Intraosseous arterial alteration of maxilla influencing implant-related surgeries.

OBJECTIVES: To investigate the intraosseous arterial pathways and anastomoses in the alveolar aspects of the maxilla in order to better understand the arterial scattering pattern. MATERIALS AND METHODS: Eleven cadavers were selected for macroscopic intraosseous arterial analyses by corrosion casting. The red-colored acrylic resin was injected into the external carotid arteries. The specimens were kept in an enzymatic solution at 36 °C for about 60 days, depending on the process progression. After removal of the soft tissues and drying, the bone was macerated by potassium hydroxide to analyze the course and the mean diameters of the intraosseous anastomoses. RESULTS: Vertico-oblique and horizontal intraosseous arteries and anastomoses between the greater palatine-, posterior superior alveolar-, and infraorbital arteries were detected. The vertico-oblique anastomoses were found on the anterolateral wall of the maxilla and the alveolar crest with a mean diameter of 0.46 mm; nevertheless, the horizontal (transalveolar) anastomoses were identified in the interdental septum/alveolar crest with the mean diameter of 0.41 mm. From the horizontal anastomoses, small intraseptal branches supplied the territory of the alveolar socket in various directions. CONCLUSIONS: The localization of intraosseous arterial anastomoses is critical in implant-related surgeries, predominantly to maintain proper circulation. CLINICAL RELEVANCE: Based on vertico-oblique and transalveolar anastomoses, simultaneous buccal- and palatal flap elevation (particularly on the palatal side) should be avoided to minimize patient morbidity and intra- or postoperative complications. Moreover, preserving transverse loops in the interdental septum is essential during implant surgeries, which can significantly influence collateral periosteal and osteal circulation to prevent ischemia.

A Simple Method to Retract the Descending Palatine Neurovascular Bundle During Osseous Removal of Posterior Interferences in Le Fort I Osteotomy.

ABSTRACT: For accurate repositioning of the maxilla in Le Fort I osteotomy, bone removal around the descending palatine neurovascular bundle and maxillary tuberosity is frequently required. Such task can be challenging due to the high vascularity of the region, which is the most common site of hemorrhage during removal of bony interferences. Although a rare occurrence, ligation of the descending palatine artery in cases of intraoperative vascular damage can be related to the development of aseptic necrosis. This article reports a simple technique for retraction and protection of the descending palatine neurovascular bundle during bony removal related to a posterior maxillary impaction, which can be easily reproduced in orthognathic selected cases.

Assessment of the knowledge of canalis sinuosus amongst dentists and dental students: An online-based cross-sectional study.

INTRODUCTION: Canalis sinuosus (CS) is a neurovascular canal that corresponds to a small branch of the infraorbital canal. This study aimed at assessing the knowledge and detection performance of CS amongst dentists and dental students. MATERIALS AND METHODS: Four-hundred and five dentists and dental students answered a questionnaire with three parts: 1. Socio-demographical; 2. Clinical cases with cone- beam computed tomography (CBCT) sections showing CS and 3. Previous knowledge about CS. The chi-squared test and Spearman's correlation test were used to compare results as appropriate. p-values below .05 were considered statistically significant. RESULTS: Most participants did not identify CS in any CBCT. There was an association between the number of correct answers and dental specialties. Most individuals had not learned about CS previously. There was an association between past knowledge of CS and gender, highest academic degree, working environment, dental specialty and number of correct answers but not with age or experience in Dentistry. CONCLUSION: This study suggests that most dentists are not aware about CS and do not know how to diagnose it. Previous knowledge about CS positively influenced its identification in CBCT.

Course of the Maxillary Vein and its Positional Relationship With the Mandibular Ramus Require Attention During Mandibuloplasty.

