 3.15 kg in control group whereas there was no weight loss of in the study group. There was statistically significant increase in bite force in the study group compared to the control group with p value < 0.05. Early callus formation was seen in study group compared to control group. Conclusion: Our results showed that patients who were supplemented with whey protein had no loss of body weight, better masticatory efficiency, better healing of the fracture sites and overall early recovery.

Obturator prostheses with intramucosal retention system in patients with maxillectomy.

PURPOSE: To evaluate the intramucosal retention system in patients' masticatory efficiency and quality of life in this case series. MATERIAL AND METHODS: A total of 3 individuals with maxillectomy were included for rehabilitation with a complete obturator prostheses with an intramucosal retention system (OPI). The complete obturator prostheses was made for 60 days, and electromyography assessments and bite force were applied before, after 30, 60, and 90 days of surgery and prostheses installation. The University of Washington Quality of Life Questionnaire (UW-QoL) and the Obturator Functional Scale (OFS) were also administered at baseline and in the same follow-up periods. The electromyography was evaluated on both sides of the masseter, temporalis, and buccinator muscles while chewing hard and soft food. The maximum bite force was recorded in the central incisors and both sides of the first molar region. RESULTS: Bite force values increased in the first molar region, and muscular electrical activity remained constant. Items related to the taste and swallowing of the UW-QOL impacted. Most OFS questionnaire data responses indicated that patients improved in swallowing liquid foods and appearance. CONCLUSIONS: The rehabilitative capacity improves masticatory efficiency and QoL in adults maxilectomized and rehabilitated with OPI analysis in the study. Further clinical studies should be encouraged to determine the effectiveness of this retentive system.

Gonial angle and late implant loss: A retrospective clinical study.

PURPOSE: Occlusal overload can cause late implant loss. However, whether the magnitude of the occlusal force is a risk factor for late implant loss remains unclear. Thus, this clinical study aimed to determine the relationship between the gonial angle (GoA), which is associated with the magnitude of occlusal force, and late implant loss. METHODS: All implants with fixed prostheses placed at the Niigata University Hospital between April 2006 and August 2019 were included in this retrospective study. The implants with and without late loss were compared. Relevant variables, including smoking habits, diabetes mellitus status, remaining dentition, implant length and diameter, prosthesis design, retention systems, splinting, and GoA were assessed. Log-rank test and Cox proportional hazards regression analysis were used to estimate the adjusted hazard ratio (aHR) and to calculate the corresponding 95% confidence intervals (CI) for late implant loss. RESULTS: A total of 919 patients (349 men and 570 women) with 2512 implants were included in this study. Cox proportional hazards regression analysis revealed that a 10° decrease in the GoA (aHR, 1.588; 95% CI, 1.115-1.766; P = 0.010), smoking habits (aHR, 3.909; 95% CI, 2.131-7.168; P < 0.001), and male sex (aHR, 2.584; 95% CI, 1.376-4.850; P = 0.003) were significantly associated with late implant loss. CONCLUSIONS: Within the limitations of this retrospective study of 2512 implants, smaller GoA, smoking habits, and male sex were risk factors for late implant loss.

The comparison between various methods of mandibular reconstruction based on finite element analysis.

The Mandible can be damaged by pathological factors, tumors, trauma, infection, and needs a surgical operation for reconstruction and restoring function. There are different methods for the reconstruction of mandible. Based on the surgical approach, primary reconstruction of mandible by reconstruction plate after resection is necessary for maintaining mandibular symmetric and esthetic of the lower third of the face. A finite element model of mandible and masticatory muscles was produced from a normal person (male with 35-year-old). The normal model was resected from the left sixth tooth to the second tooth. The pathological model was reconstructed in different conditions by macro plate. Different conditions were analyzed and compared based on bite force on right fifth tooth, stress developed on screws and macro plate. The finite element analysis results showed that maximum bite force and lower stress on screws were seen in the pathological model (condition 5) when one macro plate and six screws were inserted in the mid-body. The findings showed that the use of two macro plates causes lower stress on it than when we use one. Use of one macro plate and six screws is the best choice in mandibular immobilization which decrease the stress applied on bone and increase the bite force. Because of less stress developed on macro plates and screws, use of two macro plates or one macro plate in mid-body area are also preferred.

Minimal clinically important difference in maxillofacial trauma patients: a prospective cohort study.

