Comparison of condylar position after free fibular flap mandibular reconstruction using computer-assisted and traditional techniques.

OBJECTIVES: To compare the changes in condylar position after mandibular reconstruction with free fibular flap(FFF) and the differences between computer-assisted techniques and traditional methods on CT images. METHODS: Thirty-four patients who underwent mandibular reconstruction with free fibular flap were selected according to the inclusion and exclusion criteria. In the 3D group, virtual surgical planning (VSP) with osteotomy cutting plate and placement guiding plate were used, while the traditional group underwent freehand reconstruction. The CT data of 68 temporomandibular joints (TMJs) were recorded before and immediately after surgery. The condylar position was evaluated by measuring the anterior space (AS), posterior space (PS) and superior space (SS), and the ln (PS/AS) was calculated according to the method proposed by Pullinger and Hollender. RESULTS: In the patients included in the 3D group, the condyle on the ipsilateral side moved slightly backward; however, in the patients in the traditional group, the ipsilateral side moved considerably anteroinferior. No obvious changes on the contralateral side were noted. In the 3D group, 33% of ipsilateral condyles were in the posterior position postoperatively when compared with the preoperative position (13%). In the traditional group, the number of ipsilateral condyles in the anterior position increased from 4 to 10, accounting for 53% postoperatively. Contrary to the traditional group, the 3D group presented less condylar displacement on the ipsilateral side postoperatively. CONCLUSIONS: This study showed a decreased percentage of change in condylar position postoperatively when VSP was used. Virtual surgical planning improved the accuracy of FFF mandibular reconstruction and made the condylar position more stable.

Radical resection and reconstruction in patients with adenoid cystic carcinoma in the minor salivary glands of the palate.

BACKGROUND: This study evaluated the clinical outcomes of the patients with adenoid cystic carcinoma (ACC) of the minor salivary glands of the palate. METHODS: Forty-four patients with stage I-II disease and 14 patients with stage III-IV disease underwent radical excision and reconstruction with a facial-submental artery island flap (FSAIF) and titanium mesh plus a free anterolateral thigh flap (ALTF) and radiotherapy respectively. Patients with stage III-IV disease subsequently received cobalt Co 60 adjuvant radiotherapy. Ki-67 expression was determined semiquantitatively in 52 patients with ACC by based on the cytoplasm staining intensity and percentage of positively stained tumor cells. RESULTS: The median (range) follow-up was 32.9 (14-58) months. Forty-one (71.7%) patients survived without disease recurrence. Nine patients (15.5%) survived with recurrent tumors (four with local recurrence, three with regional recurrence requiring salvage surgery, and two with distant metastasis); among these patients, five had overlapping recurrence. Eight patients (13.8%) died of regional, distant, or multiorgan metastasis (range: 22-42 months). The overall median (95% CI) survival time was 32.5 (25.0-39.5) months, and the median (95% CI) progression-free survival time was 32.9 (28.5-36.9) months. Rates of survival and recurrence differed significantly between patients with low- and high-grade tumors, patients with clinical stage I-II disease and those with stage III-IV disease, patients with and without lymph node metastasis, patients who underwent radical excision with versus without radiotherapy, and patients with low and high Ki-67 expression. CONCLUSION: Radical resection and reconstruction with FSAIF is suitable methods for the the treatment of stage I-II ACC of the minor salivary glands of the palate. Stage III-IV tumors require radical resection, reconstruction with titanium mesh and free ALTF, and radiotherapy.

Reconstruction of Large Acquired Palatal Defects Using Facial-Submental Artery Island Flap.

