Incidence of barodontalgias and their relation to oral/dental condition in personnel with responsibility in military flight

GONZÁLEZ-SANTIAGO MM, MARTÍNEZ-SAHUQUILLO-MÁRQUEZ A, BULLÓN-FERNÁNDEZ P. INCIDENCE OF BARODONTALGIAS AND THEIR RELATION TO ORAL/DENTAL CONDITION IN PERSONNEL WITH RESPONSABILITI IN MILITARY FLIGHT. MED ORAL  2004;9:92-105.

SUMMARY

OBJECTIVES: The aim of the present study was to investigate the incidence of barodontalgias in a sample of 506 patients, all of whom are personnel with responsibility in military flight. An additional aim was to correlate this incidence with various oral pathologies and their subsequent treatment.
Design of the study: The ICAO and CPITN indices in flight personnel who underwent the obligatory official examination at the Straits Air Command Hospital were investigated, in each case taking the data of the initial examination. Any effects that occurred in simulated flights, conducted in a hypobaric chamber, were also recorded. Any case of barodontalgia was investigated in depth, relating it to the pathology that caused it, and observing the result of the treatment employed.
RESULTS: There were three cases of barodontalgia (2.63%). The pain was essentially of posterior localisation (92.3%), and in the majority of cases was described as acute and localised (61.5%). In a high percentage it did not disappear after landing (61.5%). The pathologies were varied, and the treatments were in keeping with these. The result after the therapeutic phase was entirely satisfactory in 69.2%.
If we correlate the appearance of barodontalgias with other variables, in the patients who experienced them we record a larger number of fillings (P = 0.1617) and a smaller number of teeth missing (P = 0.6603). The Caries Index is similar in the two groups (P = 0.9187). The average ICAO is higher (P = 0.3345) in those patients who suffered from pain, though it must be pointed out that the low number of cases means it is difficult to record statistically significant results.
CONCLUSIONS: Our results showed an incidence of barodontalgia in the study population of 2.63%, overall. In real flight the incidence was 2.4% and in the ascents conducted in the hypobaric chamber it was 0.2%. On the other hand, no statistically significant differences were found between the results for the Indices of Oral Health of the patients affected by barodontalgia and those not so affected, although the ICAO was greater.

Key words: ICAO, CPITN, barodontalgia, hypobaric chamber, epidemiology, flight personnel.

INTRODUCTION

Barodontalgias are defined as toothache that arises when there are changes in ambient pressure. They result from a combination of two basic factors, on the one hand the change in pressure (whether positive or negative), and on the other hand the particular anatomical characteristics of the pulp chamber, in which there is richly innervated tissue surrounded by hard, rigid walls.

If there is an increase or decrease in pressure, the pulp is unable to adapt and, in combination with other additional factors, this will cause pain, which is sometimes so intense that it can lead to loss of consciousness. Therefore a better definition of barodontalgia would be dental pain resulting from the inability of the pulp chamber to balance its internal pressure after changes have occurred in the ambient pressure (1, 2).

This pathology has been known for centuries and has been widely studied and discussed. Numerous theories have been elaborated in unsuccessful attempts to explain its aetiopathogenesis, which still remains obscure (3).

Pain is the main symptom of this clinical entity, and may be acute or dull, in most cases appearing suddenly, and of great intensity. It can be so severe that it leads to physical and mental incapacity, involving a high risk of accidents that would endanger the life of the person suffering from barodontalgia, or even of everyone else as well if we are talking about an aircraft with crew or passengers (2, 4, 5).

also wished to evaluate whether there is any relation between the level of oral/dental health or disease in the study population and the development of barodontalgias, as well as treatment of the oral pathology that causes it and the subsequent response, both in flight and in the hypobaric chamber.

MATERIAL AND METHOD

1 - THE POPULATION SELECTED

The population selected comprised 506 persons, all males, attached to military units located in the southern zone.

The study was carried out in the period 1995-2000 among all the military flight personnel who passed the obligatory annual examination of the Hospital of the Straits Air Command (Mando Aéreo del Estrecho, MAEST). These data were supplemented with the results of ascents in the hypobaric chamber conducted at the CIMA (Centre for Instruction in Aerospace Medicine) during the same period.

The clinical histories and examinations were always carried out by the same person, observing the same routine in each case and rejecting patients for whom a complete record was not obtained for any reason, or who did not meet the conditions previously described.

