Human masseter muscle fiber type properties, skeletal malocclusions, and muscle growth factor expression

PURPOSE

We identified masseter muscle fiber type property differences in subjects with dentofacial deformities.

PATIENTS AND METHODS

Samples of masseter muscle were collected from 139 young adults during mandibular osteotomy procedures to assess mean fiber areas and percent tissue occupancies for the 4 fiber types that comprise the muscle. Subjects were classified into 1 of 6 malocclusion groups based on the presence of a skeletal Class II or III sagittal dimension malocclusion and either a skeletal open, deep, or normal bite vertical dimension malocclusion. In a subpopulation, relative quantities of the muscle growth factors IGF-I and GDF-8 gene expression were quantified by real-time polymerase chain reaction.

RESULTS

Fiber properties were not different in the sagittal malocclusion groups, but were very different in the vertical malocclusion groups (P ≤ .0004). There were significant mean fiber area differences for type II (P ≤ .0004) and type neonatal-atrial (P = .001) fiber types and for fiber percent occupancy differences for both type I-II hybrid fibers and type II fibers (P ≤ .0004). Growth factor expression differed by gender for IGF-I (P = .02) and GDF-8 (P < .01). The ratio of IGF-I:GDF-8 expression associates with type I and II mean fiber areas.

CONCLUSION

Fiber type properties are very closely associated with variations in vertical growth of the face, with statistical significance for overall comparisons at P ≤ .0004. An increase in masseter muscle type II fiber mean fiber areas and percent tissue occupancies is inversely related to increases in vertical facial dimension.

Intracellular trafficking pathways involved in the gene transfer of nano-structured calcium phosphate-DNA particles

Nano-structured calcium phosphate (NanoCaP) particles have been proven to be a powerful means of non-viral gene delivery. In order to better understand the mechanisms through which NanoCaPs-mediated mammalian cell transfection is achieved, we have sought to define the intracellular trafficking pathways involved in the cellular uptake and intracellular processing of these particles. Previous work has indicated that NanoCaP-DNA complexes are most likely internalized via endocytosis, however the subsequent pathways involved have not been determined. Through the use of specific inhibitors, we show that endocytosis of NanoCaP particles is both clathrin- and caveolae-dependent, and suggest that the caveolaer mechanism is the major contributor. We demonstrate colocalization of NanoCaP-pDNA complexes with known markers of both clathrin-coated and caveolar vesicles. Furthermore, through the use of quantitative flow cytometry, we present the first work in which the percent internalization of CaP-DNA complexes into cells is quantified. The overall goal of this research is to foster the continued improvement of NanoCaP-based gene delivery strategies.

Cytochrome c oxidase deficiency in human posterior cricoarytenoid muscle

BACKGROUND

Mitochondrial alterations occur in skeletal muscle fibers throughout the normal aging process, resulting from increased accumulation of reactive oxide species (ROS). These result in respiratory chain abnormalities, which decrease the oxidative capacity of muscle fibers, leading to decreased contractile force, sarcopenia, or fiber necrosis. Intrinsic laryngeal muscles are a cranial muscle group that possesses some distinctive genotypic, phenotypic, and physiologic properties. Their susceptibility to mitochondrial alterations resulting from biological processes that increase levels of oxidative stress may be one of these distinctive characteristics.

OBJECTIVES

The incidence of cytochrome c oxidase (COX) deficiency (COX(-)) was determined in human posterior cricoarytenoid (PCA) muscle when compared with the human thyrohyoid (TH) muscle, an extrinsic laryngeal muscle that served as "control" muscle. Ten PCA and 10 TH muscles were harvested postlaryngectomy from 10 subjects ranging in age from 55 to 86 years. Differences in COX(-) were compared within and between muscle types using tissue section staining and standard morphometric analysis.

RESULTS AND CONCLUSIONS

COX(-) fibers were identified in both the PCA and TH muscles. The PCA muscle had 10 times as may affected fibers as the TH muscle, with significant differences in COX(-) found between muscle type and fiber type (P=0.003). Almost all of this effect was the result of elevated levels of COX(-) in type I fibers from the PCA muscle (P=0.002) that showed a strong positive correlation with increased age. These results suggest that increased mitochondrial alterations may occur in the PCA muscle during normal aging.

Complications associated with anesthesia administration for dental treatment in a special needs clinic

The goal of this study was to identify and quantify complications occurring with the administration of anesthesia for the dental treatment of patients with special needs. Anesthesia providers completed a standardized evaluation form, delineating possible complications for 202 consecutive ambulatory patients receiving anesthesia in a special needs clinic. Statistical analysis of four types of administered anesthesia showed that the overall complication rate was 23.8%. Evaluation of the data showed complications that were considered either mild (95.8%), or moderate (4.2%), while no reports of severe complications occurred. Airway obstruction and nausea/vomiting were the most frequently encountered complications. Variables found to affect the incidence of anesthetic complications included ASA classification, anesthetic technique, Mallampati airway classification, and type of dental procedure performed. An evaluation of the results of the study showed that the majority of complications that occurred with anesthesia during care of patients with special needs were mild and did not lead to severe adverse events. Our findings show that anesthesia administered during dental treatment for patients with special needs is safe and effective.

