Masticatory function and related factors after oral oncological treatment: A 5-year prospective study.

BACKGROUND: Chewing ability is often compromised in patients with oral cancer. The aim of this study was to identify which factors affect masticatory performance in these patients. METHODS: Patients with primary oral cancer were assessed for up to 5 years after primary treatment. Healthy controls were assessed once. A mixed-model analysis was performed, with masticatory performance as outcome measure. RESULTS: A total of 123 patients were included in the study. Factors positively associated with masticatory performance were number of occlusal units (OU), having functional dentures, and maximum mouth opening (MMO). The impact of tumor location and maximum bite force (MBF) differed per assessment moment. Masticatory performance declined for up to 1 year but recovered at 5 years after treatment. CONCLUSION: Masticatory performance in patients treated for oral cancer is affected by MBF, MMO, number of OU, and dental status. These should be the focus of posttreatment therapy.

The association between a mixing ability test and patient reported chewing ability in patients treated for oral malignancies.

INTRODUCTION: Mastication has been assessed in several ways in the past. Both patients reported and objective assessment methods have been developed. The University Medical Center (UMC) Utrecht has developed a mixing ability test (MAT) using a two-coloured wax tablet. The present study investigates the association between the mixing ability test and a chewing related questionnaire in patients treated for oral malignancies. PATIENTS AND METHODS: In a cohort study, patients treated for oral malignancies were assessed 4-6 weeks before and 4-6 weeks after treatment, as well as 6 months, 1 year and 5 years after treatment. The mixing ability test was assessed using 10 and 20 chewing strokes and was compared to seven questions about several aspects of mastication. Regression analysis was performed and density plots were drawn for statistical analysis. RESULTS: One hundred and twenty-three patients were included in this study. The questionnaire was less predictive for the 10-chewing stroke test and the test was less discriminatory for different food types than the 20-chewing stroke mixing ability test. Three questions about the ability to chew solid, soft and thickened liquid food types were found to be significantly predictive for the 20-chewing stroke test. Threshold values on the mixing ability index were around 20 for the ability to chew solid food types and 24 for soft food types. CONCLUSION: The 10-chewing stroke mixing ability test is less suitable than 20-chewing strokes for patients with and treated for oral cancer. The 20-chewing stroke mixing ability test has a fair association with self-reported outcomes.

Health-related quality of life after segmental resection of the lateral mandible: Free fibula flap versus plate reconstruction.

OBJECTIVES: Segmental resection of the mandible causes functional, aesthetic and social problems affecting health-related quality of life (HRQoL). It is often assumed that reconstruction with composite free flaps guarantees better function and aesthetics than bridging the defect with reconstruction plates. METHODS: Using the European Organization for Research and Treatment of Cancer questionnaires (EORTC QLQ-C30 version 3.0 and EORTC QLQ-H&N35), we compared HRQoL in patients who received free fibula flaps versus reconstruction plates after segmental resection of the lateral mandible. RESULTS: Thirty-seven completed questionnaires (18 fibula reconstructions and 19 patients with reconstruction plates) were available. Reconstruction with a free fibula flap did not provide clear additional benefit to bridging the defect with a reconstruction plate after segmental resection of the lateral mandible. In particular aspects known to have the most impact on HRQoL like swallowing, speech and chewing were not influenced by the type of reconstruction. CONCLUSIONS: Reconstruction of segmental defects of the lateral mandible with free fibula flap and reconstruction plate resulted in comparable HRQoL. If dental rehabilitation by means of dental implants is not anticipated in the fibula, then plate reconstruction with adequate soft tissue remains a suitable technique for the reconstruction of segmental defects of the lateral mandible.

Micro-structured calcium phosphate ceramic for donor site repair after harvesting chin bone for grafting alveolar clefts in children.

