Does Self-Citation Influence Quantitative Measures of Research Productivity Among Academic Oral and Maxillofacial Surgeons?

PURPOSE: Quantitative measures of research productivity depend on the citation frequency of a publication. Citation-based metrics, such as the h-index (total number of publications h that have at least h citations), can be susceptible to self-citation, resulting in an inflated measure of research productivity. The purpose of the present study was to estimate the effect of self-citation on the h-index among academic oral and maxillofacial surgeons (OMSs). MATERIALS AND METHODS: The present study was a cross-sectional study of full-time academic OMSs in the United States. The predictor variable was the frequency of self-citation. The primary outcome of interest was the h-index. Other study variables included demographic factors and citation metrics. Descriptive, bivariate, and regression statistics were computed. RESULTS: The study sample consisted of 325 full-time academic OMSs. Most surgeons were men (88.3%); approximately 40% had medical degrees. The study subjects had an average of 23.5 ± 37.1 publications. The mean number of self-citations was 15 + 56. The sample's mean h-index was 6.6 ± 7.6 and was associated with self-citation (r = 0.71, P < .001). Approximately 9% of subjects had a change in their h-index after removing self-citations. After adjusting for PhD degree, total number of publications, and academic rank, an increasing self-citation rate influenced the h-index (r = 0.006, P < .001). Surgeons with more than 14 self-citations were more likely to have their h-index influenced by self-citation. CONCLUSION: Self-citation among full-time academic OMSs does not substantially affect the h-index. Surgeons in the top quartile of self-citation rates are more likely to influence their h-index.

What Is the Quality of the Evidence in the Craniomaxillofacial Surgery Literature?

PURPOSE: Evidence-based practice is an important concept for surgeons. The purpose of this study was to assess the quality of evidence in the craniomaxillofacial surgery (CMS) literature. MATERIALS AND METHODS: This was a retrospective cohort study of patient-oriented articles published in 9 journals. The primary predictor variable was the year of publication (September 2007 to August 2008 or September 2012 to August 2013). Secondary predictor variables were journal, impact factor, subject (eg, reconstruction, esthetic surgery), and funding. The outcome variable was the level of evidence (levels 1 to 4), evaluated using the Center for Evidence-Based Medicine criteria. Descriptive, bivariate, and regression statistics were computed. RESULTS: The study sample included 2,824 articles. The mean weighted journal impact factor was 1.6 ± 0.6 (range, 0.7 to 2.9). Fifty-two percent of articles were published in the Journal of Craniofacial Surgery or the Journal of Oral and Maxillofacial Surgery. The most frequent subject area was craniomaxillofacial pathology (934 articles; 33.1%). Eight percent of studies were funded. There were 97 (3.4%) level 1, 562 (19.9%) level 2, 228 (8.1%) level 3, and 1,937 (68.6%) level 4 studies. In a multiple regression model, year of publication (odds ratio [OR] = 1.2; P = .05), impact factor (OR = 2.4; P < .001), category (OR = 1.4; P < .001), and funding (OR = 1.6; P < .001) were associated with higher-quality evidence. CONCLUSION: The quality of evidence in the CMS literature is low. Higher levels of evidence are associated with more recent publications, journal impact factor, topic area, and funding.

Application of the Mandible Injury Severity Score to Pediatric Mandibular Fractures.

PURPOSE: The Mandible Injury Severity Score (MISS) has been used to evaluate adult mandibular fractures. The purpose of this study was to evaluate the MISS in a cohort of pediatric patients. PATIENTS AND METHODS: This was a retrospective study of pediatric patients treated for mandibular fractures over a 20-year period. Patients were included if they had computed tomographic imaging available for review and had at least 1 post-treatment visit. The primary predictor variable was the MISS. Secondary predictors were demographic and injury-associated factors. The outcome was treatment-associated complications. Descriptive, bivariate, and multiple logistic regression statistics were computed. RESULTS: One hundred sixteen patients with mandibular fractures were identified; 73 (62.9%) met the inclusion criteria. The sample's mean age was 8.5 ± 4.1 years; 44% were girls. Motor vehicle collisions (60%) and falls (15.1%) were the most common mechanisms. More than 50% of patients had an extra-mandibular injury. The mean MISS was 13.5 ± 7.8. Forty-five percent of the sample underwent open reduction and internal fixation. Complications were noted in 20.5% of patients, of which malocclusion was the most common (8.2%). Increasing MISS was associated with complications (P < .001). After controlling for the effects of age, mechanism, cervical spine and skull base injuries, and treatment, patients with an MISS of at least 14 were significantly more likely to have a complication (odds ratio = 4.0; 95% confidence interval, 1.05-15.0; P = .04). CONCLUSIONS: In pediatric patients with mandibular fractures, increased severity of injury is associated with complications, even after controlling for the effects of multiple confounders, including open treatment.

Is Canine Eruption Velocity Affected by the Presence of Allograft Within a Repaired Alveolar Cleft?