The present study estimated the minimal clinically important difference (MCID) for pain on a visual analogue scale - numerical rating scale (VAS-NRS) and mean bite force (MBF) in patients treated for maxillofacial trauma (MFT). This cohort study included 120 MFT patients treated according to AO principles. Preoperative and four-week postoperative pain on the VAS-NRS, and MBF were measured to calculate MCIDs as indicators of functional rehabilitation. The patient's perspective of the treatment was assessed using a four-item anchor question. The MCID was determined by two anchor-based approaches, namely, the change difference (CD) method and receiver operating characteristic (ROC) curve method. According to the CD method, the MCID for pain was 2.4 and the MBF was 147.9 N. Based on the ROC curve, the MCID for pain was 2.5 (sensitivity 91.7%, specificity 47.2%) and MBF was 159.1 N (sensitivity 71.4%, specificity 61.1%). This study demonstrated a high sensitivity (>70%) for MCID, which implies that pain reduction of 2.4-2.5 points on the VAS-NRS and a gain in MBF of 147.9-159.1N are clinically relevant for patients treated for MFT.

Changes in occlusion after orthognathic surgery: a systematic review and meta-analysis.

PURPOSE: This study aims to systematically review and identify the changes of occlusion in patients after orthognathic surgery. METHODS: The protocol was developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) and was registered to the International Prospective Register of Systematic Reviews (PROSPERO) under the registration number CRD42021253129. Studies included were Original articles only, Additionally, studies were included if the outcome of occlusal force was measured pre- and postoperatively and if occlusal forces resulted from a long follow-up of a minimum of 1 year following orthognathic surgery using adequate measurement tools. Non-English articles, case reports, case series, and non-original articles, including systematic reviews and literature reviews, were excluded. RESULTS: The search strategy yielded a total of 978 articles. Of the 978 articles, 285 were duplicates. After reading the titles and abstracts, 649 articles were excluded, and full-text articles of the remaining 47 studies were reviewed independently by two authors for eligibility wherein 33 articles were excluded, because they did not meet the inclusion criteria. Finally, a total of 14 studies were processed for critical review. CONCLUSION: The occlusal force increased after orthognathic surgery, although not to the level of the control group; however, the maximal bite force remained unchanged. Immediately after orthognathic surgery, chewing and swallowing forces increased. Significant reductions in the postoperative occlusal contact pressure areas was also observed.

Relationship between bite force, occlusal contact area, and three-dimensional facial soft tissue in dentofacial deformities

ABSTRACT Purpose This study aimed to investigate three-dimensional facial soft tissue dimensions, maximum bite force (MBF), and occlusal contact area in patients with DFD. In addition, we analyzed the relationship between MBF and the three-dimensional facial measurements. Methods Thirty-two patients with skeletal Class III DFD and 20 patients with Class II DFD underwent a soft tissue evaluation using surface laser scanning, as well as MBF and occlusal contact area assessments. The DFD groups were compared with each other and with 25 healthy subjects. Results Significant morphological differences were found in the transversal, vertical, and anteroposterior dimensions between Class II DFD and Class III DFD. Both DFD groups presented an increased linear distance of chin height, which was strongly related with decreased MBF magnitude. The DFD groups exhibited lower MBF and occlusal contact area, with no significant differences between Class II and Class III DFD. Conclusion The presence of DFD affected 3D measurements of facial soft tissue, causing variations beyond normal limits, lower MBF, and occlusal contact area in both Class II and Class III DFD patients. The vertical dimension might have influenced the lower MBF magnitude in the studied skeletal deformities.

Safety and Efficacy of Resveratrol in Healing of Maxillofacial Fractures: A Randomized Controlled Study.