OBJECTIVE: To evaluate the feasibility and clinical effect of facial-submental artery island flap (FSAIF) in the repair of palatal defects, and to provide reference for the clinical application of submental artery island flap. METHODS: Nine patients with palatal defects, the range of nasal palatal perforation defects were 3 cm × 4cm to 3 cm × 6 cm (median 3 cm × 5.4 cm), were repaired by FSAIF, and the sizes of FSAIF were 4 cm × 9cm to 4 cm × 12 cm (median 4 cm × 10.4 cm,). Postoperative clinical efficacy was evaluated, including infection and necrosis of mucosal flap and postoperative palatal fistula perforation. Patients were followed up to evaluate their chewing, swallowing, speech function, and satisfaction of appearance. RESULTS: All patients were successfully repaired with FSAIF. Followed up 13∼35 months, there was no palatal fistula perforation in all patients. The speech, agitation, and swallowing function were not affected and the patients were satisfied with the appearance. CONCLUSION: FSAIF is a safe and reliable method for palatal defect repair.

Bilateral, buccinator myomucosal advancement flaps to reconstruct central upper labial myomucosal defects after ablation of early-stage cancer in minor salivary glands.

BACKGROUND: Reconstruction of upper labial myomucosal defects is surgically challenging. AIMS: We evaluated whether central defects could be repaired using bilateral, buccinator myomucosal advancement flaps (b-BMAFs). METHODS: We evaluated five patients with early-stage, minor salivary gland mucoepidermoid carcinomas (low-grade [n = 2], intermediate-grade [n = 2], and high-grade [n = 1]) who underwent central, upper labial myomucosal reconstruction using b-BMAFs after cancer ablation. We treated two men and three women aged 25-59 years. Tumors ranged in size from 1.8 × 1.8 to 2.5 × 2.2 cm. Clinical stages were I and II in two and three patients, respectively. Defect dimensions ranged from 2.8 × 2.8 to 3.5 × 3.2 cm. RESULTS: All patients underwent successful reconstruction of central, upper labial myomucosal defects using b-BMAFs and were satisfied with the esthetic results. Adequate orbicularis oris and speech function were maintained. No reduction in mouth opening was observed. Patients were followed up for 24-36 months; one pulmonary metastasis was observed at 36 months postoperatively. CONCLUSION: Placement of b-BMAFs is safe and feasible when reconstructing central, upper labial myomucosal defects after ablation of early-stage, minor salivary gland cancer.

Full cheek defect reconstruction using ALTF versus RFF: Comparison of quality of life, clinical results, and donor site morbidity.

OBJECTIVES: This study aimed to compare the quality of life (QOL) of patients, clinical results of the recipient site, and morbidities of the donor site between the use of free anterolateral thigh flaps (ALTFs) and radial forearm flaps (RFFs) for reconstruction of full cheek defects following tumor resection. MATERIALS AND METHODS: We retrospectively reviewed 52 patients who underwent reconstruction of full cheek defects using free ALTFs and free RFFs following tumor ablation at our center. The range of mouth opening, speech, swallowing, facial appearance, donor site complications, and subjective symptoms based on the University of Washington Quality of Life (UW-QOL) questionnaire findings were assessed in the ALTF and RFF groups at 3, 12, and 36 months after surgery. RESULTS: Quality of life, range of mouth opening, facial appearance, mood and anxiety, donor site appearance, subjective feeling, and functional impairment were better in the ALTF group than in the RFF group based on the physical examination findings and questionnaire scores. CONCLUSION: This study found better QOL and better functional results at the recipient site and minor morbidities at the donor site with the use of free ALTFs in the reconstruction of full cheek defects.

Comprehensive treatment of massive macroglossia due to venous and lymphatic malformations.

