Sung-Kiang Chuang

Paan without tobacco: an independent risk factor for oral cancer.

Oral cancer is the second most common cancer in women and the third most common in men in Pakistan. Tobacco is smoked and chewed extensively in Pakistan. Paan is a quid of piper betel leaf that contains areca nut, lime, condiment, sweeteners, and sometimes tobacco, which is also used extensively. We did this study to clarify the independent association of paan and oral cancer. Between July 1996 and March 1998, we recruited biopsy‐proven, primary cases of oral squamous‐cell carcinoma, from 3 tertiary teaching centers in Karachi, Pakistan, and controls pair‐matched for age, gender, hospital and time of occurrence, excluding persons with a past or present history of any malignancy. There were 79 cases and 149 controls. Approximately 68% of the cases were men, 49 years old on average, the youngest being 22 years old and the eldest 80. People with oral submucous fibrosis were 19.1 times more likely to develop oral cancer than those without it, after adjusting for other risk factors. People using paan without tobacco were 9.9 times, those using paan with tobacco 8.4 times, more likely to develop oral cancer as compared with non‐users, after adjustment for other co‐variates. This study identifies an independent effect of paan without tobacco in the causation of oral cancer. Its findings may be of significance in South Asian communities where paan is used, and among health‐care providers who treat persons from South Asia. Int. J. Cancer 86:128–131, 2000.

Morbidity Associated With Oral Mucosa Harvest for Urological Reconstruction: An Overview

PURPOSE To present a systematic review of the literature regarding complications associated with the donor site following oral mucosa harvest for urethral reconstruction. MATERIALS AND METHODS The authors conducted a database search for relevant literature during the time period January 1966 through January 1, 2007, regarding complications associated with oral mucosa graft harvest for use in urethral transplantation. Bibliographies of database hits were searched for pertinent papers. RESULTS The most common harvest sites were the buccal and mandibular labial mucosa. The most frequent complications at both mucosal harvest sites were scarring and contracture. These 2 complications limit jaw opening and have been found to last for as long as 4 weeks. Labial mucosa harvest is associated with the additional morbidity of perioral neurosensory defect because of the procedures proximity to the mental nerve. When nerve damage occurs, it usually subsides within 10 months postsurgery. Patients report relatively the same quality of life following harvest from both donor sites, although buccal mucosa harvest was associated with less postoperative discomfort, less neurosensory defect, and less salivary flow change. Following oral mucosa harvest, patients should be able to ingest oral fluids within 24 hours, solid foods within 2 days, and return to a normal dietary regimen within 1 week of harvest. CONCLUSION When harvesting oral mucosa for urethral reconstruction, sound surgical principles will ensure the patient the best chance of avoiding postoperative complications at the donor site. Oral and maxillofacial surgeons should advise both urologists and their patients of the potential complications associated with both oral mucosa harvesting sites.

Implant loading protocols for edentulous patients with fixed prostheses: a systematic review and meta-analysis.

PURPOSE To report on the effect of immediate implant loading with fixed prostheses compared to early and conventional loading on implant and prosthesis survival, failure, and complications. MATERIALS AND METHODS An electronic and manual search was conducted to identify randomized controlled clinical trials (RCTs) as well as prospective and retrospective studies involving rough surface implants and implant fixed complete dental prostheses for edentulous patients. RESULTS The 62 studies that fulfilled the inclusion criteria featured 4 RCTs, 2 prospective case-control studies, 34 prospective cohort studies, and 22 retrospective cohort studies. These studies yielded data from 2,695 patients (2,757 edentulous arches) with 13,653 implants. Studies were grouped according to the loading protocol applied; 45 studies reported on immediate loading, 8 on early loading, and 11 on conventional loading. For the immediate loading protocol with flap surgery, the implant and prosthesis survival rates ranged from 90.1% to 100% and 93.75% to 100%, respectively (range of follow-up, 1 to 10 years). When immediate loading was combined with guided flapless implant placement, the implant survival rates ranged from 90% to 99.4%. For the early loading protocol, the implant and prosthesis survival rates ranged from 94.74% to 100% and 93.75% to 100%, respectively (range of follow-up, 1 to 10 years). For the conventional loading protocol, the implant and prosthesis survival rates ranged from 94.95% to 100% and 87.5% to 100%, respectively (range of follow-up, 2 to 15 years). No difference was identified between maxilla and mandible. CONCLUSIONS When selecting cases carefully and using dental implants with a rough surface, immediate loading with fixed prostheses in edentulous patients results in similar implant and prosthesis survival and failure rates as early and conventional loading. For immediate loading, most of the studies recommended a minimal insertion torque of 30 Ncm. The estimated 1-year implant survival was above 99% with all three loading protocols. Caution is necessary when interpreting these results, as there are many confounding factors that affect treatment outcomes with each of the loading protocols.