2 - MATERIALS USED IN CLINICAL EXAMINATION

Clinical examination involved the use of Prodont No. 5 intra-oral flat mirrors, a Maillefer No. 4/6 double exploratory probe, dental silk, OMS periodontal probe and if interproximal caries was suspected, Agfa Dentus M2 Comfort intra-oral radiographic films and a device for positioning them, the Zentra-X from H&W. Intra-oral radiology equipment was used, made by Trophy radiologic, CCX and the Orthopantomograph used was made by Trophy, model Odontorama PC. The plates for the orthopantomographies used were from Fujifilm, model HR, size 15x30. The results were recorded using the Official Examination Chart of the Hospital of the MAEST and one that was devised specially for this study.

3 - HYPOBARIC CHAMBER

This chamber is located at the CIMA and is used for reproducing the conditions of barometric pressure and hypoxia that flight personnel have to withstand at different altitudes, and their effects. It is the ideal tool for submitting our patients to the various experiences that make up the so-called Physiological Training.

The chamber is made by ETC, model APTF 10M, and consists of two sections, a main compartment and a fast decompression compartment, separated by a partition in which there is a vacuum safety door (1).

4 - STUDY METHOD

The study consists of two quite separate parts:

CLINICAL EXAMINATION OF THE FLIGHT PERSONNEL: first the patient's particulars were taken, such as his age, rank, position, unit, type of aircraft he flies in, length of time he has been flying, and his medical history is investigated. Then the flight personnel undergo a thorough examination in the odontology consulting room, noting the following on a dental chart: caries (specifying the tooth and surface/s affected), where teeth are missing, and fillings (differentiating between amalgam, composites and temporary fillings). Whether the patient has any type of prosthesis, fixed or removable, is also recorded (specifying the type and material of which it is made) or whether he has implants and, finally, examination for the presence of periodontal disease. The indices for the incidence of each pathology: IC, ICAO (6), CPITN (7), are obtained from these data, and are correlated with the conditions of pressure at which it developed.

Next, an orthopantomography is carried out in the Radiology Department, for completing the dental chart, noting the presence of wisdom teeth, canines or any other tooth included, endodontics and the condition thereof, presence of apical areas, height of the alveolar process, root residues and the presence of radiolucent or radiopaque areas requiring more detailed investigation.

The odontologist informs the patient of the result of the examination, advising him of the treatment that is most appropriate to his pathology, and answering his questions. This type of examination is obligatory for flight personnel once a year.

When the patient reports having experienced an episode of barodontalgia, this is investigated thoroughly (type of pain, localisation, tooth) both clinically and radiologically, making a distinction between development in a real flight or during a session in the hypobaric chamber. If necessary, additional tests are carried out, or further consultations with the otorhinologist, neurologist or maxillofacial surgeon to discover the nature of the problem.

Once the pathology has been diagnosed it is treated. The form of treatment will depend on the lesion that is found. The usual treatments are employed against barodontalgias, with some very positive results, provided they are precise and thorough. The patient's treatment will be regarded as satisfactory when he is asymptomatic both in a new session in the hypobaric chamber and in real flight.

Examination of flight personnel and suitability qualification are carried out in accordance with the general provisions given in the Spanish Official Gazette (B.O.D.) No. 204, which are currently in force (8).

SESSION IN THE HYPOBARIC CHAMBER: in this part of the study, incidents were recorded relative to the total of the population studied in the course of two flight profiles, although there are others. A flight profile is sought in which the maximum ceiling of real altitude of the aeroplane is reached, or its upper limit of pressurisation.

STATISTICAL STUDY

The statistical study of the data consisted of a descriptive analysis of all of the variables. In addition, the qualitative variables were analysed by means of contingency tables using Pearson's chi-squared tests. For the quantitative variables, an analysis of variance was performed, supplemented with the Bonferroni correction for determination of the groups that characterised the difference. The software used was SPSS 6.0.

RESULTS

Of the 506 persons studied, the results relate to 499, the other seven having been rejected through absence of any data or examination.

The average age was 35 years; they were divided into four age groups for the study. Average flying time was 10 years and eight months approximately. The personnel examined were also divided into four groups for the study.

The population studied belongs to different flying units, namely 56.7% in helicopters and 43.3% in planes. The same percentage applies with reference to pressurisation, with about 216 individuals flying in pressurised aeroplanes and 283 in unpressurised aeroplanes.