OBJECTIVES: The purpose of this study was to evaluate the use of synthetic bone graft material as a filling material at the mandibular symphysis donor site of autologous bone in children. MATERIALS AND METHODS: A blinded patient group comprised 20 patients with unilateral (UCLP) or bilateral (BCLP) cleft of lip and palate, all with an indication for alveolar cleft repair. The study took the form of a prospective randomized clinical trial. We used lateral cephalograms for the measurement of the symphyseal donor area defect both peroperatively and at 12 months postoperatively. The data obtained were digitalized and the treatment outcome expressed in numbers. Comparisons with a previous study were made. Histology of biopsies and CT scans were used for visualising bone formation. RESULTS: This study demonstrates that the micro-structured, resorbable calcium phosphate ceramic provides good regeneration properties for the repair of a critical size bony defect in children. One year postoperatively, the measurements taken from lateral cephalograms show that there is scarcely any visible residual defect. Histological investigations of the bone biopsies show solid, induced bone formation and almost complete resorption of the micro-structured calcium phosphate. CONCLUSIONS: The findings of this study (novel in children) indicate that micro-structured resorbable calcium phosphate is an excellent alternative to autologous bone. The digital findings showed a restored donor site defect significantly indicating the efficacy (i.e., osteoconductivity and resorbability) of this bone substitute. The biopsy histology demonstrated the overall presence of newly formed vital bone and the resorption of the bone substitute. Its use for grafting the alveolar cleft is currently researched and it may become the new standard. CLINICAL RELEVANCE: As co-morbidity and prolonged operation time at the donor operation site are inherent to the alveolar cleft repair procedure, the use of the described bone substitute is winning progress.

Donor site complications in bone grafting: comparison of iliac crest, calvarial, and mandibular ramus bone.

PURPOSE: To compare the donor site complication rate and length of hospital stay following the harvest of bone from the iliac crest, calvarium, or mandibular ramus. MATERIALS AND METHODS: Ninety-nine consecutively treated patients were included in this retrospective observational single-center study. RESULTS: Iliac crest bone was harvested in 55 patients, calvarial bone in 26 patients, and mandibular ramus bone in 18 patients. Harvesting of mandibular ramus bone was associated with the lowest percentages of major complications (5.6%), minor complications (22.2%), and total complications (27.8%). Harvesting of iliac crest bone was related to the highest percentages of minor complications (56.4%) and total complications (63.6%), whereas harvesting of calvarial bone induced the highest percentage of major complications (19.2%). The length of the hospital stay was significantly influenced by the choice of donor site (P = .003) and age (P = .009); young patients with the mandibular ramus as the donor site had the shortest hospital stay. CONCLUSIONS: Harvesting of mandibular ramus bone was associated with the lowest percentage of complications and the shortest hospital stay. When the amount of bone to be obtained is deemed sufficient, mandibular ramus bone should be the first choice for the reconstruction of maxillofacial defects.

Neck and shoulder function in patients treated for oral malignancies: a 1-year prospective cohort study.

BACKGROUND: Neck and shoulder complaints can be a direct result of a neck dissection. METHODS: Maximal active lateral flexion of the neck, forward flexion and abduction of the shoulder, and self-perceived function were determined in 145 patients treated for oral cancer. RESULTS: No short-term influence of radiotherapy was found on measured range of motion and self-perceived neck and shoulder function (p > .05). One year after a bilateral neck dissection, patients showed deteriorated lateral flexion of the neck, whereas patients treated with a unilateral modified radical neck dissection still reported pain during neck movements. Maximal forward flexion of the shoulder recovered to the level of healthy controls, but maximal abduction was still reduced in all patients. CONCLUSIONS: Neck dissection, tumor site, and extensive reconstruction are related to deterioration of shoulder function shortly after intervention. Maximal active shoulder abduction was affected most.

Free vascularized flaps for reconstruction of the mandible: complications, success, and dental rehabilitation.