Crown-to-Implant Ratios of Short-Length Implants

Excessive crown-implant ratios have been cited in the literature as being detrimental to long-term implant survival. However, unfavorable crown-implant ratios have not yet been established. The primary aim of this study was to determine the crown-implant ratios of single-tooth implant-supported restorations on short-length implants in a clinical practice, and to evaluate the health of these implants via mesial and distal first bone-to-implant contact levels. Additionally, the relationship between crown-implant ratios and proximal first bone-to-implant contact levels will be evaluated. In this retrospective cohort study, the cohort was composed of 194 patients who possessed at least 1 single 5.7 mm or 6 mm length plateau design implant-supported restoration that had been surgically placed between February 1997 and December 2005. A chart review was performed to acquire the most recent radiographs in which both the entire crown and the implant were visible. The length of the crown and implant was measured directly from the radiographs using consistent magnification to calculate the crown-implant ratio. Mesial and distal first bone-to-implant contact levels were measured using 3 times magnification and were mathematically corrected for distortion. The last available radiograph was used to measure bone levels. Follow-up time was calculated from the day of implant placement to the date of the last available radiograph. Statistical analyses with analysis of variance mixed models were used. Data from 309 single implant-supported fixed restorations were tabulated and included in the study. The mean (SD) follow-up time was 20.9 (23.2) months, with a range of 15.6 to 122.8 months. The mean crown length (SD) was 13.4 (2.6) mm, with a range of 6.2 to 21.7 mm. The mean (SD) crown-implant ratio was 2.0 (0.4) and ranged from 0.9 to 3.2. The average mesial and distal first bone-to-implant contact levels (SD) measured from the radiographs were -0.2 (0.7) mm and -0.2 (0.9) mm, respectively. No statistically significant relationship was observed between increasing crown-implant ratios and decreasing mesial and distal first bone-to-implant contact levels around the implant with P values of .94 and .57, respectively. In this investigation, mesial and distal first bone-to-implant contact levels on short-length implants fall within the established guidelines for success. Also, there are no associations between crown-implant ratios and first bone-to-implant contact levels.

Dimensional changes of peri-implant soft tissue over 2 years with single-implant crowns in the anterior maxilla

OBJECTIVE To compare the peri-implant soft tissue dimensions after insertion of single-implant crowns in the anterior maxilla. MATERIALS AND METHODS Twenty patients were accepted according to well-defined inclusion criteria and randomized to porcelain-fused-to-metal (PFM) or all-ceramic groups. Follow-up was at: Baseline (B), Crown Insertion (CI), 1-year (1Y), and 2-year (2Y). The following parameters were statistically analysed: distance implant shoulder to marginal peri-implant mucosa (DIM), papilla height (PH), width of keratinized mucosa (KM), crestal bone level (CBL), full mouth plaque score (FMPS), full mouth bleeding score (FMBS), and probing pocket depth. RESULTS Between groups measurements for DIM, PH, KM, CBL, FMPS, and FMBS showed no statistically significant differences except the distal CBLs to adjacent tooth. DIM (mid-facial) decreased from B to CI remaining stable at 1Y and 2Y (p-value 0.0014). DIM mesial and distal aspects significantly increased from B to CI showing signs of stability at the 2Y. PH between B and CI increased at the mesial site and at the distal site, thereafter, peri-implant soft tissues were stable at the 2Y. CONCLUSION The insertion of an implant crown affects the peri-implant mucosa morphology by an apical displacement at the mid-facial aspect and coronal at mesial and distal sites.

