The Effectiveness of Preformed Tooth Protectors During Endotracheal Intubation: An Upper Jaw Model

Protective potential of different mouthguard thicknesses against perianaesthetic dental trauma: a patient specific-finite element study

Perianaesthetic dental trauma is a common anaesthesia-related complication. Theprevious studies have shown a lack of knowledge regarding mouthguard usage and controversial results related to perianaesthetic dental trauma prevention. This study aimed to conduct a finite element analysis of the compressive and tensile stresses on the tooth-periodontal ligament-bone complex using custom-made mouthguards of different thicknesses and glass fibre splints to prevent perianaesthetic dental trauma. Custom-fitted ethylene-vinyl acetate mouthguards of two different thicknesses (2 and 3 mm) and glass fibre splint were modelled. A linear static finite element analysis was performed by applying a rigid Macintosh laryngoscope to the palatal surface of the maxillary central incisors at 150 N. The model without a mouthguard and glass fibre splint showed the highest stress values at the palatinal root surfaces during the impact. Increasing the mouthguard thickness significantly decreased the stress-strain values regardless of the presence of the glass fibre splint. Maximum stresses in the group using the 3 mm mouthguard were the lowest compared with the other groups.

Anti-Toothbreaker: A Novel Low-Budget Device Enabling Contactless Dental Protection and a Forbidden Technique during Direct Laryngoscopy for Endotracheal Intubation

BACKGROUND

Iatrogenic dental injury is the most common complication of conventional laryngoscopy during orotracheal intubation. The main cause is unintended pressure and leverage forces from the hard metal blade of the laryngoscope. The aim of this pilot study was to introduce and test a novel, reusable low-budget device not only providing contactless dental protection during direct laryngoscopy for endotracheal intubation, but also enabling, in contrast to established tooth protectors, active levering with conventional laryngoscopes for easier visualization of the glottis.

METHODS

A constructed prototype for intrahospital usage was evaluated by seven participants on a simulation manikin for airway management. Endotracheal intubation was performed with and without the device using a conventional Macintosh laryngoscope (blade size 4) and a 7.5 mm endotracheal tube (Teleflex Medical GmbH, Fellbach, Germany). Necessary time and success of first pass were determined. Degree of visualization of the glottis with and without the device was stated by the participants according to the Cormack and Lehane (CL) classification system and the Percentage of Glottic Opening (POGO) scoring system. In addition, subjective physical effort, feeling of safety regarding successful intubation, and risk for dental injury were queried on a numeric scale between 1 and 10.

RESULTS

All participants except one stated that the intubation procedure was easier with usage of the device than without it. On average, this was subjectively perceived as being approximately 42% (range, 15-65%) easier. In addition, time to first pass success, as well as degree of glottis visualization, subjective physical effort, and feeling of safety regarding risk for dental injury, were clearly better with usage of the device. Concerning feeling of safety regarding successful intubation, there was only a minor advantage. No difference in first pass success rate and number of total attempts could be observed.

CONCLUSION

The Anti-Toothbreaker is a novel, reusable low-budget device which might not only provide contactless dental protection during direct laryngoscopy for endotracheal intubation, but also enables, in contrast to established tooth protectors, active levering with conventional laryngoscopes for easier visualization of the glottis. Future human cadaveric studies are needed to investigate whether these advantages also prove themselves there.

Evaluation of dental status using a questionnaire before administration of general anesthesia for the prevention of dental injuries

Background

Dental evaluation and protection are important for preventing traumatic dental injuries when patients are under general anesthesia. The objective of the present study was to develop a questionnaire based on dentition-related risk factors that could serve as a valuable tool for dental evaluation and documentation.

Methods

We developed a questionnaire for dental evaluation before administration of general anesthesia, investigated the association between patient-and-dentist responses and mouthguard fabrication, and assessed response agreement between 100 patients.