PURPOSE: To evaluate complications and success of mandibular reconstruction with free fibula flaps, iliac crest flaps, and forearm flaps with reconstruction plates and to evaluate dental rehabilitation after these reconstructions. PATIENTS AND METHODS: Eighty-three patients with segmental mandibular defects were included. Correlation analyses were used to determine the relationship between reconstruction type and clinical parameters with recipient-site complications and success. The dental rehabilitation was evaluated in successfully reconstructed survivors. RESULTS: Multivariate analyses showed significant correlations between flap type and success (P < .0001). Of the patients, 51 (61%) were alive 2 years after the reconstruction. Mandibular reconstruction with a free forearm flap and reconstruction plate was associated with higher complication rates at the recipient site and higher failure rates compared with reconstruction with free vascularized bone flaps. Of the 32 successfully reconstructed survivors, 14 (44%) had a complete dental rehabilitation, of which 10 had dental implants and 4 did not. Only 6 (29%) of the edentulous survivors ultimately had an implant-supported prosthesis. CONCLUSIONS: Reconstruction of the mandible with a free vascularized bone flap is superior to reconstruction with a free forearm flap with a reconstruction plate. Complete dental rehabilitation was reached in fewer than half of the surviving patients.

Mastication in patients treated for malignancies in tongue and/or floor of mouth: A 1-year prospective study.

BACKGROUND: People confronted with oral cancer run a high risk of deteriorated masticatory performance. Reduced masticatory function may affect quality of life and food choice. An altered food choice may result in lower intakes for key nutrients and weight loss. METHODS: Dental state, bite force, and masticatory performance were determined in a group of 45 patients with squamous cell carcinoma of the tongue and/or floor of mouth. Measurements were performed before surgery and at various moments after surgery and/or radiotherapy. RESULTS: Surgical intervention had a large negative impact on oral function. Radiotherapy further worsened oral function. Also, the recovery of oral function 1 year after surgery was less prominent for the surgery-radiotherapy group than for the surgery group. CONCLUSION: Objective determination of oral function 1 year after surgery showed that patients treated for malignancies in the tongue and/or floor of mouth had significantly deteriorated masticatory performance, bite force, and dental state.

Oral function after oncological intervention in the oral cavity: a retrospective study.

PURPOSE: To assess self-perceived oral function of patients with oral cavity cancer at different stages of treatment, ie, before oncologic intervention, 5 weeks after intervention, and 5 years after intervention. PATIENTS AND METHODS: A cohort of 158 patients with malignancy in the oral cavity treated by surgery in 1999 or 2000 was included. From this cohort we interviewed 69 patients by telephone in 2005 and collected data on dental status, disorders of chewing and swallowing, xerostomia, preference of food consistency, tube nutrition, weight loss, and speech for different stages of treatment. RESULTS: For patients treated in the maxilla region we observed a significant (P < .05) recovery of perceived chewing ability after 5 years to the level experienced before oncologic intervention. Patients treated in the mandible region reported a deteriorated dental state, chewing ability, lip competence, and xerostomia after 5 years. Patients treated in the tongue and mouth-floor region experienced deterioration for dental state, chewing ability, and xerostomia after 5 years compared with the level before the oncologic intervention. CONCLUSIONS: Our telephone interview on oral function provided supplementary information on how patients experienced their problems with oral function during various phases of oncologic treatment. A retrospective interview may thus help to add information to incomplete retrospective data.

Satisfaction level and masticatory performance of patient rehabilitated with implant-supported overdentures / Nível de satisfação e performance mastigatória de pacientes reabilitados com sobredentaduras suportada por implantes

Purpose: To compare the masticatory performance and satisfaction levels of subjects with normal dentition and subjects with implant-supported overdentures with two types of attachments (ball and bar-clip retention systems). Methods: The sample comprised 24 subjects, 12 edentulous patients and 12 dentate subjects. The denture wearers received two dental implants and new maxillary and mandibular dentures. Three months after the first surgical phase, the mandibular dentures were connected to the implants by a gold ball attachment. Two months later new mandibular overdentures were made with a bar-clip attachment. Satisfaction levels (modified OHIP-EDENT and verbal rating scale) and masticatory performance (chewing for 40 masticatory cycles) were measured with the old dentures, with the unattached new dentures, and with the new dentures with ball and bar-clip attachments. Data were analyzed by Friedman and chi-square tests. Results: Both masticatory performance and satisfaction levels significantly improved after implant treatment. No significant differences were observed between the overdentures with ball and bar attachments. However, the masticatory performance after treatment was still significantly lower than the performance of the healthy subjects. Conclusion: The rehabilitation of edentulous patients with overdenture with ball or bar-clip attachment improves both satisfaction and masticatory performance, but the outcomes levels are not equal as those found for dentate subjects.

