Vascular Complications in Le Fort I Osteotomy: Incidence, Reasons, and Management of the Intraoperative Hemorrhage.

PURPOSE: The aim of this study was to investigate the incidence, types, and reasons for the intraoperative hemorrhage during Le Fort I osteotomy. METHODS: The study sample was composed of the population of the patients who underwent orthognathic surgery from April 2011 to February 2017. The vascular complications of the patients who underwent Le Fort I osteotomy during the surgery were identified. Type of the bleeding, suspected vessel, amount of the intraoperative blood loss, cause, and management of the bleeding were specified and investigated. Descriptive statistics were computed for each study variable. RESULTS: A total of 200 patients underwent Le Fort I osteotomy. The sample's mean age was 22.4 ± 5.8 and 55.5% of patients were female. The intraoperative vascular complication was seen in only 10 (5%) samples. The suspected source of the hemorrhage was the descending palatine artery (DPA) in 8 (4%) cases, while the pterygoid venous plexus in the other 2 (1%) cases. The cause of the bleeding was suspected down-fracture in 8 cases, while pterygomaxillary junction (PMJ) separation in the other 2 cases. DPA was ligated with ligation clips and cauterized in arterial injury cases. The hemorrhage was taken under control using a hemostatic matrix with thrombin (Surgiflo, Ethicon, USA) in the venous bleeding cases. CONCLUSIONS: The down-fracture of the maxilla was found to be more related to the occurrence of vascular complications. Severe bleeding was managed by the use of the hemostatic matrix with thrombin and this hemostatic agent can be used to control this type bleedings in orthognathic surgery.

Evaluation of the Pterygomaxillary Separation Pattern in Le Fort I Osteotomy Using Different Cutting Instruments.

PURPOSE: Pterygomaxillary separation (PMS) is considered the main reason for serious complications associated with Le Fort I osteotomy. The aim of this study was to evaluate whether a piezo surgery, ultrasonic bone scalpel, or conventional bur used in Le Fort I osteotomy has an influence on PMS patterns. MATERIALS AND METHODS: Using a retrospective cohort study design, we enrolled a sample composed of patients who underwent orthognathic surgery. The primary predictor variables were the cutting instruments (ultrasonic bone scalpel, piezo surgery, and Lindeman bur) used to perform Le Fort I osteotomy. Other variables were demographic and anatomic parameters. The outcome variable was the type of PMS pattern, classified as follows: type 1, PMS at the pterygomaxillary junction (ideal PMS); type 2, PMS at the greater palatine foramen; type 3, PMS from the posterior wall of the maxillary sinus; and type 4, PMS with lateral or medial pterygoid fracture. Anatomic parameters, that is, the thickness and width of the pterygomaxillary junction and distance of the greater palatine foramen, were measured on preoperative cone-beam computed tomography images. The pattern of PMS was evaluated on postoperative cone-beam computed tomography. Data were analyzed using analysis of variance and the Pearson χ2 test. P < .05 was considered statistically significant. RESULTS: This study sample was composed of 96 PMSs in 48 patients. The most common type of PMS was type 1 (58), followed by type 4 (21), type 2 (10), and type 3 (7). A statistically significant relation was found between the cutting instrument and the ideal separation (type 1 PMS) pattern (P = .032), and the highest rate of the ideal separation pattern was seen in the ultrasonic bone scalpel group, at 24 of 32, compared with 22 of 38 in the piezo surgery group and 12 of 26 in the conventional bur group. CONCLUSIONS: According to the study, the ultrasonic bone scalpel is safer than other cutting instruments in terms of the ideal separation of the pterygomaxillary junction.

Risk Factors Influencing Recovery of Neurosensory Disturbances Following Sagittal Split Ramus Osteotomy.