Results

Protective mouthguards were fabricated for 27 patients who were identified as having a high risk of dental injury. There was a strong association between dentists' responses and mouthguard fabrication, depending on the general oral health status, use of ceramic prosthesis, presence of masticatory pain related to periodontal diseases, gingival edema, and implants (P < 0.05). Response agreement between patients and dentists for items related to dental pain, loss of dental pulp vitality, root canal therapy, dental trauma, aesthetic prosthesis, tooth mobility, and implant prosthesis was high (Cohen's kappa coefficient κ ≥ 0.6).

Conclusions

A high agreement was observed between patient-dentist responses and a strong association with mouthguard fabrication for items pertaining to ceramic prosthesis, masticatory pain, and dental implants. Patients with a "yes" response to these items are recommended to undergo a dental evaluation and use a dental protective device while under general anesthesia.

Mechanical strain to maxillary incisors during direct laryngoscopy

Background

While most Direct laryngoscopy leads to dental injury in 25–39% of cases. Dental injury occurs when the forces and impacts applied to the teeth exceed the ability of the structures to dissipate energy and stress. The purpose of this study was to measure strain, (which is the change produced in the length of the tooth by a force applied to the tooth) strain rate, and strain-time integral to the maxillary incisors and determine if they varied by experience, type of blade, or use of an alcohol protective pad (APP).

Methods

A mannequin head designed to teach and test intubation was instrumented with eight single axis strain gauges placed on the four maxillary incisors: four on the facial or front surface of the incisors and four on the lingual or back, near the insertion of the incisor in the gums to measure bending strain as well as compression. Anesthesiology faculty, residents, and certified registered nurse anesthetists intubated with Macintosh and Miller blades with and without APP. Using strain-time curves, the maximum strain, strain rate, and strain time integral were calculated.

Results

Across the 92 subjects, strain varied 8–12 fold between the 25th and 75th percentiles for all four techniques, but little by experience, while strain rate and strain integral varied 6–13 fold and 15–26 fold, respectively, for the same percentiles. Intubators who had high strain values with one blade tended to have high strains with the other blade with and without the APP (all pairwise correlation rho = 0.42–0.63).

Conclusions

Strain varies widely by intubator and that the use of the APP reduces strain rate which may decrease the risk of or the severity of dental injury.

Creating protective appliances for preventing dental injury during endotracheal intubation using intraoral scanning and 3D printing: a technical note

Digital dentistry has influenced many dental procedures, such as three-dimensional (3D) diagnosis and treatment planning, surgical splints, and prosthetic treatments. Patient-specific protective appliances (PSPAs) prevent dental injury during endotracheal intubation. However, the required laboratory work takes time, and there is the possibility of tooth extraction while obtaining the dental impression. In this technical report, we utilized new digital technology for creating PSPAs, using direct intraoral scanners and 3D printers for dental cast fabrication.

Displacement of deciduous tooth into hypopharynx due to endotracheal intubation

Intubation may lead to several dental complications. Furthermore, a tooth damaged during intubation may be subsequently dislocated. In the present case, the upper primary incisor was avulsed during intubation and, unbeknownst to the anesthesiologist, displaced to the larynx. We report here on the findings and indicate appropriate treatment. Intubation for general anesthesia in children can result in tooth damage and/or dislocation of primary teeth with subsequent root resorption. Prevention is key, and thus it is critical to evaluate the patient's dental status before and after intubation. Furthermore, anesthesiologists and dentists should pay close attention to this risk to prevent any avulsed, dislocated, or otherwise displaced teeth from remaining undetected and subsequently causing serious complications.

Protective dental splint for oroendotracheal intubation: experience of 202 cases

Background

Dental injury as a result of oroendotracheal intubation during general anesthesia is very common. We report our experiences of using mouthguard to prevent dental injury during intubation based on our protocol.

Methods

This retrospective study enrolled patients referred for preanesthetic evaluation, those patients with a history of any of the dental treatments to their anterior teeth listed on our fabrication protocol from January 1, 2009 to June 30, 2010.

Results

No cases of dental trauma during oroendotracheal intubation were reported among the 202 patients who used a protective device. 66% of the patients had risk factors for hard tissue damage aged 10-40 years. At the ages of 40-70 years, the incidence of risk group for periodontal damage was higher.

