Chia-Fu Yang

Importance of Patient’s Cooperation in Surgical Treatment for Oral Submucous Fibrosis

PURPOSE The aim of this study was to investigate the results of surgical treatment for oral submucous fibrosis (OSF) in patients who did or did not cooperate with the rehabilitation regimen. PATIENTS AND METHODS There were 54 patients who had surgical treatment of trismus caused by OSF. Split-thickness skin grafts were used to repair surgical defects after surgery on the fibrous bands. According to postoperative collaboration in the rehabilitation regimen, patients were defined as non-cooperative patients (group I) and cooperative patients (group II). Group I (n = 28) and group II (n = 26) were analyzed separately for changes in preoperative, intraoperative, and postoperative interincisal distances (ID) for at least 6 months after surgery. RESULTS The mean preoperative ID was 18.9 mm (range, 8 to 25 mm) in group I and 18 mm (range, 7 to 25 mm) in group II. The intraoperative ID increased to an average of 39 mm in group I and 38.5 mm in group II. The mean final follow-up ID was 22 mm in group I and 36.1 mm in group II. When evaluating the changes of ID, only a statistically significant difference was found at final visit between groups. CONCLUSIONS In our study, we found the patients cooperation is the primary requirement for success in the treatment of OSF.

Intraoral vertical ramus osteotomy for correction of mandibular prognathism: long-term stability.

Various techniques and modifications have been introduced in the treatment of mandibular prognathism. However, there are still few reports concerning long-term stability, especially using the intraoral vertical ramus osteotomy (IVRO) method. The purpose of this study was to investigate the long-term stability for correction of mandibular prognathism using IVRO. Twenty-five mandibular prognathism patients were treated by bilateral IVRO, and were evaluated cephalometrically by reference to the menton. A set of 3 standardized lateral cephalograms were obtained from each subject preoperatively (T1), immediately postoperatively (T2), and after 2 years postoperatively (T3). Relapse was defined as forward movement of menton after the 2-year follow-up. The mean setback of the menton was 12.8 mm in horizontal direction and 0.9 mm downward in vertical direction. The average follow-up was 33.9 months. The mean relapse was 1.3 mm (10.2% = 1.3 of 12.8) in forward direction and 0.6 mm in upward direction. There was no significant movement in the vertical direction. However, significant relapse was shown in the horizontal direction, even though the amount was small. The long-term stability of our present study suggested that IVRO is useful for correction of mandibular prognathism.

Surgical Management of Accidentally Displaced Mandibular Third Molar into the Pterygomandibular Space: A Case Report

Surgical removal of the mandibular third molar is a regular surgical procedure in dental clinics, and like all operations, it may have some complications, such as infection, bleeding, nerve injuries, trismus and so on. An accidentally displaced lower third molar is a relatively rare complication, but may cause severe tissue injury and medicolegal problems. As few papers and cases have been published on this topic, we report this case to remind dentists on ways to prevent and manage this complication. The patient, a 28‐year‐old male, had his right lower mandibular third molar extraction in January 2006. The dentist resected the crown and attempted to remove the root but found that it had suddenly disappeared from the socket. Assuming that the root had been suctioned out he closed the wound. The patient was not followed up regularly because he studied abroad. About 3 months later, the patient felt a foreign body sensation over his right throat, and visited a local hospital in Australia. He was told after a computed tomography (CT) scan that there was a root‐like radio‐opaque image in the pterygomandibular space. The patient came to our hospital for further examination and management in June 2006. We rechecked with both Panorex and CT and confirmed the location of the displaced root. Surgery for retrieving the displaced root was performed under general anesthesia by conventional method without difficulty, and the wound healed uneventfully except for a temporary numbness of the right tongue. This case reminds us that the best way to prevent a displaced mandibular third molar is to evaluate the condition of the tooth carefully preoperatively, select adequate instruments and technique, and take good care during extraction. If an accident does occur, dentists should decide whether to retrieve it immediately by themselves or refer the case to an oral and maxillofacial surgeon, and should not try to remove the displaced root without proper assurance. Localization with images and proper surgical methods are the keys to retrieving the displaced fragment successfully. When immediate retrieval is decided on, Panorex and occlusal view are useful in localizing the displaced fragment. When the fragment moves into a deeper space or the retrieval has been delayed for months, three‐dimensional CT seems to be a better choice.