Sialadenosis in patients with advanced liver disease

Sialadenosis (sialosis) has been associated most often with alcoholic liver disease and alcoholic cirrhosis, but a number of nutritional deficiencies, diabetes, and bulimia have also been reported to result in sialadenosis. The aim of this study was to determine the prevalence of sialadenosis in patients with advanced liver disease. Patients in the study group consisted of 300 candidates for liver transplantation. Types of liver disease in subjects with clinical evidence of sialadenosis were compared with diagnoses in cases who had no manifestations of sialadenosis. The data were analyzed for significant association. Sialadenosis was found in 28 of the 300 subjects (9.3%). Among these 28 cases, 11 (39.3%) had alcoholic cirrhosis. The remaining 17 (60.7%) had eight other types of liver disease. There was no significant association between sialadenosis and alcoholic cirrhosis (P = 0.389). These findings suggest that both alcoholic and non-alcoholic cirrhosis may lead to the development of sialadenosis. Advanced liver disease is accompanied by multiple nutritional deficiencies which may be exacerbated by alcohol. Similar metabolic abnormalities may occur in patients with diabetes or bulimia. Malnutrition has been associated with autonomic neuropathy, the pathogenic mechanism that has been proposed for sialadenosis.

Redefining the biologic width in severe, generalized, chronic periodontitis: implications for therapy

BACKGROUND

Previous studies demonstrated significant variability in the histologic biologic width in periodontal health and mild periodontitis. The purpose of this study was to determine whether the previously established dimensions of the biologic width applied to subjects with severe, generalized, chronic periodontitis.

METHODS

Twenty-eight subjects, aged 29 to 45 years, with severe, generalized, chronic periodontitis were included in the study. There were 18 males and 10 females, and 19 (68%) of the patients were smokers. Clinical and radiographic measures were taken by calibrated examiners. The clinical biologic width was determined from the most coronal level of clinical attachment to the crest of the alveolar bone for proximal surfaces only and compared to the histologic biologic width previously reported.

RESULTS

The clinical biologic width in subjects with severe, generalized periodontitis was significantly greater than previously reported (P <0.001). For all evaluable proximal sites, the mean clinical biologic width was 3.95 mm versus the mean histologic biologic width of 2.04 mm. The greatest clinical biologic widths were seen with pockets <2 mm (5.02 +/- 2.48 mm; range: 1.60 to 9.00 mm) and 2 to 4 mm (4.16 +/- 1.32 mm; range: 0.20 to 6.40 mm).

CONCLUSIONS

The mean clinical biologic width in subjects with severe, generalized, chronic periodontitis seemed to be significantly greater than the histologic biologic width previously reported for subjects not demonstrating significant periodontal pathology. In addition, sites with shallow probing depths demonstrated the greatest biologic width, suggesting that these sites may be at increased risk for losing clinically significant attachment during surgical procedures.

Exploring dental students' perceptions of cultural competence and social responsibility

The improvement of basic cultural competency skills and the creation of a greater community-minded spirit among dental students are important parts of dental education. The purpose of our study was to assess changes in dental students' attitudes and beliefs about community service and changes in cultural competencies after participation in a two-year program of non-dental community service (Student Community Outreach Program and Education, SCOPE). During 2003-07, two identical twenty-eight-item surveys were administered to SCOPE participants/completers. In the first, students reported on their attitudes after program completion. In the second, students reported retrospectively on their attitudes prior to starting the program. One hundred twenty-six post- and pre-intervention surveys were matched and assessed for changes in student attitudes after program participation. Based on factor analysis, four distinct scales were identified: 1) community service, 2) cultural competence, 3) communication, and 4) treatment perspective. Over time, statistically significant changes (p<.05) in student attitudes and beliefs were found for scales 1 (p=.017), 2 (p=.001), and 3 (borderline significance, p=.057). Scale 4 showed no significant difference (p=.108). These scales indicate main focus areas to help guide future dentists in acquiring relevant sociocultural competencies and enabling community-minded attitudes. Overall, this study provides support for the addition of a non-dental community service-learning program into the preclinical curriculum.

Quantification of myosin heavy chain RNA in human laryngeal muscles: differential expression in the vertical and horizontal posterior cricoarytenoid and thyroarytenoid

BACKGROUND

Human laryngeal muscles are composed of fibers that express type I, IIA, and IIX myosin heavy chains (MyHC), but the presence and quantity of atypical myosins such as perinatal, extraocular, IIB, and alpha (cardiac) remain in question. These characteristics have been determined by biochemical or immunohistologic tissue sampling but with no complementary evidence of gene expression at the molecular level. The distribution of myosin, the main motor protein, in relation to structure-function relationships in this specialized muscle group will be important for understanding laryngeal function in both health and disease.