PURPOSE: The maxillary vein is associated with major hemorrhage, an intraoperative risk factor during mandibuloplasty. Our objectives in this study were to identify the anatomical course of the maxillary vein relative to the mandible, and to ascertain the relationship of its course with that of the maxillary artery. METHODS: Thirteen sides of 13 cadavers in the possession of the Department of Anatomy of Tokyo Dental College were used. The maxillofacial region was first dissected, after which the upper part of the mandibular ramus was removed and the maxillary artery, maxillary vein, and pterygoid venous plexus were identified. The length of the maxillary vein and its height from the mandibular plane were then measured, and its anatomical course was recorded. RESULTS: The maxillary vein ran downward along the inner aspect of the temporal muscle, then from the base of the coronoid process it ran horizontally near the bone surface of the inner aspect of the mandibular ramus. After joining the inferior alveolar vein, it joined the superficial temporal vein to form the retromandibular vein. The mean length of the maxillary vein was 22.2 ±â€Š3.2 mm. At the posterior margin of the mandibular ramus, its mean height above the mandibular plane was 34.2 ±â€Š5.4 mm. From the posterior margin of the mandibular ramus to the lowest point of the mandibular notch, the maxillary vein was located within the areolar connective tissue directly above the periosteum adjoining the inner aspect of the mandibular ramus. CONCLUSIONS: In the wide area from the center of the maxillary notch to the posterior margin of the mandibular ramus, the maxillary vein runs extremely close to the periosteum on the inner aspect of the mandibular ramus, suggesting that it may pose a risk of hemorrhage in various oral surgical procedures.

Vascularized Composite Parietal Bone Flap for Immediate Reconstruction of a Hemi-Maxillectomy Defect in an Infant.

BACKGROUND: Surgical resection of maxillary tumors can result in defects that can be difficult to reconstruct by conventional means due to the complex functional and anatomic nature of the midface and lack of regional bone flap options in the head and neck. Many reconstructive methods have been used to repair maxillary defects, but the ideal technique for the reconstruction of hemi-maxillectomy defects in growing pediatric patients has yet to be determined. METHODS: The authors present a rare pediatric patient with melanotic neuroectodermal tumor of infancy resulting in a hemi-maxillectomy defect after resection that was reconstructed using a pedicled vascularized composite flap consisting of temporalis muscle, pericranium, and parietal bone. RESULTS: The patient achieved successful long-term bony reconstruction of his right maxilla with this flap. Stable skeletal fixation with adequate orbital support was maintained over a >3-year follow-up period. CONCLUSION: A vascularized composite parietal bone flap is a reliable reconstructive option for reconstruction of large maxillectomy defects providing low donor-site morbidity, adequate globe support, excellent long-term skeletal stability, and malar symmetry in rapidly growing pediatric patients. Successful reconstruction for a rare patient with maxillary melanotic neuroectodermal tumor of infancy requiring hemi-maxillectomy was demonstrated with >3-year follow-up.

Determination of baseline alveolar mucosa perfusion parameters using laser Doppler flowmetry and tissue spectrophotometry in healthy adults.

Objectives: To determine the baseline perfusion parameters of the alveolar mucosa using laser Doppler flowmetry and tissue spectrophotometry (LDF-TS) in healthy adults.Material and methods: Forty-two healthy adult subjects of either sex were tested. The perfusion of the alveolar mucosa was evaluated using a laser Doppler flowmetry and tissue spectrophotometry using O2C 'oxygen to see' device. The measurements encompassed the maxillary and mandibular mucosa at 20 different points.Results: The O2C device is a reliable method for noninvasive measurement of different perfusion parameters of the oral mucosa. The hemoglobin saturation values (So2 in %), as well as relative amount of hemoglobin in arbitrary units (AU) of the maxillary mucosa demonstrated lower values of that in the mandible. The flow value (AU) exhibited a significant difference in the posterior molar region only, while the velocity value (AU) showed a significant difference across all points except for the anterior region.Conclusion: the present study provides a set of brand-new perfusion parameters of the microcirculation of the alveolar mucosa using LDF-TS. The study suggests a variation of the perfusion parameters between the maxilla and the mandible. Differences in the anatomy of the blood supply, the thickness of the mucosa and the cortical bone, may be attributed to this variation. Further studies using different probes and a combination of ultrasonic measurements and SDF imaging will aid in giving a better overview of the perfusion in the oral mucosa.

Canalis sinuosus: anatomical variation or structure?

