Platelet-Rich Fibrin in Oral Surgery and Implantology: A Narrative Review.

Background: The application of blood concentrates has gained popularity in dentistry in recent years. Platelet-rich fibrin (PRF) has been discussed frequently due to a high content of growth factors and the option of chair-side manufacturing in a simple centrifugation process. PRF is free from adjuvants and inexpensive to produce. The number of studies reporting beneficial effects of PRF in various clinical applications such as alveolar ridge preservation, sinus floor elevation, management and prevention of medical-related osteonecrosis of the jaw, third molar extractions, and guided bone regeneration in dentistry has increased recently. However, to date, neither clinical recommendations nor guidelines are available. The present narrative review aims to summarize the level of evidence on the clinical application of PRF within the field of oral surgery and implantology. Summary: A literature search in Pubmed and Medline has identified 34 articles as a basis for this narrative review. The effectiveness of the clinical application of PRF has been analyzed for five indications within dentistry: medical-related osteonecrosis of the jaw, wisdom tooth extraction, guided bone regeneration, sinus floor elevation, and alveolar ridge preservation. The amount of data for third molar extractions, socket preservation, and guided bone regeneration is extensive. Less data were available for the use of PRF in combination with sinus floor elevations. There is a lack of studies with scientific evidence on PRF and medical-related osteonecrosis of the jaw; however, studies positively impact patient-related outcome measures. Most studies report on beneficial effects when PRF is additionally applied in intrabony defects. There is no evidence of the positive effects of PRF combined with bone graft materials during sinus floor elevation. However, some benefits are reported with PRF as a sole filling material. Key Messages: Many recently published studies show the positive clinical impact of PRF. Yet, further research is needed to ensure the validity of the evidence.

Facial scars resulting from a transbuccal approach during osteosynthesis of a sagittal split osteotomy: A retrospective study.

The purpose of the current study was to assess the quality of facial linear scars. The Stony Brook Scar Evaluation Scale (SBSES) was developed and validated as a tool to assess postoperative scars. Postoperative facial scars were rated using high-quality macrophotographs and SBSES by three independent raters at baseline and three months thereafter. Percentage agreement (PA) and intraclass correlation coefficient (ICC) were used to measure interrater and intrarater reliability. Scar outcomes ranging from 0 (worst) to 5 (best) were evaluated against age and gender. One-hundred-sixty-six patients with a mean age of 30.6 years (range of 17-59) were included in this study. Forty-four were male (26.5%), and 122 were female (73.5%). Mean total SBSES scores were 4.63 (range of 4.56-4.76) at baseline and 4.60 (range of 4.54-4.72) at three months. As patient's age increased, mean total SBSES scores also decreased significantly (r = -0.216, p = 0.005). Gender did not significantly affect raters' perception of scar cosmesis (p = 0.847). Interrater reliability showed an ICC of 0.675 (95% CI, 0.609-0.731) and a PA of 65.4% at baseline, and an ICC of 0.655 (95% CI, 0.585-0.715) and a PA of 64.2% at three months. Intrarater reliability found ICCs ranging from 0.988 to 0.990 and a PA of 96.8% with 3 separate raters. Within the limitations of the study it seems that the transbuccal approach during osteosynthesis of a sagittal split osteotomy seems still to be acceptable when the patient gives his or her informed consent and advanced instruments like an angled screwdriver are not available.

Growth Factor Release within Liquid and Solid PRF.

