Need for dental care among medical staff working in the China Antarctic stations

ABSTRACT

Even though China Antarctic medical care has made huge progress, dental care has always been a neglected area. Dental health is well-known to be closely related with life quality and work efficiency. Hence, knowing the dental care situation there and providing ways to improve are urgently needed. We choose doctors who worked in China Antarctic station as a window to see the whole picture by sending questionnaire. The results showed dental visits ranked second high, the ratio of doctors who got pre-departure dental knowledge education and screen is low. What is worse, none of them got any after-departure dental check. Their dental knowledge is not as good as we expect, and they were troubled by dental problems in Antarctic. Interestingly, most dental problems were treated by non-dentist with no essential equipment, but 2/3 of them were satisfied with the outcome. As for the dental-related diet and behaviour, snacks eating and alcohol drinking are the strongest predictors of dental pain and gum problem. Those findings are crucial to Antarctic dental care and research.

KEYWORDS:

• China Antarctic station
• dental care
• dental problems
• medical staff

Introduction

China set its first Antarctic base in 1985, and since then, the Antarctic medical care has made progress in physical and psychological aspects, including traumatic care, sleeping mode, nutritional intake and medical facilities. Regrettably, dental problem has always been a neglected area. According to the 30th Chinese Antarctic expedition in 2013, dental check was not included in routine physical examination, neither was the dental attendance times recorded in medical room visits report [1].

However, dental issues are common in Antarctic bases of different countries. In the India stations, 2% illness were related with dental issues, oral ulcers rise to 8% in winter [2]. In the Japan station, dental problem ranks to the third [3]. In another report about Antarctic evacuation cases in 10 years, apart from internal medicine, dental problems consist of the rest 2/3 evacuation [4]. In China, the latest and only dental records we can find were published in 2021. In a 198-day voyage on the “Xuelong 2” polar scientific expedition ship, dental problem ranks NO. 4 in the total medical visits [5]. Usually, China Antarctic stations are not equipped with dental specialist and professional facilities, thereby no treatment can be done in there. The situation will get worse in winter because of the total darkness, extreme-low temperature, strong wind and slippery road condition, in which the evacuation is almost impossible. Therefore, knowing the dental care situation there and providing ways to solve is urgently needed.

The research was done to evaluate the dental-related issues by sending questionnaire to doctors who worked in Antarctic stations. We choose doctors group to study is because we have access to them and their feedback can reflect at least part of the picture of China Antarctic stations. This information will be helpful to Antarctic dental care and research.

Methods

We connected 42 members from a list that contains the phone number of doctors from 26 ^th to 38^th (2009–2021) who worked in China Antarctic stations. We then send them the questionnaire through wechat (a Chinese instant messaging and social media app) from February to April in 2022. The response rate was 79% (33 doctors). The questionnaire is in a closed-ended format with questions about their basic characteristics and dental-related life in Antarctic stations, including recalled clinic visits frequency, pre/after-arrival dental screen, dental knowledge education, their own dental problems, the uneasiness caused by dental problems, dental-related diet and behaviour. A copy of the questionnaire can be found in Appendix S1.

Analysis

The missing values of important variables were imputed with the expectation maximisation algorithm [6]. Tetrachoric, Polychoric, and point-biserial correlations were implemented to calculate the correlation coefficients between dental issues and other variables. Univariate analysis was performed to identify the potential risk factors of dental issues. Due to the restriction of sample size, we considered using the hierarchical regression model with more variables being considered simultaneously, instead of using the full model or stepwise variable selection strategy. More precisely, basic information, including age and gender, was routinely included in the first step, regardless of the significant test. In the second step, another variable was added to assess the added predictive power compared with that of the null model or model solely included age and gender. In general, we only considered the most significant variable in the univariate analysis for hierarchical regression models. Analyses were performed using R v.4.2.1 and SPSS v.22 (IBM Corp., Armonk, NY, USA).

Results

Participants

Overall, 90.9% of the doctors who worked in Antarctic are male, female are 9.1%. Their ages are between 38 and 62 years old (Medium = 44, SD = 8.46) with 3 females and 30 males (33 in total). More than half doctors (66.5%) worked in Antarctic over 6 months (Table 1).

Table 1. Antarctic doctor characteristics.

Doctor’s characteristics	n	%
Age
<45 years old (including 45)	17	51.5
>45 years old	16	48.5
Sex
Male	30	90.9
Female	3	9.1
Antarctic work duration
<6 months (including 6)	11	33.4
>6 months	22	66.6

Clinic visits frequency recalled by doctors in Antarctic

According to the doctors’ recall (Table 2), in the illness they met, orthopaedics issues ranked to the first (71.88%), dermatologic and dental issues ranked to the second high (65.63%).

Table 2. Clinic visits frequency.

