Advanced anesthesia

The author reviews the technique of intradiploic anesthesia (an easy and elegant technique), and uses anatomical and clinical evidence to show that these new possibilities, if correctly used, make this the technique of choice in modern dental surgery.

Intradiploic (transcortical) anesthesia, its means, its options (*)

- Dr Villette's injector enables rotation of the injection needle.

— The special needle perforates the cortical bone as it rotates and enables the injection with no leak of anesthetic.

by the Doctor Alain VILLETTE Dental surgeon (F-49300 Cholet)

Introduction

Intradiploic anesthesia, as its name indicates, involves injecting the anesthetic solution into the spongy bone (the diploe). In order for this to be achieved, it is necessary to go through the cortical bone, hence it can also be referred to as transcortical. transcortical.

Examined at this angle, it is no different to intraseptal anesthesia which has the same end result, except, the method used for the administration of intradiploic anesthesia differs to those of intraseptal anesthesia. The latter can possibly provoke necrosis of the papilla, or in rare cases, bone sequestrum, both of which are impossible with intradiploic anesthesia.

We reviewed the advantages of intraseptal anesthesia, and we will see that there are many other advantages of intradiploic anesthesia in the maxilla.

- Intraseptal anesthesia is completely effective and instantaneous after administration of the lowest dose of anesthetic.

— It is fast-acting (when there are no complications): three minutes

- It is elegant. The anesthesia is limited to the teeth requiring treatment and does not leak into the soft tissue.

- It is scalable over time, depending on the quantity injected and the presence or absence of a vasoconstrictor.

Intradiploic anesthesia: its means

They are numerous, simple and effective.

Review of accepted use

In order to use the needle injector correctly, it is necessary to:

- Anesthetise a 3 millimetre diameter area on a vertical line with the septum, at the collar line.

- Position the lip protection guard.

- Position the end of the needle perpendicular to the cortical bone, generally two millimetres minimum under the collar line remaining vertical to the septum.

- Place the needle on very fast rotation, minimum of 5 000 rotations/minute and guide the needle during perforation.

- Inject one third to half of a cartridge of anesthetic very slowly in order to obtain immediate anesthesia of the two teeth nearest the site of injection.

If injection is impossible, remove the needle after having placed it on rotation in order to not cause pain to the patient;

45 (*) The opinions expressed in this publication are solely those of the author.

LE CHIRURGIEN-DENTISTE DE France – 1st MARCH 1984 - N° 239

verify that no bone chips are obstructing it, by purging it into the spittoon. Replace it in the treatment site (perforation site) without turning, and inject very slowly. This procedure should be handled in the same way as shown in X-rays 1 and 2.

- For an experienced practitioner, this procedure that takes a long time to describe, takes approximately two minutes and should be completely painless.

- Gingival anesthesia: 45 seconds to 1 minute for a child.

- Perforation: 1 to 3 seconds.

- Injection of half a cartridge: 1 minute.

- At the end of this time, dental work can begin immediately: size of cavity, pulpectomy, extraction.

Conclusion Administered in this fashion, one can note that intradiploic anesthesia is equally as effective as intraseptal anesthesia, while being more elegant and less dangerous.

- No pressure of injection.

- Easier, the single perforation point becomes a 0.5 cm high area,

- No longer any risk of papillary necrosis or bone sequestrum.

- Finally, it provides an admirable solution to the reputed difficulty of intraseptal anesthesia, that of the isolated tooth. In this case, it is simply necessary to cross the cortical bone without having to deal with the contiguous tooth.

This becomes a much easier operation.

Intradiploic anesthesia: its options

In everyday practise, it has been observed that there are variations in results according to the amount of solution injected, particularly in the maxilla.

It is well-known among practitioners accustomed to the use of intraseptal anesthesia, that in the case of children, half a cartridge (or slightly more) injected between 5 and 6 lower teeth, can frequently lead to mental nerve anesthesia, in other words, the equivalent of a Spix anesthesia starting at tooth 6, without hemilingual anesthesia.

Based on these findings, we have decided to visualize the area occupied by the anesthesia after an intradiploic injection.

Injection of the usual radio-opaque biocompatible solution (hexabrix and telebrix 38) did not produce any result irrespective of whether it had been mixed with anesthetic solutions or not, the

radio-opaqueness was too weak.

— Therefore, we decided to work with fresh cadavers, thus enabling the injection of more radio-opaque solutions, but on the other hand preventing the diffusion of the product via the blood stream.

Equipment The material we used

Radiographies nº l X-rays taken with needles in place, after injection. Wide interradicular spacing can be observed, giving the practitioner a large choice of perforation sites. Contrary to what the X-ray may suggest, the needle does not pass via the top of the septum.

Radiographies n°2 X-rays taken with needles in place after injection. By remaining vertical to the papilla, spongy bone can almost always be found which will enable an easy and smooth injection. Contrary to what the X-ray may suggest, the needle is indeed perpendicular to the cortical bone, 2 to 3 mm below the collar line.