PURPOSE: To assess the rate of canine eruption in alveolar clefts repaired with cancellous autograft versus cancellous autograft mixed with allograft. MATERIALS AND METHODS: This was a retrospective cohort study of patients in mixed dentition who underwent primary repair of uni- or bilateral alveolar cleft defects. Patients were divided into 2 groups based on the method of bony reconstruction (group 1, iliac crest autograft; group 2, iliac crest autograft harvested through a minimal access approach and mixed 1:2 with demineralized bone allograft). Secondary predictor variables were demographic and anatomic factors potentially related to canine eruption. The outcome variable was the velocity of canine eruption, measured as the change in vertical distance from the incisal edge to the maxillary occlusal plane (millimeters per month). Descriptive, bivariate, and linear regression statistics were computed. RESULTS: The study sample included 57 alveolar cleft defects; 19 were repaired with autograft alone and 38 were repaired with autograft plus allograft. The sample's mean age was 9.9 ± 2.3 years at the time of repair. Thirty-one clefts (54.4%) were part of a bilateral deformity. Canine root formation was 50% complete at the time of surgery in most patients (59.6%). Mean duration of follow-up was 23.7 ± 13.2 months. Mean canine eruption velocity was 0.20 ± 0.18 mm per month and was not associated with the method of bony repair (P = .58). CONCLUSION: The use of allograft bone to augment bone graft volume results in similar rates of canine eruption compared with autograft bone alone.

Craniofacial reconstruction with poly(methyl methacrylate) customized cranial implants.

BACKGROUND: Secondary cranioplasty with customized craniofacial implants (CCIs) are often used to restore cerebral protection and reverse syndromes of the trephined, and for reconstruction of acquired cranial deformities. The 2 most widely used implant materials are polyetheretherketone and poly(methylmethacrylate) (PMMA). Previous series with CCIs report several major complications, including implant infection leading to removal, extended hospital stays, and surgical revisions. With this in mind, we chose to review our large case series of 22 consecutive PMMA CCI cranioplasties treated by a single craniofacial surgeon. METHODS: A cohort of 20 consecutive patients receiving 22 PMMA implants during a 2-year period was identified and outcomes reviewed. The mechanism of initial insult, time from craniectomy to cranioplasty, anesthesia time, major and minor postoperative complications, radiation history, and length of follow-up were statistically analyzed. RESULTS: There were no complications related to infection, hematoma/seroma, or cerebrospinal fluid leak (0/22, 0%). Two patients experienced major complications related to persistent temporal hollowing (PTH) following standard CCI cranioplasty, which required revision surgery with modified implants (2/22, 9%). One minor complication of self-resolving transient diplopia was noted (1/22, 5%). CONCLUSIONS: In this consecutive series, PMMA CCIs were associated with a very low complication rate, suggesting that PMMA may be a preferred material for CCI fabrication. However, with 10% (2/20) of patients experiencing PTH and dissatisfaction related to asymmetry, future research must be directed at modifying CCI shape, to address the overlying soft-tissue deformity. If successful, this may increase patient satisfaction, prevent PTH, and avoid additional costs of revision surgery.

Overcoming cross-gender differences and challenges in Le Fort-based, craniomaxillofacial transplantation with enhanced computer-assisted technology.

BACKGROUND: Sex-specific anthropometrics, skin texture/adnexae mismatch, and social apprehension have prevented cross-gender facial transplantation from evolving. However, the scarce donor pool and extreme waitlist times are currently suboptimal. Our objective was to (1) perform and assess cadaveric facial transplantation for each sex-mismatched scenario using virtual planning with cutting guide fabrication and (2) review the advantages/disadvantages of cross-gender facial transplantation. METHODS: Cross-gender facial transplantation feasibility was evaluated through 2 mock, double-jaw, Le Fort-based cadaveric allotransplants, including female donor-to-male recipient and male donor-to-female recipient. Hybrid facial-skeletal relationships were investigated using cephalometric measurements, including sellion-nasion-A point and sellion-nasion-B point angles, and lower-anterior-facial-height to total-anterior-facial-height ratio. Donor and recipient cutting guides were designed with virtual planning based on our team's experience in swine dissections and used to optimize the results. RESULTS: Skeletal proportions and facial-aesthetic harmony of the transplants (n = 2) were found to be equivalent to all reported experimental/clinical sex-matched cases by using custom guides and Mimics technology. Cephalometric measurements relative to Eastman Normal Values are shown. CONCLUSIONS: On the basis of our results, we believe that cross-gender facial transplantation can offer equivalent, anatomical skeletal outcomes to those of sex-matched pairs using preoperative planning and custom guides for execution. Lack of literature discussion of cross-gender facial transplantation highlights the general stigmata encompassing the subject. We hypothesize that concerns over sex-specific anthropometrics, skin texture/adnexae disparity, and increased immunological resistance have prevented full acceptance thus far. Advantages include an increased donor pool with expedited reconstruction, as well as size-matched donors.