Aim: The purpose of this study was to obtain data concerning growth factor release within liquid and solid platelet-rich fibrin (PRF) matrices and to estimate the amount of potential interindividual variations as a basis for further preclinical and clinical trials. Therefore, we aimed to determine possible differences in the release of growth factors between liquid and solid PRF. Materials and Methods: Blood samples obtained from four subjects were processed to both liquid and solid PRF matrices using a standard centrifugation protocol. Five growth factors (vascular endothelial growth factor, VEGF; epidermal growth factor, EGF; platelet-derived growth factor-BB, PDGF-BB; transforming growth factor-ß1, TGF-ß1; and matrix metallopeptidase 9, MMP-9) have been evaluated at six time points by ELISA over a total observation period of 10 days (1 h, 7 h, 1 d, 2 d, 7 d, and 10 d). Results: Growth factor release could be measured in all samples at each time point. Comparing liquid and solid PRF matrices, no significant differences were detected (p > 0.05). The mean release of VEGF, TGFß-1, PDGF-BB, and MMP-9 raised to a peak at time point five (day 7) in both liquid and solid PRF matrices. VEGF release was lower in liquid PRF than in solid PRF, whereas those of PDGF-BB and MMP-9 were higher in liquid PRF than in solid PRF at all time points. EGF had its peak release already at time point two after 7 h in liquid and solid matrices (hour 7 EGF solid: mean = 180 pg/mL, SD = 81; EGF liquid: mean = 218 pg/mL, SD = 64), declined rapidly until day 2, and had a second slight peak on day 7 in both groups (day 7 EGF solid: mean = 182 pg/mL, SD = 189; EGF liquid: mean = 81 pg/mL, SD = 70). Conclusions: This study detected growth factor release within liquid and solid PRF matrices with little variations. Further preclinical trials are needed to precisely analyze the growth factor release in larger samples and to better understand their effects on wound healing in different clinical indications.

[Metronidazole - spectrum of activity, use and side effects]. / Metronidazol ­ Wirkungsspektrum, Anwendung und Nebenwirkungen.

This contribution gives an overview of the use, therapeutic effects and side effects of the antibiotic substance Metronidazole. Metronidazole is effective in the treatment support of paradontitis, microbial-caused halitosis, perioral skin infections and odontogenic hard or soft tissue abscess formations related to anaerobic bacterial infections. Due to its anti- parasitic effect, Metronidazole is also effective in the treatment of protozoa. In adults and children from 12 years on, 200 mg Metronidazole to a maximum of 2000 mg Metronidazole per day can be administered. In children below 12 years of age, an antibiotic dose of Metronidazole between 20 to 30 mg per kilogram body weight is advised.

Intravenous ibuprofen versus diclofenac plus orphenadrine in orthognathic surgery: a prospective, randomized, double-blind, controlled clinical study.

OBJECTIVES: The aim of this prospective, randomized, double-blind, controlled clinical study was to evaluate the analgesic effect of ibuprofen versus diclofenac plus orphenadrine on postoperative pain in orthognathic surgery. MATERIAL AND METHODS: Patients who underwent orthognathic surgery were randomized into two groups to receive intravenously either 600 mg of ibuprofen (I-group) or 75 mg diclofenac plus 30 mg orphenadrine (D-group), both of which were given twice daily. Additionally, both groups were given metamizole 500 mg. Rescue pain medication consisted of acetaminophen 1000 mg and piritramide 7.5 mg as needed. To assess the pain intensity, the primary end point was the numeric rating scale (NRS) recorded over the course of the hospital stay three times daily for 3 days. RESULTS: One hundred nine patients were enrolled (age range, 18 to 61 years) between May 2019 and November 2020. Forty-eight bilateral sagittal split osteotomies (BSSO) and 51 bimaxillary osteotomies (BIMAX) were performed. Surgical subgroup analysis found a significant higher mean NRS (2.73 vs.1.23) in the BIMAX D-group vs. I-group (p = 0.015) on the third postoperative day. Additionally, as the patient's body mass index (BMI) increased, the mean NRS (r = 0.517, p = 0.001) also increased. No differences were found between age, gender, length of hospital stay, weight, operating times, number of patients with complete pain relief, acetaminophen or piritramide intake, and NRS values. No adverse events were observed. CONCLUSION: The results of this study demonstrate that ibuprofen administration and lower BMI were associated with less pain for patients who underwent bimaxillary osteotomy on the third postoperative day. Therefore, surgeons may prefer ibuprofen for more effective pain relief after orthognathic surgery. CLINICAL RELEVANCE: Ibuprofen differs from diclofenac plus orphenadrine in class and is a powerful analgetic after orthognathic surgery.

[Local anesthesia in children: standard and limits]. / Lokalanästhesie bei Kindern: Standard und Grenzen.