Osteosarcoma of the Jaws: Factors Influencing Prognosis

PURPOSE To evaluate patient, tumor, and treatment variables associated with survival in patients with jaw osteosarcoma (JOS) and to compare survival in patients treated before 1991 with those managed with more aggressive treatment protocols since 1992. PATIENTS AND METHODS This is a retrospective cohort study of patients with JOS treated at Massachusetts General Hospital from 1967 through 2007. Patients were divided by treatment date into Group 1, 1967 to 1991 (n = 30) and Group 2, 1992 to 2009 (n = 17). Medical records were reviewed to collect the following: demographic, radiographic, tumor-specific, treatment, and survival data. The 2 subgroups were statistically compared. RESULTS There were 47 patients (32 males, 15 females) with a mean age of 30.9 years (range 4 to 74). Mandibular location showed a trend toward improved survival (P = .06). Average tumor size was 4.38 cm (range 0.5 to 9.0 cm). Larger tumors were associated with decreased overall survival (P = .016). Higher grade tumors had decreased overall survival (P = .01). Clear surgical margins were obtained in 67% of patients. Clear surgical margins correlated with improved survival (P = .002). Maxillary JOS constituted 83% of those with positive margins. Overall, 5-year survival was 68%. Improved 5-year survival was noted in group 2 (77%) compared with group 1 (52%) [P = .0073]. Patients who developed secondary osteosarcomas (n = 10) had 4.5-fold increased risk of death (P = .01). Recurrence was associated with 7-fold increased risk of death (P = .0008). Thirteen patients died of JOS. CONCLUSIONS Improved survival was noted in treatment group 2. This group benefited from improved imaging, earlier diagnosis and more aggressive treatment that included improved surgical clearance. A clear survival advantage for neoadjuvant chemotherapy was not demonstrated.

Prognostic Factors Affecting the Duration of Disability After Third Molar Removal

PURPOSE The purposes of this investigation were 1) to estimate the duration of disability after third molar removal and 2) to identify factors associated with prolonged recovery. MATERIALS AND METHODS This was a prospective cohort study composed of subjects enrolled in the American Association of Oral and Maxillofacial Surgeons Age-Related Third Molar Study. The predictor variables were grouped as follows: demographic, health status, anatomic, pathologic, medications, and complications. The outcome variable was the duration of postoperative disability measured as the number of days the subject reported inability to perform normal daily activities after third molar removal. Bivariate and multiple linear regression analyses were used. The level of statistical significance was P < .05. RESULTS The study sample included 4,004 subjects who had 8,748 third molars removed. The mean duration of postoperative disability was 1.4 ± 1.8 days (range, 0-26; median, 1 day). In the multiple linear regression model, age, female gender, number of third molars removed, mandibular third molar removal, full-bony impaction, sum of antibiotics or pain medications, and complications were associated with prolonged recovery (P < .05). Erupted third molars, periodontal disease or other preoperative pathology, and use of chlorhexidine were associated with earlier return to normal daily activities (P < .05). CONCLUSION The study results suggest that third molar removal is associated with a mean delay in returning to normal activities of less than 2 days. Several factors were statistically associated with time to return to normal activities.

Survey of Residents Who Have Participated in Humanitarian Medical Missions

PURPOSE To survey physicians who participated in humanitarian missions as residents to assess the value of this experience on residency training and future career choices. MATERIALS AND METHODS An anonymous 26-question survey was electronically mailed to 45 individuals identified as having participated in a cleft lip/palate mission during residency. The survey was created and distributed, and the data were collected using the online survey engine Survey Monkey. RESULTS Thirty-nine individuals (86.7%) completed the survey. Of these, 27 were men (69.2%) and 12 were women (30.8%). Thirty-two (82.1%) were oral and maxillofacial surgeons, 4 (10.3) were plastic and reconstructive surgeons, 1 (2.6%) was an otolaryngologist, and 2 (5.1%) were pediatric dentists. Twenty-five respondents (64.1%) stated that, before their first mission, they had not operated on a primary cleft lip; 21 (53.8%) noted that they had not operated on a primary cleft palate before their first mission. Thirty-six (92.3%) noted that their mission experience improved their ability to repair facial clefts. Thirty-seven (94.9%) believed their mission experience improved their overall surgical skill. All respondents (n = 39, 100%) believed their mission experience improved their overall ability to evaluate patients with cleft. Thirty-six (92.3%) believed their experience in humanitarian missions made them more culturally sensitive/competent health care providers. Thirty-eight respondents (97.4%) believed these missions made them more socially aware of the differences in access/availability of health care globally. Thirty-eight (97.4%) believed that participation in a humanitarian mission was a high point of their residency. Thirty-seven (94.9%) planned to participate in humanitarian medical missions during their career after residency. CONCLUSION All respondents believed that participation in a humanitarian mission during residency was a positive part of their training. In addition, these missions allowed the residents to develop as surgeons and improve their awareness of global health care and cultural competence. Given these important educational aspects, participation in a humanitarian mission should be considered a required part of residency training.

