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.

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.

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.

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.

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.

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.

Distribution of the maxillary artery in the deep regions of the face and the maxilla: Clinical applications.

Composite tissue allotransplantation of the face has led to renewed interest in the vascularization of the maxilla. The maxillary artery, which is deep within the tissue and difficult to access, is considered the main artery of the maxilla. The objective of this study was to describe the distribution of the maxillary artery in the deep regions of the face and maxilla. Twenty-four maxillae were studied, of which 20 were injected with latex and four with India ink. The maxillary artery in the pterygopalatine fossa gave rise to the sphenopalatine artery, infraorbital artery, descending palatine artery, and posterior superior alveolar artery in all 24 cases. The posterior superior alveolar artery gave rise to a periosteal branch and an intraosseous branch (in the wall of the maxillary sinus) in 18 cases. The branch passed through part of the wall and the entire wall in eight and ten cases, respectively, and anastomosed at the anterior nasal spine and the infraorbital foramen. The descending palatine artery presented as a single trunk in four cases, a greater palatine artery and a lower palatine artery in 18 cases, and four branches in two cases. Intraosseous and periosteal anastomoses were found along with anastomosis through the incisive foramen, which were obstructed in three cases. The vascular territories were studied. The maxillary artery created an intraosseous and periosteal anastomotic network, explaining the supply pathways during different surgical procedures, risk of hemorrhage with orthognathic surgery (Le Fort type I) in a sinus lift for preimplant surgery, and the vascular territories.

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.

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.

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.

Anatomy of the Le Fort I segment: Are arterial variations a potential risk factor for avascular bone necrosis in Le Fort I osteotomies?

PURPOSE: Osteotomies of the Le Fort I segment are routine operations with low complication rates. Ischemic complications are rare, but can have severe consequences that may lead to avascular bone necrosis of the Le Fort I segment. Therefore the aim of this study was to investigate the blood supply and special arterial variants of the Le Fort I segment responsible for arterial hypoperfusion or ischemic avascular necrosis after surgery. MATERIAL AND METHODS: The arterial anatomy of the Le Fort I segment's blood supply using 30 halved human cadaver head specimens was analyzed after complete dissection until the submicroscopic level. In all specimens the arterial variants of the Le Fort I segment and also the arterial diameters measured at two points were evaluated. RESULTS: The typical known vascularization pattern was apparent in 90% of all specimens, in which the ascending palatine (D1: 1,2 mm ± 0,34 mm; D2: 0,8 mm ± 0,34 mm) and ascending pharyngeal artery (D1: 1,3 mm ± 0,58 mm; D2: <0,4 mm) were both supplying the Le Fort I segment. However in 10% of all specimens, the Le Fort I segment was dependent on the ascending pharyngeal artery alone and the missing ascending palatine artery was replaced with the anterior branch of the ascending pharyngeal artery (D1: 1,9 mm ± 0,32; D2: 1,0 mm ± 0,3 mm). CONCLUSION: This study is the first description of a special type of arterial variation of the Le Fort I segment. The type of this arterial variation, its clinical relevance and potential consequences are explained. Individuals with this special arterial anatomy may clinically be at a high risk for hypoperfusion and avascular segment necrosis after surgery. An individualized operation plan may prevent ischemic complications in at-risk patients.

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). CONCLUSIONS: 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

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.

Pathosis or Additional Maxillary Neurovascular Channel? A Case Report.

This case report highlights an incidental finding of an anatomic variation of a neurovascular channel in close proximity to the maxillary right permanent lateral incisor (tooth #7). A 32-year-old patient presented with discomfort and a history of trauma in childhood to the right maxillary central incisor (tooth #8). A periapical radiograph of tooth #8 revealed an incidental finding of a radiolucent area in the apical one third of the right maxillary lateral incisor (tooth #7) root with the appearance of inflammatory apical root resorption. A cone-beam computed tomographic scan taken to assess the suspected area of resorption revealed this to be a neurovascular channel within the bone passing distal to the apex of tooth #7, which has been superimposed over the root of tooth #7 on the periapical radiograph. This case report highlights that additional bone channels are a common finding in the maxillary alveolus. These channels can in fact be the canalis sinuosus (or branches of it), a bone channel that is a frequent anatomic variant arising from the infraorbital canal. The canalis sinuosus has been reported rarely in the literature, but it should be considered to be a potentially common finding in the maxillary incisal region. Clinicians are made aware of the presence of additional neurovascular bone channels such as the canalis sinuosus when interpreting radiographs for assessing periapical status of teeth and for surgical planning in the anterior maxilla.

Orthognathic Considerations of Vascular Malformations.

Vascular malformations affect the craniofacial skeleton in many ways, depending on the type of the lesion and its location. The lesions may exert a mass effect and cause thinning or thickening of the bone or cause expansion from direct bony infiltration. Orthognathic surgery can be used to correct any malocclusion or open bite deformities after the soft tissues are addressed.

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.