Conclusions

Preanesthetic consultation was effective for preventing dental injury, so preanesthetic questionnaire and proper dental consultation would be helpful.

[Tooth injury in anaesthesiology]

BACKGROUND AND OBJECTIVES

Dental injury is the most common complication of general anaesthesia and has significant physical, economic and forensic consequences. The aim of this study is to review on the characteristics of dental injury associated with anaesthesiology and existing methods of prevention.

CONTENTS

In this review, the time of anaesthesia in which the dental injury occurs, the affected teeth, the most frequent type of injury, established risk factors, prevention strategies, protection devices and medico-legal implications inherent to its occurrence are approached.

CONCLUSIONS

Before initiating any medical procedure that requires the use of classic laryngoscopy, a thorough and detailed pre-aesthetic evaluation of the dental status of the patient is imperative, in order to identify teeth at risk, analyze the presence of factors associated with difficult intubation and outline a prevention strategy that is tailored to the risk of dental injury of each patient.

[Financial and medicolegal impact of dental trauma]

INTRODUCTION

Dental injuries are among the most common complications of general anesthesia. Yet few studies have assessed the costs and factors that involve the responsibility of the anesthetist.

STUDY DESIGN

A retrospective study was conducted at the university hospital of Reims on 46 cases of dental injuries directly related to anaesthesia.

RESULTS

Ten patients made a claim for compensation. Two of them have received compensation following a medical expertise, which revealed for the first patient a possible alternative to general anaesthesia, and the second, hardware failure of intubation. The Administrative Court was entered once in 9 years. The global insurance-cost amounts to 4476 euros for all patients. The review of all cases of anaesthesia shows clearly that the dental claims are associated with a significant under clinical evaluation of dental status and criteria for difficult intubation during the anaesthesia. The information to the patient on this risk is not obvious from reading the anaesthesia records. No mouth guard was used.

CONCLUSION

This work proves that the statements of caution are the most common and a minority of dental trauma lead to a claim. Claims are due to the high cost of dental care repair. The proportion of patients receiving benefits is extremely low. Medical expertise is an essential part of the evaluation of medical responsibilities. No compensation was paid without expertise. The lack of physical examination and information are contrary to our professional obligations and may involve our responsibility. The lack of patient information is not generated for compensation to the extent that the consequences of failure are easily dental weighed against the benefits of the entire medical-surgical procedure that the patient has agreed.

[French clinical guidelines for prevention of perianaesthetic dental injuries: long text]

INTRODUCTION

Dental injuries represent the most common claims against the anaesthesiologists. Dental lesions are frequent complications of orotracheal intubation and major causal factors are, firstly, preexisting poor dentition, and, secondly, difficult laryngoscopy and tracheal intubation. The aim of this work was to prioritize propositions for prevention in perianaesthetic dental injury and for care in case of dental trauma.

METHOD

A GRADE consensus procedure consisting of three rounds was conducted. A purposively selected heterogeneous panel (n=15) of experts, comprising 10 practitioners in anesthesiology, one practitioner who is jurist and anaesthesiologist, two practitioners in maxillofacial surgery, and two practitioners in dentist surgery. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion of the board members. The guidelines represent the best current evidence based on literature search and professional opinion.

RESULTS

The entire panel completed all three rounds and 31 plus six propositions were written for adult and paediatric clinical practice in anaesthesiology, respectively. The experts highlight the interest of preoperative visit for minimizing dental injuries: the practitioner must identify risk factors for difficult intubation and ventilation, describe precisely patient's preoperative dental condition, including upper incisor most commonly involved teeth in dental trauma. Patients have to be informed by practitioner for risk dental injury and anaesthesiology staff must choose his anesthesia protocol before the induction of intubation narcosis, avoiding insufficient anaesthesia and lack of experience by the anaesthesiologist. The choice of accurate proceeding during laryngoscopy, tracheal intubation and extubation for example, can aid in the prevention of dental injury, reduce the number of claims and the cost of litigation process.

DISCUSSION

These guidelines delineate an approach for the prevention of perianaesthetic dental trauma and for the immediate or urgent care in case of perianaesthetic dental injury.