There were thirteen cases of barodontalgia (2.63%), twelve of them in flight (2.4%) and just one (0.2%) during training in the hypobaric chamber. The average age of the patients who suffered pain was 35 years and the average flying time was 10 years and 3 months approximately. Tables 1 and 2 show the relation between barodontalgic pain, age and flying time.

Relating the appearance or non-appearance of barodontalgias with other variables, we find that the patients who experienced them had a larger number of fillings (P = 0.1617), both of resin composites and of silver amalgam, and a lower index of teeth missing (P = 0.6603). The caries index is similar in the two groups (P = 0.9187). The average ICAO is therefore higher (P = 0.3345), as can be seen in Fig. I. The number of endodontics, apical areas and teeth replaced with fixed prostheses is also greater in patients who experienced pain. There is no connection between the appearance of barodontalgias and the presence of periodontitis.

Fig. 1. Relationship between icao and presence of barodontalgia

In general, the flight crews of pressurised aircraft (5.1%) are more affected than those of unpressurised aircraft (0.7%), and in a high percentage, those pilots who fly solo (61.5%). Of those affected, 8 are aeroplane pilots, 3 are crew members and 2 are mechanics.

The pain started during the ascent in six cases (46.2%), during the descent in three (23.1%), and the other four cases (30.8%) appeared during other manoeuvres: acceleration, deceleration or cruising.

The patients located the pain essentially in the posterior sector, six of them in the maxilla and another six in the mandible. Only one case appeared in the anterior mandibular sector and none in the anterior maxillary sector. Thus, the maxilla was affected in 46.2% of cases and the mandible in 53.8%.

The pain affected the lower incisors, second lower molar and lower wisdom teeth in one case, the first upper premolar in two; in four cases, the tooth causing the pain was the first upper molar, and it was the first lower molar in another four. The most significant point is perhaps that the first molar, both lower and upper, was the origin of the pain in 61.5% and the other locations only made up 38.5% of the total.

The pain was described by those affected as acute and localised in eight cases (61.5%), acute and diffuse in two (15.4%), dull and localised in two others (15.4%) and only one described it as dull and diffuse (7.7%). The main characteristics of the pain are its acute character (76.99%) and according to the patients it is localised in a high percentage (76.9%).

The painful effects do not appear at any particular altitude, it can vary from 3000 to 25,000 feet. The same applies to its disappearance, which varies between 10,000 and 3000 feet, although the most significant point is that in the majority of cases the pain did not disappear (61.5%). The results are presented in Table 3.

The pathology that affected the tooth (Fig. 2) that caused the pain was caries in three cases (23.1%), two of them with apical area. In five there was a previous filling (38.5%): three with caries not involving the pulp, one involving the pulp and one with apical area. Three patients presented endodontics with apical area (23.1%) and the other two cases corresponded to impacted wisdom teeth and to a periapical condition caused by injury (15.4%).

Fig. 2. Tooth condition causing the pain

The dental treatments for these pathologies (Fig. 3) were extraction in five cases (38.5%), refilling in three (23.1%) and endodontic treatment in the other five (30.8%), although in one of those cases, where endodontic treatment had been provided previously, the treatment had to be repeated, and owing to the persistence of a sinus, an apicectomy was performed (7.7%). The distribution by age is shown in Table 4.

Fig. 3. Treatments carried out

The result after the therapeutic stage (Fig. 4) was satisfactory in eight cases (69.2%). In one patient, re-treatment was necessary, and subsequent apicectomy (7.7%). Another patient presented a new episode of barodontalgia in another wisdom tooth. The other three cases remained asymptomatic although the apical area persisted, therefore we refer to them as satisfactory treatment but with sequelae (23.1%). The treatment was considered satisfactory when the patient did not have any pain, in the hypobaric chamber or in real flight.

Fig. 4. Results

Some patients who suffered barodontalgias also presented other associated barotraumas. Barosinusitis was the commonest, being diagnosed in four cases, followed by barootitis in one case.

DISCUSSION

Considering the size of the population in other studies such as that of Maxwell-Field with 63,720 ascents in a chamber cited by Fleury et al. (9), that of Randolph Field with 62,000 ascents described by Gibert, Colin and Chikhani (10) and that of Kollmann which described the results of a flight simulation in 11,617 persons (11), our sample (506 persons) may seem small, but what is certain is that in our Armed Forces the number of persons with flight responsibility is much smaller than for example in the United States, and it must also be pointed out that when we talk of ascents in a chamber, the total number does not assume a sample of equal size.