Objetivo: Comparar o nível de satisfação e a performance mastigatória dos indivíduos com dentição normal e pacientes reabilitados com uma sobredentadura suportada por implantes com dois tipos de conectores diferentes, sistema de retenção bola e barra. Metodologia: Vinte e quatro indivíduos participaram do estudo, sendo 12 pacientes desdentados e 12 indivíduos dentados totais. Os desdentados receberam dois implantes e novas dentaduras, superiores e inferiores. Três meses depois da primeira fase cirúrgica, a dentadura inferior foi conectada aos implantes através do sistema bola. Dois meses depois, uma nova sobredentadura inferior foi realizada, porém desta vez conectado através do sistema barra-clipe. O nível de satisfação (OHIP-EDENT adaptado e escala verbal de medição) e a performance mastigatória (mastigação por 40 ciclos mastigatórios) foram medidos em vários momentos do tratamento, com as dentaduras antigas, novas não conectadas por implantes, e depois de ter conectado a sobredentadura pelo sistema bola e barra-clipe. O teste de Friedman e o teste qui-quadrado foram aplicados para analisar os resultados.Resultados: O nível de satisfação e a performance mastigatória melhoraram significativamente após a reabilitação com os implantes. Nenhuma diferença foi observada entre as sobredentaduras com sistema bola e barra-clipe. Entretanto, a performance mastigatória ainda permaneceu significativamente menor que a performance dos indivíduos dentados. Conclusão: A reabilitação de pacientes edêntulos reabilitados com sobredentadura com bola ou barra-clipe melhora tanto o nível de satisfação quanto a performance mastigatória, porém ainda abaixo do nível dos indivíduos com dentição normal.

Quantitative dynamic contrast-enhanced MRI for the assessment of mandibular invasion by squamous cell carcinoma.

The objective of this study was to determine the value of dynamic contrast-enhanced MRI (DCE-MRI) for the preoperative assessment of mandibular invasion in squamous cell carcinomas (SCC), adjacent or fixed to the mandible. DCE-MRI was performed with gadolinium diethylene triamine pentaacetic acid (Gd-DTPA). Data were obtained from 25 patients. From pharmacokinetic analysis of the tissue uptake of Gd-DTPA, the DCE-MRI parameters (k(ep), K(trans) and v(e)) were determined, with k(ep) representing the exchange rate constant, K(trans) the volume transfer constant and v(e) the volume of extracellular space per unit volume of tissue. The histology of the resection specimens was used as gold standard for the extent of mandibular invasion. SCC with medullary invasion showed higher mean k(ep) and K(trans) compared with SCC without medullary invasion (ANOVA, p<0.001). ROC analysis of k(ep) and K(trans) revealed reliable threshold values for medullary invasion. In conclusion, DCE-MRI can discriminate SCC with medullary invasion from SCC without medullary invasion and may serve as a valuable tool in preoperative tumour staging with regard to the delineation of medullary invasion.

The influence of mandibular advancement surgery on oral function in retrognathic patients: a 5-year follow-up study.

PURPOSE: Previous studies have shown that patients with mandibular retrognathism who were scheduled for orthognathic surgery have a lower maximum bite force and an impaired chewing performance. Surgical correction of this deformity is supposed to lead to an improvement of these oral functions. One year after surgery, no significant changes could be shown in these patients. However, a longer follow-up might demonstrate an improvement after all. PATIENTS AND METHODS: Maximum bite force and chewing performance were determined in 12 patients with a mandibular retrognathism before mandibular advancement surgery and at least 5 years after surgery. Chewing performance (median particle size) was determined with a sieving method after chewing 15 strokes on an artificial test food. Maximum bite force was recorded bilaterally at the level of the first molars. RESULTS: Five years after surgery, chewing performance was improved, especially in patients with a poor performance before treatment. An increase of the maximum bite force could not be shown. CONCLUSION: Surgical correction of mandibular retrognathism had a positive effect on oral function 5 years after surgery, although it could not be detected 1 year after surgery. However, the function of the masticatory system was still impaired when compared with controls.

