Ninety-one osteoporosis patients affected with bisphosphonate-related osteonecrosis of the jaw: a case series.

Bisphosphonate (BP)-related osteonecrosis of the jaw (BRONJ) presents with necrotic bone in the mouth in the setting of BP exposure. It has been studied in cancer patients taking high-dose BP, but BRONJ has also been noted in patients taking lower-dose BP for osteoporosis. The purpose of this study was to characterize the phenotypes and outcomes in a large series of patients with osteoporosis and BRONJ in the setting of BP exposure. We conducted a retrospective case series. The sample was composed of subjects with BRONJ and osteoporosis. Subjects with a history of BP treatment for myeloma or metastatic cancer to the bones were excluded. Descriptive statistics were computed for the study variables. Ninety-one cases of BRONJ met the inclusion criteria. Subjects had a median age of 71 years and were predominantly female (94.5 %). The median time of BP exposure was 60 months (range 2-120). Most subjects were treated with alendronate (82.4 %). The mandible was involved more frequently (58.2 %) than the maxilla (37.3 %). Subjects commonly (65.9 %), but not universally, reported pain. For subjects with treatment outcome data (n = 0), most reported improvement (80.0 %). Although BRONJ is an uncommon condition, the absolute number of cases is fairly large due to the very large number of patients taking BPs for osteoporosis. The findings of this study confirm that BRONJ primarily affects the mandible, a substantial minority present without pain, and patients typically improve with treatment.

Does the use of a piezoelectric saw improve neurosensory recovery following sagittal split osteotomy?

Neurosensory disturbance of the inferior alveolar nerve (IAN) is an adverse effect associated with sagittal split osteotomies (SSO). The purpose of this work was to evaluate neurosensory recovery of the IAN when SSOs were performed with piezoelectric (PZ) versus reciprocating (RP) saws. This was a prospective split-mouth study of patients undergoing bilateral SSO using a PZ saw on one side and an RP saw on the other. The primary outcome of interest was neurosensory recovery, as assessed using the functional sensory recovery (FSR) scale defined by the UK Medical Research Council. Descriptive, bivariate, and regression statistics were computed. Twenty patients (40 SSOs) with a mean age of 19.9 ± 3.2 years were included. The mean mandibular movement did not differ significantly (P = 0.50) between the PZ and RP groups. All patients achieved FSR within 1 year of surgery (range 34-249 days). The median time to FSR overall was comparable between the PZ and RP groups (94.5 days and 101.5 days, respectively; P = 0.20). However, at the time FSR was achieved, PZ SSO sites were more likely to have higher neurosensory scores when compared to RP SSO sites (hazard ratio 2.3, 95% confidence interval 1.1-4.9, P = 0.04).

What are the defining characteristics of the most cited publications in orthognathic surgery?

The purpose of this study was to identify the characteristics associated with highly cited papers in orthognathic surgery. This was a cohort study of articles published in the English-language literature from 1900 to 2017. Citation databases were searched for papers related to orthognathic surgery and the most frequently cited papers were identified. For each paper, the following variables were collected: region of origin, time-period of publication, corresponding author specialty, journal of publication, topic area, study design, and number of citations. The outcome variable was the citation index (citations per year). North American investigators published 70% of the 100 most-cited articles in orthognathic surgery. The majority of papers were from oral and maxillofacial surgeons. Frequent content areas were diagnosis, virtual planning, fixation/stability, and complications. The majority (54%) of studies were cohort or case report/series. The mean number of citations was 235.0±126.5; the mean citation index was 9.9±6.1 citations per year. Time-period, content area, and study design were associated with the citation index (all P<0.001). Time-period, content area, and study design predicted the citation index (all P≤0.009). Among frequently cited papers in orthognathic surgery, oral and maxillofacial surgeons had the highest volume of contributions. Diagnosis, treatment planning, and complications were the most common topics studied.

Frailty approach for the analysis of clustered failure time observations in dental research.