PURPOSE: The main goal of the present study was to verify the presence, spatial location, the end of the canalis sinuosus (CS) trajectory and size of CS using cone beam computed tomography (CBCT) to characterise it as either a structure or an anatomical variation. METHODS: A trained examiner specialist in dental radiology and imagenology selected 200 CBCT images of the maxilla from 107 (53.5%) female and 93 (46.5%) male individuals aged between 18 and 85 years. RESULTS: A total of 133 (66.5%) patients had CS, being 61 (45.86%) unilateral and 72 (54.14%) bilateral. A higher frequency of CS was observed in males (P < 0.05) and no relationship was found between its presence and age. The end of the CS trajectory was more frequent in the regions of central incisor (n = 91; 44.39%), followed by lateral incisor (n = 45; 21.95%) and canine (n = 29; 14.15%). In our sample, the majority of these canals had a diameter of up to 1 mm (n = 198/205; 96.6%). No statistically significant relationship between diameter and the end of the CS trajectory, with location (i.e. bilateral or unilateral) was found. Gender and age had no influence on diameter, spatial location and the end of the CS trajectory (P > 0.05%). CONCLUSION: As CS was frequently found in our sample, it can be considered an anatomical structure, and as such, it is fundamental that the dentist requests a CBCT examination before performing any invasive procedure in the maxillary region to preserve this important structure.

Vascular malformation of the sphenoid and temporal bone: A diagnostic dilemma.

We present a rare case of a vascular anomaly of the sphenoid and temporal bones causing an expandable mass of the temporal region with dependent patient positioning and characteristic osseous changes on imaging. Initial diagnosis considerations included multiple myeloma (MM), fibrous dysplasia (FD), Paget's disease, lymphoma, meningoencephalocele (MEC), and vascular malformation (VaM). VaMs of the head and neck are rare and typically arise in the mandible and maxilla. However, this case demonstrates a unique finding of a VaM of the sphenoid and temporal bones with important radiological features to distinguish the diagnosis of vascular anomaly from other etiologies.

Mirror Image Based Three-Dimensional Virtual Surgical Planning and Three-Dimensional Printing Guide System for the Reconstruction of Wide Maxilla Defect Using the Deep Circumflex Iliac Artery Free Flap.

A patient was diagnosed with squamous cell carcinoma of the maxillary sinus and consequently underwent a unilateral total maxillectomy and reconstruction using an anterolateral thigh (ALT) free flap. Soft tissue transplantation without a bone graft at the large maxillary defect site caused a midfacial collapse, which worsened, especially after radiotherapy. The 3-dimensional positioning of the composite flap for wide maxillary reconstruction is aesthetically important. To achieve ideal symmetry and aesthetics, a mirror image was created using the normal contralateral side. Through computer simulation, the function and symmetry of the virtually reconstructed maxilla was evaluated, and the surgical guide was made using a 3D printing system. Based on the prepared surgical guide, a deep circumflex iliac artery (DCIA) free flap was harvested, and its implementation in the reconstruction ultimately led to satisfactory results. Utilization of mirror image based virtual surgical planning and a 3D printing guide is a significantly effective method for maxilla reconstruction with DCIA flaps.

Laser-Assisted Indocyanine Green Imaging for Assessment of Perioperative Maxillary Perfusion During Le Fort I Osteotomy: A Pilot Study.

PURPOSE: To determine the changes in maxillary perfusion during different stages of Le Fort I osteotomies as measured by laser-assisted indocyanine green imaging (LAICGI) and to determine whether various clinical factors affect maxillary vascular perfusion. MATERIALS AND METHODS: The medical records of those who had undergone Le Fort I osteotomy with LAICGI at the University of Illinois from 2016 to 2017 were reviewed retrospectively. The maxillary perfusion levels using LAICGI were measured before induction, after induction, after down fracture, after segmentalization (for segmental osteotomies), and after wound closure. The effects of clinical variables, including gender, race, American Society of Anesthesiologists physical status, type of Le Fort I osteotomy, intraoperative status of the descending palatine vessels, maxillary movements (anteroposterior, vertical, transverse), and hemodynamic data (mean arterial blood pressure, heart rate), were analyzed. RESULTS: Compared with the preoperative baseline values, the indocyanine green (ICG) levels decreased after down fracture and mobilization, segmentalization, and wound closure; no statistically significant differences were found among these 3 points. Segmentalization did not affect the ICG levels compared with the nonsegmentalized cases. Male gender and the amount of maxillary impaction were significantly associated statistically with decreased ICG levels, although the difference was not clinically significant. CONCLUSIONS: Compared with the baseline levels, maxillary perfusion, as measured by LAICGI, decreased from down fracture to wound closure. Segmentalization did not appear to influence maxillary perfusion, although male gender and impaction were associated with decreased perfusion. Because of its safety and convenience, LAICGI shows promise as a method of assessing maxillary perfusion in future largescale prospective studies linking perioperative perfusion to the occurrence of aseptic necrosis.