Objectives: To assess the efficacy of resveratrol in improving functional outcomes following open reduction and internal fixation of maxillofacial fractures. Study Design: A single-center, randomized, parallel group, prospective, double-blind clinical trial was conducted on 40 patients between the age 20 and 60 years, requiring open reduction and internal fixation of maxillofacial fractures. The selected patients were randomly divided into two groups, Group 1 (placebo) and Group 2 (resveratrol) where tablets resveratrol 500 mg were given twice daily for 1 month following open reduction and internal fixation of fractured segments. Bite force was calculated pre-operatively and on the 1st, 4th, 8th and 12th week postoperatively. Serum markers osteocalcin and alkaline phosphate were calculated pre-operatively and at 4th and 12th week postoperatively. Results: Bite force (690.55 ± 262.00) in the resveratrol group was higher than the placebo group (553.27 ± 300.08) at 12th week postoperatively. However, the difference was non-significant statistically (p = 0.132). Resveratrol group (116.80 ± 55.25) showed better maintenance of serum ALP level as compared to placebo group (107.90 ± 42.99) at 12th week postoperatively, but again it lacked statistical significance (p = 0.573). Resveratrol group after initial reduction at 4th week showed serum osteocalcin levels nearly equal to the preoperative values at 12th week, while the placebo group showed a decline both at 4th and 12th week postoperatively. However, these results were not statistically significant (p = 0.065). Conclusion: There was no statistically significant difference in bite force, serum ALP level and serum osteocalcin levels between placebo group and resveratrol group. Though not statistically significant but early increased level of serum osteogenic markers, better restoration of bite force in group 2 (tab. Resveratrol) indicates toward its possible optimistic role in maxillofacial fracture healing. More studies with larger sample sizes are needed in order to confirm the efficacy of this drug in maxillofacial fracture.

Comparative Evaluation of Masticatory Bite Force in Mandible Fractures Treated with Three-Dimensional Curved Locking Strut Plate Versus Straight Locking Miniplate.

Aims and Objectives: To compare the efficacy of titanium 2.0-mm curved locking strut plate and 2.0-mm straight locking miniplate with regard to their intraoperative use and the stability of fixation achieved both, clinically and radiographically. Materials and Methods: Forty patients with 62 sites of mandibular fractures requiring open reduction and internal fixation were included in the study. The sample was divided into two groups of twenty patients each depending upon whether patient received three-dimensional 2.0-mm locking curved strut plate (group A) or 2.0-mm straight locking miniplates (group B). Mouth opening, teeth in the fracture line, degree of displacement, time taken, neurosensory and bite force evaluation were done preoperatively, 1st, 7th day, 2nd week, 4th week, 6th week and 12th week postoperatively. Results: Positive correlation was found between preoperative and postoperative bite force values at subsequent follow-up weeks. At 3rd month evaluation, the change in bite force from the previous follow-up visit was significantly greater in group A (locking strut plate) than group B (locking miniplate) in the incisor, left molar and right molar region. Statistically significant difference was observed between the two groups regarding time taken (P < 0.016) depicting less time taken for placement of three-dimensional 2.0-mm locking curved strut plate(group A) 20.30 ± 4.85 min as compared to 27.30 ± 6.82 min for fixation with 2.0 mm straight locking miniplates in group B. Conclusion: The findings were suggestive that the both systems had better adaptation during fixation, comparable radiographic reduction and increased stability in postoperative period. However, 3D locking strut plate took relatively lesser operative time, offered good rigidity and better stabilization of fractured segments in three dimensions along with significant improvement in the masticatory bite force postoperatively.

Effect of Dry Needling on Morphofunctional Capacity of Masticatory Muscles, and Bite Force in Patients with Temporomandibular Disorders of Muscular Origin / Efeito do Agulhamento a Seco na Capacidade Morfofuncional dos Músculos Mastigatórios e na Força de Mordida em Pacientes com Disfunções Temporomandibulares de Origem Muscular

The presence of myofascial trigger points in the masticatory muscles can lead to pain and may be related to temporomandibular dysfunction. The dry needling technique (DN) is employed for mechanical disruption and deactivation of trigger points in skeletal muscles. The purpose of this observational longitudinal clinical study was to determine the morphofunctional capacity of the masseter and temporalis muscles, and bite force in patients with temporomandibular disorders of muscular origin after DN of the masseter muscle. Twenty-one patients with the presence of trigger points in the masseter muscle were selected. Electromyographic activity of the masseter and temporalis muscles was assessed during the mandibular tasks of rest, protrusion, right and left laterality, and maximal voluntary contraction (MVC). Muscle thickness at rest and dental clenching at MVC was measured with ultrasound. Molar bite force (right and left) was analyzed with a digital dynamometer. Patients were evaluated before and seven days after intervention with DN. Data were subject to the paired t test for dependent samples (p<0.05). There was significant difference in the left masseter muscle in right laterality (p=0.01), right temporalis muscle thickness in MVC (p=0.05), and right (p=0.01) and left (p=0.008) molar bite force, after DN. The authors suggest that DN was efficient in the positive changes in the morphofunctional performance of the stomatognathic system. (AU)