The investigation was approached in an innovative manner, in that it included results obtained in real flight and in the hypobaric chamber, which makes it different from other published studies. The bibliography mostly gives articles describing animal experiments (12-14), mainly rats (15-17); others only include barodontalgias that developed in a chamber, both hypobaric and hyperbaric (11, 18, 19), not in real flight.

In the epidemiology section, we must emphasise that there is little data on the state of oral health of the adult population (20, -23), and the indices mainly relate to the child population.

With reference to the hypobaric chamber, it must be explained that the study only includes the results of the obligatory ascents that the personnel with flight responsibility undergo every five years. Both the variables (characteristics of the type of flight, functional norms, previous examinations, etc.) and the chamber (make and model) were already determined, although they did not vary.

As already mentioned in the introduction, and although the frequency of this pathology varies, it is considered that barodontalgias appear at an average rate of 2% (24). In our study we observed an incidence of 2.63%. Just as is thought by other authors (25, 26), it is more than likely that there is a greater incidence than that diagnosed, since there are patients who do not report small barotraumatic incidents to avoid compromising their careers.

In the hypobaric chamber, the results of studies like that of Maxwell-Field reflect an incidence of 0.95% (9). In our results as well, a much lower incidence can be observed in the chamber than in real flight (at a ratio of 12:1). The explanation is to be found in the rules governing the operation of the chamber, as no ascent is to be performed by any person suffering from upper respiratory tract infection or any other problem that prevents him compensating, nor in the case of recent filling, endodontic treatment or surgery, greatly extending the times recommended by EUROMED (5). This decrease in incidence when precautions are maximised is a strong argument in favour of a high-quality preventive policy.

Regarding the figure of 2% of barodontalgias in healthy teeth given by many authors (27- 29), the results do not permit us to express an opinion, since no case was presented that might be classified in this category, as a pathological cause explaining the pain was always found.

In fact, pain was the main clinical characteristic. According to the patients, the pain was very severe. With respect to its intensity and nature, the results do not agree with other authors (26, 30), since practically all of the patients describe it as very intense and acute. We are thus in tune with the assertion made by Seoane et al. (24), who stated that the pain could become incapacitating for the patient. This involves a special risk, above all in situations with a single crew member, or in situations where, because of the characteristics of the mission, atmospheric conditions or the ground relief, it is not possible to land. Again in the study, the proportion of those describing it as an acute pain is much higher than those who describe is as a dull pain. Perhaps the explanation of this is that, in the case of a barodontalgia, the distinction between the two is far more academic than clinical, and that the patients describe a pain of great intensity and rapid onset as acute.

Just as was described by Blanchard (26), in the majority of cases the pain was localised (thus contradicting the description by Brickman (30)), thus making diagnosis much easier. Nor were there many cases in which the pain was radiated, just two, and in both the problem teeth were associated with the maxillary sinus.

Barodontalgia occurred at varying altitude, and more often during ascent than during descent and other manoeuvres (acceleration, deceleration or cruising), confirming various studies (30).

The characteristics of the pain are related to the pathology that causes it; thus, in cases where the pain was acute and transient during the ascent, the subsequent diagnosis was of caries, acute pulpitis, restorations marginally filtered or with inadequate cavity bases. The most relevant piece of information was perhaps the momentary character of the pain that reflects a vital tooth, although a pulp in the process of necrosis can give the same symptoms if pulp residues remain that have not yet undergone necrosis.

The pain appeared during the descent in cases of pulp necrosis, both in teeth with caries and those with fillings. In these cases the characteristic difference was that the pain persisted despite having landed. The patients also added the descriptions of throbbing and of progressive development. When questioned about the altitude of appearance, they stated an interval from when some discomfort started, which increased to pronounced pain. An acute pain also appeared during the descent in the case of impacted wisdom teeth. The pain developed rapidly.

In patients with pain that started suddenly in manoeuvres of cruising, acceleration or deceleration, teeth with the apex affected were observed, without establishing a more definite diagnosis because no anatomopathological investigation was performed.

When the pain persisted at ground level, the clinical signs and symptoms were the usual ones for a particular pathology.

Another point of discrepancy with authors such as Rauch (31) and Fleury (9) relates to the treatments that are to be adopted at a particular dental surgery. For acute, severe and transient pain during ascent, they are both of the opinion that the only treatment possible is endodontics, whereas it is shown in the study that some cases corresponding to this profile are teeth that are perfectly viable with more conservative treatment, which is more in line with that described by Ferjentisk (32).