TGF-β1 and IL-10 single nucleotide polymorphisms as risk factors for oral cancer in Taiwanese

Cytokine production capacity varies among individuals and depends on cytokine gene polymorphisms. Transforming growth factor‐beta 1 (TGF‐β1) plays a significant role in regulating the proliferation and apoptosis of epithelial cells. Interleukin 10 (IL‐10) is an immunoregulatory cytokine with biological functions of anti‐inflammation, immunosuppression, allergy, and anti‐agenesis. The two cytokines are supposed to play an important role in carcinogenesis. The association between cytokine gene polymorphisms with oral cancer (OC) was investigated. We studied the association between the polymorphism in TGF‐β1 (G to C polymorphism at codon 25 <+915>) and IL‐10 (−1082 G/A, ‐819 C/T, and −592 C/A) and the risk of OC in patients (n = 162) and healthy controls (n = 118) in Taiwan. All genotyping experiments were performed using the polymerase chain reaction sequence‐specific primer (PCR‐SSP) method. It was found that the codon 25 GC genotype of TGF‐β1 is significantly higher in frequency in patients with OC compared with a healthy control group (p < 0.0001). People with the GC genotype in codon 25 had an 11.09‐fold increased risk of OC [odds ratio (OR) = 11.09; 95% confidence interval (CI) = 6.16–113.23]. IL‐10 polymorphisms in −819 and −592 positions correlated with the risk of OC (p < 0.0001). The IL‐10 ‐592 C allele‐containing genotypes posed an increased risk of OC (OR = 1.79, 95% CI = 1.11–2.91). People with the CT genotype in IL‐10 ‐819 had a 3.32‐fold increased risk of OC (OR = 3.32; 95% CI = 1.64–6.94). The results suggest that polymorphisms in TGF‐β1 and IL‐10 may have a significant influence on the development of OC.

Role of cytokine gene (interferon-γ, transforming growth factor-β1, tumor necrosis factor-α, interleukin-6, and interleukin-10) polymorphisms in the risk of oral precancerous lesions in Taiwanese

Oral squamous cell carcinoma can be preceded by some benign oral lesions with malignant potential, including leukoplakia, erythroplakia, oral lichen planus, and oral submucous fibrosis. There are different degrees of inflammatory cells infiltration in histopathology. Inflammatory cytokines may play a pathogenic role in the development of oral precancerous lesions (OPCLs). Genetic polymorphisms of cytokine‐encoding genes are known to predispose to malignant disease. We hypothesized that the risk of OPCLs might be associated with cytokine gene polymorphisms of interferon (IFN)‐γ, transforming growth factor (TGF)‐β1, tumor necrosis factor (TNF)‐α, interleukin (IL)‐6, and IL‐10. In the present study, 42 OPCL patients and 128 controls were analyzed for eight polymorphisms in five different cytokine genes [IFN‐γ (+874 T/A), TGF‐β1 (codons 10 T/C and 25 G/C), TNF‐α (−308 G/A), IL‐6 (−174 G/C), and IL‐10 (−1082 A/G, –819 T/C, and −592 A/C)]. Cytokine genotyping was determined by the polymerase chain reaction sequence‐specific primer technique using commercial primers. Allele and genotype data were analyzed for significance of differences between cases and controls using the Chi‐square (χ2) test. Two‐sided p < 0.05 were considered to be statistically significant. A series of multivariate logistic regression models, adjusted for age, sex, betel quid chewing, alcohol consumption, and smoking, was constructed in order to access the contribution of homozygous or heterozygous variant genotypes of polymorphisms. The TNF‐α (−308) polymorphism was significantly associated with OPCLs. There were significant differences in the distribution of AA, GA, and GG genotypes between OPCL patients and controls (p = 0.0004). Patients with the AA or GA genotype had a 3.63‐fold increased risk of OPCLs. The TGF‐β1 (codon 10 and 25) polymorphism was also significantly associated with OPCLs (p < 0.001). The IL‐6 polymorphism was significantly associated with OPCLs. There are significant differences in the distribution of CC, GC, and GG genotypes between OPCL patients and controls (p < 0.001). Patients with the CC or GC genotype had a 35‐ or 20.59‐fold increased risk of OPCLs. There were no significant differences in the distribution of IL‐10 and IFN‐γ genotypes between different groups of control individuals and OPCL patients. The IL‐6, TGF‐β1, and TNF‐α gene polymorphisms may have a significant association with the development of OPCLs.