A presença de pontos gatilhos miofasciais nos músculos mastigatórios pode gerar dor e estar relacionada à disfunção temporomandibular. A técnica de agulhamento a seco (AS) é utilizada para rompimento mecânico e desativação do ponto gatilho nos músculos esqueléticos. O objetivo deste estudo clínico longitudinal observacional foi determinar a capacidade morfofuncional dos músculos masseter e temporal, bem como a força de mordida, em pacientes com distúrbios temporomandibulares de origem muscular após AS no músculo masseter. Foram selecionados vinte e um pacientes com presença de pontos de gatilho no músculo masseter. A atividade eletromiográfica dos músculos masseter e temporal foi avaliada durante tarefas mandibulares de repouso, protrusão, lateralidade direita e esquerda, e contração voluntária máxima (CVM). A espessura muscular em repouso e a contração dental na CVM foram medidas por ultrassom. A força de mordida molar (direita e esquerda) foi analisada com um dinamômetro digital. Os pacientes foram avaliados antes e sete dias após a intervenção com DN. Os dados foram submetidos ao teste t pareado para amostras dependentes (p<0,05). Houve diferença significante no músculo masseter esquerdo na lateralidade direita (p=0,01), espessura do músculo temporal direito na CVM (p=0,05) e força de mordida molar direita (p=0,01) e esquerda (p=0,008), após AS. Os autores sugerem que o AS foi eficaz nas alterações positivas no desempenho morfofuncional do sistema estomatognático. (AU)

Comparison of bite force evaluation for mandibular angle fracture fixation by conventional miniplates versus new design miniplates: a clinical study.

PURPOSE: To evaluate postoperative masticatory efficacy of a new design non-compression titanium miniplate compared to conventional non-compression titanium miniplate on the basis of bite force for treatment of mandibular angle fractures. METHODOLOGY: The prospective study included 20 patients with mandibular angle fractures randomly categorized into 2 groups: Group I, fixation of angle fractures by conventional miniplates, and Group II, fixation of angle fractures by new design miniplates. Evaluation was done for clinical outcome, primarily bite force; radiological outcome; and associated postoperative morbidities at different time intervals. RESULTS: The results showed to be highly significant in terms of mean operating time for plate adaptation and fixation and bite force adaptation (p = 0.003 at follow-up of 6 months) for the newer miniplate compared to the conventional miniplate. No statistically significant difference was seen for postoperative paresthesia, malunion, non-union, occlusal discrepancy, or hardware failure. CONCLUSION: Within the limits of the study, it appears that the single, monocortical, non-compression, superior border new design miniplate proved to be a successful procedure for treating non-comminuted mandibular angle fractures specifically in terms of enhanced postoperative masticatory efficiency as compared to conventional miniplates. Further clinical studies with larger sample size can derive a more comprehensive conclusion.

Bite force evaluation at maximal intercuspal position: An in vivo comparative study between stainless steel and zirconia crowns on primary molar teeth.

Objective: The objective of this study was to clinically evaluate and compare the mean bite force changes at maximum intercuspal position, along with parental satisfaction following full crown restoration using stainless steel crown/zirconia crown on primary molar teeth using digital occlusal analysis system T-Scan III (Tekscan Corp, Boston, Mass., USA). Materials and Methods: Thirty-six primary molars of children aged 6-9 years with pulpal involvement were selected for the study. The selected teeth were allocated to either of the two groups using simple random sampling technique: Group A = stainless steel crowned teeth and Group B = zirconia crowned teeth. The mean bite force was recorded before the placement of the crown, after the placement of the crown, and after 1 month-follow-up. The inter-group and intra-group comparison was done among the groups. After the placement of the crown, parents were asked to fill out a questionnaire for assessing parental satisfaction. Results: A significant result in the bite force on crowned tooth, vertical dimension was seen from baseline to 1-month follow-up between the SSC and zirconia groups. In the zirconia crown group, the mean bite force was more compared to the stainless steel crown group. Parents' satisfaction was higher with zirconia crown in terms of color and esthetics. Conclusion: SSC is more acceptable than zirconia crown since occlusal re-equilibration was attained better in SSC as compared to zirconia crown.

Comparison of Occlusal Digital Analysis Using T-Scan in Orthognathic Surgery with Only Conventional Orthodontic Patients.