Because dental implant failure patterns tend to cluster within subjects, we hypothesized that the risk of implant failure varies among subjects. To address this hypothesis in the setting of clustered, correlated observations, we considered a retrospective cohort study where we identified a cohort having at least one implant placed. The cohort was composed of 677 patients who had 2349 implants placed. To test the hypothesis, we applied an innovative analytic method, i.e., the Cox proportional hazards model with frailty, to account for correlation within subjects and the heterogeneity of risk, i.e., frailty, among subjects for implant failure. Consistent with our hypothesis, risk for implant failure among subjects varied to a statistically significantly degree (p=0.041). In addition, the risk for implant failure is significantly associated with several factors, including tobacco use, implant length, immediate implant placement, staging, well size, and proximity of adjacent implants or teeth.

Multi-center randomized clinical trials in oral and maxillofacial surgery: modeling of fixed and random effects.

The multi-center randomized clinical trial (MCCT) is an important tool to evaluate treatment of rare diseases. An important and challenging analytic consideration is how to model the variability of the set of clinical centers composing an MCCT. The purpose of this paper was to demonstrate how changing the assumptions regarding the variability (fixed effect versus random effect) of the set of clinical centers may alter the results. The data for this paper were derived from a recently completed MCCT. The MCCT was designed as a prospective, randomized clinical trial comparing the stability of two techniques, i.e., wire versus rigid internal fixation (RIF), for stabilizing the mandible after bilateral sagittal split ramus osteotomy (BSSO) for patients requiring mandibular advancement. Three treatment centers were involved. The key outcome variable was change in mandibular position (B-point) over time. We developed two different analytic models by varying the underlying statistical assumptions regarding the variability of the clinical treatment centers, i.e., random or fixed effects. Analyses based on the random-effects model demonstrated no significant difference between treatment groups in terms of relapse (P=0.13). With the fixed-effects model, however, wire fixation had significantly more relapse at B-point over time than RIF (P=0.02). The results from these two sets of analyses demonstrate how changing assumptions regarding the variability of the set of clinical centers can alter the interpretation of the treatment effect. The choice of statistical modeling of the set of clinical centers is an important consideration when performing analyses of MCCTs and it is a decision that should be made prior to initiating the study.

Ibuprofen in the treatment of UV-B-induced inflammation.

Ibuprofen and placebo were compared in a randomized, double-blind, cross-over study of 19 psoriatic patients receiving UV-B phototherapy to evaluate the symptomatic relief of UV-B-induced inflammation. Signs and symptoms of UV-B-induced inflammation (erythema, pruritus, skin pain, general discomfort, and nocturnal restlessness) were assessed for each treatment. An evaluation of 104 treatments disclosed that, although ibuprofen significantly reduced technician-observed erythema, it was not significantly different from placebo for the five other end points studied. Separate evaluations of higher dose UV-B treatments showed a small, but statistically significant, reduction with ibuprofen for four of the six end points evaluated. The data suggest that ibuprofen is more effective than placebo for the relief of symptoms associated with UV-B-induced inflammation after high dose UV-B phototherapy for psoriasis, but the drug has limited usefulness in the treatment of sunburn reaction from these same doses.

HIV status and the risk of post-extraction complications.

Tooth extraction is commonly performed for patients infected with the human immunodeficiency virus (HIV). We undertook a prospective study to determine if HIV-positive patients had an increased risk for complications following tooth extraction. The study sample was composed of patients who presented for tooth extraction to the outpatient oral/maxillofacial surgery clinic at Grady Memorial Hospital, Atlanta, GA. The predictor variable was HIV status (positive or negative). The outcome variable was the presence or absence of a post-extraction complication. Other study variables were grouped into the following sets: (1) demographic, (2) past medical and social history, (3) clinical, (4) laboratory values, and (5) treatment. Between 11/93 and 4/96, 166 patients were enrolled. The study sample was composed of the 151 patients who completed the study protocol and consisted of 76 HIV-positive and 75 HIV-negative patients. The post-extraction complication rates were 22.3 and 13.3% for the HIV-positive and -negative groups, respectively (relative risk = 1.68, 95% confidence interval = 0.82 to 3.42, p = 0.15). The types of complications that occurred were similar in both groups. While the data suggest an increased rate of post-extraction complications in the HIV-positive group, the difference in complication rates between the two groups was not statistically significant. In addition, the complications were minor, self-limiting, and readily treated. Based on these findings, we believe that tooth extraction is a low-risk procedure in HIV-positive patients. Treatment may be rendered routinely to patients who present on an outpatient basis without the need for an extensive pre-operative work-up, unless otherwise indicated by relevant history.