OBJECTIVES

We determined the quantity of MyHC genes expressed in human posterior cricoarytenoid (PCA) and thyroarytenoid (TA) muscle using real-time quantitative reverse-transcriptase polymerase chain reaction in a large number of samples taken from laryngectomy subjects. The PCA muscle was divided into vertical (V) and horizontal (H) portions for analysis.

RESULTS AND CONCLUSIONS

No extraocular or IIB myosin gene message is present in PCA or TA, but IIB is expressed in human extraocular muscle. Low but detectable amounts of perinatal and alpha gene message are present in both of the intrinsic laryngeal muscles. In H- and V-PCA, MyHC gene amounts were beta greater than IIA greater than IIX, but amounts of fast myosin RNA were greater in V-PCA. In TA, the order was beta greater than IIX greater than IIA. The profiles of RNA determined here indicate that, in humans, neither PCA nor TA intrinsic laryngeal muscles express unique very fast-contracting MyHCs but instead may rely on differential synthesis and use of beta, IIA, and IIX isoforms to perform their specialized contractile functions.

Margin and local recurrence after sublobar resection of non-small cell lung cancer

BACKGROUND

Local recurrence is a major concern after sublobar resection (SR) of non-small cell lung cancer (NSCLC). We postulate that a large proportion of local recurrence is related to inadequate resection margins. This report analyzes local recurrence after SR of stage I NSCLC. Stratification based on distance of the tumor (<1 cm vs >or=1 cm) to the staple line was performed.

METHODS

We reviewed 81 NSCLC patients (44 female) who underwent operation over an 89-month period (January 1997 to June 2004). Mean forced expiratory volume in one second percentiles (FEV1) was 57%. Mean age was 70 (46-86) years. There were 55 wedge and 26 segmental resections. There were 41 tumors with a margin <1 cm and 40 with a margin >or=1 cm. Local recurrence was defined as recurrence within the ipsilateral lung or pulmonary hilum.

RESULTS

There were no perioperative deaths. Mean follow-up was 20 months. Margin distance significantly impacted local recurrence; 6 of 41 patients (14.6%) developed local recurrence in the group with margin less than 1 cm versus 3 of 40 patients (7.5%) in the group with margin equal to or more than 1 cm (P = .04). Of the 41 patients with margins <1 cm, segmentectomy was used in 7 (17%), whereas in the 40 patients with the >or=1 cm margins, segmentectomy was used in 19 (47.5%).

CONCLUSIONS

Margin is an important consideration after SR of NSCLC. Wedge resection is frequently associated with margins less than 1 cm and a high risk for locoregional recurrence. Segmentectomy appears to be a better choice of SR when this is chosen as therapy.

Dental health status of liver transplant candidates

A prerequisite dental evaluation is usually recommended for potential organ transplant candidates. This is based on the premise that untreated dental disease may pose a risk for infection and sepsis, although there is no evidence that this has occurred in organ transplant candidates or recipients. The purpose of this study was to assess the prevalence of dental disease and oral health behaviors in a sample of liver transplant candidates (LTCs). Oral examinations were conducted on 300 LTCs for the presence of gingivitis, dental plaque, dental caries, periodontal disease, edentulism, and xerostomia. The prevalence of these conditions was compared with oral health data from national health surveys and examined for possible associations with most recent dental visit, smoking, and type of liver disease. Significant risk factors for plaque-related gingivitis included intervals of more than 1 yr since the last dental visit (P = 0.004), smoking (P = 0.03), and diuretic therapy (P = 0.005). Dental caries and periodontal disease were also significantly associated with intervals of more than 1 yr since the last dental visit (P = 0.004). LTCs with viral hepatitis or alcoholic cirrhosis had the highest smoking rate (78.8%). Higher rates of edentulism occurred among older LTCs who were less likely to have had a recent dental evaluation (mean 88 months). In conclusion, intervals of more than 1 yr since the last dental visit, smoking, and diuretic therapy appear to be the most significant determinants of dental disease and the need for a pretransplantation dental screening evaluation in LTCs. Edentulous patients should have periodic examinations for oral cancer.

General dentists' evaluation of anesthesia sedation education in U.S. dental schools

To assess the quality and quantity of sedation education in U.S. dental schools, a prospective, questionnaire-based survey was administered to general dental practitioners who graduated in 2003. Questionnaires were sent via facsimile to recent dental graduates using a list obtained through the American Dental Association. The response rate was 54 percent; 718 of the 1,328 nine-question surveys were returned. The response to the questionnaires indicates a perceived need for sedation care by the majority of recent graduates and low overall satisfaction with the quality of sedation education in U.S. dental schools. The general consensus of most 2003 dental school graduates is that they have gained little or no hands-on experience in sedation techniques and would have supported an increase in tuition and fees if an institution were to offer more efficient sedation training. With increased popularity and high patient demand for sedation techniques, the new dentist feels a need for sedation education before graduation.