- on the one hand, a two day old cadaver of a male approximately sixty years of age, partially dentated, (mandibular X-rays) - on the other hand, a cadaver of a sixty-five year-old male, partially dentated (maxillary retro-alveolar X-rays), slightly formolized.

- A minium solution diluted in white spirit. The solution was prepared in order to obtain maximum fluidity while maintaining radio-opaqueness.

The resulting mixture had an “oily” consistency.

- A classic injector mounted on a portable micro motor.

- The minium solution is placed in empty anesthetic cartridges.

Method

- The perforation is made using a cartridge half-filled with anesthetic. The anesthetic cartridge is then replaced by a cartridge filled with the minium solution in order to avoid sedimentation of the solution and its centrifugation in the cartridge during perforation,

- The injection is made in four steps: a quarter, a half, three-quarters, a whole cartridge, and an X-ray taken immediately after each quarter injected.

- The injections are made unilaterally to show the movement of the solution through the palatal suture and the medial mandibular line.

Results: Radio n°3: 1/2 cartridge injection between 46 and 47.

We can already note the apices of 46 and 47 are already saturated in the solution and that the solution has been transported by a vessel subjacent to the inferior dental canal.

LE CHIRURGIEN-DENTISTE DE France – 1st MARCH 1984 – N° 239

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Radio n° 4: After injection of one cartridge, i.e. 1.8 cm3. We see that the diffusion is more distal, mesial (apex of 45 is attained), and more towards the dental canal.

Radio nº 5: A more anterior view of the previous case. We can note that the solution reaches the median line having been transported by vessels linked to the apices.

Radio nº 6: Additional injection of a quarter carpule between 42 and 43, with anterior view. It can be observed that the apices of 42 and 43 are saturated, but copious amounts of the solution have also passed into the opposite hemimandibula via the vascular pathway.

Radio n° 7: A view of the left hemimandibula which did not receive an injection.

We note a very attractive diffusion along the vascular pathway, enabling observation of apical and periodontal circulation.

Radio nº 8: Injection of a quarter cartridge between 25 and 26. The apices of 25 and 26 are saturated in the solution.

Radio nº 9: After injection of 1/2 cartridge. The diffusion spreads to the apex of 27 and the spongy bone previously occupied by 24.

Radio n°10: After injection of one entire cartridge. We can note that the solution moves towards the sinus roof from the 27 to the 23.

Radio n° 11: A more anterior view shows that all the spongy bone under the nasal fossa has been saturated.

Radio nº 12: Median view showing the passage of the solution through the palatal suture.

Discussion of the results.

Before drawing any conclusions concerning this procedure, the following two remarks should be noted:

- Firstly, the injected solution has a higher viscosity than an anesthetic solution; therefore its diffusion is slower in time and space.

Next, we can consider that in a living person, the arterial system, which has an afferent orientation with regard to the maxilla, cannot be used by the product to move away from the injected area. However, the venous system (the return pathway of the efferent system) is an open door for the distribution of the product.

In the case of cadavers, the arterial door is also open, enabling the distribution of the product out of the injected area.

- One can therefore say without any major risk of error, that diffusion of anesthetics in living tissue is more accurate but less widespread. On the one hand, very little or none will pass the median line which is confirmed by the clinical practice (anesthesia between 45 and 46 has never enabled treatment of 35 or 34).

On the other hand, it will only diffuse in the soft tissue via the venous pathway. In other words, once it has travelled through the interior of the bone,

Now, the following may be observed: in the maxilla, one cartridge of anesthetic diffuses into the entire maxilla and spreads in the sinus roof where the three endings of the superior dental nerve can be found. This very interesting observation is confirmed by clinical practice which we will see later on.

In the mandibula, the diffusion is oriented more previously; therefore, the recurring effect of the anesthetic is less, which is confirmed by clinical practice.

Conclusion This procedure carried out on cadavers shows the diffusion of a minium solution, which is undoubtedly less accurate and more widespread than in a living person. However, this provides very important proof that instantaneous anesthesia of a hemimaxilla is possible with a single injection.

Clinical trial

Table 1 is written in chronological order during a working day in the dental office. The amount of anesthetic injected, the injection site and the treated teeth were noted

(the term treated teeth refers to:: size of cavity, biopulpectomy, extraction.), this without palatal anesthesia.

TABLE I (aside from)

The observations in this clinical table enable us to state that: - a single injection site is generally required for anesthesia (according to the amount injected) of the tooth or teeth to be treated in the maxilla.

This site is generally situated between 5 and 6, an easy access point where the cortical bone is thinner; — the pain of gingival anesthesia in the upper incisor-canine block can be eradicated by transforming the anesthesia distally to the canine and slightly increasing the doses; — the palatal anesthesia is unnecessary except in cases of palatal apical surgery; — the same result can be obtained in the mandibula, bearing in mind that the recurrent effect of the anesthesia is less, generally one tooth and anesthesia of a group of teeth often results in mental nerve anesthesia.

Conclusion

Aside from any problems relating to its execution, we can say that intradiploic anesthesia offers new possibilities clinically as well as the following advantages:

— It is instantaneous, while completely eradicating the risk of papilla necrosis, bone sequestra and inflammation of the ligaments.