This study evaluated the outcomes of comprehensive treatment for massive macroglossia. Eleven patients with massive macroglossia due to venous malformations (VMs) and lymphatic malformations (LMs) underwent incision excision of two-thirds of the central wedge of the tongue; two of these patients underwent resection of lesions in the lower lip or floor of the mouth during initial treatment. In subsequent treatment, three patients underwent orthognathic surgery or resection of lesions in the lower lip and submental region, and four patients underwent one or two sclerotherapies. No patient had complications resulting from anaesthesia or surgery. Patients were followed up at 6 months postoperative, and all signs associated with the lesions had disappeared. The mean follow-up duration was 30.8 months. The aesthetic outcome was excellent for nine patients and satisfactory for two. Nine patients could take a soft diet and two a solid diet. Eight patients presented normal speech and three presented intelligible speech. Comprehensive treatment including incision excision of two-thirds of the central wedge of the tongue, as well as orthognathic surgery, the resection of lesions in the oral and maxillofacial region, and sclerotherapy, is effective for patients with massive macroglossia due to VMs and LMs.

Comparison of the reconstruction of through-and-through cheek defects involving the labial commissure following tumor resection using four types of local and pedicle flaps.

BACKGROUND: The reconstruction of through-and-through cheek defects involving the labial commissure following cancer ablation is a surgical challenge. METHODS: This study evaluated 35 patients with buccal squamous cell carcinoma (SCC) involving the labial commissure who underwent Abbe-Estlander (A-EF), folded extended supraclavicular fasciocutaneous island (SFIF), folded pectoralis major muscle (PMMF), or folded extended vertical lower trapezius island myocutaneous (TIMF) flap reconstruction of through-and-through cheek defects involving the labial commissure following radical resection. RESULTS: The A-EF and SFIF groups differed significantly (P < 0.05) from the PMMF and TIMF groups in terms of tumor clinical stage and type of treatment. The inner PMMF (median 6.3 × 4.5) and TIMF (median 9.8 × 6.7) skin paddle dimensions were larger than those of the A-EF (median 1.8 × 2.2) and SFIF (median 5.5 × 4.3) groups (P < 0.05). The outer PMMF (median 6.3 × 6.6) and TIMF (median 9.8 × 13.2) dimensions were larger than those of the A-EF (median 1.8 × 3.8) and SFIF (median 5.5 × 4.6) groups (P < 0.05). The esthetic results, orbicularis oris function, and speech function were significantly (P < 0.05) better in the A-EF group than in the SFIF, PMMF, and TIMF groups. The patients were followed for 6-38 months (median 26.8, 25.0, 22.1, and 20.8 months in the A-EF, SFIF, PMMF, and TIMF groups, respectively). At the final follow-up, 4 (80.0%) patients in the A-EF, 7 (87.5%) in the SFIF, 5 (55.6%) in the PMMF, and 5 (38.4%) in the TIMF groups were alive with no disease; 1 (20.0%), 1 (22.2%), 2 (22.2%), and 4 (30.8%) patients, respectively, were alive with disease; and 2 (22.2%) patients in the PMMF and 4 (30.8%) in the TIMF group had died of local recurrence or distant metastases at between 9 and 38 months. There was a significant survival difference in the A-EF and SFIF groups compared with the PMMF and TIMF groups (P < 0.05). CONCLUSIONS: The A-EF is suitable for reconstructing defects of clinical stage II disease; the SFIF for clinical stage II or III disease; the PMMF for clinical stage III or IV; and the TIMF for clinical stage rCS III or rCS IV disease.

Cancer-associated fibroblasts confer cisplatin resistance of tongue cancer via autophagy activation.

Cancer-associated fibroblasts (CAFs) play important roles in carcinogenesis and progression of tongue squamous cell carcinoma (TSCC). However, effect of CAFs on chemotherapy resistance of TSCC remains largely obscure. Here, we cultured the matched primary CAFs and normal fibroblasts (NFs) pairs and detected their roles in cisplatin sensitivity of TSCC, as well as autophagy-related protein LC3 and Beclin1 expressions. During exposure to cisplatin, TSCC with CAFs group exhibited significantly increased cell viability and IC50, but reduced apoptosis than that with NFs group. Meanwhile, cisplatin increased the LC3-II and Beclin1 levels of those TSCC co-cultured with CAFs. Activation of cisplatin-induced autophagic flux was inhibited by CQ, which can accumulate LC3-II protein and increase punctate distribution of LC3 localization. Beclin1 siRNA also decreased the cisplatin-induced autophagy. Both CQ and Beclin1 siRNA increased cisplatin-induced apoptosis but inhibited viability of TSCC co-cultured with CAFs. In vivo, combination of cisplatin and CQ significantly inhibited the growth of xenografted tumors than cisplatin alone. Taken together, our findings highlight the important role of CAFs in cisplatin resistance of tongue cancer via autophagy activation, suggesting that inhibition of autophagy could be an optimal strategy for chemoresistance of TSCC.