PURPOSE: The aim of this study is to determine the risk factors influencing the recovery time of neurosensory disturbances (NSD) following sagittal split ramus osteotomy. METHODS: One hundred twenty-seven patients (254 operated sites) underwent sagittal split ramus osteotomy due to dentofacial deformities between the period of 2011 and 2017. These patients were followed up for at least 1 year, and the data obtained from changes in sensation of inferior alveolar nerve were recorded subjectively. The subjects were categorized according to age, gender, type of deformity, nerve manipulation, side of the jaw, and the amount of the mandibular movement. The relationship between the above-mentioned parameters, and the recovery time of NSD were investigated. Pearson χ analysis was used, and the value of significance was accepted as P < 0.05. RESULTS: The recovery time of NSD is significantly correlated with the age of the patients, the amount of the mandibular movement (>7 mm), and the nerve manipulation (P < 0.05). There was no statistically significant correlation found between the recovery time of NSD and gender, type of deformity, side of the jaw (P > 0.05). CONCLUSIONS: The recovery time of NSD may prolong in cases of large amounts of mandibular movements more than 7 mm or the nerve manipulation. The older age may increase the risk of permanent NSD.

Evaluation of Stress in Tilted Implant Concept With Variable Diameters in the Atrophic Mandible: Three-Dimensional Finite Element Analysis.

The beneficial mechanical properties provided by greater diameter or short implants increases their usage in the tilted implant concept. The aim of the present study is to compare the stress distribution of 4 different treatment models including variable implant numbers and diameters under a static loading protocol in the atrophic mandible using 3-dimensional finite element analysis. Three models included 2 tilted and 2 vertically positioned implants with different diameters, whereas 2 distally placed short implants were added to the fourth model. The von Mises stress as well as the maximum and minimum principal stress values were evaluated after applying 200 N bilateral oblique loads to the first molar teeth with the inclination of 45° to the longitudinal axis. Tilted implants were associated with higher stress values when compared with vertical implants in all models. The lowest stress values were obtained in the fourth model, including short implants. Although all stress values showed slight increases by descending implant diameters, the stress values of the model including implants with 3.3-mm diameter were within physiologic limits. All in all, an increasing number or diameter of implants may have a positive effect on implant survival. In addition, when narrow-diameter implants need to be inserted in the tilted implant concept, combination with short implants may be recommended for long-term success.

The changes of self-esteem, sensitivity to criticism, and social appearance anxiety in orthognathic surgery patients: A controlled study.

OBJECTIVES: To evaluate the changes of psychologic parameters, such as self-esteem, sensitivity to criticism, and social appearance anxiety, in skeletal Class III patients undergoing orthognathic surgery and to compare the psychologic status of skeletal Class III patients with control subjects. METHODS: The first group consisted of 60 patients with a mean age of 22.07 ± 1.30 years who did not need orthognathic surgery. The second group comprised 45 patients with skeletal Class III malocclusion (mean age 21.40 ± 2.02 years) who were evaluated in terms of psychologic changes from before to after surgery. A third group consisted of 50 Class III patients (mean age 20.09 ± 2.59 years) who were evaluated before surgery and a different 50 Class III patients (mean age 22.15 ± 2.03 years) who were investigated after surgery. The Rosenberg Self-Esteem Scale and the Social Appearance Anxiety Scale were used to evaluate psychologic parameters both before and after surgery. Analysis was carried out with the use of independent- and dependent-sample t tests, 1-way analysis of variance, and post hoc Tukey test. RESULTS: Self-esteem of the patients with skeletal Class III malocclusion increased, and sensitivity to criticism and social appearance anxiety decreased significantly after the surgery (P <0.001). In the patients with Class III malocclusion, self-esteem was significantly lower and social appearance anxiety significantly higher before orthognathic surgery than in the control group, and at the postoperative evaluation Class III patients had significantly higher self-esteem than the control group (P <0.001). CONCLUSIONS: Through the improvement in facial appearance after surgery, patients' self-esteem increases and their sensitivity to criticism and social appearance anxiety decrease.

Does Guided Bone Regeneration Prevent Unfavorable Bone Shapes in Distraction Gap?