Efficacy of laparoscopic fundoplication in controlling pulmonary symptoms associated with gastroesophageal reflux disease

BACKGROUND

Gastroesophageal reflux disease (GERD)-induced pulmonary symptoms (PS) can be difficult to control. The effectiveness of laparoscopic fundoplication (LF) in controlling PS among patients with medically recalcitrant GERD is poorly documented. We evaluated our results in controlling important PS in patients with GERD undergoing LF.

METHODS

Seventy-four patients (28 men, 46 women) were identified with clinically important PS from a prospective cohort of 155 patients undergoing elective LF for recalcitrant GERD. Median age was 52.5 years (range, 29-84 years). Sixty-seven (91%) patients were taking proton pump inhibitors at the time of operation. Quality of life by using the SF36 physical (PCS) and mental (MCS) component summary scores (normal, 50) and heartburn severity by using the health-related quality of life (HRQOL) (best score, 0; worst score, 45) were measured.

RESULTS

All 74 patients with PS survived operation, and minor morbidity occurred in 5 (7%) patients. Median hospital stay was 2 days (range, 1-6 days), and return to normal activity was seen at 2.2 weeks (range, 1-8 weeks). Median follow-up was 12 months. PS were improved significantly (P < .01) for hoarseness (62% to 17.6%), bronchospasm (60% to 9.5%), and aspiration (22% to 1.4%). Before LF, 11 (14.9%) patients required bronchodilators or oral steroids. Postoperatively such therapy was required in only 3 (4.2%) patients (P = .019), with no patient requiring oral steroids. Patients with poorer control of their GERD on the basis of high HRQOL scores had significantly more PS after operation.

CONCLUSIONS

A significant number of patients with medically recalcitrant GERD (46% from our prospective database) have important PS. LF can improve PS, decrease requirement for pulmonary medications, as well as improve typical reflux symptoms and quality of life.

Frictional resistances of different bracket-wire combinations

BACKGROUND

It has been suggested that the frictional resistance of ceramic brackets can be reduced by either lining the slots with stainless steel or by contouring the base of the slot.

OBJECTIVES

The objectives of this investigation were to compare in vitro the static and kinetic frictional resistances of ceramic brackets with metal lined slots ("Clarity", CL), stainless steel brackets ("Miniature Twin", MT), and two ceramic brackets with different slot designs ("Contour", CO; "Transcend", TR).

METHOD

Two sizes (0.018 x 0.025 inch; 0.021 x 0.025 inch) of stainless steel (SS), nickel titanium (NiTi) and beta titanium (beta-Ti) wires were drawn through the brackets. All brackets had 0.022 inch slots, and the brackets and wires were used once. The brackets were of different widths: CL, 0.180 inch; CO, 0.114 inch; MT, 0.118 inch; TR, 0.138 inch. An Instron Universal Testing Machine was used in this study.

RESULTS

There were no significant static or kinetic frictional differences when the smaller 0.018 x 0.025 inch wires were drawn through the brackets. There were no statistically significant static or kinetic frictional differences between the CL-CO, CL-MT and CO-MT bracket pairs when the 0.021 x 0.025 inch wires (SS, NiTi, beta-Ti) were used. There were no significant kinetic frictional resistance differences between the CL-TR and MT-TR when the SS wires were used. In general the static and kinetic resistances of the 0.021 x 0.025 inch wires of NiTi wire < SS wire < beta-Ti wire. Regardless of wire type some of the lowest kinetic resistances were found with the narrow CO brackets with the rounded slot bases. The highest static and kinetic frictional resistances were found with the wide TR bracket, and with stainless steel and beta-Ti wires.

CONCLUSION

The high static and kinetic frictional resistances of ceramic brackets can be reduced either by lining the slots with stainless steel or by reducing the bracket width and rounding the slot base.

Students' perceived importance of diversity exposure and training in dental education

Intercultural competence is an important component of the doctor-patient relationship in the multicultural climate evolving in the United States. We hypothesized that 1) exposure to racial and ethnic diversity in the student body, faculty, staff, and patient population in dental school and 2) a dental school curriculum that includes presentations on issues concerning racial and ethnic diversity will contribute to students' feeling more competent and confident to enter the multicultural work environment that is rapidly developing in the United States. A Likert-type scale questionnaire was administered to 627 fourth-year dental students enrolled in seven dental schools representing geographically diverse regions of the United States. Of these, 376 questionnaires were returned for a response rate of 60 percent. Results indicated that both the perception of diversity in the school environment and the presentation of diversity-specific content in the curriculum had moderately positive and significant correlations with the students' perception of their competency or ability to serve and work with diverse populations. The respective Pearson correlation coefficients for diversity in the school environment and diversity curriculum were .497 (p<.001) and .459 (p<.001). These results support the hypotheses that diversity exposure and training in the dental school environment are important for dental students entering a multicultural workplace.

