Life-threatening hemorrhage associated with dental implant surgery: a review of the literature

Strategies for prevention and treatment of vascular and nerve injury in mandibular anterior implant surgery

Important anatomical structures such as mandibular incisive canal, tongue foramen, and mouth floor vessels may be damaged during implant surgery in the mandibular anterior region, which may lead to mouth floor hematoma, asphyxia, pain, paesthesia and other symptoms. In severe cases, it can be life-threatening. The insufficient alveolar bone space and the anatomical variation of blood vessels and nerves in the mandibular anterior region increase the risk of blood vessels and nerves injury during implant surgery. In case of vascular injury, airway control and hemostasis should be performed, and in case of nerve injury, implant removal and early medical treatment should be performed. In order to avoid vascular and nerve injury during implant surgery in the mandibular anterior region, it is necessary to be familiar with the anatomical structure, take cone-beam computed tomography and design properly before surgery, and use digital technology during surgery to achieve accurate implant placement. This article summarizes the anatomical structure of the mandibular anterior teeth region, discusses the prevention strategies of vascular and nerve injuries in the mandibular anterior teeth region, and discusses the treatment methods after the occurrence of vascular and nerve injuries, so as to provide clinical reference.

Simultaneous labial and lingual augmented corticotomy assisted presurgical orthodontics in class III patients: the morphological aspects of the mandibular anterior ridge with cone-beam computed tomography

OBJECTIVES

This study aims to investigate the changes in alveolar bone following the simultaneous performance of labial and lingual augmented corticotomy (LLAC) in patients with insufficient alveolar bone thickness on both the labial and lingual sides of the mandibular anterior teeth during presurgical orthodontic treatment.

MATERIALS AND METHODS

Thirth-five surgical patients with skeletal Class III malocclusion were included: 19 (LLAC group) accepted LLAC surgery during presurgical orthodontic treatment, and 16 (non-surgery group, NS) accepted traditional presurgical orthodontic treatment. Cone-beam computed tomography (CBCT) scans were obtained before treatment (T0) and at the completion of presurgical orthodontic treatment (T1). The amount of vertical alveolar bone and contour area of the alveolar bone in the labial and lingual sides of mandibular incisors were measured.

RESULTS

After presurgical orthodontic treatment, the contour area of the alveolar bone at each level on the lingual side and alveolar bone level on both sides decreased significantly in the NS group (P < 0.001). However, the labial and lingual bone contour area at each level and bone level increased significantly in the LLAC group (P < 0.001). The bone formation rate in the lingual apical region was the highest, significantly different from other sites (P < 0.001).

CONCLUSIONS

During presurgical orthodontic treatment, LLAC can significantly increase the contour area of the labio-lingual alveolar bone in the mandibular anterior teeth to facilitate safe and effective orthodontic decompensation in skeletal Class III patients.

CLINICAL RELEVANCE

This surgery has positive clinical significance in patients lacking bone thickness (< 0.5 mm) in the labial and lingual sides of the lower incisors.

Dental implant in anterior mandible according to mandibular lingual foramens and lingual mucosal vessels: using fusion volumetric images from computed tomography and magnetic resonance imaging

BACKGROUND

Perforation of the lingual cortex while placing dental implants in the interforaminal region of the mandible can cause severe hemorrhage. The purpose of this study was to evaluate the features of mandibular lingual foraminals (MLFs) and locational relationship between them and lingual mucosal vessels (LMVs) by CT/MRI fusion volumetric images.

METHODS

37 images within complete anterior mandibular region using both MSCT and three-dimensional volumetric interpolated breath-hold examination (3D-VIBE) MRI were taken from our imaging archives. After exclusion of 11 for lesions or artifacts, 26 CT/MRI fusion volumetric images were included to evaluate the frequency, diameter, and position of MLFs. The anterior mandibular region was divided into 4 equal segments under each teeth, and 40 regions were got from C5 to D5. Furthermore, the positional relationship between MLFs and LMVs was analyzed in this coordinate system.