Kaplan-Meier analysis of dental implant survival: a strategy for estimating survival with clustered observations.

The study's purposes were to estimate dental implant survival in a statistically valid manner and to compare three models for estimating survival. We estimated survival using three different statistical models: (1) randomly selecting one implant per patient; (2) utilizing all implants, assuming independence among implants from the same subject; and (3) utilizing all implants, assuming dependence among implants from the same subject. The cohort was composed of 660 patients who had 2286 implants placed. Due to the high success rates of implants, the five-year survival point and standard error estimates varied little among the three models. Patients at high risk for implant failure (smokers) manifested greater variation in the standard error estimates among the three models, 8.2%, 4.0%, and 5.6%, respectively. To obtain statistically valid survival confidence intervals when performing Kaplan-Meier survival analyses, we recommend adjusting for dependence when there are multiple observations within the same subject.

Predicting dental implant survival by use of the marginal approach of the semi-parametric survival methods for clustered observations.

The analyses of clustered survival observations within the same subject are challenging. This study's purpose was to compare and contrast predicted dental implant survival estimates assuming the independence or dependence of clustered observations. Using a retrospective cohort composed of 677 patients (2,349 implants), we applied an innovative analytic marginal approach to produce point and variance estimates of survival predictions given the covariates smoking status, implant staging, and timing of placement adjusted for clustered observations (dependence method). We developed a second model assuming independence of the clustered observations (naïve method). The 95% confidence intervals for survival prediction point estimates given the naive method were 5.9% to 14.3% more narrow than the dependence method estimates, resulting in an increased risk for type I error and erroneous rejection of the null hypothesis. To obtain statistically valid confidence intervals for survival prediction of the Aalen-Breslow estimates, we recommend adjusting for dependence among clustered survival observations.

Risk factors for dental implant failure: a strategy for the analysis of clustered failure-time observations.

This study's objective was to identify, in a statistically valid and efficient manner, the risk factors associated with dental implant failure. We hypothesize that factors exist which can be modified by clinicians to enhance outcome. A retrospective cohort study design was used. Cohort members had >or= one implant placed. Risk factors were classified as demographic, health status, implant-, anatomic-, or prosthetic-specific, and reconstructive variables. The outcome variable was implant failure. The cohort was composed of 677 patients who had 2349 implants placed. Based on the adjusted multivariate model, factors associated with implant failure were tobacco use, implant length, staging, well size, and immediate implants (p

Risk factors associated with dental implants in healthy and medically compromised patients.

A total of 104 consecutive patients treated with 313 Nobelpharma implants was studied to determine the medical risks associated with dental implants. There did not appear to be an increased implant failure rate or an increase in perioperative morbidity in patients with a compromised medical status. Age; sex; and concurrent use of hypoglycemic agents, supplemental female hormones, or steroids also did not correlate with increased implant failure or perioperative morbidity. Implant procedures using a variety of pain-/anxiety-control agents failed to reveal any increase in anesthetic-related complications. However, the number of implants placed per patient did correlate with implant failure. It appears that implant surgery and the required anesthetic appear to be safe procedures even in the medically compromised patient.

Risk factors for infection following operative treatment of mandibular fractures: a multivariate analysis.

Utilizing a retrospective study design and a study sample of 284 consecutive patients, we measured the association between five different risk factors and the development of infection following the operative management of mandibular fractures. The five risk factors analyzed were age, sex, number of fractures per patient, time from admission to treatment, and treatment modality. The overall infection rate was 5.3 percent. The infection rate for each treatment modality was (1) 0 percent for closed reduction, (2) 20.0 percent for open reduction and internal fixation with wire osteosynthesis, and (3) 6.3 percent for open reduction and rigid internal fixation. To measure the association between the various risk factors and postoperative infection, we used multivariate logistic regression. After controlling for potential confounding variables, the only risk factor statistically associated with postoperative infection was treatment modality.