The use of local anesthetics is known to be safe and efficient in surgical and dental treatments. Local anesthetics are essential in dentistry for appropriate pain control as they inhibit nociception generated during surgical and dental procedures. However, among other precautions, attention has to be paid to the individual maximum dose of the local anesthetics that is administered. This is especially important for children who are, due to their low body weight, more prone to adverse events following substance overdose. Therefore, this contribution gives advice for general dentists on the accurate use and maximum dose of local anesthetics in children.

[Application of tranexamic acid within the field of dentistry]. / Die Anwendung von Tranexamsäure (Cyklokapron®) in der Zahnmedizin.

The antifibrinolytic agent tranexamic acid (TXA) is well known for its capacity to effectively reduce intraoperative blood loss. The effect mechanism of TXA is based on the indirect inhibition of fibrin degradation, whereby existing blood clots within the surgical area are stabilized. Consecutively, the amount of blood loss can be reduced. Due to its great efficacy to minimize blood loss and its low rate of unintended side effects, TXA is regularly used in different surgical fields. Within the field of dentistry TXA is not applied on a regular basis, however, it presents a highly effective and convenient treatment option to reduce bleeding complications.

Complex Mandibular Reconstruction for Head and Neck Squamous Cell Carcinoma-The Ongoing Challenge in Reconstruction and Rehabilitation.

Large head and neck squamous cell carcinoma (HNSCC) tumors affecting the mandible require a versatile reconstruction to maintain form, function, and quality of life. Large defect reconstruction of soft and hard tissue in the head and neck necessitates, at best, one vascular system including various tissues by large dimensions. The subscapular flap system seems to meet these standards. A retrospective study was conducted focusing on clinical data, including an analysis of the quality of life with the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaires, (QLQ-C30 and QLQ-H&N43). A total of 154 patients (122 males, 32 females; age range: 31-71 years, mean: 54.5 years) treated at our department from 1983 through to 2019 were included. Of the subscapular system free flaps (SFFs), 147 were based on the angular artery branch of the thoracodorsal pedicle (95.45%), and the remaining seven cases (4.55%) were lateral scapular border flaps. Mean mandible defect length was 7.3 cm. The mean skin paddle dimension was 86.8 cm2. The most common recipient artery was the thyroid superior artery (79.22%). Major postoperative complications occurred in 13 patients (8.44%). This study confirms that SFFs offer excellent soft and hard tissue quality, component independence, a large arc of rotation length, and a large gauge of pedicle, making them the gold standard for the reconstruction of large composite defects of mandibular HNSCC tumors.

Concordance of tumor infiltrating lymphocytes, PD-L1 and p16 expression in small biopsies, resection and lymph node metastases of oropharyngeal squamous cell carcinoma.

OBJECTIVE: The incidence of oropharyngeal squamous cell carcinoma (OPSCC), especially human papillomavirus (HPV)-associated, is increasing worldwide. Immunotherapy become available for patients with carcinomas in the head and neck region, however without ideal biomarker. Markers like PD-L1 vary in the clone of the antibody used, and the method of evaluation. Adequate and reliable immune cells characterization and evaluation is still not found. Furthermore, studies analyzing representativeness of different tissue samples are scarce. We analyzed small biopsy, lymph node (LN) metastasis and resected OPSCC, in regards of tumor infiltrating lymphocyte (TIL) density, PD-L1 and p16 expression. MATERIAL AND METHODS: Patients with OPSCC diagnosed from 2000 to 2016, with small biopsy, resection specimen and LN metastasis samples were selected. We analyzed TILs on hematoxylin-eosin stain, and PD-L1 and p16 expression in tumor cells. Concordance between different tumor locations was evaluated. RESULTS: 93 patients, with 65 small biopsies, 72 resection specimens, and 70 LN metastases were included. TILs, p16 and PD-L1 demonstrated very high concordance. Additionally, PD-L1 expression in the small biopsies was more representative of the PD-L1 expression in the resection specimens, than the LN samples. CONCLUSION: TILs density can be reliably assessed using hematoxylin-eosin stain with high concordance between the small biopsy, resection specimen and LN metastasis. Evaluation of concordance of p16 expression is very high, nevertheless some cases might be misdiagnosed on a small biopsy or lymph node metastasis. Evaluation of PD-L1 expression is very reliable on the biopsy specimen. Different PD-L1 clones and methods of evaluation still remain to be addressed.