Comparison of mutational changes in involved N1 lymph nodes with those in primary tumors in stage II non–small cell lung cancer: a pilot study

OBJECTIVES

Surgical resection is the standard treatment for stage II non-small cell lung cancer, but recurrence rates approach 60%. This study compared mutational changes in involved lymph nodes and primary tumors from patients with stage II non-small cell lung cancer to determine whether risk factors for recurrence could be identified.

METHODS

Forty patients with resected stage II non-small cell lung cancer (excluding T3 N0 disease) were studied. Microdissection was performed on primary tumors and lymph nodes. Analysis was performed across 9 genomic loci by using polymerase chain reaction amplification. The ratio of fractional allelic loss between involved lymph nodes and primary tumors was used to stratify patients into high-risk (fractional allelic loss ratio of >or=1) and low-risk (fractional allelic loss ratio of <1) groups.

RESULTS

The median age of the patients was 68 years (range, 42-85 years). Median follow-up was 30 months. Fractional allelic loss was greater in patients with squamous carcinomas compared with that in adenocarcinomas, but survival was similar (35 vs 39 months). The median survival was 35 months in high-risk patients and was not reached in low-risk patients (P =.3). Disease-free survival was 24 months in high-risk patients and was not reached in low-risk patients (P =.35). In the subset with adenocarcinoma (n = 18), median survival was 24 months in the high-risk group; no deaths occurred in low-risk patients (P =.01). Also, disease-free survival was 14 months in high-risk patients and was not reached in the low-risk patients (P =.05).

CONCLUSIONS

Squamous cancers demonstrate greater mutational changes than adenocarcinomas; this does not affect outcome. The patients with low-risk adenocarcinomas demonstrated superior outcomes compared with those of other patients. These results should be confirmed in larger studies.

Minimally invasive esophagectomy: outcomes in 222 patients

OBJECTIVE

To assess our outcomes after minimally invasive esophagectomy (MIE).

SUMMARY BACKGROUND DATA

Esophagectomy has traditionally been performed by open methods. Results from most series include mortality rates in excess of 5% and hospital stays frequently greater than 10 days. MIE has the potential to improve these results, but only a few small series have been reported. This report summarizes our experience of 222 cases.

METHODS

From 1996 to 2002, MIE was performed in 222 patients. Indications for operation included high-grade dysplasia (n = 47) and cancer (n = 175). Neoadjuvant chemotherapy was used in 78 (35.1%) and radiation in 36 (16.2%). Initially, a laparoscopic transhiatal approach was used (n = 8), but subsequently our approach evolved to include thoracoscopic mobilization (n = 214).

RESULTS

There were 186 men and 36 women. Median age was 66.5 years (range, 39-89). Nonemergent conversion to open procedure was required in 16 patients (7.2%). MIE was successfully completed in 206 (92.8%) patients. The median intensive care unit stay was 1 day (range, 1-30); hospital stay was 7 days (range, 3-75). Operative mortality was 1.4% (n = 3). Anastomotic leak rate was 11.7% (n = 26). At a mean follow-up of 19 months (range, 1-68), quality of life scores were similar to preoperative values and population norms. Stage specific survival was similar to open series.

CONCLUSIONS

MIE offers results as good as or better than open operation in our center with extensive minimally invasive and open experience. In this single institution experience, we observed a lower mortality rate (1.4%) and shorter hospital stay (7 days) than most open series. Given these results, we are now developing an intergroup trial (ECOG 2202) to assess MIE in a multicenter setting.

Outcomes of minimally invasive antireflux operations in the elderly: a comparative review

BACKGROUND AND OBJECTIVES

The objectives of this study were to assess the impact of age following laparoscopic fundoplication (LF).

METHODS

From March 1993 to November 1998, 193 patients underwent LF. Patients comprised 150 young individuals (age<60; median 41) and 43 older individuals (age>60; median 68). Follow-up included heartburn scores, dysphagia scores, and quality of life determined by the Short Form 36 Health Survey (SF36).

RESULTS

Older patients had more cardiac disease, psychiatric disorders, prior cancers, and upper abdominal operations (P<0.05). DeMeester scores were similar (young 70/older 69). Complications occurred in 13 (8.7%) of the young and 5 (11.6%) of the older patients (P=0.142). No perioperative deaths occurred. Length of stay was longer (P<0.000) in older patients (2.9 versus 1.6 days); resumption of oral intake (young-1.2; older-1.3 days) and return to normal activity (young-3.6; older-4.4 weeks) were similar. Follow-up was available in 102 young (median 17 months) and 35 older (median 18 months) patients. Heartburn and dysphagia scores were excellent in both groups. SF36 scores were similar in both groups. Only 6 (5.9%) of the young group and 1 (2.9%) of the older group were dissatisfied (P=0.652).