Gastrostomy Placement Rates in Infants with Pierre Robin Sequence: A Comparison of Tongue-Lip Adhesion and Mandibular Distraction Osteogenesis.

BACKGROUND: This study was conducted to compare the gastrostomy rates in infants with Pierre Robin sequence treated with tongue-lip adhesion or mandibular distraction osteogenesis. METHODS: This was a retrospective study of symptomatic plastic and reconstructive surgery patients treated over an 8-year period. The primary predictor variable was surgical intervention (tongue-lip adhesion or distraction osteogenesis). Secondary predictor variables were categorized as demographic and clinical factors. The primary outcome was the need for gastrostomy tube placement. Secondary outcomes were complication rates, costs, and length of stay. RESULTS: Thirty-one tongue-lip adhesion and 30 distraction osteogenesis patients were included in the study. The groups were statistically comparable with regard to demographic and clinical factors (p > 0.18). Gastrostomy rates were higher in patients who underwent tongue-lip adhesion (48 percent) versus those who underwent distraction osteogenesis (16.7 percent; p = 0.008). In an adjusted model, subjects undergoing tongue-lip adhesion were more likely to require gastrostomy tube for nutritional support (OR, 6.5; 95 percent CI, 1.7 to 25.2; p = 0.007). There were two major complications in the tongue-lip adhesion group and none in the distraction osteogenesis group. There were three minor complications in the tongue-lip adhesion group and five in the distraction osteogenesis group. Total operating room costs were higher for distraction osteogenesis (p = 0.05), and total hospital costs and length of stay were higher for tongue-lip adhesion (p < 0.05). CONCLUSIONS: Among infants with symptomatic Pierre Robin sequence, treatment by distraction osteogenesis is associated with a lower risk for gastrostomy placement for nutritional support. Hospital costs are higher for tongue-lip adhesion. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Treatment of Pediatric Condylar Fractures: A 20-Year Experience.

BACKGROUND: The purpose of this study was to define patterns of injury and treatment for condylar and subcondylar fractures and evaluate short-term outcomes in the pediatric population. METHODS: A retrospective chart review was performed on pediatric patients with mandibular condylar fractures who presented between 1990 and 2010. Computed tomographic imaging was reviewed for all patients to assess fracture characteristics. Mandibular fractures were codified using the Strasbourg Osteosynthesis Research Group and Lindahl classification methods. RESULTS: Sixty-four patients with 92 condylar fractures were identified. Of these patients, 29 had isolated condylar fracture and 35 had a condylar fracture associated with an additional mandibular arch fracture. The most common fracture patterns were diacapitular fracture in the Strasbourg Osteosynthesis Research Group system (n = 46) and vertical condylar head fracture in the Lindahl system (n = 14). Condylar fracture with additional mandibular arch fractures were treated with maxillomandibular fixation more often than patients with condylar fracture [n = 40 (74.1 percent) versus n = 14 (25.9 percent); p = 0.004]. No condylar fracture was treated in an open fashion. Forty-three patients returned for follow-up. The median follow-up period was 81 days (interquartile range, 35 to 294 days). Ten patients had complications (23.3 percent). The most common complication was malocclusion (n = 5). Nine of 10 patients with complications had condylar fracture with an additional mandibular arch fracture. CONCLUSIONS: Closed treatment of condylar fractures yields satisfactory results in pediatric patients. Pediatric patients with condylar fractures combined with additional arch fractures experience a higher rate of unfavorable outcomes.

Do Quantitative Measures of Research Productivity Correlate with Academic Rank in Oral and Maxillofacial Surgery?

Academic promotion is linked to research productivity. The purpose of this study was to assess the correlation between quantitative measures of academic productivity and academic rank among academic oral and maxillofacial surgeons. This was a cross-sectional study of full-time academic oral and maxillofacial surgeons in the United States. The predictor variables were categorized as demographic (gender, medical degree, research doctorate, other advanced degree) and quantitative measures of academic productivity (total number of publications, total number of citations, maximum number of citations for a single article, I-10 index [number of publications with ≥ 10 citations], and h-index [number of publications h with ≥ h citations each]). The outcome variable was current academic rank (instructor, assistant professor, associate professor, professor, or endowed professor). Descriptive, bivariate, and multiple regression statistics were computed to evaluate associations between the predictors and academic rank. Receiver-operator characteristic curves were computed to identify thresholds for academic promotion. The sample consisted of 324 academic oral and maxillofacial surgeons, of whom 11.7% were female, 40% had medical degrees, and 8% had research doctorates. The h-index was the most strongly correlated with academic rank (ρ = 0.62, p < 0.001). H-indexes of ≥ 4, ≥ 8, and ≥ 13 were identified as thresholds for promotion to associate professor, professor, and endowed professor, respectively (p < 0.001). This study found that the h-index was strongly correlated with academic rank among oral and maxillofacial surgery faculty members and thus suggests that promotions committees should consider using the h-index as an additional method to assess research activity.