Severe Delayed Hemorrhage After Cosmetic Rhinoplasty in the Setting of Maxillary Vascular Malformation.

Late epistaxis after rhinoplasty is a rare but potentially life-threatening occurrence. This case report concerns a 20-year-old woman who had severe epistaxis 5 and 10 days after a closed rhinoplasty with internal osteotomies and who ultimately required transcatheter arterial embolization for definitive control of the hemorrhagic source. Arterial hypervascularity, with signs of arteriovenous malformation, of the midface at the level of the piriform aperture and maxilla was seen on angiography.

Blood flow changes using a 3D xenogeneic collagen matrix or a subepithelial connective tissue graft for root coverage procedures: a pilot study.

BACKGROUND: The study investigated the early healing process following the treatment of single Miller class I and II recessions with a 3D xenogeneic collagen matrix (CMX) or connective tissue graft (CTG). METHODS: This pilot investigation was designed as a single-center randomized controlled parallel trial. A total of eight subjects (four per group) were treated with either CMX or CTG in the anterior maxilla. Vascular flow changes were assessed by laser Doppler flowmetry (LDF) before and after surgery and at days 1, 2, 3, 7, 14, and 30 while clinical evaluations took place at baseline and at days 60 and 180. Pain intensity perception was evaluated by the short-form McGill pain questionnaire (SF-MPQ), at days 1 and 14. RESULTS: The vascular flow fluctuated similarly in both groups pre- and post-operatively, but the CTG exhibited a more homogeneous pattern as opposed to CMX that showed a second phase of increased blood flow at 14 days. Clinically, the CTG led to greater change in mean root coverage and keratinized tissue gain but CMX was associated with lower early pain intensity scores. CONCLUSIONS: Within the limits of the study, the vascular flow alterations during the early healing of both graft types followed a similar pattern. The CMX was associated with a second peak of increased blood flow. CLINICAL RELEVANCE: The vascular flow changes after the application of CMX for single tooth recession root coverage did not show major differences from those observed after the use of a CTG. A trend for better clinical performance in terms of root coverage and keratinized tissue gain was noted for the CTG, but the initial patient morbidity was less for CMX.

Contemporary CBCT diagnostics-discovery of a new artery with possible impact on surgical planning: the anterior superior palatal alveolar artery.

PURPOSE: An ongoing clinical trial regarding intra- and post-surgical morbidity in maxillary apicoectomies showed significant higher morbidity for upper canines and palatal roots of upper 1st premolars. Analysis of available presurgical cone beam computed tomography (CBCT)-scans revealed the existence of an unknown bone-canal branching off from the bone-canal or groove of the anterior superior alveolar artery (asaa). Aim of the study was the determination of the contents of this newly found bone canal in human cadaver heads, its prevalence as possible standard anatomical structure and its automatized detection with a contemporary high-resolution TRIUM-CBCT-device in vivo. METHODS: 35 human cadaver heads were dissected, the prevalence of the bone-canal determined and its contents analyzed by histology. 835 consecutive routine high-resolution TRIUM-CBCT-scans from routine patients were analyzed by an automatized detection- and tracing-algorithm for in vivo-determination of prevalence of this bone canal. Automatized detection and additional manual tracing were statistically evaluated by SSPS 20.0 software. RESULTS: The bone-canal was found in 96% of the anatomical specimens, its content identified as artery not described until now and named after the first finder "Arteria Kurrekii". Automatized tracing of TRIUM-CBCT-scans with additional manual tracing revealed an in vivo prevalence of this newly found artery of 95% (p ≤ 0.05). CONCLUSIONS: The newly found anterior superior palatal alveolar artery (aspaa-"Arteria Kurrekii") might have the same clinical impact for surgical procedures in the maxilla as the posterior superior alveolar artery (psaa). Its first detection was enabled by high-resolution TRIUM-CBCT devices and prevalence as standard anatomical structure proven in vivo by automatized CBCT-scan analysis.