Weight gain in infants with Pierre Robin sequence.

OBJECTIVE: To determine weight gain during treatment with the modified palatal plate (MPP) in infants with isolated and syndromic Pierre Robin Sequence (PRS) suffering from micrognathia, upper airway obstruction (UAO), and failure to thrive (FTT), the authors conducted a retrospective study of infants treated with the MPP. METHODS: The main outcome measure was infant weight (g) for up to three months after birth. Demographic and outcome data (associated syndromes, comorbidities, presence of cleft lip or palate, intubation attempts, tracheotomy and cleft repair) were collected. RESULTS: 14 children born January 2010 - December 2019 were included. The majority (86%) of infants showed highly significant weight gain (p < 0.001) within a 3-month period (mean pretreatment weight 3147 g with a SD of 425 g vs mean weight at three months 4435 g with a SD of 635 g). Syndromic PRS was found in 7% of infants. 43% of nonsyndromic PRS patients were found to have other congenital anomalies. Genetic testing showed normal karyotypes in 93% of infants and a microdeletion in 7% of infants. 21% of infants required tracheotomy, but no patients required mandibular distraction (MDO) or tongue-lip adhesion (TLA) to relieve UAO. CONCLUSION: PRS infants treated with the MPP showed highly significant weight gain within a 3-month period and did not require mandibular surgery for early airway management, but faster gain of weight might have implications for strategies to perform surgery at an earlier point in time.

PRF in dentistry ­ a short synopsis about implementation and workflow / PRF in der Zahnmedizin

Platelet-rich fibrin (PRF) is a blood concentrate system derived from human peripheral blood. A solid and a liquid PRF-based matrix can be obtained by centrifugation in accordance with specific centrifugation protocols without the addition of anticoagulants or external chemicals. In dentistry, oral- and cranio-maxillo-facial surgery, PRF-based matrices are used on different subjects. The healing benefits of platelet-rich preparations together with the low risk profile and disposability of a simple preparation procedure should encourage more clinicians to incorporate PRF as a treatment option in their practice to accelerate healing, reduce adverse events, and improve patient outcomes.

In vivo Implantation of a Bovine-Derived Collagen Membrane Leads to Changes in the Physiological Cellular Pattern of Wound Healing by the Induction of Multinucleated Giant Cells: An Adverse Reaction?

The present study evaluated the tissue response toward a resorbable collagen membrane derived from bovine achilles tendon (test group) in comparison to physiological wound healing (control group). After subcutaneous implantation in Wistar rats over 30 days, histochemical and immunohistochemical methods elucidated the cellular inflammatory response, vascularization pattern, membrane protein and cell absorbance capacity. After 30 days, the test-group induced two different inflammatory patterns. On the membrane surface, multinucleated giant cells (MNGCs) were formed after the accumulation of CD-68-positive cells (macrophages), whereas only mononuclear cells (MNCs) were found within the membrane central region. Peri-implant vascularization was significantly enhanced after the formation of MNGCs. No vessels were found within the central region of the membrane. Physiological wound healing revealed no MNGCs at any time point. These dynamic changes in the cellular reaction and vascularization within the test-group are related typical indications of a foreign body reaction. Due to the membrane-specific porosity, mononuclear cells migrated into the central region, and the membrane maintained its integrity over 30 days by showing no breakdown or disintegration. The ex vivo investigation analyzed the interaction between the membrane and a blood concentrate system, liquid platelet-rich fibrin (liquid PRF), derived from human peripheral blood and consisting of platelets, leukocytes and fibrin. PRF penetrated the membrane after just 15 min. The data question the role of biomaterial-induced MNGCs as a pathological reaction and whether this is acceptable to trigger vascularization or should be considered as an adverse reaction. Therefore, further pre-clinical and clinical studies are needed to identify the types of MNGCs that are induced by clinically approved biomaterials.