CONCLUSIONS

Despite differences in comorbid disease, outcomes were similar in both groups. LF should be considered a therapeutic option in the older patient with reflux.

Comparison of skeletal and dental changes between 2-point and 4-point rapid palatal expanders

Rapid palatal expansion has been a clinically accepted technique used by orthodontists for over 100 years. Its primary goal is to maximize orthopedic and minimize orthodontic movements of teeth. Historically, this was best accomplished by including 4 teeth in the appliance. However, including more teeth makes construction and insertion more difficult. The appliance also is less comfortable for patients and hinders oral hygiene. The 4-point hyrax expander can be modified by removing the 2 anterior wires, creating a 2-point expander between the first molars only. The purpose of this study was to determine the difference, if any, between midpalatal suture separation and dental expansion produced between 2-point and 4-point palatal expanders. Thirty subjects between the ages of 6 and 16 years were randomly assigned to either the 2-point (n = 15) or the 4-point group (n = 15). The groups were compared on dental and radiographic landmarks. The groups showed no statistical differences in total molar cusp width, molar gingival width, canine cusp width, canine gingival width, or diastema width. There were slight differences in arch perimeter and midpalatal suture separation. The results of this study showed that the 2-point appliance produced similar effects on the midpalatal suture and the dentition as did the 4-point appliance. It might therefore be considered instead of the 4-point appliance to successfully produce adequate skeletal and dental expansion.

Identification of factors influencing matriculation decisions by dental school applicants

Recent dental school surveys have indicated a slight decrease in the overall number of dental school applicants. As a result, competition for the most highly qualified students is increasing among dental schools. A number of factors may contribute to an applicant's decision on where to matriculate, such as tuition costs, cost of living in an area, location of the dental school, reputation, availability of financial aid, and the school's facilities. Identifying the reasons why students choose to attend a specific school may be an important first step in formulating a strategic plan for recruitment. As a result, a survey was sent to all students (250) interviewed at the University of Pittsburgh School of Dental Medicine for the 2000-01 admissions cycle. The results of this survey were compared to a similar survey sent following the 1994-95 admissions cycle. In addition, the results of the University of Pittsburgh surveys were compared to a similar survey conducted by a different northeastern dental school. The factors rated most important in 1994-95 were reputation, facilities, and location, in order. In 2000-01, location, curriculum, tuition, and reputation were rated the most important factors, in order. This information may assist admissions officers in formulating an effective recruitment strategy for the most highly qualified applicants.

Diagnostic accuracy of intraoral film and direct digital images for detection of simulated recurrent decay

This study compared the diagnostic accuracy of bitewing images for detection of simulated recurrent caries using the following imaging modalities: Ektaspeed Plus film and different digital imaging system technologies comprised of a charge-coupled device (CCD) based digital imaging unit, a photo-stimulable phosphor (PSP) based unit and contrast- and brightness-enhanced PSP images.

STUDY DESIGN

Twenty-four extracted posterior teeth with MOD inlay preparations were secured in models simulating a natural arrangement of teeth. Lesions were created in proximal boxes using dental burs of varying sizes. Defects were filled with wax and plaster and preparations were restored with composite or amalgam.

RESULTS

Averages of receiver operating curve areas (Az) revealed diagnostic performances of Az = 0.74 for film, Az = 0.80 for CCD, Az = 0.73 for unenhanced PSP and Az = 0.64 for enhanced PSP. The differences between these means were significant (MANOVA p < 0.0001). Unenhanced PSP produced significantly poorer performance than other modalities. CCD performance was not significantly better than enhanced PSP. Lesions under radiopaque composite restorations were easier to detect, followed by those under amalgam and radiolucent composites across imaging modalities and lesion locations. Based on lesion location, those located at the buccal point angle were easiest to detect, followed by those at mid-gingival floor and lingual-point angle sites.

CONCLUSIONS

Contrast and brightness-enhanced digital images enabled better signal detection and a comparable performance with film for detection of artificially induced recurrent caries.