Perioperative dental injury at a tertiary care health system: An eight-year audit of 816,690 anesthetics

Among all complications of airway management, dental injury is the most common cause of patient complaints with medicolegal consequences. Over an 8-year period, data on dental injury were collected within a large university hospital system that included community, tertiary, and quaternary care centers. Patient characteristics were compared among all patients receiving anesthesia care using billing data collected from the same period. Of the 816,690 patients who received anesthesia care, there were 360 dental injuries, giving an overall incidence of 1:2,269 (0.044%). Patients receiving general anesthesia were at an increased risk for dental injuries, with an incidence of 1:1,754 (0.057%) compared with patients receiving monitored anesthesia care in whom the incidence was 1:12,500 (0.008%). Patients in the age group 18 to 65 years had a higher incidence of dental injuries of 1:1,818 (0.055%) compared with pediatric patients, who had an incidence of 1:7,692 (0.013%). Emergency procedures were not associated with an increased risk of dental injury in the 816,690 cases. However, of the 360 patients who sustained a dental injury, emergency procedures were associated with a higher incidence of injuring multiple teeth.

[Dental trauma and anaesthesiology: epidemiology and insurance-related impact over 4 years in Rouen teaching hospital]

OBJECTIVES

Dental injuries are the first cause of sinistrality in anaesthesiology. However, few insurance-related data are available concerning the publicly-owned establishments, in particular on the cost of the complaints deposited. We studied the epidemiology of dental trauma in a teaching hospital and brought it closer to the induced insurance-related costs.

PATIENTS AND METHODS

We conducted a retrospective study, examining the files of declaration of dental trauma, from January 2005 to December 2008. The litigations for dental injuries treated by Quality and Services Department were also analysed.

RESULTS

Seventy-two cases of dental lesions were declared, i.e. 1/1528 general anaesthesias. Concerning the risk factors of lesion, 47 patients (65%) presented bad dental conditions identified during the pre-anaesthetic consultation; 27 patients (37%) had criteria for difficult intubation listed on the sheet of anaesthesia. The association of the 2 factors was found among 20 patients. The indication of information to the patient on the dental risk was registered on the sheet of anaesthesia in 17% of cases. The Quality and Services Department recorded 23 complaints for dental trauma over the period. In 4 cases the complaint was followed by a compensation for an average amount equal to 608 (256-1002) Euros, i.e., a total cost of 2434 Euros.

CONCLUSIONS

The two main risk factors of dental lesion are well identified with the consultation of anaesthesia and are noted on the file. However, information to the patient on this risk is seldom notified. The incidence of dental lesions is important, but few complaints open right to financial repair for a very low insurance-related total amount.

[Intubation-linked dental injuries. Relevance of individually adaptable tooth protection models]

BACKGROUND

Tooth damage during anaesthesia could be reduced by using tooth protectors during endotracheal intubation. The effectiveness of different models was investigated using an upper jaw model.

METHOD

A total of 6 individual adaptable dental protectors (Endoragard and Camo, with wax or silicone filling, respectively, Beauty pink dental wax with and without tissue inserts) were examined in three different categories. The upper jaw was covered with each dental shield and then loaded with a force of 150 N via a blade of a laryngoscope. Subsequently, force reduction was measured in axial as well as horizontal directions. Furthermore, the reduction in oral view was determined by measuring the thickness of each dental shield with a micrometer.

RESULTS

The combination of Camo and silicone achieved the maximum horizontal force reduction value (39.2 N). Endoragard and silicone achieved the best axial value (21.6 N). Beauty pink wax had the thinnest dental shield (2.8 mm), whereas the combination of Camo and silicone gave the most limited view inside the oral cavity (3.8 mm).

CONCLUSION

Preformed dental shields are useful for reducing the force applied to the teeth and potentially reducing the probability of tooth damage during laryngoscopy. However, the shield with the highest force reduction capability is relatively large and expensive which makes general use almost impossible. The model Beauty pink was slightly less force reducing and could be considered as an inexpensive and yet effective tool for clinical assignment.