PURPOSE: Complications related to distraction osteogenesis can cause degradation of newly regenerated bone. Additionally, an unfavorable shape of the regenerated bone at the distraction gap can reduce the quantity of regenerated bone. The aim of the present study was to report on the prevention of unfavorable shapes of regenerated bone using guided bone regeneration during distraction. MATERIALS AND METHODS: Bilateral alveolar distraction was performed in 10 beagle dog mandibles. One side of the mandible formed the experimental group and the other side served as the control group. In the experimental group, guided bone regeneration was performed simultaneously with distraction osteogenesis. In the control group, only alveolar distraction was applied. At the end of a 1-week latent period, all mandibles were distracted 10 mm (1 mm/day). After the distraction period, 3 months were allowed for consolidation. After consolidation, all the dogs were euthanized, and the shape of the regenerated bone was determined to be either favorable or unfavorable. Densitometric evaluation and area measurements were performed using computed tomography scans. Statistical evaluation was performed using the independent t test, with a significance level of P < .05. RESULTS: In the experimental group, no unfavorable bone shape developed in the distraction gap, and the new bone had a surface and volume similar to those of the segments. In contrast, in the control group, 4 mandibles had an unfavorable bone shape in the distraction gap and 4 showed favorable bone healing with no defect. The surface area of the regenerating bone in the experimental group was significantly greater than that in the control group. Also, the surface area differed significantly between the experimental and control groups (P < .05). However, the densitometric values did not differ between the 2 groups (P < .05). CONCLUSIONS: Concomitant use of guided bone regeneration with distraction osteogenesis could be an optimal method for generating a favorable bone shape within the distraction gap.

Current management concepts for bisphosphonate-related osteonecrosis of the jaw: a review.

Bisphosphonate (BP) drugs are used to preserve bony tissue in patients diagnosed with osteoporosis and metastatic bone disease. However, these drugs are associated with rare but serious complications. The most commonly encountered adverse effect is bisphosphonate-related osteonecrosis of the jaw (BRONJ). Diagnosis and treatment of teeth that are likely to cause infection and the replacement or adjustment of dentures or restorations that could lead to trauma are the key steps that can be taken before the initiation of BP therapy in order to prevent the development of BRONJ. To date, the most efficacious management approach for BRONJ has not been clearly established. This article presents current approaches for the treatment of BRONJ, including conservative drug therapy and surgical therapy, and discusses new treatment modalities.

Effects of Surgical and Nonsurgical Rapid Maxillary Expansion on Palatal Structures.

AIM: The aim of the present study was to compare the effects of surgical and nonsurgical rapid maxillary expansion (RME) in skeletally mature patients. MATERIALS AND METHODS: Surgically assisted rapid maxillary expansion (SARME) was used in 18 patients (2 males, 16 females) with a mean age of 19.90 years. Two nonsurgical RME groups were constructed to compare the expansion changes of SARME. Eighteen patients in maximum pubertal peak (12 males, 6 females) with a mean age of 13.04 years comprised the growing RME group, while the nongrowing RME (NG-RME) group consisted of 18 skeletally mature patients (1 male, 17 females) with a mean age of 16.41 years. Thirteen linear and 2 angular measurements were made on the study models taken before expansion (T0) and after 3 months of retention period (T1). Intragroup differences were evaluated with paired t test and the intergroup differences were analyzed with 1-way analysis of variance. RESULTS: All groups showed significant transversal skeletal and dental expansion. The palatal width changes at gingival and midpalate levels were the highest in the NG-RME group (6.85 and 5.84 mm, respectively). The most molar tipping was in the NG-RME group (15.00°) and the palatal vault angle showed the most increase in the SARME group (9.77°). The greatest expansion at the base of palatal vault was in the SARME group (4.42 mm). CONCLUSIONS: The pattern of expansion was rotation of the maxillary halves for SARME and lateral displacement of the dentoalveolar structures for NG-RME. Patients with severe skeletal discrepancy or increased age are good candidates for SARME.

Clinical Outcomes After Immediate and Late Implant Loading for a Single Missing Tooth in the Anterior Maxilla.

PURPOSE: This study compared the clinical outcomes of 1-year follow-up of immediate and late implant loading after implant restoration of a single tooth in the anterior maxilla. MATERIALS AND METHODS: Thirty-three patients with missing teeth in the anterior maxilla were included in this study (18 immediate loading and 15 late loading). Standard periapical radiographs were obtained to evaluate the vertical bone loss around the implant. For both implant groups, periimplant parameters (probing depth, gingival bleeding index, gingival index (GI), modified plaque index, width of keratinized gingiva) were evaluated. RESULTS: There were no significant differences in bone loss, the widths of keratinized gingiva, the GI, and modified plaque index between the immediate implant loading and late implant loading groups (P > 0.05). A significant difference in the probing depth was observed between these groups at the initial and 1-month evaluations (P < 0.05). Significant differences in bleeding indices between these groups were observed at months 3 and 6 (P < 0.05). CONCLUSIONS: When selecting appropriate patients (adequate primary stability, patient compliance with the surgeon's recommendations), immediate implant loading may be an alternative method to late loading protocol for replacement of a missing tooth in anterior maxilla.