The Effect of Reading Aloud Exercises for Complete Denture Patients during the Functional Rehabilitation Period.

PURPOSE: The focus of this study was to evaluate the effect of reading aloud on masticatory performance and patient satisfaction of patients rehabilitated with conventional complete dentures for the first time. MATERIALS AND METHODS: Sixty-two edentulous patients who received conventional complete denture treatment for the first time were randomly divided into two equal groups. After insertion of the dentures, patients in group I were asked to read a news report three times per day for 4 weeks, while those in group II did not read. The reading duration increased by 5 minutes per week, from 5 minutes in the first week to 20 minutes in the fourth week. The patients' mouth opening during reading aloud was advised to gradually increase throughout the training project. Two and four weeks after insertion of the dentures, masticatory performance was assessed using the sieving method, and patient satisfaction was measured using a visual analogue scale, which combined the patient's perceptions in relation to comfort, esthetics, stability, ability to talk, and ability to chew. RESULTS: There were significant improvements in masticatory performance with reading aloud exercises after the insertion of complete dentures (p < 0.001) at the 2- and 4-week follow-up visits. Masticatory performance also showed significant improvement within each group in the follow-up periods (p < 0.001). No significant differences were found between the two groups in patient satisfaction (p > 0.05) at 2 weeks, but at 4 weeks, patient satisfaction regarding stability, ability to talk, and ability to chew was significantly higher for group I (p < 0.001). CONCLUSIONS: The results of this study suggest that reading aloud exercises significantly improved early masticatory performance and patient satisfaction for denture wearers who were treated with conventional complete dentures for the first time, and may be a useful clinical application for more effective denture treatment.

Bond strengths of porcelain to cobalt-chromium alloys made by casting, milling, and selective laser melting.

STATEMENT OF PROBLEM: Cobalt-chromium (Co-Cr) alloys have been widely used for metal-ceramic fixed prostheses and can be fabricated using conventionally cast or new computer-aided technology. However, the effect of different manufacturing methods on the metal-ceramic bond strength needs further evaluation. PURPOSE: The purpose of this in vitro study was to evaluate the metal-ceramic bond strength of a Co-Cr alloy made by casting, milling, and selective laser melting (SLM). MATERIAL AND METHODS: Co-Cr specimens (25×3×0.5 mm) were prepared using a cast, milled, or SLM method and layered with ceramic (8×3×1.1 mm). Metal-ceramic bond strength was measured by a 3-point bend test according to ISO9693. The area fraction of adherence porcelain (AFAP) was determined by measuring the Si content of the specimens with scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS). The metal-ceramic bond strength and AFAP results were analyzed using 1-way analysis of variance and the Bonferroni post hoc test (α=.05). SEM/EDS and metallurgic microscopy were also used to study the specimens' morphology, elemental composition, and metallurgic structure. RESULTS: No significant differences (P>.05) were found for the bond strength among cast, milled, and SLM Co-Cr alloys. The milled and SLM groups showed significantly more porcelain adherence than the cast group (P<.001). The surface morphologies and oxidation characters of cast, milled, and SLM Co-Cr alloys were similar, whereas the metallurgic structures were different. CONCLUSIONS: The bond strength between ceramics and Co-Cr alloys is independent of the manufacturing method. However, milling- and SLM-produced alloys had better porcelain adherence.