RESULTS

62 MLFs (73.81%) were located below the incisors, followed by premolars (21.43%) and canines (4.76%). Female bias, the mean diameter of the female was 0.08 mm while the male was 0.21 mm. The total number of LMVs was most distributed on lingual side of C1 and D1. According to Spearman's correlation coefficient, the location of MLFs was related to LMVs. The MLFs in fourth segment of D1 were positively moderately correlated with LMVs in fourth segment of D4, while the MLFs in third segment of C1 showed a weak positive correlation with LMVs in third segment of D4.

CONCLUSIONS

The features and the correlation between MLFs and LMVs in CT/MRI fusion volumetric images may offer reference to dentists when only MLFs can been seen on routine preoperative CT examination of implants.

TRIAL REGISTRATION

Retrospectively registered. (D2018-072).

Hemorrhagic Complications in Implant Surgery: A Scoping Review on Etiology, Prevention, and Management

This article seeks to provide the most relevant aspects of the etiology, prevention, and management of bleeding in routine implant surgery. A comprehensive and systematic electronic search was conducted in MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews databases until June 2021. Further references of interest were retrieved from bibliographic lists of the selected articles and the "Related Articles" feature of PubMed. Eligibility criteria were papers about bleeding, hemorrhage, or hematoma associated with routine implant surgery on human subjects. Twenty reviews and 41 case reports fulfilled eligibility criteria and were included in the scoping review. Involved implants were mandibular in 37 and maxillary in 4 cases. The major number of bleeding complications was in the mandibular canine region. The most injured vessels were sublingual and submental arteries, due mainly to perforation of the lingual cortical plate. Time to bleeding occurred intraoperatively, at suturing, or postoperatively. The most reported clinical manifestations were swelling and elevation of the mouth floor and the tongue with partial or complete airway obstructions. First aid to manage airway obstruction was intubation and tracheostomy. For active bleeding control, gauze tamponade, manual or digital compression, hemostatic agents, and cauterization were applied. When conservative procedures failed, hemorrhage was controlled by intra- or extraoral surgical approaches to ligate injured vessels or by angiographic embolization. The present scoping review provides knowledge and evidence on the most relevant aspects of the etiology, prevention, and management of implant surgery bleeding complications.

Relevant factors of posterior mandible lingual plate perforation during immediate implant placement: a virtual implant placement study using CBCT

BACKGROUND

To explore the influence of cross-sectional type and morphological parameters at the mandibular molar sites on lingual plate perforation (LPP) during the immediate implant placement (IIP).

METHODS

181 implants were virtually placed in the mandibular molar sites on the cone beam computed tomography (CBCT). Each cross-section of the implantation site was divided into the Undercut (U)/Parallel (P)/Convex (C) types. Morphologically relevant parameters were measured on the cross-sections, including width of the upper end (Wb), width of the lower end (Wc), vertical height (V), angle between the natural crown axis and the alveolar bone axis (∠β), LC depth (LCD), LC height, and angle between the horizontal line and the line connecting the most prominent point and the most concave point of lingual plate (∠α). Besides, the distance from the end of the virtual implant and the lingual bone plate of the cross-section (D_IL) was calculated. Relationships between all the morphologically relevant parameters and the D_IL were further analyzed.

RESULTS

A total of 77 (42.5%) cross-sections were classified as U-type, which was the most common one, accounting for 63% of the second molar regions. All LPP cases and most of the nearly LPP (87.9%) cases occurred at the U-type cross-sections, and the relationship between the D_IL and the morphological parameters can be expressed by a multivariate linear equation.

CONCLUSIONS

The occurrence rate of U-type cross-sections in the second molar region was very high, and the risk of LPP should be considered during IIP. Except for the U-type, significant large LCD, small Wc, and large ∠β were the important relevant factors. CBCT and multivariate linear equations could help to assess the LPP risk and provide a reference for implant placement design pre-surgery.

Accuracy evaluation of cone beam computed tomography applied to measure peri-implant bone thickness in living patients: an ex vivo and in vivo experiment

OBJECTIVES

This study aims to study the accuracy of cone beam computed tomography (CBCT) for measuring peri-implant bone thickness in living patients via a novel visualization method (NVM).