The effect of maximum bite force on marginal bone loss in mandibular overdenture treatment: an in vivo study.

The impact of bite force on the marginal bone response around implants is a subject of debate. This study focused on the effect of maximum bite force on marginal bone levels in mandibular implant overdenture treatment. In addition, the effect of the sequence of 3 different loading conditions on marginal bone loss was evaluated in vivo. The patient population consisted of a group of 18 patients. They received 2 implants in the mandible and a new denture without attachments during the period of submerged implant healing. After second stage surgery, the denture was provided with a ball, magnet or bar-clip attachment. There was a transition of attachment type after 3 and 6 months of function. The sequence in which the attachments were used was randomised. Radiographic marginal bone loss was measured after the period of submerged implant healing and after 3, 6 and 9 months of functional implant loading. Maximum bite force measurements were obtained just prior to second stage surgery with the new denture without attachment. Bite force measurements were also obtained after 3, 6 and 9 months of loading with the implant-retained overdenture. The latter 3 values were averaged. The mean bone loss during the period of submerged healing and during functional loading was 1.7 mm (0.7 mm) and 1.3 mm (0.6 mm), respectively. A relationship between maximum bite force during the period of submerged healing or during the period of functional loading on the one hand and the amount of marginal bone loss on the other could not be demonstrated. The sequence in which the different attachment types were used did not influence the observed amount of marginal bone loss.

Masticatory function in retrognathic patients, before and after mandibular advancement surgery.

PURPOSE: Mandibular retrognathia is a dentofacial deformity that can be surgically corrected. The purpose of this study was to evaluate the influence of orthognathic surgery on masticatory function in a sample of retrognathic patients and to compare these findings with those of controls. PATIENTS AND METHODS: Eleven retrognathic patients were tested before and 1 to 1.5 years after mandibular advancement surgery and compared with 12 controls. The median particle size after chewing a silicon rubber test food, the maximum bite force, and the electromyographic activity (EMG) of the anterior temporalis and the masseter muscles during isometric clenching and during chewing were determined. Patients, before and after treatment, and controls were statistically compared by analysis of variance. RESULTS: Surgical correction of mandibular retrognathia did not change chewing efficiency, maximum bite force, EMG during maximal clenching, EMG during chewing, or the EMG/bite-force relationship. Compared with controls, the chewing efficiency, maximum bite force, EMG during maximal clenching, and EMG during chewing values were lower. No difference for the EMG/bite-force ratio at maximal clenching was found, indicating similar muscle efficiency for patients and controls. However, in the range of 10% to 40% of the maximum bite force, the slope of the EMG/bite-force regression line was steeper for the patients than for the controls, indicating decreased muscle efficiency for patients. CONCLUSIONS: The results of this study suggest that in retrognathic patients, function of the masticatory system is impaired. Oral function was not influenced by mandibular advancement surgery.

Nasolabial esthetics after Le Fort I osteotomy and V-Y closure: a statistical evaluation.

The Le Fort I osteotomy results in predictable long-term effects. The soft tissues, however, can be difficult to control because of considerable variation in their adaptation. Several adverse reactions can take place, including thinning and lateral retraction of the lip, accentuation of the nasolabial groove, reduced vermilion exposure, and increase of the nasolabial angle. In this study on 51 selected patients, the V-shaped wound in the vestibule of the maxilla after the Le Fort I osteotomy was closed with a "Y," with the bast of the "Y" in the midline of the upper lip (V-Y closure). Forward multiple regression analysis was calculated for each bony landmark. Regression equations were formulated if P < .05. The equation with the bony point with the highest r2 value was considered the most important independent variable. The selected independent variables were used to form 4 subgroups with identical vectors of movements: impaction, advancement, impaction and advancement, and dorsal impaction. In these 4 subgroups, forward multiple regression analysis was used to select equations with the highest r2 value (P < .05). The selected equations demonstrated that a V-Y plasty as single soft tissue procedure suffices only in advancement cases, and only if the nose does not need additional upward rotation. In the other 3 subgroups, additional procedures are necessary, such as alar cinch suture, reduction of the anterior nasal spine, or grinding of the paranasal area in order to prevent the above-mentioned adverse soft tissue changes.