Total Videothoracoscopic Lobectomy Versus Open Thoracotomy for Early-Stage Non–Small-Cell Lung Cancer

Lobectomy remains the standard procedure for early-stage non small-cell lung cancer (NSCLC). Advances in minimally invasive surgery allow lobectomy to be performed by videothoracoscopy (VATSLOBE). The objective of this study was to compare open thoracotomy (OPENLOBE) to VATSLOBE in the treatment of early-stage NSCLC. A retrospective review over a 6-year period at a single tertiary care center identified 31 patients treated by VATSLOBE. A comparison was made with 31 patients undergoing OPENLOBE during the same time period. The cases were matched for age, pulmonary function testing, tumor size, and comorbidities. The VATSLOBE technique was carried out using four 1 cm thoracoports, one of which was enlarged to a 4-6 cm access incision for lobe retrieval. OPENLOBE was performed by standard posterolateral thoracotomy. The VATSLOBE group had a longer operative time (214.03 min) compared to OPENLOBE (140.67 min). There was no difference in the extent of lymph node dissection or in morbidity between the two groups. VATSLOBE patients had their chest tubes removed earlier (4.77 vs. 8.16 days) and stayed in the hospital for a shorter time (7.07 vs. 11.94 days) compared to OPENLOBE patients. In this retrospective review, lobectomy performed by the videothoracoscopic approach was comparable to OPENLOBE in terms of lymph node dissection, morbidity, and long-term survival. VATSLOBE had the advantages of a shorter hospital stay and fewer days with a chest tube. Minimally invasive surgery for early-stage lung cancer should be further investigated in multi-institutional controlled trials.

Changes in facial movement after maxillary osteotomies

PURPOSE

Determine changes in facial movement while smiling after maxillary Le Fort I osteotomies.

MATERIALS AND METHODS

Twenty patients (ages 15 to 38) treatment-planned for maxillary Le Fort I osteotomies were divided into two groups. Group A consisted of 10 patients who underwent superior and/or posterior positioning of the maxilla. Group B consisted of 10 patients who underwent anterior and/ or inferior repositioning of the maxilla. All patients underwent preoperative and postoperative (3 to 8 months) videographic analysis of a maximal closed mouth smile by the Johnson Maximal Static Response Assay, evaluating four landmarks around the mouth and nose (alar base--A, cheilion--C, labrale superioris--Ls, and intermediate between cheilion and labrale superioris--Im).

RESULTS

Group A was noted to have a statistically significant decrease in movement of the face at points C and Im. No significant change was seen for points Ls and A. Group B was noted to have a statistically significant increase in movement of the face at point A, C, and Im. Point Ls was also found to increase, however not significantly.

CONCLUSION

Surgical repositioning of the maxilla anteriorly and/or inferiorly lengthens the facial musculature resulting in an increase in facial movement while smiling. Likewise surgically repositioning the maxilla superiorly and/or posteriorly reduces the length of the facial musculature, resulting in a decrease in facial movement while smiling.

Long-term stability of rapid palatal expander treatment and edgewise mechanotherapy

Previous studies on long-term stability of orthodontic treatment primarily have focused on the stability of the lower arch treated with edgewise appliances. The aim of this study was to evaluate the long-term stability of the upper and the lower dental arches of patients treated with a rapid palatal expander. The sample comprised of 165 dental casts randomly selected from patients who had been out of retention for 8 to 10 years at a mean age of 30 years. Measurements were made directly on dental casts obtained at the three time intervals: before treatment, after treatment, and after retention. Differences over time between the upper and the lower dental arches and between intervals were analyzed by a two-way multivariate analysis of variance (MANOVA) and post hoc Bonferroni t tests. Differences between after treatment and after retention were statistically significant (P < 0.006) for all except lower intermolar width. However, only for lower and upper arch lengths and perimeters were the differences greater than 2.0 mm. Treatment with the rapid palatal expander presented good stability for upper intercanine width, upper and lower intermolar widths and incisor irregularity. Lower intercanine, arch length, and perimeter presented poor stability.

Obliterative bronchiolitis after lung and heart-lung transplantation. An analysis of risk factors and management

With a prevalence of 34% (55/162 at-risk recipients) and a mortality of 25% (14/55 affected recipients), obliterative bronchiolitis is the most significant long-term complication after pulmonary transplantation. Because of its importance, we examined donor-recipient characteristics and antecedent clinical events to identify factors associated with development of obliterative bronchiolitis, which might be eliminated or modified to decrease its prevalence. We also compared treatment outcome between recipients whose diagnosis was made early by surveillance transbronchial lung biopsy before symptoms or decline in pulmonary function were present versus recipients whose diagnosis was made later when symptoms or declines in pulmonary function were present. Postoperative airway ischemia, an episode of moderate or severe acute rejection (grade III/IV), three or more episodes of histologic grade II (or greater) acute rejection, and cytomegalovirus disease were risk factors for development of obliterative bronchiolitis. Recipients with obliterative bronchiolitis detected in the preclinical stage were significantly more likely to be in remission than recipients who had clinical disease at the time of diagnosis: 81% (13/15) versus 33% (13/40); p < 0.05). These results indicate that acute rejection is the most significant risk factor for development of obliterative bronchiolitis and that obliterative bronchiolitis responds to treatment with augmented immunosuppression when it is detected early by surveillance transbronchial biopsy.