MATERIAL AND METHODS

The validity of the NVM was verified ex vivo by measuring the same peri-implant bone thicknesses in bovine ribs by using raw postoperative CBCT (clinical measurement, CM), the visualized fused images obtained using the NVM (visualized fused measurement, VF), and hard tissue sections (gold standard measurement, GS). The NVM was applied by deconstructing the postoperative CBCT model into the Model_post-bone and Model_implant and replacing it with bone from preoperative CBCT and standard implant models, respectively. In vivo, 52 implants were included, and the VF of each implant was obtained using data processing methods similar to those used ex vivo. Then, we compared the results of CM and VF.

RESULTS

Ex vivo, the VF was similar to GS, while CM usually underestimated the peri-implant bone thickness, especially at the implant shoulder (P < 0.01). In vivo, on CBCT, areas with a peri-implant bone thickness of 0-0.50 mm were not visible, while those with a thickness of 0.50-1.00 mm were occasionally visible. There was less underestimation of bone along the implant long axis.

CONCLUSIONS

Thin peri-implant bones could be completely underestimated on CBCT. CBCT scans alone are insufficient to warrant surgical intervention. Our NVM facilitates the accurate visual assessment of implant dimensions.

CLINICAL RELEVANCE

The thickness of peri-implant bone could be completely underestimated when thinner than 1.0 mm in living patients. Familiarity with these confusing CBCT results may help clinicians and patients avoid further unnecessary evaluation, misdiagnosis, and invasive treatment.

Epistaxis in dental and maxillofacial practice: a comprehensive review

The lifetime incidence of epistaxis in dental and maxillofacial practice has been reported to be as high as 60% and can be caused by dental implant placement, Le Fort I osteotomy, intranasal supernumerary tooth, odontogenic tumors, blood disorders and maxillofacial trauma. Most epistaxis cases are minor and easily managed with direct compression on the nares for 10 minutes. For more significant or recurrent epistaxis, other techniques might include electrocautery, anterior or posterior nasal packing, or Foley catheter balloon. For patients with refractory epistaxis, cauterization of the sphenopalatine artery under endonasal endoscopy or embolization of the internal maxillary artery should be performed. Epistaxis control is required in patients diagnosed with inherited or acquired bleeding disorders or with drug-induced coagulopathies during dental procedures. In these cases, hemostatic system adjustment and hemostasis achieved by local and adjunctive methods are required. Dentists and maxillofacial surgeons must be aware that the nasal cavity is a potential source of perioperative hemorrhage. Depending on the invasiveness of the dental intervention, preoperative involvement of the hematologist and cardiologist is usually necessary to reverse anticoagulation or to cease anticoagulant therapy.

Vascular and neurosensory evaluation in relation to lingual canal anatomy after mandibular midline implant installation in edentulous patients

Objectives

The aim of this study is to investigate vascular and neurosensory complications in edentulous patients following the installation of mandibular midline single implants in relation to lingual canals.

Materials and methods

After performing a cone beam computed tomography scan for the 50 recruited patients, the relationship between the potential implant site and the lingual canals was assessed, and all vascular and neurosensory complications were recorded.

Results

Six patients (12%) reported profuse bleeding during implant placement, and 13 (26%) reported transient neurosensory changes, which were resolved after 3 months. According to the virtual implant planning, 44 patients (88%) would have their implants touching the lingual canals, six of them reported vascular changes (14%), and 12 out of 44 patients reported neurosensory changes (27%). For the six patients who would have their implants not touching the lingual canals, one patient reported transient neurosensory changes.

Conclusions

The mandibular lingual canals are constant anatomic landmarks. Injury to the supra-spinosum lingual canals may occur during midline implant placement, depending on the implant length and the bone height.

Clinical relevance

Despite that injury to the supra-spinosum lingual canals during implant insertion does not result in permanent vascular or neurosensory complications, caution is required to avoid the perforation of the lingual cortices.

Implementation of contextualized, emergency management cognitive aids in a periodontics clinic

BACKGROUND

Emergencies in outpatient clinics are rare. However, potentially catastrophic events can be challenging to manage due to a variety of factors, including limited equipment and staff. The purpose of this quality improvement project was to improve the staff knowledge and familiarity with critical performance elements for emergencies encountered in the setting of a periodontics clinic.