Clinical experience with a novel structure designed bridging plate system for segmental mandibular reconstruction: The TriLock bridging plate.

The innovative TriLock Bridging Plate System (Medartis AG, Switzerland) was developed to reduce common complications related to conventional mandibular reconstruction plates. The novelties regarding the plating system concern the cross-strut structure in the centerpiece, the bendable side elements and the reduction of the plate's thickness to 2.0 mm 4 different models are available, which cover lateral and central segmental mandibular defects. The plating system has only been introduced at selected maxillofacial units so far and clinical assessment is still lacking. Thus, the aim of the study was to analyze the novel Bridging Plate system in terms of its clinical applicability, rate of trimming and postoperative outcomes in a first investigation over 6 months. The study includes 25 patients with segmental mandibular resection, who underwent reconstruction with TriLock Bridging Plates. According to the assessment parameters, excellent clinical applicability was stated in 48%. The overall trimming rate was found to be 88%. Mostly adaptions to the distal bendable elements of lateral plates were performed. The occurrence of postoperative complications was 16%. Plate fracture occurred in 4%. With reference to the results, the novel plating system represents a viable method for segmental mandibular reconstruction, however, further evaluation is needed, for a more detailed analyzation.

Clinical evaluation of semi-automatic open-source algorithmic software segmentation of the mandibular bone: Practical feasibility and assessment of a new course of action.

INTRODUCTION: Computer assisted technologies based on algorithmic software segmentation are an increasing topic of interest in complex surgical cases. However-due to functional instability, time consuming software processes, personnel resources or licensed-based financial costs many segmentation processes are often outsourced from clinical centers to third parties and the industry. Therefore, the aim of this trial was to assess the practical feasibility of an easy available, functional stable and licensed-free segmentation approach to be used in the clinical practice. MATERIAL AND METHODS: In this retrospective, randomized, controlled trail the accuracy and accordance of the open-source based segmentation algorithm GrowCut was assessed through the comparison to the manually generated ground truth of the same anatomy using 10 CT lower jaw data-sets from the clinical routine. Assessment parameters were the segmentation time, the volume, the voxel number, the Dice Score and the Hausdorff distance. RESULTS: Overall semi-automatic GrowCut segmentation times were about one minute. Mean Dice Score values of over 85% and Hausdorff Distances below 33.5 voxel could be achieved between the algorithmic GrowCut-based segmentations and the manual generated ground truth schemes. Statistical differences between the assessment parameters were not significant (p<0.05) and correlation coefficients were close to the value one (r > 0.94) for any of the comparison made between the two groups. DISCUSSION: Complete functional stable and time saving segmentations with high accuracy and high positive correlation could be performed by the presented interactive open-source based approach. In the cranio-maxillofacial complex the used method could represent an algorithmic alternative for image-based segmentation in the clinical practice for e.g. surgical treatment planning or visualization of postoperative results and offers several advantages. Due to an open-source basis the used method could be further developed by other groups or specialists. Systematic comparisons to other segmentation approaches or with a greater data amount are areas of future works.

Assessment of tumor margins in head and neck cancer using a 3D-navigation system based on PET/CT image-fusion - A pilot study.

OBJECTIVES: Determination of tumor margins in patients with squamous cell carcinoma of the head and neck (SCCHN) is mostly based on preoperative magnetic resonance imaging (MRI) or computed tomography scans (CT). Local recurrence of disease is often correlated with the presence of positive resection margins after surgical treatment. Positron emission tomography/computed tomography (PET/CT) imaging plays a crucial role in the assessment of patients with SCCHN. The purpose of this study was to determine whether PET/CT could predict tumor extension. METHODS: In 12 patients who underwent surgical treatment of primary SCCHN (Stage III-IV) F18-FDG PET/CT image-fusion was performed on a 3D navigation-system based workstation. Image-guided needle biopsies were obtained from four different, color-coded metabolic areas within the tumor. The histopathological findings were correlated with findings on corresponding PET/CT scans. RESULTS: 81.3% of biopsies from the central area were positive. Specimens taken from the outer metabolic zone were positive in 66.7% of the patients. The highest incidence of positive biopsies was found in the zone adjacent to the outermost area. There was a statistically significant difference in positive tumor histopathology when comparing the various metabolic zones (p = 0.03). CONCLUSION: Exact determination of tumor is an important research topic, although results remain controversial. The results of this study suggest that in some cases PET scans may overestimate tumor extension.