Changes in dimension of neurovascular canals in the mandible and maxilla: A radiographic finding in patients diagnosed with MRONJ.

BACKGROUND: The aim of this retrospective study was to compare the morphological features of neurovascular canals and foramina of patients with medication-related osteonecrosis of the jaws (MRONJ) and healthy individuals by using cone beam computed tomography (CBCT). MATERIAL AND METHODS: The CBCT images of 58 patients under bisphosphonate therapy diagnosed with MRONJ and age gender- matched controls were retrospectively evaluated. The diameter of mandibular and nasopalatine canal and mandibular, mental and lingual foramina were measured on several sections of CBCT. The value of mental index (MI) and panoramic mandibular index (PMI) were also assessed. RESULTS: The mean value of diametric measurements for all neurovascular canals and foramina in MRONJ patients were narrower than controls. Left mandibular foramen was the most affected area (p<0.001). There were significantly difference in all measurements of mental foramen, lingual foramen and mandibular incisive canal between two groups (p<0.05). PMI of MRONJ subjects were also significantly differences in both sides (p<0.05). CONCLUSION: In MRONJ patient, neurovascular canals and foramina are affected due to the alterations in bone remodeling. Therefore, the diametric measurement of neurovascular canals and assessment of MI and PMI on CBCT, is a potentially useful method for detection of early changes associated with bisphosphonate therapy and for predict areas where new necrosis may occur.

Tomographic Evaluation of Prevalence, Position, and Diameter of the Intraosseous Branch of the Posterior Superior Alveolar Artery in Fully Edentulous Individuals.

The objective of this study was to evaluate the presence, position, and diameter of the intraosseous branch (IObr) of the posterior superior alveolar artery in fully edentulous patients. Two-hundred five computed tomography scans of fully edentulous patients were analyzed. The presence of the IObr was investigated in the coronal plane at the lateral wall of the maxillary sinus. In patients in whom the IObr was detected, the artery diameter was measured, and the distance from the artery to the bone crest of the alveolar ridge, the maxillary sinus floor, and the distance of the maxillary sinus floor to the bone crest of the alveolar ridge were measured as well. A descriptive statistical analysis of these parameters was conducted. The IObr was identified in the maxillary sinus in 105 tomography images (51.2%), and its diameter varied between 0.8 and 3.3 mm (1.29 ±â€Š0.49 mm). The IObr presented with an artery diameter less than 1 mm in 29% of the patients, between 1 and 2 mm diameter in 61% of the patients and with a diameter larger than 2 mm in 10% of patients. Regarding the IObr topography, the distance from the artery to the floor of the maxillary sinus was 9.62 ±â€Š4.59 mm, and the distance from the artery to the top of crestal bone was 15.15 ±â€Š4.47 mm. At least 10% of edentulous patients are at risk of bleeding complications during interventions in the maxillary sinus.

Location of the extraosseous and intraosseous arterial anastomosis of the maxillary sinus in edentulous specimens.

OBJECTIVES: The aim of this anatomical study was to measure the distance from the intraosseous and extraosseous arterial anastomoses of the maxillary sinus to the alveolar ridge in edentulous specimens dissected from human cadavers. MATERIALS AND METHODS: Forty edentulous maxillary specimens were dissected, anatomically prepared, and injected for a better visualization of the maxillary sinus artery. RESULTS: This study showed that the mean distance from the alveolar ridge to the extraosseous anastomosis was 16 mm for the second maxillary molar, 12 mm for the first maxillary molar, and 13 mm for the second maxillary premolar. For the intraosseous anastomosis to the alveolar ridge, the mean distance was 17 mm for the second maxillary molar, 13 mm for the first maxillary molar, and 14 mm for the second maxillary premolar. CONCLUSIONS: Under the conditions of this study, we found that the mean distance from the alveolar crest to the extraosseous anastomosis and intraosseous anastomosis was shortest for the first maxillary molar and second maxillary premolar and greatest for the second maxillary molar. CLINICAL RELEVANCE: These findings provide data whose relevance for clinical dentistry is that they can be applied to minimize the risk of damage to the arterial network of the maxillary sinus during surgical procedures in this region.