METHODS

Emergency cognitive aids tailored to the clinic's resources were created for anaphylaxis, airway obstruction, and sublingual hemorrhage. The project pre-post-test repeated measures design evaluated the effectiveness of cognitive aids using a combination of hands-on simulation, written knowledge assessments, and self-efficacy surveys. Training sessions and simulations were provided to the clinic's existing care teams made up of a periodontist and two dental assistants with an anesthetist who was present for simulations involving sedation. Due to the small sample size (N = 14) and non-normal distribution, all metrics were evaluated using non-parametric statistics.

RESULTS

Significant improvements were found in knowledge assessment (-2.310, P = 0.021) and self-efficacy (-2.486, P = 0.013) scores when retention after a training session before and after the introduction of cognitive aid was compared. The mean simulation scores and times improved steadily or reached maximum scores during the project progression.

CONCLUSION

Training sessions before and after cognitive aid introduction were effective in improving knowledge, self-efficacy, and simulation performance. Future projects should focus on validating the process for creating contextualized cognitive aids and evaluating the effectiveness of these cognitive aids in larger samples.

A life-threatening dental implant: A case report

BACKGROUND

Intraoral bleeding complications in implant surgery are infrequent; nevertheless, serious and life-threatening complications have been described, generally related to mandibular implants.

PURPOSE

This article presents the exceptional case of a 24-year-old woman who underwent repeated delayed life-threatening episodes of intraoral bleeding following uncovering of a maxillary dental implant. Local measures afforded only temporary control.

RESULTS

The episodes were successfully managed by embolising the greater descending palatine artery, and the patient remains now under close follow-up.

CONCLUSIONS

Early recognition of shock secondary to hemorrhage following intraoral surgery is of paramount importance.

Ultrasound and CBCT analysis of blood flow and dimensions of the lingual vascular canal: A case control study

Objective

To assess the correlation between the diameter of the mandibular lingual vascular canal (MLVC) as determined on CBCT examination to blood flow and arterial diameter as determined by ultrasound Doppler analysis (USG) in dentate and edentulous patients.

Methods

20 subjects were equally distributed into two groups based on the status of their dentition. Group 1 included dentate subjects (DE) and Group 2 included edentulous subjects (ED).The subjects from both the groups underwent CBCT scan for the assesement of the diameter of the MLVC.Similarly, USG was done to assess the diameter of the sublingual artery anastomosis and blood flow in the anterior mandible. Data was analysed using Karl Pearson's Correlation coefficient test and Student's unpaired 't' test.

Results

Irrespective of the status of the dentition and age, a positive correlation was noted between the diameter of foramen on CBCT examination and the diameter of anastomosing artery as studied by the USG (r ​= ​0.290).Similarly, a positive correlation was observed between the diameter of foramen on CBCT and the volume of blood entering the mandible (r ​= ​0.447).A positive correlation (r ​= ​0.138) was observed between the diameter of the anastomosing artery and the volume of blood entering the mandible.

Conclusion

The anterior mandible has a rich vascular supply independent of age and status of the dentition.The dimensions and location of MVLC could be assessed on a CBCT prior to implant placement so that the operating surgeon has an idea about the vascularity of the region. Further studies with higher sample size should be undertaken to confirm these findings.

Radiomorphometric analysis of edentulous posterior mandibular ridges in the first molar region: a cone-beam computed tomography study

Purpose

The aim of our study was to determine the prevalence and degree of lingual concavities in the first molar region of the mandible to reduce the risk of perforating the lingual cortical bone during dental implant insertion.

Methods

A total of 163 suitable cross-sectional cone-beam computed tomography images of edentulous mandibular first molar regions were evaluated. The mandibular morphology was classified as a U-configuration (undercut), a P-configuration (parallel), or a C-configuration (convex), depending on the shape of the alveolar ridge. The characteristics of lingual concavities, including their depth, angle, vertical location, and additional parameters, were measured.