Although some patients experienced associated barotraumas (mainly barootitis and barosinusitis), we did not encounter anyone who mentioned having suffered dizziness associated with barodontalgic pain, despite the fact that Eidelman (33) found an important relation between these two pathologic entities. Nor did we record the problems of gas entrainment in the tissues that other authors described (34), possibly because there was proper observance of the recommendations for avoiding the development of submucosal emphysema after surgery in the orofacial region.

The sequelae resulting from a possible delayed dental barotrauma were not included in the study, owing to the difficulty that would be encountered in determining whether the pain was a late consequence of the pressure variations or simply the natural development of a pathological process.

Cases that were easily diagnosed were encountered in the study. Most of the patients were able to locate the tooth causing the pain and presented a clear and demonstrable pathological process, although there were some problematic differential diagnoses with barosinusitis, barootitis and neuralgias, in which, in view of the clinical case history and examination, other specialists were consulted, who established the definitive diagnosis. In some situations a thorough clinical examination was necessary, testing for sensitivity to axial and transverse percussion, palpation and thermal tests, plus a complete radiological examination with periapical or bite-wing radiographs, as recommended by Stafne (35).

The subject of barodontalgias arouses much controversy among various authors, but not in the area of treatment, where nearly everyone is in agreement. As is reflected in the literature, the treatments that were carried out in the cases studied are those usually employed in dental practice for these pathologies. The immediate treatment consisted of administration of analgesics in those cases where the pain persisted after the descent. Antibiotics and anti-inflammatory drugs were prescribed for patients when they were considered to be necessary to control infection and then proceed with endodontic treatment.

The explanation for the large number of exodontic treatments employed is to be sought in the intensity of the pain. This is usually so great that the patient asked for treatment that would ensure the pain would not return. This desire was even greater in those cases where the tooth had already undergone endodontic treatment and it was necessary to repeat this treatment or undergo surgical treatment (apicectomy) with an uncertain or medium-term result.

For a patient with caries without involvement of the pulp, careful filling of the tooth was employed. In cases where the pulp was affected, rigorous endodontics of the root canal was advised. No author recommended any other type of treatment (direct pulp capping or pulpotomy) owing to the enormous risk this involves (10).

Even in the case of non-vital teeth, a conservative method was advised, because although there are doubts as to whether the periapical lesions will heal after the root canal treatment, the absence of symptoms in the majority of cases augurs well for the future. In these patients, disappearance of the apical area will be expected, carrying out regular checks. After the endodontic treatment, all the patients were recommended to have a metal-porcelain crown with total coverage to be fitted, for protecting the tooth structure that remains. In one case, with persistence of a vestibular sinus, an apicectomy was performed to avoid the risk of the patient suffering a new painful episode.

For retained wisdom teeth, the solution most advisable was extraction owing to the dramatic symptoms, their inclined position (which made difficult eruption probable) and because of the possibility of repeat infections. In addition, there was a high risk that if they remained in the mouth, the lower second molars could be damaged.

In incisors affected by injury, with pathology of the pulp alone, root canal treatment was carried out.

Despite the preventive measures, barodontalgias continue to affect personnel with flight responsibility. Observing the results, the first point to be noted is that the pain mainly affects the posterior sector, i.e. in twelve of the thirteen cases, and especially the first molar, both upper and lower (61.5%). The reason is anatomical, because in the posterior sector the chamber is much smaller and the pulp reacts more aggressively to any circumstance involving compression of the tissue.

More cases appeared among pilots than among other members of the flight crews, and especially in those flying (61.5%). In modern aeroplanes the whole crew is subject to the same variables. The only differential elements are stress, and in some cases the oxygen mask and the anti-G suit, so although they are not essential elements in the aetiopathogenesis they must be taken into account as supplementary factors.

The pain occurs more frequently in planes than in helicopters, in a ratio of 11 to 2. The differences between them are the flying altitude and pressurisation, though the latter is variable. The fact that a cockpit is pressurised does not mean that there are no variations in pressure, but that it is proportional to the external pressure, though less. Commercial airliners flying at altitudes of 30,000 feet have a cabin pressure from 4 to 6000 feet. Military combat aircraft have ceilings of 50 to 60,000 feet, and the cabin pressure in them can reach 20,000 feet in extreme circumstances. However, unpressurised aeroplanes do not usually exceed 13,000 feet, to avoid exposing the crew to the effects of hypoxia (2). Accordingly, the pilot of a military combat plane may be subjected to a cabin pressure that is much higher compared with the pilots of other aeroplanes, despite flying in pressurised aircraft. This explains why, against all expectation, the incidence of barotraumas is greater among flight personnel of high-performance aircraft.