Determination of lingual vascular canals in the interforaminal region before implant surgery to prevent life-threatening bleeding complications.

OBJECTIVES: Profuse hemorrhage and airway obstruction may occur during or after the implant surgery in the interforaminal region. The prevention from this complication requires identifying the location of the mandibular lingual vascular canals (MLVCs). The purpose of this study was to evaluate the anatomical variations of MLVCs and to determine the safety margins for implant placement in interforaminal region. MATERIALS AND METHODS: Computer tomography (CT) images of 200 consecutive patients were reexamined retrospectively by a radiologist and a maxillofacial surgeon to evaluate the presence of the MLVCs entering the mandible. The diameter and the number of the canals, the distance between the entrance of the canal and mandibular midline, and the height of the entrances of the canals from the inferior mandibular margin were measured. RESULTS: Two hundred and thirty-six median lingual canals (MLCs) and 159 lateral lingual canals (LLCs) were found in 200 patients. Significant differences were found between the number of lingual canals in the midline and canine regions (P < 0.001). CONCLUSION: There is a potential risk of complications due to the injuries of the vessels entering the lingual cortical bone through a number of bone canals during implant placement in the interforaminal region.

Assessment of Candida species colonization and denture-related stomatitis in bar- and locator-retained overdentures.

The aim of this study was to assess the prevalence of denture-related stomatitis (DRS) in different attachment-retained overdenture wearers and its association with particular colonizing Candida species. Thirty-seven edentulous patients with implant-supported maxillary or mandibular overdentures were enrolled. A full clinical history was obtained, including details of patients' oral hygiene practices and the levels of erythema based on Newton's classification scale. Swabs were taken from the palate and investigated mycologically to identify the yeast colonies. Quantitative and qualitative microbiological assessments were performed, which included recording the total numbers of colonies (cfu), their color, and their morphological characteristics. Significant differences were found in cfu values between the attachment and inner surfaces of locator- and bar-retained overdentures (P < .05). Candida albicans was the most common species in both evaluations, being isolated from 81.3% of bar-retained overdentures and 38.1% of locator-retained overdentures. DRS developed in all patients using bar-retained overdentures but in only 71.4% of those using locator-retained overdentures. No statistically significant relationship was found between bar and locator attachments according to smoking habit, overnight removal, or plaque and gingival indices (P > .05).

Anterior mandibular zone safe for implants.

During implantology procedures, one of the most serious complications is damage of the inferior alveolar nerve (IAN). The mandibular incisive nerve is described as a terminal branch of the IAN and provides innervation to the lower anterior teeth and canines. The incisive nerve and canal are located in the interforaminal area. Although numerous studies report IAN damage during implant placement, few reports in the literature describes sensory disturbances, such as neuropathic pain, related to mandibular incisive nerve damage. The purpose of this retrospective clinical study was to evaluate the risk of neuropathic pain caused by implant placement in the interforaminal region of the mandible. Panaromic radiographs of patients who were treated with dental implants in the Department of Maxillofacial Surgery, Faculty of Dentistry at Erciyes University, between 2007 and 2012, were examined. Fifty-five patients with suspected relationship between mandibular incisive canal and dental implant were included into this study. Computed tomography scans were obtained from 10 patients who have postoperative neuropathic pain. Relationship between dental implant and mandibular incisive nerve was evaluated using a three-dimensional software program. Mandibular incisive nerve perforation by at least 1 implant was observed in all 10 patients. Descriptive analyses were also provided. Neuropathic pain may occur after implant placement in the interforaminal region due to the perforation of the incisive canal and nerve. According to the results of this retrospective study, the incisive canal and nerve perforation should be considered as a complication of implant surgery in the mandibular anterior area.

Two case reports involving implants and fractured healing caps.

The widespread use of endosseous osseointegrated implants to replace missing natural teeth increases the chances of implant complications and failures, despite the high initial success rate reported in the literature. Implant and healing cap fracture are possible rare complications that can cause significant problems for both clinicians and patients. This article reports on 2 unique cases of implant and healing cap fracture, their possible causes, and how the cases were managed.