Use of a modified high submandibular approach to treat condylar base fractures: Experience with 44 consecutive cases treated in a single institution.

PURPOSE: The aim of this article is to present our experience treating fractures of the condylar base with a modification of the high submandibular approach (HSA). MATERIALS AND METHODS: Between June 2012 and April 2015, 44 fractures of the condylar base were treated in the Department of Oral and Maxillofacial Surgery of the Medical Hospital of Graz using the modified HSA. RESULTS: We did not observe any damage (even transient) to the facial nerve or any complication related to violation of the parotid capsule (such as a salivary fistula, Frey syndrome, or a sialocele). CONCLUSIONS: This approach provides good access to the condylar base, ensuring easier internal fixation, excellent protection of the facial nerve and parotid gland, and good cosmetic results.

Intraindividual comparison of preoperative (99m)Tc-MDP SPECT/CT and intraoperative and histopathological findings in patients with bisphosphonate- or denosumab-related osteonecrosis of the jaw.

PURPOSE: Bisphosphonate- or denosumab-related osteonecrosis of the jaw (BRONJ/DRONJ) requires reliable preoperative assessment of the extent of disease for surgical planning. The aim of this study was to compare the extent of BRONJ/DRONJ as detected by Tc-99m-methylene diphosphonate (MDP) bone scintigraphy with intraoperative and histopathological findings, and to assess the additional value of hybrid single photon emission computed tomography/computed tomography (SPECT/CT) for evaluation of disease. MATERIAL AND METHODS: Twenty-one patients with BRONJ/DRONJ underwent three-phase bone scintigraphy including SPECT/CT. The diagnostic certainty using conventional SPECT or fused SPECT/CT imaging was compared. Location and extent of disease on scintigraphic imaging and pre- and intra-operative clinical assessment were compared. Intraoperative and histopathological findings served as reference standard. RESULTS: A total of 29 sites of BRONJ/DRONJ were histopathologically confirmed in 21 patients. Bone scintigraphy demonstrated increased perfusion in 57.1% of patients, increased blood pool in 76.2%, and increased tracer accumulation at the metabolic phase in all patients. The intensity of tracer accumulation at the metabolic phase correlated significantly with clinical stage of disease (rs = 0.47, p = 0.03). Clinical examination (p < 0.0001), but not SPECT (p = 0.19), underestimated the extent of disease as determined by surgical evaluation. SPECT/CT offered a significantly higher diagnostic certainty (p < 0.0001). CONCLUSION: In patients with BRONJ/DRONJ, the true extent of osseous lesions as determined by surgery is significantly underestimated by clinical examination. Tc-99m-MDP bone scintigraphy can reliably predict the extent of disease. Hybrid SPECT/CT may significantly increase the diagnostic certainty of anatomical localization.

Early detection of pulp necrosis and dental vitality after traumatic dental injuries in children and adolescents by 3-Tesla magnetic resonance imaging.

OBJECTIVES: More than 50% of all children suffer a traumatic dental injury (TDI) during childhood. In many cases, dentists apply root canal treatment (RCT), which is performed on an average of 7-10 days after replantation. Our aim was to evaluate whether RCT is necessary in many cases, and whether revitalization of affected teeth is possible and measurable by visualization using 3T magnetic resonance imaging (MRI). MATERIAL AND METHODS: Seven healthy children with TDI were treated by repositioning of the affected teeth and reduction of alveolar process fractures followed by splinting. Two weeks after initial treatment, splints were removed. After 6 weeks, all children received 3-Tesla (3T), three-dimensional, high-resolution MRI with a 20-channel standard head and neck coil. The mean age of the children (male/female = 5:2) was 10.8 years (range, 8-17 years). In addition, all children received conventional dental examination for tooth vitality and dental sensitivity to cold and tenderness on percussion. RESULTS: 3T MRI provided excellent images that allowed fine discrimination between dental pulp and adjacent tooth. Using four in-house optimized, non-contrast-enhanced sequences, including panoramic reconstruction, the assessment and analysis of the dental pulp was sufficiently feasible. We could demonstrate reperfusion and thus vitality of the affected teeth in 11 sites. In one child, MRI was able to detect nonreperfusion after TDI of the affected tooth. MRI results were confirmed by clinical examination in all cases. As a consequence of this expectant management and proof of reperfusion and tooth vitality by 3T MRI, only one child had to be treated by RCT. CONCLUSION: 3T MRI is a very promising tool for visualization and detection in the field of dental and oromaxillofacial diseases. By using new 3T MRI sequences in children with TDI, we could demonstrate that RCT are not necessary in every case, and thus could prevent unnecessary treatment of children in the future. Larger studies should follow to confirm the potential benefit in clinical practice.