A model for fetal cleft lip repair in lambs.

Fetal wounds heal without inflammation and scar formation. This phenomenon may, in the future, be applicable to human cleft lip and palate repair. However, extensive experimental work must first be done to document the benefits of in utero repair. We developed a large animal model for creation and repair of a complete cleft lip and alveolus using fetal lambs. The cleft lip and alveolus deformity was created in eight 75-day-gestation fetuses (term = 145 days) and either repaired in three layers or left unrepaired. There were four sham-operated fetuses, and all animals were alive at harvest. Repaired, unrepaired, and control fetuses were harvested at 7, 14, 21, and 70 days following surgery. The unrepaired fetuses demonstrated a complete cleft lip and alveolus with an oronasal fistula. The maxilla was asymmetrical, with the greater segment deviated toward the cleft and with decreased anterior maxillary width. In contrast, repaired cleft lip and alveolus animals showed no scar, normal thickness of the lip, and a symmetrical maxilla. Histologic analysis of the repaired wounds showed evidence of tissue regeneration without scar formation. The results of this preliminary study indicate that the fetal lamb cleft lip and alveolus model is technically feasible with an excellent survival rate. Healing occurs without scar formation. In the repaired animals, the maxilla was symmetrical. This model will be used to document facial growth following in utero repair of a cleft lip and alveolus.

Human immunodeficiency virus serostatus and the risk of postextraction complications.

Despite the increasing prevalence of human immunodeficiency virus (HIV) disease in the population and the increasing likelihood that HIV-positive (HIV+) patients may have an extraction, little is known about the risk of postoperative complications in this group. The goal of this investigation was to assess the risk of postoperative complications in HIV+ patients after tooth extraction. The study was designed as a retrospective cohort study with a sample consisting of 145 males who underwent tooth extraction. The patients' medical and dental records were reviewed to identify HIV serostatus, to document the frequency and type of postoperative complications, and to collect data on potential confounding variables. Forty-four patients were identified as HIV+. The postoperative complication rate in HIV+ patients was 20.9% and for HIV-negative (HIV-) patients 2.9% (relative risk = 7.0, 95% confidence interval = 2.0-25.0, P = 0.001). Furthermore, as the manifestations of the symptoms of HIV infection became more severe, the postextraction complication rate also increased (P = 0.008). The results of this study suggest that HIV+ patients have an increased risk of postextraction complications and as the level of HIV disease increases, the risk of complications also increases. While the findings of this study are consistent with studies based on case series, prospective cohort studies are required to confirm the findings.

Fetal cleft lip repair in lambs: histologic characteristics of the healing wound.

Sequential surgical procedures in cleft lip/palate (CL/P) patients result in scar formation that is believed to be associated with midface growth retardation. By use of a previously developed fetal lamb model, wound healing characteristics were investigated after in utero CL repair. It is hypothesized that scarless healing after fetal CL repair occurs without inflammation and scar formation. CL wounds were created in mid-second-trimester fetal lambs and either repaired in three layers (mucosa, muscle, and skin) or left unrepaired. Fetuses were then harvested at 7, 14, and 21 days postoperatively, and the wound site was examined microscopically. When created at 75 days' gestation (term = 145 days), fetal lamb CL wounds heal rapidly without inflammation and scar formation. By day 21 postoperatively, there was complete regeneration of skin, muscle, and mucosa, as well as epidermal appendages. With this model, it will be possible to compare the effects of scarless fetal CL repair with those of postnatal repair on midface growth.

Special considerations for the pediatric emergency patient.

Management of pediatric maxillofacial infections and trauma continue to challenge the clinician, because both conditions are uncommon. Therefore, individual clinicians might not see enough cases to formulate systematic and consistent treatment plans. When one is evaluating pediatric maxillofacial infections, the location of infection (upper or lower face) can serve as a diagnostic aid to develop a differential diagnosis and to initiate empiric treatment. When evaluating pediatric maxillofacial injuries while implementing acute treatment measures, the clinician should also be aware of the potential for late adverse sequalae owing to alteration of growth. In the absence of controlled studies, however, growth alternation from traumatic injuries to the facial skeletal remains a plausible but unproved hypothesis.