Effect of heating palladium-silver alloys on ceramic bond strength.

STATEMENT OF PROBLEM: The effects of different heat treatments on the internal oxidation and metal-ceramic bond in Pd-Ag alloys with different trace elements require further documentation. PURPOSE: The purpose of this in vitro study was to determine whether heat treatment affects the metal-ceramic bond strength of 2 Pd-Ag alloys containing different trace elements. MATERIAL AND METHODS: Thirteen cast specimens (25×3×0.5 mm) from each of 2 Pd-Ag alloy groups (W-1 and Argelite 61+3) were allocated to heat treatments before porcelain application: heating under reduced atmospheric pressure of 0.0014 MPa and 0.0026 MPa and heating under normal atmospheric pressure. Bond strengths were evaluated using a 3-point bending test according to ISO9693. Results were analyzed using 2-way ANOVA and Tukey HSD test (α=.05). Visual observation was used to determine the failure types of the fractured specimens. Scanning electron microscopy and energy dispersive spectroscopy were used to study morphologies, elemental compositions, and distributions in the specimens. RESULTS: The W-1 group had a mean bond strength significantly higher than that of Argelite 61+3 (P<.001). Heating under reduced atmospheric pressures of 0.0014 MPa and 0.0026 MPa resulted in similar bond strengths (P=.331), and both pressures had significantly higher bond strengths than that of heating under normal atmospheric pressure (P=.002, P<.001). Heating under different air pressures resulted in Pd-Ag alloys that contained either Sn or In and Ga, with various degrees of internal oxidation and different quantities of metallic nodules. CONCLUSIONS: Heating under reduced atmospheric pressure effectively improved the bond strength of the ceramic-to-Pd-Ag alloys.

Effect of oxidation heat treatment on the bond strength between a ceramic and cast and milled cobalt-chromium alloys.

There is a dearth of dental scientific literature on the effect of different oxidation heat treatments (OHTs) (as surface pretreatments) on the bonding performance of cast and milled cobalt-chromium (CoCr) alloys. The objective of this study was to evaluate the effect of different OHTs on the bond strength between a ceramic and cast and milled CoCr alloys. Cobalt-chromium metallic specimens were prepared using either a cast or a milled method. Specimens were subjected to four different OHT methods: without OHT; OHT under normal atmospheric pressure; OHT under vacuum; and OHT under vacuum followed by sandblasting. The metal-ceramic bond strength was evaluated using a three-point bending test according to ISO9693. Scanning electron microscopy and energy-dispersive spectroscopy were used to study the specimens' microstructure and elemental composition. The bond strength was not affected by the CoCr manufacturing method. Oxidation heat treatment performed under normal atmospheric pressure resulted in the highest bond strength. The concentration of oxygen on the alloy surfaces varied with the different pretreatment methods in the following order: OHT under normal atmospheric pressure > OHT under vacuum > without OHT ≈ OHT under vacuum followed by sandblasting.

Effect of pretreatments on the metal-ceramic bonding strength of a Pd-Ag alloy.

OBJECTIVES: The purpose of this study was to evaluate the efficacy of surface treatments on the bonding properties between a metal and ceramic. METHODS: Sixty metal specimens were divided equally into four groups of 15 samples each. These groups received different treatments (Gr1: 250µm Al2O3+preoxidation; Gr2: 250µm Al2O3+degassing; Gr3: 120µm Al2O3+preoxidation; Gr4: 120µm Al2O3+degassing). Bond strengths were evaluated using a three-point bending test. The results were analyzed using 2-way ANOVA and Tukey's test. Scanning electron microscopy and energy dispersive spectroscopy were used to observe the microscopic features, elemental compositions and distributions, and diffusion in the specimens. Mechanical profiler was used to measure the roughness of metal surface. RESULTS: The bond strengths of the four groups ranged from 45.00±3.63MPa to 51.61±5.91MPa, with significant differences (P<.05). The specimen that received the pretreatment of 250µm Al2O3 air-particle abrasion+degassing had the highest bond strength. Heating under different oxygen partial pressures caused the final Pd-Ag alloys to have varying degrees of internal oxidation and different quantities of metallic nodules. None of the elements in either the ceramic or the Pd-Ag alloy layer diffused into the other layer. CONCLUSIONS: The metal-ceramic specimen subjected to air-particle abrasion with 250µm Al2O3 and degassed before porcelain firing had significantly higher bond strength than specimens treated differently.