Vertical ridge augmentation using sandwich osteotomy: 2 case reports.

The placement of dental implants in atrophic jaws is a challenging procedure due to inadequate bone quantity. This anatomic limitation can be overcome by various treatment methods such as onlay bone graft, inlay bone graft (known as sandwich osteotomy), and distraction osteogenesis. Two female patients with complaints of atrophic mandible were included in this study. Both patients were treated with a segmental mandibular sandwich osteotomy with interpositional grafts. This is called a sandwich osteotomy technique because a section of the jaw bone is separated from the main part and a bone graft is inserted between the 2 parts. The postoperative period was uneventful, and sufficient bone gain was obtained in both patients. Sandwich osteotomy is an effective technique to gain vertical bone height in atrophic jaws.

Three-dimensional palatal morphology and upper arch changes following nonsurgical and surgical maxillary expansion in adults.

OBJECTIVE: The objective of this study was to evaluate the effects of nonsurgical rapid maxillary expansion (RME) and surgically assisted RME (SARME) on palatal morphology and upper arch dimensions using three-dimensional (3D) models in skeletally mature patients. STUDY DESIGN: Thirty-eight skeletally mature patients with a maxillary transverse deficiency were divided into RME and SARME groups. Nineteen patients in the RME group (mean age, 19.16 ± 2.25 years) were treated using a full-coverage bonded acrylic splint expander; 19 patients in the SARME group (mean age, 20.38 ± 3.36) were treated using the banded palatal expansion appliance with hyrax screws. The 3D models were obtained before and after expansion. The maxillary dental arch widths, maxillary first molar angulation, palatal area, and palatal volume were calculated on the 3D models. RESULTS: All variables showed statistically significant changes after the retention period (P < .001). The maxillary arch width between first premolars (P < .05), the palatal area (P < .01), and the palatal volume (P < .05) significantly increased in the SARME group compared to the RME group. The maxillary first molar tipping in the RME group was significantly higher than that in the SARME group (P < .01). CONCLUSIONS: Although SARME has more positive effects in skeletally mature patients, nonsurgical RME can be considered as an alternative by evaluating surgical risks, periodontal status, and the need for skeletal expansion.

Is it possible to shorten the jaws using contraction osteogenesis?

PURPOSE: This study investigated whether shortening of osteotomized jaws is possible. MATERIALS AND METHODS: Nine sheep were used (2 as controls and 7 as experimental subjects). Distraction devices that had previously been activated to 10 mm were fixed to the mandibles of all animals bilaterally and used in reverse as a contraction device. Control and experimental animals were sacrificed at 1 month and 3 months. Bone in the area of contraction was evaluated using radiodensitometry and microscopy. RESULTS: The mandibles were shortened an average of 5.5 mm. Exaggerated bone formation was seen around the osteotomized cortical bone. When histologic slices from experimental animals were examined 1 month after the contraction period, fibrous pseudoarthrosis formation was seen centrally, with hyaline cartilage around it, whereas normal bone formation was seen in the outer part. The hyaline cartilage had turned into normal bone 3 months after the end of contraction. CONCLUSIONS: It is possible to shorten bones using contraction osteogenesis.

Evaluation of the effects of guided bone regeneration and periosteum on newly formed bone in a distraction gap.

We determined the causes of bone resorption within a distraction gap and determined whether it could be prevented via guided bone regeneration during distraction. Another goal was to determine the effect of periosteum in bone healing in a distraction gap.Twelve sheep mandibles were bilaterally distracted. One side of the 6 sheep mandibles formed the control group; the other side was the study group, from which the periosteum was excised and distraction was performed. In the other 6 sheep, on the study side, guided bone regeneration was applied with distraction; on the other study side, guided bone regeneration was applied, and the periosteum was excised at the distraction. At the end of a 1-week latent period, all subjects were distracted 10 mm (1 mm/d), and we waited 3 months for consolidation. At the end of this period, all animals were killed, and radiologic evaluations of the newly formed bone within the distraction gap were conducted.The surface area of the regenerating bone in the membrane groups was significantly higher than in the groups without a membrane. However, no additional effect of the periosteum on the bone surface area was observed. No significant difference between the groups in densitometric values was observed.Concomitant use of guided bone regeneration with distraction osteogenesis may be the optimal way to generate a flat bone surface within a distraction gap.