Artificial dermis as the substitute for split-thickness skin graft in the treatment of oral submucous fibrosis.

Objectives: The aim of this study was to investigate the viability of artificial dermis as a substitute for split-thickness skin graft in the treatment of oral submucous fibrosis (OSF). Methods: The study was conducted on 21 patients who had undergone surgical treatment of trismus caused by OSF. Artificial dermis grafts were used to repair the surgical defects after surgery on the fibrous bands. The changes in the interincisal distances (IDs) were analyzed in the preoperative, intraoperative, and postoperative stages. All the patients were followed up for at least 3 months. Results: All the patients habitually chewed betel nuts. The overall success rate was 100% without any or only partial graft loss. There were no reports of immunologic reactions or significant complications. The mean preoperative, intraoperative, and final follow-up IDs were 15.5, 35, and 25 mm, respectively. Evaluation of the changes in the IDs revealed statistically significant differences between the values recorded at the different stages. Conclusions: Artificial dermis may be an alternative to split-thickness skin grafts in patients with OSF with moderate trismus.

Artificial Dermis Graft on the Mandible Lacking Periosteum After Excision of an Ossifying Fibroma: A Case Report

Collagen‐based grafts have often been used as artificial tissue substitutes for the repair of tissue and organ defects. It is common surgical knowledge that autogenous or artificial skin grafts take well on the intact periosteum of bone. However, many experienced surgeons indicate that auto‐genous or artificial skin grafts subsist poorly on the bone surface without periosteum. Therefore, primary closure is usually recommended in the wound healing of exposed bone. Vestibuloplasty might be needed to create enough depth of vestibule in the future. In this case report, we describe a peripheral ossifying fibroma surgically excised leaving a bony defect, which was covered by a piece of artificial dermis. Satisfactory result of the repaired surgical defect showed no need of vestibuloplasty after 6 years of follow‐up.

Interdisciplinary Management of Dental Implant Patient: A Case Report

Maxillary molars can over‐erupt when their antagonists are lost and there are no replacements. When the opposing molars severely extrude into the edentulous space, it is difficult to replace the missing teeth with either fixed or removable prostheses. We present the following case report, providing a solution for this type of problem. A two‐stage posterior subapical osteotomy was used to reestablish the intermaxillary space. Following orthodontic treatment and implant placement, the patient regained occlusal harmony and normal masticatory function.

Eye patch sandwich technique for stabilizing the intraoral skin graft to the cheek.

It is very important to secure skin graft in the defect of oral cavity. The tie-over bolster technique is the most common method for securing intraoral skin grafts. However, gauze is the best material as a bolster that can easily accumulate saliva and debris and cause odor and discomfort to the patient. We describe an alternative technique to stabilize intraoral skin graft between 2 aluminous eye patches and to readily keep the oral hygiene during the securing period.

Clinical evaluation of a new bilayer artificial dermis for repair of oral mucosal defects: report of two cases.

Free mucosal grafts or split‐thickness skin grafts have been used in patients undergoing repair procedures for oral mucosal defects. Conventional methods require the creation of second surgical wounds for use as donor sites. We applied two bilayers of artificial dermis to repair a buccal mucosal defect in one case and vestibular extension in another case. After removal of the sutures, no infection, pain, or hemorrhage developed in these patients. The results of granulation and epithelialization were good. Satisfactory appearance and function were achieved in both cases. Therefore, bilayer artificial dermis may be recommended for the repair of oral mucosal defects.