Botulinum toxin therapy for temporomandibular joint disorders: a systematic review of randomized controlled trials

The objective of this study was to undertake a systematic review to assess the efficacy of botulinum toxin therapy (BTX) for temporomandibular joint disorders (TMDs). A comprehensive search of major databases through PubMed, EMBASE, and Cochrane CENTRAL was conducted to locate all relevant articles published from inception to October 2014. Eligible studies were selected based on inclusion criteria and included English language, peer-reviewed publications of randomized controlled trials comparing BTX versus any alternative intervention or placebo. Quality assessment and data extraction were done according to the Cochrane risk of bias tool and recommendations. The entire systematic search and selection process was done independently by two reviewers. Five relevant study trials were identified, involving 117 participants. Two trials revealed a significant between-group difference in myofascial pain reduction, another trial that compared BTX with fascial manipulation showed equal efficacy of pain relief on TMDs, while the remaining two trials showed no significant difference between the BTX and placebo groups. Because of considerable variations in study methods and evaluation of results, a meta-analysis could not be performed. Based on this review, no consensus could be reached on the therapeutic benefits of BTX on TMDs. A more rigorous design of trials should be carried out in future studies.

Comparison of methohexital and propofol use in ambulatory procedures in oral and maxillofacial surgery.

PURPOSE Short-acting anesthetic agents, such as propofol and methohexital, are commonly used for ambulatory procedures in the practices of oral and maxillofacial surgeons (OMS). This study compares the safety and anesthetic outcomes of propofol and methohexital. In addition, the study compares the safety and outcomes of these agents when administered either by an OMS who simultaneously provides anesthesia and performs the procedure (anesthetist/surgeon), or by a non-OMS provider of anesthesia (anesthesiologist or certified registered nurse anesthetist; CRNA) whose sole obligation is to provide anesthesia. MATERIALS AND METHODS This is a prospective study of anesthesia techniques used in an office-based ambulatory setting by OMS throughout the United States, in which either propofol or methohexital was used for sedation/anesthesia. The study variables included demographic information, anesthetic agent, adverse outcomes related to anesthesia, operative procedure, and provider of anesthesia. These variables were compared with the patient group that received a benzodiazepine/narcotics regimen for sedation (control group). Bivariate (contingency tables) and multivariate (logistic regression) analyses were conducted. P < or = .05 was considered statistically significant. RESULTS The study included 47,710 patients who met the inclusion criteria: 26,147 (54.8%) patients were in the propofol group, 15,859 (33.2%) were in the methohexital group, and 5,704 (12.0%) were in the benzodiazepine group. Among all study patients, 333 (0.7%) had an adverse event. The most common complication was nausea and vomiting without aspiration. Of the patients in the propofol group, methohexital group, or benzodiazepine group, 0.4%, 1.1%, and 0.8% had an adverse event, respectively. The higher number of complications among patients in the methohexital group compared with patients in the other 2 groups was statistically significant. Of 26,147 patients in the propofol group, 23,799 (91.0%) received anesthesia from an anesthetist/surgeon (OMS), and 2,368 (9.1%) from an anesthesiologist or nurse anesthetist (non-OMS). A total of 109 patients (0.4%) had an adverse event. The majority of patients who received anesthesia from a non-OMS were in the propofol group (2,368 of 2,404 patients; 98.5%). There was no statistically significant difference in the occurrence of adverse outcomes when comparing patients in the propofol group who received anesthesia from an OMS with those who received anesthesia from a non-OMS (P = .24, bivariate analysis; P = .33, multivariate analysis). CONCLUSIONS There is a statistically significant increase in adverse events related to methohexital compared with propofol or benzodiazepine/narcotics for anesthesia. Propofol appears to have the lowest risk for adverse events. There is no statistically significant difference in the number of adverse outcomes between the administration of propofol for ambulatory surgery by OMS as an anesthetist/surgeon and anesthesiologist/nurse anesthetist. It remains critical that our specialty maintains the highest standards, to provide safe anesthesia and to reduce adverse anesthetic events.