The Nasopalatine Canal in Adults on Cone Beam Computed Tomograms-A Clinical Study and Review of the Literature.

AIM: The aims of this study were to assess the location, morphology and anatomical dimensions of the nasopalatine canal (NPC) on cone beam computed tomographic (CBCT) images and to compare our findings with recent reports on this matter. A detailed knowledge of anatomical variations is mandatory in skeletal surgery of the anterior maxilla. PATIENTS AND METHODS: Two hundred CBCT scans of the mid-facial region were analyzed from adult patients at the Outpatient Clinic of the Department of Oral and Craniomaxillofacial Surgery, University of Hamburg, Germany. Patients were scanned using standard exposure time at normal patient positioning inside the CBCT device. Three-dimensional (3D) CBCT images were carefully analyzed regarding NPC location, morphology and anatomical dimensions, and variations of radiological morphology, with respect to age and gender. RESULTS: In the sagittal plane, the NPC typically appeared as a canal with a mean length±standard deviation (SD) of 11.15±2.87 mm. The oral cavity opening of the canal is the incisive foramen, with a mean diameter of 4.49±1.71 mm. At the entrance to the nasal floor, in most cases, two apertures were found (Y-canal morphology), but also three or four openings were observed. In particular cases, the canal presented a cylindrical aperture with only one exit to the nasal floor. The average width of the NPC at the level of the nasal floor was 3.43±1.54 mm. The labiopalatal width of the NPC measured perpendicular to the long axis of the canal on sagittal plane was 2.48±1.33 mm. Interpretation of NPC morphology was significantly different when analyzing the images in the sagittal plane only, but the technique allowed demonstration of all aspects using the combined 2D/3D interpretation. CONCLUSION: The NPC may exhibit important anatomical variations, both with regard to morphology and its dimensions. To avoid any potential complications during dentoalveolar surgery, careful preoperative evaluation is required. 3D imaging is recommended to determine canal topography and dimensions, and to assess the individual anterior maxilla's dimensions prior to surgical procedures, such as dental implant insertion or bone augmentation.

Prevalence of Stafne's bone cavity--retrospective analysis of 14,005 panoramic views.

AIM: Stafne's bone cavity (SBC) is a very rare defect, affecting only selected parts of the mandibular bone. Its etiology is unknown. On two-dimensional images, it appears as a narrowed cavity and might be interpreted as a space-occupying process inside the bone. The aim of the present study was to investigate the prevalence of SBC on panoramic views, and compare these results to published reports. MATERIALS AND METHODS: A total of 14,005 panoramic views were examined retrospectively with regard to the presence of SBC. All images were analyzed regarding typical characteristics as originally described by Stafne. RESULTS: A total of 11 cases fulfilled diagnostic criteria of SBC (0.08%). All patients were men (100%), at a mean age of 58.1 years (range=38-75 years). Eight patients (72.7%) had SBC on the left side, three patients on the right side (27.3%). In eight cases, SBC was found in the mandibular corpus (72.7%), and in three cases in the mandibular angle (27.3%). Correlating with published results, SBC was found at a relative frequency of 0.13%. CONCLUSION: SBC on panoramic views or other imaging modalities should alert the clinician to exclude other potential pathologies. In doubtful cases, surgical procedures might be necessary to verify the diagnosis.