Aim and Objectives: The aims of this study were to compare the changes in occlusal parameters, TMJ status clinically in patients after the completion of orthognathic surgery, and patients undergoing only orthodontic treatment and with patients having normal occlusion, using T-Scan. Methodology: This prospective controlled clinical trial, consisting of three groups with a sample size of twelve. Group 1 consisted of patients who underwent orthognathic surgery and orthodontic treatment. Group 2 consists of patients who underwent only orthodontic treatment (camouflage). Clinical examination of the patient (TMJ and Occlusal status) and T-Scan was performed at the time of debonding of the orthodontic brackets, 6 months and 1-year after first evaluation for group 1 and 2 patients. Results: The collected data between groups are compared and interpreted. The statistical analysis was performed using STATA/IC version 16.1 statistical software. Intragroup comparison for the study variables occlusion time, disocclusion time and maximum bite force between different time periods (T1, T2, T3) for all the three intervention groups using repeated measures. Hypothesis testing for maximum bite force, occlusion time and disocclusion time in orthognathic group (Group 1) as compared to orthodontic group (Group 2) for three different time periods using repeated measures ANOVA and Bonferroni test showed P value < 0.05 which is statistically significant. Conclusion: In conclusion, evaluation of occlusion using T-Scan give us an insight of the discrepancies in occlusion which is useful during pre-operative planning and especially in the post-operative follow-up period during the retention phase. Examination of TMJ in these patients at various intervals is necessary as any minor occlusal disturbances may lead to TMJ disorders.

Associations between temporomandibular disorders, pain, jaw and masticatory function in dentofacial deformity patients: A cross-sectional study.

BACKGROUND AND OBJECTIVE: Patients with dentofacial deformity often present with impaired masticatory function, orofacial pain and temporomandibular disorders (TMD). This study investigates the relationship between TMD, pain, jaw and masticatory function at different stages of orthognathic surgical (OS) treatment. METHODS: A total of 120 OS patients were prospectively recruited and grouped as pre-orthodontic (group 1), pre-surgery (group 2), 4-month post-surgery (group 3), 24-month post-surgery (group 4), in addition to 30 controls (group 0). Outcomes were assessed using: Jaw Function Limitation Scale (JFLS), McGill pain questionnaire, DC/TMD instrument, voluntary maximum bite force (MVBF), and masticatory efficiency (ME) using two-coloured chewing gum. Data were analysed using structural equation modelling. RESULTS: The prevalence of non-painful TMD did not differ between groups (p = .827). However, the prevalence of painful TMD differed between groups (p = .001). Among the painful TMDs, the highest prevalence was observed for masseter myalgia in group 2 (p = .031), and importantly group 4 did not differ from group 0 (p = .948). The MPQ score was significantly higher in group 1 (p = .001) compared to group 0, and the JFLS score was significantly higher in groups 1, 2 and 3 compared to group 0. Notably, MPQ (p = .756) and JFLS (p = .572) scores in group 4 were not different from group 0. However, MVBF (p = .996) and ME (p = .991) did not differ between groups 1 and 4. The association of self-reported pain and jaw function with the masticatory function was observed in OS patients. CONCLUSION: OS was not associated with a negative impact on TMD. Jaw function and pain levels were similar to controls at the 24-month follow-up. The masticatory function was further affected by the surgery and seems to require a longer recovery time. Moreover, it was confirmed that pain and TMD were associated with limitations in jaw function and impacts on masticatory function.

Bite Force Evaluation in Implant-Assisted Prosthetic Rehabilitation of Reconstructed Jaws Utilizing Vascularized Free Fibula Flap: A Retro-Prospective Cohort Study.

Introduction: Maxillary and mandibular defects due to tumor ablation pose considerable challenges to the reconstructive surgeon and in prosthetic management. Dental implants placed in vascularized fibula free flaps are considered to be a dependable technique for prosthetic rehabilitation in head and neck cancer patients. Although, there is evidence of survival of dental implants in the reconstructed jaw bones, there is lack of information regarding the masticatory performance and prosthetic success. The maximum bite force achieved through the prosthetic appliance is a measure of the therapeutic outcome. The purpose of this study was to determine the maximum bite force achieved through implant-assisted prosthetic rehabilitation in reconstructed jaw bones utilizing vascularized free fibula flap. Methods: The study included a total of 65 implants, from 16 patients who underwent surgical resection of jaw bones due to benign tumors followed by rehabilitation with implant-assisted fixed or removable prosthesis. The maximum bite force was determined with a transducer. Occlusal interferences were analyzed with mounted casts. The parameters were reviewed every 3 months have T 0 marked the baseline assessment, and T 3, T 6, T 9, T 12, and T 15 were subsequent review periods. Results: The mean occlusal force was increased in most of the patients through 15 months (P < 0.01). The maximum bite force measured in the reconstructed mandible and maxilla were 225.63 N and 176.51 N, respectively. Occlusal interferences were absent in 68.8% of the study population. Conclusion: The bite force measured in reconstructed maxilla and mandible is comparable to the masticatory force measured with conventional implant supported prosthesis in native mandible and maxilla.