- A small dose of anesthetic no longer causes anesthesia of soft tissue (and therefore enables work on two symmetric hemimaxillae in the same visit).

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TABLE I

Patient’s name Quantity

injected in terms of cartridge

fraction

Lieu de perforation

Treated teeth Observations

M. Goisc 1/2 22 distal 21 23.24 missing

M. Guet 3/4 15.16 15.17 Voluminous 1/2 13.14 11 maxilla

Mlle Cho 3/4 23.24 24.22.21 Mme Gaut 1 14.15 15.11 M. Brau j + 1/4 24.25 22.24 Ex 24 M. Aud 1 14.13 15.12 Mme And 1 16 location 17.12 16 missing Mme Chenu 3/4 15.16 17.15 M. Grim 1 37.38 36.37.38 Ex 38 Vincent

sign in 2 mn Mme Bonn 3/4 25.26 27 Vestibular

gingivectomy27 M. Que 3/4 24.25 25.22 M. Trin 3/4 24.25 22.25 Mme Dido 3 15.16 16.11 Mlle Chol 3/4 15.16 17.15.12 Mme Bran 3/4 14.13 14.13.12.11 Ex 14 pulpectomy

13.12,11 Mme Grau 1 25.26 27 M. Brou 1 36.37 37.38 slightly Vincent sign

Mlle Hail 1 35.36 35.37 Mme dues 1 24.25 22 devitalisation Mme Sour 3/4 15 mesial 16.12 14.13 missing Mlle Alb 1/2 15.16 17 Few extensible

commissure M. Breg 1 + 1/2 25,26 26.21.22 Mme Pas 3/4 25.26 26.27 M. Pail 1 23.24 21.22.24 Mlle Herg 1/2 25.26 27 M. dues 3/4 16 location 18.17.14 16 missing Mme Brem 3/4 13.14 11 no vaso Mme Maud 3/4 23.24 23.21 Mme Chas 3/4 23 distal 21.22.23 24 missing M. Math 1 48 vestibular 48 48 ex

perforation through the free gengiva

M. Mori 1 15.16 17.16.12.11 pulpectomy 1 6 cavities 11.12

Mme Gib 1 15.16 16.12 pulpectomy 16 M. Lois I 25.26 27.22 Mme Lize I 15.17 18.17.15 16 missing Mlle Maill 1 15.16 16.17.12 M. Desco 1 24 distally 24.21 25 missing Mme Oge 1/2 1.3.14 12 Mme Breg 1 15.16 17.16.12 Mlle Paill 1 14.15 16.17.11 M. Gail 1 + 1/3 24.25 21.22.26.27 M. Dubr 1 26.27 26.27.24 M. Gab 1 25.24 25.23.22 Mme Bouc 3/4 46.47 46.47.45 size 46

Ex 47.45 Mlle Bonn 1/2 25.26 26,24

Patient’s name Quantity injected

in terms of cartridge fraction

Perforation site Treated teeth Observations

M. Bull 1 26.27 26.27 – 24.23.22 24.23.22

collar cavity M. Paill 3/4 44.43 44.42 M. Gab 3/4 46.47 47.45 Mlle Cast 1 26.27 27.24 Mme Gau 1 27 mesially 27.24 (25 and 26

missing) M. Boiss 1 23.24 21.22.23.24 M. Mori 3/4 26.25 21.22.24.25.26.27 M. Coul 3/4 13.14 11.12 Mme Gais 1/2 22 distally 21 23.24 missing Mme Maud 3/4 37 mesially 38 36 missing Mlle Chol 1/2

1 /2 25.26 15.14

27 11

same visit

- It suppresses painful palatal anesthesia.

— The anesthetic can be adapted to the length of the procedure by changing the quantity of anesthetic and the use or not of a vasoconstrictor.

- It enables anesthesia of up to seven teeth in the maxilla with only one site of injection which is generally between 5 and 6, or 4 and 5 (table I).

- It enables the eradication of gingival anesthesia of the upper incisor-canine block (a very unpleasant anesthesia) by transferring it between 3 and 4, which was easily accepted here.

— It enables instantaneous mandibular anesthesia of two or more teeth or even a hemimandibula, the latter leading to mental nerve anesthesia but no anesthesia of one side of the tongue. We can therefore state that this technique is necessary at a time when patients are becoming more and more demanding concerning effectiveness, rapidity and innocuousness of the procedures that we practice.

Bibliography

SALAGARAY LAFARGUE F. La anestesia en odontostomatologia. Edita Hoechst Iberica. S.A.

VAILLAND J.-P. Anesthésie loco-régionale en endodontie. Revue française d'endodontie. Volume 2 nº 2. 1983. VILLETTE A. Recherche d'un injecteur pour une anesthésie intra diploïque facile. Thèse de 3e cycle ; Nantes 1978. VOLPELIERE A. Indications et limites de l'anesthésie intra septale. Thèse de 2e cycle ; Nantes 1978.

Acknowledgements

The author would like to thank the Anatomy laboratory of the Medical Faculty of Nantes for having opened their doors to him and for their assistance in his work.

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