Flumazenil reversal of conscious sedation induced with intravenous fentanyl and diazepam

The addition of a benzodiazepine antagonist to the dental anesthesiologist's armamentarium should provide added safety for conscious sedation using benzodiazepines. A double-blind, placebo-controlled clinical trial of flumazenil, the first available benzodiazepine antagonist, was performed to evaluate its safety and efficacy following conscious sedation induced by diazepam and fentanyl. Flumazenil was found to reverse rapidly much of the central nervous system depression induced by fentanyl and diazepam conscious sedation. Flumazenil appears to be a valuable adjunct for dentists who administer intravenous benzodiazepines for conscious sedation.

Pulp test response of the maxillary anterior teeth in cleft palate patients

The relative pulpal responsiveness of the six maxillary incisors to electrical and cold thermal stimuli was tested in patients with complete unilateral and bilateral clefts. The six maxillary anterior teeth were tested at random to electrical stimuli. After a 5-minute interval, the same teeth were tested at random to cold stimuli with an ice pencil. Unilateral and bilateral cleft palate patients had statistically significant higher mean electrical pulp test thresholds for the maxillary anterior teeth than the noncleft palate patients. No statistically significant difference between unilateral and bilateral cleft palate patients was found in electric pulp test responses of the maxillary anterior teeth. No statistically differences in electric pulp test responses and cold test responses of the maxillary anterior teeth in both cleft palate and noncleft palate individuals based on differences in sex were observed. No statistically significant difference in cold test responses were observed between cleft palate and noncleft palate patients. Cleft palate patients who completed orthodontic treatment within 1 year of testing showed elevated mean electrical pulp test thresholds as did noncleft palate patients who received orthodontic treatment within 1 year of testing.

Skeletal age assessment using the first, second, and third fingers of the hand

The purpose of this study was to determine whether skeletal age assessments using the first, second, and third fingers of the hand are as valid as those using the entire hand-wrist. Previous studies have demonstrated that treatment can be better oriented to the unique physiologic characteristics of the individual if skeletal age is used to assess maturational status. The sample was selected from the files of the Bolton-Brush Foundation and consisted of radiographs of 19 male and 20 female subjects whose yearly hand-wrist radiographs were available covering the age span of 10 to 16 years for girls and 12 to 18 years for male subjects. Two maturity indicators, the sesamoid and the epiphyseal-diaphyseal stages of ossification, were evaluated. Reliability of the method was tested by the t test for paired comparisons and the Pearson product-moment correlation. To determine the validity of the method, an analysis of variance (ANOVA) was used. In addition, the Pearson product-moment correlations between the two methods were performed and the 95% confidence intervals for mean differences for each sex and time were calculated. As indicated by the ANOVA, the two methods differed by a statistically significant amount, with the three-fingers assessments being slightly more advanced than the hand-wrist assessments. Although they differed, for the male subjects, the three-fingers method never deviated from that of the hand-wrist by more than 2.89 months with a minimum deviation of 0.32 months. For the female subjects, the maximum deviation was 4.45 months with a minimum of 1.55 months.(ABSTRACT TRUNCATED AT 250 WORDS)

A simple procedure to assess esthetic preference for dentofacial treatment

A procedure is described in which lateral facial photographs were cut apart and reassembled in ways that approximated desired esthetic change. Two groups of subjects were asked to complete the Sassouni "cut-up-paste-back" procedure. Group 1 consisted of 20 adult dental professionals; group 2 comprised 18 college students unacquainted with dental studies. Both groups made similar alterations on a photograph at the beginning and at the end of a 2-week period. Photographic alterations were highly similar to written descriptions of intended changes. The "cut-up-paste-back" procedure is a simple and inexpensive way to facilitate dentist-patient communication during treatment planning. The procedure also has applicability for research in facial esthetic preference.

Evaluation of bitewing intervals in children

With 1,153 pairs of bitewing radiographs representing data collected from 145 patients, we determined that the average positive bitewing interval was 17.7 months, which is consistent with published recommendations of 12- to 24-month intervals.

Actions of N-methyl aspartate and its antagonist aminophosphonovalerate on the A5 catecholamine cell group in rat

When N-methyl-D,L-aspartic acid was injected into the A5 catecholamine cell group of the rat, a dose-dependent decrease in blood pressure and heart rate was obtained. These cardiovascular changes were subsequently blocked by the (-) and (+) isomers of the aspartate receptor blocker 2-amino-5-phosphonovalerate (2-amino-5-phosphonopentanoic acid). The (-) isomer was 2-4 times more potent than the (+) form.

Concerns of entering dental students

First-year students from three dental schools were surveyed during their first week of classes to assess their areas of concern. Factor analysis of the data revealed five independent areas of concern--psychosocial, academic, time, isolation, and money. A high degree of similarity was found in the order in which students ranked their concerns. Significant differences in the intensity of concern were found for academics and time. The implications of this study for future research on stress and coping behavior are discussed.