Effect of acupuncture on the molar bite force in women with chronic neck pain / Efecto de la acupuntura sobre la fuerza de mordida en mujeres con cervicalgia crónico

Objetive: To investigate the maximum molar bite force in women with chronic neck pain after treatment with acupuncture. Materials and Methods: Twenty-three women with chronic neck pain participated. Dynamometer was used to measure the right and left maximum molar bite force. Dong Bang acupuncture needles - 0.25 mm x 30 mm was inserted into the integumentary tissue. Treatment was 10 sessions, each 30 minutes long and twice a week. Results: The right (p = 0.01) and left (p = 0.004) molar bite force was assessed after treatment with acupuncture, and showed increased occlusal strength. Conclusions: This study suggests a functional improvement in the stomatognathic system in women with chronic cervical pain after treatment with acupuncture. However, it is important to note that further research is needed to fully elucidate the long-term effects and potential clinical implications of these findings in the field of pain management and rehabilitation.

Objetivo: Investigar la fuerza masticatoria máxima en mujeres con dolor crónico de cuello después del tratamiento con acupuntura. Materiales y Métodos: Participaron veintitrés mujeres con dolor crónico de cuello. Se utilizó un dinamómetro para medir la fuerza máxima de mordida del molar derecho e izquierdo. Agujas de acupuntura Dong Bang se insertaron 0,25 mm x 30 mm en el tejido tegumentario. El tratamiento fue de 10 sesiones, cada una de 30 minutos de duración, dos veces por semana. Resultados: Se observó la fuerza de mordida del molar derecho (p=0.01) e izquierdo (p=0.004) después del tratamiento con acupuntura, que mostró un aumento de la fuerza oclusal. Conclusión: Este estudio sugiere una mejora funcional en el sistema estomatognático en mujeres con dolor cervical crónico después del tratamiento con acupuntura. Sin embargo, es importante señalar que se necesita más investigación para dilucidar por completo los efectos a largo plazo y las posibles implicaciones clínicas de estos hallazgos en el campo del tratamiento y la rehabilitación del dolor.

Assessment of masticatory performance in patients undergoing orthognathic surgery: A systematic review and meta-analysis.

BACKGROUND: One of the main goals of orthognathic surgery is to improve the masticatory performance in patients with maxillofacial deformities. OBJECTIVE: The aim of this study was to evaluate the literature on assessing masticatory performance before, after orthognathic surgery and normal occlusion. METHODS: An electronic search was performed via Pubmed, Scopus, LILACs and Web of Science without any restrictions until June 2022. The articles assessing masticatory performance using a comminution assay, bite force or occlusal contact area in patients undergoing orthognathic surgery with or without comparing controls were included. The risk of bias of the selected articles was assessed using the appropriate tools according to the study design. RESULTS: Of the 2507 records identified, 21 studies were included in the qualitative evaluation and 17 studies in the meta-analysis. Nine articles were cohort studies, and the other eight were before-after studies. Moderate to high risks of bias were found among the articles. Comparing the values before and after surgery, the meta-analysis revealed a significant improvement in the bite force and occlusal contact area at 1- and 2-year post-surgery. However, regardless of the assessed parameters, the masticatory performance in patients with normal occlusion was significantly greater than those in patients undergoing orthognathic surgery at all evaluated time points. CONCLUSION: Although combined surgical orthodontic treatment can improve impaired masticatory function, assessed by the comminution method, bite force and occlusal contact area, the improvement may not reach that of normal occlusion.

Clinical and Technical Validation of Novel Bite Force Measuring Device for Functional Analysis after Mandibular Reconstruction.