Results

Lingual undercuts had a prevalence of 32.5% in the first molar region. The mean concavity angle was 63.34°±8.26°, and the mean linear concavity depth (LCD) was 3.03±0.99 mm. The mean vertical distances of point P from the alveolar crest (Vc) and from the inferior mandibular border were 9.39±3.39 and 16.25±2.44, respectively. Men displayed a larger vertical height from the alveolar crest to 2 mm coronal to the inferior alveolar nerve (Vcb) and a wider LCD than women (P<0.05). Negative correlations were found between age and buccolingual width at 2 mm apical to the alveolar crest, between age and Vcb, between age and Vc, and between age and LCD (P<0.05).

Conclusions

The prevalence of lingual concavities was 32.5% in this study. Age and gender had statistically significant effects on the lingual morphology. The risk of lingual perforation was higher in young men than in the other groups analyzed.

Floor of the mouth hemorrhage subsequent to dental implant placement in the anterior mandible

Complications in dental implant surgery are possible. Bleeding complications have been described that may be serious, particularly in the floor of the mouth. We present two cases of sublingual hematomas during dental implant osteotomies that impeded but did not close the airway. The clinical courses of these patient’s complications are reviewed. One patient had immediate hematoma formation while the other developed a hematoma overnight, presenting the next day. The treatment rendered was a precautionary in-hospital tracheotomy for the first patient and only compression control for the second. Bleeding complications during dental implant placement in the anterior mandible can be serious issues. There is a potential for sublingual hematoma that could compromise the airway by pressing the tongue against the soft palate into the pharynx. In-hospital treatment may be necessary to prevent an adverse outcome. It must be noted that a hematoma in the submandibular space is life threatening by direct airway compression.

Life-threating outcomes after dental implantation in patient with idiopathic thrombocytopenic purpura: a case report and review of literature

BACKGROUND

Patients with chronic ITP (idiopathic thrombocytopenia) frequently do not require comprehensive medication for daily life. Usually, it had been regarded that postoperative bleeding after a simple or surgical extraction is easily controlled by simple local measures even in patients with ITP. This lack of regular medication usage can sometimes lead practitioners or patients to underestimate the potential life-threatening risk of ITP. There had been no report on postoperative hemorrhage in a patient with ITP related to dental implant surgery.

CASE PRESENTATION

This report presented a life-threatening postoperative hemorrhage after dental implant surgery in an adult with chronic ITP and subsequent emergency management after severe bleeding and airway compromise.

CONCLUSION

The presented case emphasizes the thorough hematological evaluation of the patients even for patients who do not take any specific medications for asymptomatic, chronic ITP.

Incidental findings of implant complications on postimplantation CBCTs: A cross-sectional study

BACKGROUND

Survival rates of dental implants are reported to be very high and seem to indicate minimal complications related to dental implants.

PURPOSE

The aim of this report was to evaluate in a cross-sectional study the prevalence of implant positioning complications as appears in postimplantation Cone-Beam Computerized Tomography (CBCT) in two of the major imaging facilities in Bucharest, Romania.

METHODS

Demographic and implant data was collected from two of the three main CBCT facilities in Bucharest, Romania. All postimplantation CBCT imaging were assessed and evaluated for the presence of different implant positioning related complications. Data were entered into Excel spreadsheet and analyzed statistically.

RESULTS

Of the 2323 CBCT's that were analyzed, a total of 160 (6.89%) presented with implant positioning related complications. Out of those, 62 cases revealed penetration of the implant to adjacent anatomic structure. More specifically, there were 21 instances of sinus penetration, 19 instances of nasal cavity penetration, 9 instances of inferior alveolar canal penetration, and 13 instances of lingual plate perforations. There were also 15 cases of adjacent tooth injury noted.

CONCLUSIONS

Despite the popularity of dental implants, the surgical placement of these implants is not a riskless procedure. Implant mal-positioning might be life-threatening and can lead to serious bleeding, airway obstruction, and unnecessary postoperative surgeries. Complications of dental implants are not obsolete and dental implant associated problems may not be apparent immediately. Surgeons must have proper training and use evidenced-based treatment planning in order to prevent dental implant complications.