I-Yueh Huang

Malignant transformation of oral potentially malignant disorders in males: a retrospective cohort study.

BackgroundOral squamous cell carcinoma could be preceded by clinically evident oral potentially malignant disorders (OPMDs). Transformation of OPMDs to cancer has been studied in several population groups. It is difficult to undertake comparisons across populations due to variations in the methods of computation of malignancy rates among different studies. The aim of our study was to estimate the rate of malignant transformation of OPMDs taking into account the duration of follow-up and to identify the significant factors indicative of malignant potential.MethodsA total of 148 male patients with OPMDs were included. They were selected among all consecutive subjects registered at the maxillofacial clinic at a medical hospital in Kaohsiung, Taiwan. The mean follow up period was 37.8 months.ResultsThe malignant transformation rate was highest in subjects diagnosed with oral epithelial dysplasia. In this group the transformation rate was 7.62 per 100 persons-year. The rate in the group with verrucous hyperplasia (VH) was 5.21 per 100 persons-year, and in those with hyperkeratosis or epithelial hyperplasia was 3.26 per 100 persons-year. The anatomical site of OPMDs was the only statistically significant variable associated with malignancy. The hazard rate ratio (HRR) was 2.41 times for tongue lesions when compared with buccal lesions.ConclusionThe reported discrepancies of malignant transformation of OPMDs involve the follow-up time to cancer development and hence it is preferable to use a time-to-event estimation for comparisons. We found that malignant transformation of OPMDs involving the tongue was significantly higher than in other anatomical subsites after adjusting for the clinicopathological type or lifestyle factors at diagnosis.

DONOR SITE MORBIDITY AFTER HARVESTING OF PROXIMAL TIBIA BONE

Bone‐grafting procedures are common in head and neck surgery. Donor site morbidity is an important factor in deciding the site for harvest of cancellous bone. The tibia has been recommended as a harvest site. Use of the proximal tibia as a donor site is associated with few complications. Our present study used proximal tibia bone grafts to reconstruct maxillofacial defects and augment bone volume for implantation.

EFFECTIVE ERADICATION OF ORAL VERRUCOUS CARCINOMA WITH CONTINUOUS INTRAARTERIAL INFUSION CHEMOTHERAPY

We evaluated the effectiveness of intraarterial methotrexate infusion as a primary therapy for oral verrucous carcinoma (VC).

Study of the changes in collagen of the tunica albuginea in venogenic impotence and Peyronie's disease.

We identified the collagen type and content of the tunica albuginea in Peyronies disease and venogenic impotence compared with the tunica albuginea from the donor of the renal transplant and patients with penile injury. Type III collagen was detected obviously in Peyronies plaque and was also present in venogenic impotence. It can be hardly found in normal controls. The ratios of type III to type I collagen were significantly higher in Peyronies plaque while there was a moderate increase in venogenic impotence. The scarcity of type V collagen was noted in human tunica albuginea. The decreased percentage of glycine and alanine in Peyronies disease and venogenic impotence implied the abnormal composition of collagen or presence of noncollagen protein. The results suggest the biochemical aberration of the tunica albuginea might interfere with the normal function of the penile drainage system.

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.

The use of miniplate osteosynthesis for skeletal anchorage.

Background: The purpose of this study was to explore the use of miniplates as skeletal anchorages for orthodontic treatment and to investigate the stability of miniplates and the causes of failure. Methods: Forty-four miniplates were applied in the maxilla or mandible as skeletal anchorages in orthodontic treatment. Two weeks later, a force of 100 to 200 g was applied by an elastometric chain or nickel-titanium coil spring to move the teeth. To compare nominal variables related to miniplate failure, the chi-square or Fishers exact test was used. Results: The average insertion time of a miniplate was approximately 25 to 30 minutes. One miniplate loosened before orthodontic force loading. The other miniplate was removed after orthodontic force loading. The overall success rate was 95.5 percent. The authors found no significant differences in the risk factors for failure of miniplates. Conclusions: Miniplates are easy to insert for skeletal anchorage, simplify treatment mechanics, and shorten the orthodontic treatment period.

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.