Bite force measuring devices that are generally suitable for edentulous patients or patients undergoing mandibular reconstruction are missing. This study assesses the validity of a new bite force measuring device (prototype of loadpad®, novel GmbH) and evaluates its feasibility in patients after segmental mandibular resection. Accuracy and reproducibility were analyzed with two different protocols using a universal testing machine (Z010 AllroundLine, Zwick/Roell, Ulm, Germany). Four groups were tested to evaluate the impact of silicone layers around the sensor: no silicone ("pure"), 2.0 mm soft silicone ("2-soft"), 7.0 mm soft silicone ("7-soft") and 2.0 mm hard silicone ("2-hard"). Thereafter, the device was tested in 10 patients prospectively who underwent mandibular reconstruction using a fibula free flap. Average relative deviations of the measured force in relation to the applied load reached 0.77% ("7-soft") to 5.28% ("2-hard"). Repeated measurements in "2-soft" revealed a mean relative deviation of 2.5% until an applied load of 600 N. Maximum bite force decreased postoperatively by 51.8% to a maximum mean bite force of 131.5 N. The novel device guarantees a high accuracy and degree of reproducibility. Furthermore, it offers new opportunities to quantify perioperative oral function after reconstructive surgery of the mandible also in edentulous patients.

Bite force changes after surgical correction of mandibular prognathism in subjects with increased vertical dimension : A prospective clinical trial.

PURPOSE: Occlusal bite force (OBF) is the most important parameter in assessing biting efficiency. The aim of this study was to record OBF changes after surgical correction of high angle maxillary/mandibular (Max/Mand) class III patients and to compare these with that recorded in class III patients with average Max/Mand angle. MATERIALS AND METHODS: Initially included were 42 patients with severe class III skeletal malocclusion who were scheduled for orthodontic surgery: group 1-22 patients with increased vertical relationship scheduled for bimaxillary surgery; group 2-20 patients with average vertical relationship scheduled for mandibular setback only. OBF measurements before surgery (T0), at debonding (T1) and at least 3 months after debonding (T2) were recorded using a portable occlusal force gauge. The following were also measured: maximum OBF (MOBF) achieved by the subject on each side, averaged OBF on each side (AOBF) and maximum OBF at the incisal region (MIOBF). At T2, only 33 patients (group 1: 17 and group 2: 16) were included in the analysis due to loss to follow-up. RESULTS: MOBF increased significantly in group 1, while no significant changes were detected in group 2. MIOBF increased after surgical correction in both groups. Significant increase in MIOBF was observed at T1 (P < 0.001) followed by an insignificant decrease during the observation period (3-6 months after treatment; P > 0.05). The two groups differed significantly in MOBF at T1 and T2, while no statistically significant differences were detected between the groups for MIOBF changes at the various time intervals (P > 0.05). The number of posterior teeth with occlusal contacts increased in both groups. Relapse was detected in group 1 where the number of posterior teeth in contact decreased during the observation period (T1-T2). CONCLUSION: OBF greatly improved after surgical correction of the vertical morphology. Correction of high angle mandibular prognathism improves oral function in addition to esthetics.

Evaluation of occlusal function during orthognathic therapy : A prospective clinical trial using a digital registration method.

OBJECTIVES: Reduced occlusal function is a main characteristic of orthognathic patients. The present study aimed to investigate the extent of therapy-induced functional improvements in occlusal function using a digital diagnostic method. METHODS: This prospective clinical study included 41 orthognathic patients (24 women and 17 men, median age 27.26 ± 8.2 years) and 10 control patients (5 women and 5 men, median age 29.8 ± 13.5 years) with neutral skeletal and dental configurations. The patients were divided into classes I, II and III based on their cephalometry. Digital occlusal registrations in habitual occlusion in an upright sitting position were taken before (T1) and after (T2) therapy using the T­Scan Novus (Tekscan, South Boston, MA, USA) application. RESULTS: Class II and III patients showed a significantly less efficient occlusal pattern than the untreated controls regarding total antagonism (p < 0.001), time of occlusion (p = 0.004), occlusal asymmetry (p = 0.001), anterior antagonism (p < 0.001) and posterior antagonism (p < 0.001). After therapy, the occlusal pattern increased in both therapy groups, where class III patients became indistinguishable from the controls, and class II patients differed only in posterior antagonism (p = 0.035). CONCLUSIONS: The digital occlusal registration method proved to be a useful diagnostic tool and provided new insights into therapeutic effects in orthognathic patients. By precisely adjusting the occlusal function, masticatory performance improved significantly. CLINICAL RELEVANCE: Severe malocclusion leads to a significantly lower masticatory performance for patients, which can be improved by orthognathic therapy and captured by digital occlusal registration.