Comparative Finite Element Analysis of Short Implants with Different Treatment Approaches in the Atrophic Mandible.

PURPOSE: This three-dimensional finite element analysis study aimed to compare the stresses transmitted to short, tilted, and vertical implants used in different configurations and to the surrounding peri-implant bone in the atrophic mandible. MATERIALS AND METHODS: A three-dimensional model of an atrophic mandible was made using customized computer software. Four models including short, tilted, and vertical implants were constructed with and without cantilever extension. Four or six implants in different configurations were placed into the models and mounted with the same fixed prosthesis. An oblique force of 200 N was bilaterally applied to the most distal part of the fixed denture. Von Mises stress values on implants and minimum and maximum principal stress values transmitted to peri-implant bone were analyzed. RESULTS: The highest stress values recorded in the tilted implants (von Mises: 129 MPa), in the peri-implant bone around the tilted implants (minimum principal stress: -40 MPa), and overall stress values were found to be higher in the model including tilted implants with cantilever extensions. Distally placed short implants, with consequent elimination of the cantilevers, resulted in decreased stress values for all of the treatment variabilities of an atrophic mandible. Von Mises stress values were found as 129 MPa in tilted (model I), 48 MPa in short (model II), 47 MPa in short (model III), and 57 MPa in vertical (model IV) at the most distal implant location. Lower compressive stress values were noted in the bone around straight and short implants compared with the tilted implants in all models (model I, tilted: -40 MPa; model II, short: -34 MPa; model III, short: -33 MPa; model IV, vertical: -25 MPa). CONCLUSION: Distally placed short implants contributed to the reduction of stress values of the implants and the surrounding bone. The combination of two short and four straight implants without cantilevers may be a beneficial design in the rehabilitation of posteriorly atrophic mandibles.

Effects of simvastatin on mandibular distraction osteogenesis.

PURPOSE: The aim of this study was to evaluate the effects of local and systemic simvastatin application on distraction osteogenesis. MATERIALS AND METHODS: Eighteen New Zealand white rabbits underwent unilateral mandibular distraction osteogenesis. After 7 days of neutral fixation, 0.4 mm twice per day, distraction was performed for 10 days. Simvastatin was applied locally during the osteotomy phase with a gelatin sponge carrier and systemically during the distraction osteogenesis period by oral gavage. All animals were killed at the end of the consolidation period of 14 days. The distracted mandibles were harvested and evaluated by plain radiography, by peripheral quantitative computed tomography, and with histomorphometry. RESULTS: Radiographic evaluation with peripheral quantitative computed tomography showed that the area of the regenerate increased by 9.6% in the local simvastatin group and by 19.3% in the systemic simvastatin group as compared with the control group. In both experimental groups the density of the regenerate increased by 6.7% as compared with the control group. Statistical evaluation of radiographic data showed that all of these changes were not significant. Histomorphometric evaluation determined that there was no statistical difference among groups with regard to the ratios of bone tissue volume to fibrous tissue volume and bone tissue volume to marrow tissue volume. CONCLUSIONS: The results of this study suggest that simvastatin's effect on enhancing distraction regenerate is limited with the applied doses and methods.

Osseous changes in patients with medication-related osteonecrosis of the jaws.

OBJECTIVES: Medication-related osteonecrosis of the jaw (MRONJ) is a severe side effect of antiresorptive agents. The aim of this study was to investigate the osseous changes in patients with MRONJ. METHODS: Cone beam CT (CBCT) images of 25 patients with MRONJ and controls were retrospectively evaluated. Buccal, lingual, apical cortical bone thicknesses; buccal, lingual, apical intracortical and cancellous bone density; diameter of mental foramen and incisive canal, and width of mental foramen were measured. RESULTS: Buccal and apical cortical bone thicknesses were increased; however intracortical radiodensity values decreased in the Study Group when compared with the Control Group (p = 0.007, p = 0.001). Narrowing of incisive canal was observed in patients with MRONJ (p = 0.000). CONCLUSIONS: Clinician should have awareness about narrowing of incisive canal, apical and buccal cortical bone thickening, decreasing in cancellous bone radiodensity, and the lingual cortex destruction in patients with MRONJ.