Although the altitude of appearance and disappearance varies, and no pattern can be established, attention is drawn to the fact that in eight of the thirteen cases the pain did not disappear after landing. This shows that the pulp was affected irreversibly, and that although the pain was triggered at altitude, the pathological process continued to develop even in conditions of normal pressure.

It must be pointed out that although the population sample is sufficient from the statistical standpoint, the small number of cases appearing with the pathology under investigation, just thirteen, means that it is difficult to obtain statistically significant results. Despite this, trends are observed in some values in the analysis of variance (see the results section). In general, among aircraft crews there is a greater number of fillings, endodontics and teeth replaced with fixed prostheses. However, there is a lower incidence of caries, and the number of missing teeth is similar in both groups.

CONCLUSIONS

I - No statistically significant differences were found between the results for the indices of oral health corresponding to personnel with flight responsibility affected by barodontalgia and those who did not have this barotrauma, although the ICAO is greater. A larger number of fillings, endodontics and teeth replaced with fixed prostheses was also observed among those who suffered from pain.

II - The incidence of barodontalgia in the population in the study is 2.63% overall. In real flight the incidence is 2.4%, and in ascents effected in the hypobaric chamber it is 0.2%.

III - The result after the treatment stage was satisfactory in 69.2% of cases. Repeat treatment was required in 7.7%, and a new episode of barodontalgia occurred in another 7.7%, though with a different localisation. In 23.1% of the cases, although asymptomatic both in flight and in the hypobaric chamber, the apical area persists.

REFERENCES

1. Ríos F. Modificaciones fisiopatológicas y psicológicas en la altitud y su significado en medicina aeronaútica. Tesis doctoral. Madrid: Universidad Complutense: Facultad de Medicina; 1989.         [ Links ]

2. García R. Fisiopatología Clínica de las Barodontalgias. Tesina. Madrid: Universidad Complutense: Facultad de Odontología; 1992.         [ Links ]

3. Gómez P. La medicina aeronáutica desde sus orígenes hasta la era astronáutica. Tesis Doctoral. Madrid: Universidad Complutense: Facultad de Medicina; 1977.         [ Links ]

4. Engle E, Lott A. Man in flight. Biomedical Achivements in Aerospace. Leeward Publications INC. MD; 1979.         [ Links ]

5. Briz FJ. Recomendaciones del grupo de trabajo de servicios dentales de la Euromed sobre "limitación de la Administración de fármacos y/o la realización de procedimientos quirúrgicos habituales en la práctica dental". M M 1993; 49:371-4.         [ Links ]

6. Cuenca E, Manau C, Serra L, eds. Manual de Odontología Preventiva y Comunitaria. 1ª ed. Barcelona: Masson; 1991.         [ Links ]

7. Alcalá MI, Miranda MT, Gómez E, García A, Fernández-Crehuet J. Estudio del comportamiento del índice CPITN en diferentes grupos de población. Relación de sus parámetros clínicos con diversos factores de riesgo. Comportamiento del CPITN en diferentes grupos. Avances en Periodoncia 1991;3:103-7.         [ Links ]

8. Orden Ministerial número 74/ 1992 de 14 de Octubre (B.O.D. nº 204 de 19 de Octubre de 1992) por la que se establecen los requisitos para la valoración psicofísica del personal de las Fuerzas Armadas con responsabilidad de vuelo.         [ Links ]

9. Fleury J, Deboets D, Voisin D, Assaad C, Maffre N, Viou F et al. Les Aerodontalgies. Rev Stomatol Chir Maxillofac 1988;89:15-20        [ Links ]

10. Gibert AP, Colin J, Chikhani PM. Les aerodontalgies. Med Aeronaut 1957; 12:233-48.         [ Links ]

11. Kollmann W. Incidence and possible causes of dental pain during simulated high altitude flights. J Endod 1993;19:154-9.         [ Links ]

12. Seltzer S, Bender JB, Kaufman I. Histologic changes in dental pulps of dogs and monkeys following application of pressure, drugs and microrganisms on prepared cavities. Oral Surg, Oral Med, Oral Pathol 1961;14:327-46.         [ Links ]