Changes in Maxillary Canine Pulpal Blood Flow During Dentoalveolar Distraction Osteogenesis.

OBJECTIVE: The aim of this study was to assess the effects of dentoalveolar distraction osteogenesis (DD) on the pulpal blood flow (PBF) of maxillary canines. MATERIALS AND METHODS: A laser Doppler flowmeter (LDF) was used to measure PBF in maxillary canines of 10 patients undergoing DD (study group) and 10 nonsurgical subjects who received no orthodontic treatment (control group). PBF was measured at baseline, at 4 and 7 days postoperatively, at the end of distraction and at the end of consolidation in the study group and at similar time-points in nonsurgical control subjects. Data were analyzed using paired and Student t tests, with the significance level set at 0.05. RESULTS: Study findings showed that baseline PBF values did not differ significantly between groups. PBF in the control group did not vary over time; however, in the study group, an initial decrease in PBF was observed at 4 days postoperatively and was followed by a gradual increase to preoperative levels at the end of distraction. CONCLUSIONS: During the DD latency period, there appears to be a short-lived ischemic phase when perfusion of pulp tissue declines; however, blood-flow returns to normal by the end of distraction.

Cleft Le Fort I Osteotomy: A Video Presentation.

In this video, we present a single piece Le Fort I osteotomy with bone graft in a patient with a unilateral cleft lip and palate. Maxillary osteotomies in the cleft patient can be challenging because of the presence of scar, palatal or alveolar fistulae, compromised teeth, and vascularization of the segments. The video demonstrates our current approach and technique. The authors particularly want to highlight aspects of the approach, such as the incision, exposure, osteotomies, mobilization, splints, and plating. The associated manuscript discusses the depicted video as well as the blood supply to the maxilla, and postoperative patient care.

Curative Transvenous Onyx Embolization of a Maxillary Arteriovenous Malformation in a Child: Report of a New Technique.

Endovascular management of maxillary arteriovenous malformation (AVMs) can be complex. Transarterial, transvenous, and direct puncture embolization has been described. The authors report the case of a 9-year-old girl with a hemorrhagic maxillary AVM, which has been treated by transvenous embolization after failure of transarterial embolization. The venous pouch was catheterized with a detachable tip microcatheter and occluded by slow Onyx injection. Onyx filled the pouch and retrogradely reached some arterial feeders, achieving complete occlusion. Bleeding episode ceased and at 6 months follow-up no recurrence was found. Maxillary AVMs can be successfully treated by transvenous Onyx embolization.

Changes in human pulp blood flow during canine retraction.

AIM: To evaluate the effects of maxillary canine retraction on pulpal blood flow (PBF) in humans as recorded by laser Doppler flowmetry (LDF). METHODS: Maxillary canines of 24 participants were divided into two groups (n = 12 each). Teeth in the study group underwent maxillary canine retraction using mini-implants as anchorage for approximately 4 months, with 100 g of force applied via coil springs. Subjects in the control group received no orthodontic treatment. LDF measurements were recorded at baseline (T0); during retraction, at 24 hours (T1), 3 days (T2), 7 days (T3) and 1 month (T4); and at the end of retraction (T5) in the study group and at similar time-points in control subjects. Data were analyzed using the Friedman, Wilcoxon signed rank and Mann-Whitney U tests, with the significance level set at 0.05. RESULTS: No significant changes in PBF perfusion units (PU) were observed in the control group over the course of the study. However, PBF in the study group increased significantly from T0 (3.6 ± 0.2 PU) to T1 (3.7 ± 0.2 PU, p < 0.001) and decreased severely from T1 to T2 (3.3 ± 0.1, p < 0.001). PBF in the study group was still significantly lower at T3 (3.4 ± 0.1 PU, p < 0.001) in comparison to T0; however, at T4 and T5, PBF was found to have returned to pre-retraction levels. CONCLUSION: The fact that PBF values returned to initial levels within one month of the initiation of retraction despite short-term, hyperaemic, regressive changes demonstrates that the changes observed in PBF during canine retraction are reversible.