Effect of titanium preoxidation on wrought pure titanium to ceramic bond strength.

STATEMENT OF PROBLEM: The creation of high bond strength between machined computer-manufactured pure titanium and porcelain remains a problem. However, machined titanium does not form the thick titanium oxide film found in cast titanium. PURPOSE: The purpose of this study was to investigate the effects of different preoxidation treatments on the bond strength of a machined pure titanium ceramic system. MATERIAL AND METHODS: Specimens of commercially pure titanium (25 × 3 × 0.5 mm) were divided equally into 6 groups (n=8), which received different preoxidation treatments (3 hour natural oxidation; 600°C, 650°C, 700°C, 750°C, and 800°C for 3 minutes). Bond strengths were evaluated by using a 3-point bend test. The results were analyzed by using 1-way ANOVA and the least significant difference test. Twelve additional specimens of commercially pure titanium (15 × 3 × 0.5 mm) were cut for interface observation and divided equally into 6 groups that received the preoxidation treatments described previously. Scanning electron microscopy and energy dispersive spectrum were used to observe microscopic features of the interface between Ti and ceramic. RESULTS: The bond strength values of the 6 groups ranged from 23.72 ±2.53 MPa to 36.99 ±3.92 MPa, with significant differences (P<.05). The specimen that received 750°C preoxidation had the highest bond strength. The main interface elements of the 6 groups were O, Si, Ti, Sn, Al, Na, and K. Ti showed a sigmoidal diffusion curve in each group, and Si showed a sigmoidal diffusion curve in most groups. Sn was enriched in each group's interface. CONCLUSIONS: Preoxidation under vacuum before porcelain firing can effectively improve the bond strength of machined pure titanium-porcelain systems.

[Effect of different heat treatment on the bonding strength of porcelain and Co-Cr alloy].

PURPOSE: To investigate and compare the effect of different heat treatment on the metal- ceramic bonding strength and the interfacial microstructure of the Co-Cr alloy. METHODS: Thirty specimens were made according to ISO 9693,and then divided into 3 groups (n=10) through the measurements .Group A(degassed 60s):degassed and then maintained 60s in 980 degrees centigrade Group B(degassed 60s and preoxidation 60s): degassed and maintained 60s in 980 degrees centigrade, then were maintained continuously for 60s in 980 degrees centigrade after re-gassed,Group C(degassed 120s): degassed and maintained 120s in 980 degrees centigrade. The bonding strengths of the three groups were evaluated through three point bending test. Six specimens divided into 3 group were made in the same method to observe the metal-ceramic interface through scanning electronic microscope(SEM) and energy dispersive spectrum(EDS).The bonding strength data were analyzed using ANOVA and Bonferroni's test by SPSS13.0 software package. RESULTS: The mean value of bonding strength was (39.03±2.70)MPa for group A, (34.43±2.36)MPa for group B, (31.65±1.49)MPa for group C, respectively. There were significant difference between every two groups (P<0.05). SEM demonstrated that the width of interfacial transition layer was 12.3-16.4µm in group A, 15.2-21.8µm in group B and 26.3-32.2µm in group C. CONCLUSIONS: Higher metal-ceramic bonding strength for Co-Cr alloy will be formed under the situation of degassed,and maintained 60s in 980 degrees centigrade ; while extending degassed time, prolonging the heat maintained time and preoxidation after degassing will reduce metal-ceramic bonding strength.