Evaluation of a Fully Digital, In-House Virtual Surgical Planning Workflow for Bimaxillary Orthognathic Surgery.

BACKGROUND: The advantages of virtual surgical planning (VSP) for orthognathic surgery are clear. Previous studies have evaluated in-house VSP; however, few fully digital, in-house protocols for orthognathic surgery have been studied. PURPOSE: The purpose of this study was to evaluate the difference between the virtual surgical plan and actual surgical outcome for orthognathic surgery using a fully digital, in-house VSP workflow. STUDY DESIGN, SETTING, SAMPLE: This is a prospective cohort study from September 2020 to November 2022 of patients at the Victoria General Hospital in Halifax, NS, Canada who underwent bimaxillary orthognathic surgery. Patients were excluded if they had previously undergone orthognathic surgery or were diagnosed with a craniofacial syndrome. MAIN OUTCOME VARIABLES: The primary outcome variables were the mean 3-dimensional (3D) (Euclidean) distance error, as well as mean error and mean absolute error in the transverse (x axis), vertical (y axis), and anterior-posterior (z axis) dimensions. COVARIATES: Covariates included age, sex, and surgical sequence (mandible-first or maxilla-first). ANALYSES: The primary outcome was tested using Z and t critical value confidence intervals. The P value was set at .05. The 3D distance error for mandible-first and maxilla-first groups was compared using a 2-sample t-test as well as analysis of variance. RESULTS: The study sample included 52 subjects (24 males and 28 females) with a mean age of 27.7 (± 12.1) years. Forty three subjects underwent mandible-first surgery and 9 maxilla-first surgery. The mean absolute distance error was largest in the anterior-posterior dimension for all landmarks (except posterior nasal spine, left condyle, and gonion) and exceeded the threshold for clinical acceptability (2 mm) in 16 of 23 landmarks. Additionally, mean distance error in the anterior-posterior dimension was negative for all landmarks, indicating deficient movement in that direction. The effect of surgical sequence on 3D distance error was not statistically significant (P = .37). CONCLUSION AND RELEVANCE: In general, the largest contributor to mean 3D distance error was deficient movement in the anterior-posterior direction. Otherwise, mean absolute distance error in the vertical and transverse dimensions was clinically acceptable (< 2 mm). These findings were felt to be valuable for treatment planning purposes when using a fully digital, in-house VSP workflow.

Prevalence of Surgical Site Infections Following Orthognathic Surgery: A Double-Blind, Randomized Controlled Trial on a 3-Day Versus 1-Day Postoperative Antibiotic Regimen.

PURPOSE: The purpose of this study was to determine the effect of a 3- versus 1-day antibiotic regimen on the rate of surgical site infection (SSI) in patients undergoing orthognathic surgery at a department of oral and maxillofacial surgery in Halifax, Nova Scotia, Canada. MATERIALS AND METHODS: A prospective, randomized controlled trial was conducted. All patients received 1 day of intravenous antibiotics after surgery. Then, patients were randomly distributed into groups that received 2 days of additional antibiotics (group A) or placebo (group B). The primary outcome measured was the presence of SSI. The operating surgeon, concomitant extraction of teeth, surgical procedures performed, duration of intermaxillary fixation, and length of hospital stay were analyzed for an effect on SSI. Patients were followed for 1 year after surgery to identify SSIs that might have been diagnosed outside the hospital. RESULTS: The trial started with 288 patients, and 117 patients were lost to follow-up. Statistical analyses were ultimately performed on those 171 patients who were adherent to the study medication regimen. Group A (n = 86) and B (n = 85) SSI rates were 7.0 and 17.6% (number needed to treat = 10; P = .04), respectively. Mandibular bilateral sagittal split osteotomy (BSSO) was involved in 71% of SSIs. Intra- and postoperative surgical variables did not have a relevant effect on the SSI rate. Patients were followed for 1 year after surgery, and group A (n = 46) and group B (n = 44) had SSI rates of 4 and 25% (P < .05), respectively. CONCLUSIONS: Three days of postoperative cefazolin and cephalexin markedly decreases SSI rates compared with 1 day. However, the number needed to treat of 10 suggests that the benefits of the extended regimen might not outweigh the risks. The high prevalence of SSIs at the mandibular BSSO incisions might have been caused by contamination, with more saliva and reception of a lower blood supply, than maxillary Le Fort I incisions. Mandibular osteotomies could benefit from an extended antibiotic regimen to minimize SSIs and associated complications. Other surgical variables might not require special consideration for antibiotic therapy.