13. Pashley DH, Nelson R, Pashley EL. In- vivo fluid movement across dentine in the dog. Archs Oral Biol 1981;26:707-10        [ Links ]

14. Nähri M, Virtanen A, Huopaniemi T, Hirvonen T. Conduction velocities of single pulp nerve fibre units in the cat. Acta Physiol Scand 1982;116:209-13.         [ Links ]

15. Seoane J, Romero A, Esparza G, Briz F. Análisis histológico de la pulpa dentaria de la rata blanca en ambiente hiperbárico (Aproximación al conocimiento de la barodontalgia). M M 1987;43:550-3.         [ Links ]

16. Frank R, Pfister A, Loubiére R. Etude experimentale de l'aerodontalgie chez le rat blanc. Helv Odontol Acta 1967;11:79-90        [ Links ]

17. Fink BR, Kish SJ, Byers MR. Rapid axonal transport in Trigeminal nerve of rat. Brain Research 1975;90:85-95.         [ Links ]

18. Orban B, Ritchey B. Toothache under conditions simulating high altitude flight. JADA 1945;32:145-80.         [ Links ]

19. Musajo F, Passi P, Girardello GB, Rusca F. The influence of environmental pressure on retentiveness of prosthetic crowns: an experimental study. Quintessence Int. 1992;23:367-9.         [ Links ]

20. Garcillán R, Rioboo R, Rodríguez C, Bratos E. Estudio de la caries dental en una población anciana de la Comunidad de Madrid: Prevalencia según grupos de edades y sexo; análisis de su distribución por piezas dentarias; caries de cuello. Av Odontoestomatol 1996;12:149-58.         [ Links ]

21. González V, Bullón P. Estudio epidemiológico piloto de salud oral y necesidades de tratamiento en un grupo de adultos de 35 -44 años en Sevilla. Arch Odontoestomatol Prev Comunit 1989;1:25-31.         [ Links ]

22. Fernández T, De la Torre J, Lozano M, Alba J. Estudio epidemiológico de la higiene bucodental en soldados de la Base de Cerro Muriano (Córdoba). M M 1994;50:524-7.         [ Links ]

23. Carroquino R, Llodra JC, Fernández CM, Baca MP, González-Jaranay M, López E, et al. Estudio epidemiológico de enfermedades bucodentales en una muestra de 200 soldados de la guarnición militar de Granada. M M 1987;43: 554-66.         [ Links ]

24. Seoane J, Aguado A, Romero MA, Jimenez A, Mombiedro R, Ortiz S. Barodontalgia: estado actual. Interés odontoestomatológico. Rev Actual Odontoestomatol Esp 1990;50:39-43.         [ Links ]

25. Reddick E. Movement by helicopter of patients with decompression sickness. Aviat Space Environ Med 1978;49:1229-30.         [ Links ]

26. Blanchard JP. Les Aerodontalgies en pratique dentaire. Rev Odontostomatol Midi de la France 1975;33:236-43.         [ Links ]

27. Coggins LJ. Barodontalgia in relation to scuba divers. J Okla Dent Assoc 1985;75:15-6.         [ Links ]

28. Carlsson OG, Halverson BA, Triplett RG. Dentin permeability under hyperbaric conditions as a possible cause of barodontalgia. Undersea Biomed Res 1983;10:23-8.         [ Links ]

29. Crone FL. Military service groups undergoing dental examination and treatment in the Armed Forces. Tandlaegebladet 1986;90:217-23.         [ Links ]

30. Brickmann IW. Toothache in the low-pressure chamber. US Nav Med Bull 1944;43:292-6.         [ Links ]

31. Rauch J. Barodontalgia. Dental pain related to ambient pressure change. Gen Dent 1985;33:313-5.         [ Links ]

32. Ferjentsik E, Aker F. Barodontalgia: a system of classification. Mil Med 1982;147:299-304.         [ Links ]

33. Eidelman D. Vertigo of dental origin: Case reports. Aviat Space Environ Med 1981;52:122-4.         [ Links ]

34. Neblett LM. Otolaryngology and sport scuba diving. Update and guidelines. Ann Otol Rhinol Laryngol Suppl 1985;115:1-12.         [ Links ]

35. Stafne EC. Dental roentgenologic aspects of systemic disease. JADA 1950; 40:265-83.         [ Links ]