Caldwell-Luc procedure for retrieval of displaced root in the maxillary sinus

OBJECTIVE The aim of this study was to describe the standard diagnostic procedure and the application of the Caldwell-Luc approach for the retrieval of a displaced root from the maxillary sinus and to share our experience in treating this complication. STUDY DESIGN Twenty-four patients with a fractured root accidentally displaced into the maxillary sinus were referred by general dentists to our department from 2005 to 2008. All were managed by a standardized diagnostic procedure and a Caldwell-Luc approach. We recorded the age of each patient, the gender, the tooth, the size of root fragment, the type of displacement the delay between displacement and retrieval, the length of operating time, and any complications. RESULTS Over a 4-year period, we treated 24 patients, 14 being male and 10 female. Ages ranged from 14 to 55 years (average 26.4). The commonest tooth involved was the maxillary first molar; the length of the root fragments ranged from 3 to 7 mm. Seventeen of these roots were mobile and 7 fixed (4 being located between the sinus membrane and the bone and 3 immobilized by the sinus membrane. Twenty-three of the operations were completed in 30 minutes, and only 2 patients had a temporary complication of sinusitis. No infraorbital paresthesia occurred. CONCLUSIONS The standardized diagnostic procedure and Caldwell-Luc approach for the retrieval of a displaced root form the maxillary sinus is a safe, simple, and fast method with minimal complications.

Mucoceles of the oral cavity in pediatric patients

Mucoceles are quite common in the oral cavity, but reports on pediatric patients are very rare. The aims of this study were to present our data and experience in the treatment of mucoceles of the oral cavity in pediatric patients, to compare them with those of other countries, and to remind the pediatric physician to devote much attention to lesions of the oral cavity in children. This retrospective study is based on the record of the patients who received surgical treatment for mucoceles of the oral cavity with pathologic confirmation at the Department of Dentistry, Kaohsiung Medical University Hospital, Taiwan, between 2000 and 2004. Patients younger than 18 years were included in this study. The analyzed data included age, gender, site, size, histopathologic findings, surgical methods, and complications. There were a total of 289 patients with mucoceles confirmed by histopathologic examination. As many as 64 patients were younger than 18 years. Of the 64, 34 were girls and 30 were boys; 89.1% of the lesions were in the lower lip; and 48.4% of the lesions were less than 5 mm in diameter. Histopathologic findings showed that all mucoceles were of the extravasation type. As many as 30 patients were treated by carbon dioxide laser vaporization, and two cases recurred (6.67%); 34 patients were treated by surgical excision, and the recurrence rate (5.88%) was not statistically different for the treatment methods. The laser vaporization has the advantage of less bleeding, no sutures, and saving time, especially suitable for children with oral mucocele.

Comparing dose-response measurements of oral habits on oral leukoplakia and oral submucous fibrosis from a community screening program.

BACKGROUND Many studies have reported that the interaction and dose-response effects of betel quid chewing, tobacco smoking and alcohol drinking habits are important risk factors for oral cancer and precancerous lesions or conditions. These results are useful for comparing statistics, but may not be informative for personal disease-related information. METHODS This study used data from a community screening program to evaluate the dose-response effects of daily frequency and duration from oral habits in Taiwan. The receiver operating characteristic (ROC) curves were further used to compare exposure measurements on indicating the occurrence of lesions/conditions. RESULTS Our results showed that the highest prevalence was found in leukoplakia (11.1%) and followed by oral submucous fibrosis (OSF, 4.4%). Betel quid chewing habit was found to have dose-response effects on leukoplakia and OSF, cigarette smoking habit only has the dose-response effect on leukoplakia, and alcohol drinking was not associated with both oral precancers. The daily frequency of chewing habit is a better indicator than other dose-response measurements for the occurrence of precancers. In addition, the cut-off points of two to five counts per day have about 60-82% of sensitivities and 79-88% of specificities. CONCLUSIONS The cut-off points from ROC curves can provide an informative message to people with oral habits and their chances of developing diseases. High daily frequency of chewing can lead to excessive irritation to oral mucosa. Although the tobacco is never added to chewing quid in Taiwan, intensive irritation may play an important role in developing oral precancers in Taiwan.