Prevalence of Surgical Site Infections Following Orthognathic Surgery: A Retrospective Cohort Analysis.

PURPOSE: The purpose of this retrospective study was to determine the prevalence of surgical site infection (SSI) after orthognathic surgery at the Department of Oral and Maxillofacial Surgery of Capital Health and Dalhousie University (Halifax, NS, Canada). PATIENTS AND METHODS: A retrospective chart review of all patients undergoing orthognathic surgery from October 2005 through April 2013 was performed. The outcome variable was SSI. The primary predictor variable was the antibiotic used for prophylaxis. The secondary predictor variables were patient demographics, such as age, gender, medical comorbidities, and smoking status; duration of surgery; wisdom teeth extractions; single-jaw or bimaxillary surgery; and type of surgery. Data also were gathered on the diagnosis of SSIs and the treatment to resolve these infections. RESULTS: In total, 2,521 patients underwent surgery, and 253 patients did not meet the inclusion criteria; therefore, the charts of 2,268 patients were reviewed (mean ± standard deviation, 26.9 ± 11.7 yr of age). Eight percent of patients developed an SSI. None of the patient demographics was associated with an increased risk for infection. Most initial infections (62%) and most recurrent infections (78%) occurred in the mandible. Twenty-six percent of patients who developed SSIs had recurrent infections after antibiotic treatment. SSIs necessitated hardware removal for 14% of patients. Adverse effects from the antibiotics were seen in 4.2% of patients. Infection was most frequently diagnosed 11 to 15 days postoperatively. The average length of surgery for patients who did not have an SSI was 136 minutes compared with an average of 157 minutes for patients who had an SSI (odds ratio = 1.0051; 95% confidence interval, 1.0026 to 1.0076; P < .001). Wisdom teeth were extracted in 49.6% of the 2,268 cases. The mean SSI prevalence for multiple jaw procedures (9.2%) was significantly higher than that for single surgical procedures (5.3%; P = .0013). Isolated Le Fort surgeries had a significantly lower prevalence of infection compared with the mean prevalence (3.9%; P = .02), whether they were single piece or segmented (3.5 and 4.3%, respectively; P = .98). The prevalence of infection was significantly lower in the cefazolin group (6.2%) compared with the penicillin (14.3%; P < .0001) and clindamycin (10.4%; P < .02) groups. CONCLUSIONS: The prophylactic use of first-generation cephalosporins, such as cefazolin, appears to be more effective than penicillin and clindamycin for preventing SSIs in orthognathic surgery. In addition, bimaxillary surgery, mandibular procedures, and duration of surgery might demand antibiotic prophylaxis that is more effective. The presence of third molars and patient demographics are not risk factors for SSIs. A prospective randomized controlled study is underway to investigate the findings of this study.

Management of fractures of the nasofrontal complex.

Repair of fractures involving the nasofrontal region remains a mainstay of contemporary oral and maxillofacial surgery. This article discusses the epidemiology of these injuries, anatomy of the area, and management of these fractures with insight into potential complications. These include fractures of the frontal sinus, naso-orbital-ethmoidal region, root of the nose, and associated adjacent structures.

Thin serial step sectioning of sentinel lymph node biopsy specimen may not be necessary to accurately stage the neck in oral squamous cell carcinoma.