Evidence-based medicine: its role in the modern practice and teaching of dentistry.

Evidence-based medicine is a new paradigm for clinical practice. The purpose of this article is two-fold: (1) to define and review the principles of evidence-based medicine and (2) suggest mechanisms for implementing evidence-based medicine in dental education.

Reconstruction of alveolar bone defects after extraction of mandibular third molars: a pilot study.

INTRODUCTION: A documented complication of mandibular third molar extraction is the development of bony defects on the distal aspect of the adjacent second molar. The primary study purpose was to determine the efficacy of grafting third molar extraction sites with demineralized bone powder to prevent the formation of periodontal defects. MATERIAL/METHODS: With a randomized clinical trial study design and a third molar extraction surgical model, we enrolled a study sample composed of patients who required extraction of bilateral third molars. Demineralized bone powder was placed in one randomly selected extraction site per patient. The remaining extraction site served as a control. Patients served as their own controls. To assess periodontal healing, we measured plaque and gingival indexes and periodontal attachment loss on the distobuccal aspect of the adjacent second molar preoperatively and 6 months postoperatively. RESULTS: Of 14 patients enrolled, 7 patients with a mean age of 21.7 +/- 3.7 years completed the study protocol. No statistically significant differences were noted between patients who did and did not complete the study protocol (all p values > or = 0.42). There were noted statistically significant differences for the various anatomic, operative, or periodontal measures between the control and treatment teeth preoperatively (all p values > or = 0.46). Six months postoperatively, there were no statistically significant changes in the plaque or gingival indexes for the control or experimental sites. At the control sites, there was a nonstatistically significant decrease in mean attachment loss from 3.1 +/- 1.3 mm preoperatively to 1.4 +/- 1.6 mm 6 months postoperatively (p = 0.06). At experimental sites, there was a statistically significant decrease in mean attachment loss from 3.3 +/- 1.4 mm preoperatively to 0.6 +/- 0.8 mm 6 months postoperatively (p = 0.02) CONCLUSIONS: The study results suggest that demineralized bone powder may decrease attachment loss on the distal aspect of the second molar after extraction of the adjacent third molar. Additional studies are indicated to confirm the results of this pilot study. We recommend that future studies limit their study samples to patients at high risk for developing periodontal defects after third molar extraction.

Predictors of postextraction complications in HIV-positive patients.

OBJECTIVE: The purpose of this study was to identify factors associated with an increased risk for post-tooth-extraction complications in a sample of HIV-positive patients. STUDY DESIGN: A cohort of HIV-positive patients who required the extraction of one or more teeth was enrolled. The predictor variables were grouped into the following sets: demographics; medical and social history; preoperative clinical findings; preoperative laboratory measures (hematologic, immunologic, and nutritional); and treatment. The outcome variable was defined as the presence or absence of a complication following tooth extraction. Logistic regression techniques were used to identify variables associated with an increased risk for complications following tooth extraction. RESULTS: During the enrollment period, 76 HIV-positive patients were enrolled into the study cohort. Seventeen patients (22.4%) had postoperative complications. Based on the bivariate statistical analyses, variables associated with the presence of postoperative complications were red blood cell count, CD8 count, total number of positive sites tested using cell-mediated immunity skin tests, and extraction technique (p < or = 0.05). Using a stepwise logistic regression technique, the variable identified as being predictive of postoperative complications was the CD8 count (p = 0.02). The post-tooth-extraction complication rate of the HIV-positive patients in this study sample was greater than the rate reported in most other studies (22% vs. 3%-5%). The complications, however, were minor and easily treated. The variable consistently identified with an increased risk for complications was the CD8 count: the lower the CD8 count, the higher the risk for complications. The CD8 count, however, had poor predictive value. CONCLUSION: In acute clinical situations--for example, in cases of patients with significant dental pain--the results suggest that delaying treatment to obtain laboratory studies may be of little clinical value. It may be appropriate to proceed with suitable, definitive procedure(s) to alleviate symptoms.