PURPOSE: The purpose of this study was to assess the predictability of sentinel lymph node biopsy (SNB) for oral squamous cell carcinoma (OSCC) when pathologic processing is performed without serial step sectioning. MATERIALS AND METHODS: We prospectively enrolled 36 patients with T1 or T2 cN0 OSCC into this institutional review board-approved prospective cohort study, and they underwent gamma probe-guided SNB in addition to selective neck dissection. The rate of patients with negative SNB results whose neck dissection was also negative for metastasis (negative predictive value) was the primary endpoint. RESULTS: Of the 28 patients whose sentinel lymph nodes were found to be pathologically and clinically node negative by routine hematoxylin-eosin stain and immunohistochemistry, 27 were found to have no other pathologically positive nodes, corresponding to a negative predictive value of 96%. CONCLUSION: The results of this study suggest that SNB performed without the use of thin serial step sectioning may accurately predict neck stage in OSCC.

The presence of mandibular third molars during sagittal split osteotomies does not increase the risk of complications.

PURPOSE: The purpose of this study was to investigate prospectively the effects of the presence or absence of third molars during sagittal split osteotomies (SSOs) on the frequency of unfavorable fractures, degree of entrapment and manipulation of the inferior alveolar nerve (IAN), and procedural time. MATERIALS AND METHODS: The investigators designed and implemented a prospective cohort study and enrolled a sample composed of patients who underwent SSOs to correct mandibular deformities. The primary predictor variable was the status of the mandibular third molar at the time of SSO, and it was divided into 2 levels, present at the time of SSO (group I) or absent at the time of SSO (group II). The primary outcome variable was unfavorable splits. The secondary outcome variables were the degree of entrapment/manipulation of the IAN and the procedural time. Appropriate bivariate and multivariate statistics were computed, and the level of statistical significance was set at P < .05. RESULTS: Six hundred seventy-seven SSOs were performed in 339 patients: group I consisted of 331 SSOs (mean age ± SD: 19.6 ± 7.4 yrs), and group II consisted of 346 SSOs (30.4 ± 12.1 yrs). The overall rate of unfavorable fractures was 3.1% (21 of 677), with frequencies of 2.4% (8 of 331) in group I, compared with 3.8% (13 of 346) in group II (P = .3). The rate of IAN entrapment in the proximal segment was significantly lower in group I (37.2%) than in group II (46.5%; P = .01). The degree of entrapment was also significantly more severe for group II (P < .001). Third molars increased procedural time by 1.7 minutes (P < .001). CONCLUSIONS: The presence of third molars during SSOs is not associated with an increased frequency of unfavorable fractures. Concomitant third molar removal in SSOs also decreases proximal segment IAN entrapment but only slightly increases operating time.

Basosquamous carcinoma involving the anterior skull base: a neglected tumor treated using intraoperative navigation as a guide to achieve safe resection margins.

Basosquamous carcinoma (BSC) or metatypical carcinoma is a rare and controversial form of basal cell carcinoma (BCC) that was first described by MacCormac in 1910. Numerous theories have been described in the literature regarding its origin but it is generally accepted as a variant of BCC that differentiates into squamous cell carcinoma (SCC). At present, it has an unsatisfactorily established phenotype but is considered to behave more like an SCC than a BCC. A reflection of this fact is its more aggressive nature with a significantly increased incidence of local and distant metastasis. It must be distinguished histologically from so-called "collision" tumors, which represent SCC and BCC arising as separate entities in the same area. We present a unique case of a neglected, large, and locally advanced case of BCC originating from the nose, but extending into the paranasal sinuses, orbit, and anterior skull base, that was treated with en bloc surgical resection using intraoperative navigation to assist in treatment planning and margin clearance.

Facial appearance following surgical treatment for obstructive sleep apnea syndrome.

Obstructive sleep apnea syndrome (OSAS) is a serious medical condition that is associated with numerous negative health side effects. The general dentist plays an invaluable role in identifying patients with this condition. Certain OSAS patients receive significant medical and social benefits from orthognathic surgery to advance the maxilla, mandible, and chin. Anterior positioning of the maxilla and mandible is not only highly successful for curing OSAS but also results in favorable facial esthetic changes.