Reason for clinic visits	%
Orthopaedics	71.88
Dermatologic	65.63
Empyrosis	28.13
Frostbite	46.88
Influenza	15.63
Diarrhea	53.13
Acute abdominal pain	25
Cardiovascular	43.75
Psychological	15.63
Dental	65.63
other	15.63

Dental problems experienced by doctors in Antarctic

As to themselves, 28 doctors reported the experience of dental problems (84.8%). The most common dental problems are dental pain, bleeding/swollen gum and oral mucosa diseases. More than half of all problems mentioned above were experienced by 1/3 of all doctors. The most common uneasiness caused by dental problem are eating, emotions and sleeping. In 28 doctors who had dental problem, 66.7% of them got treatment and most on time (90.9%). But less than half were treated by doctors from the same station or nearby stations. Only 22.7% were treated under a licensed dentist and 27.3% were treated with essential/basic dental equipment. However, 66.2% were satisfied with the outcome (Table 3).

Table 3. Dental problem experienced by doctors in the Antarctic.

Dental problem experienced and Treatment aspects	n	%
Dental problem
dental pain	18	54.55
tooth cracked	4	12.12
bleeding/swollen gum	17	51.52
loose tooth	9	27.27
Oral mucosa diseases	17	51.52
wound in the crania-facial area	3	9.09
Uneasiness caused by dental problem
eating food	24	72.73
talking	8	24.24
drinking	6	18.18
emotion	19	57.58
sleeping	16	48.48
working	11	33.33
other	3	9.09
Treatment
got treatment	22	66.7
treatment on time	20	90.9
local doctor	9	40.9
Licenced dentist	5	22.7
essential dental equipment and instrument	6	27.3
satisfied to the outcome	15	68.2

Dental screening and education

Before departure, more than half did not receive any dental education or dental screening, among them, only about 37% went to dental clinic for dental check-up at their own will. After departure, none of them received any dental screening in the Antarctic. Among the listed eight basic dental knowledges, 69.96% doctors know more than 5 tips, but only 24.24% doctors know more than 7 tips. The top three are tips about brush teeth, the last three are tips about food, mouthwash and dental hygiene (Table 4).

Table 4. Dental screen and education.

Dental screening features	n	%
Dental education (Yes)	11	33.33
Dental screen pre-departure (Yes)	12	36.36
Dental check-up at one’s will (Yes)	7	36.84
Dental screen after-departure (Yes)	0	0
Dental knowledge
Q1	10	30.3
Q2	30	90.91
Q3	28	84.85
Q4	23	69.7
Q5	23	69.7
Q6	11	33.33
Q7	18	54.55
Q8	26	78.79

Q = Question. Q1:Fresh squeezed juice is easier to cause tooth decay than fresh fruits. Q2:Together toothbrush with dental floss, the teeth can be cleaned thoroughly. Q3:Brush the outer and inner surface of your teeth up and down, occlusal surface back and forth. Q4:Cracked teeth can happen when chewing on hard foods. Q5:Alcohol-based mouthwash can’t be used as an everyday-routine. Q6:The teeth should be cleaned by dental hygienist every 6–12 months. Q7:If you see black spot in your teeth, you should go to the dentist for help. Q8:None of the above.

Diet and dental related behaviour in Antarctic

The average Carbohydrates, Poultry, milk, vegetable and fruits intake were 33%, 34%, 14% and 18%. Most doctors drank water around 1000 ml per day (75.75%), half ate snack routinely, 91% brushed teeth 2 times or more everyday, 40.9% smoked and 22.7% drank (Table 5).

Table 5. Diet and dental related behaviour in the Antarctic.

Dietary and dental related behavioural factors	n	%
The ratio of your nutrition structure
Carbohydrates	-	33
Poultry	-	34
Milk	-	14
Vegetable and Fruits	-	18
Daily fluid intake
<1500 ml	26	78.78
>1500 ml	7	21.21
eat snack routinely (Yes)	16	48.48
The times brush teeth
<2 times (including 2)	27	81.82
>2 times	6	18.18
Smoke (Yes)	10	40.9
Drink (Yes)	13	22.7

Predicting dental problems

We aimed to explore the correlation between items of interest and the occurrence of dental pain, tooth cracked, gum problem and oral mucosa diseases. Tetrachoric, Polychoric, point-biserial correlations (Table 6) and univariate analysis (Table 7) showed that snacks eating exhibited a strong positive correlation with dental pain (r = 0.73, P = 0.005). Alcohol was positively correlated with gum problem (r = 0.61, P = 0.024; r = 0.45, P = 0.018). Other variables were only weakly related to tooth cracked and oral mucosa diseases.

Table 6. The correlation coefficients between important variables.

	v9a	v9b	v9c	v9d	v9e	v9f
gender	−0.173	−0.430	0.254	−0.098	0.254	−0.230
age	0.147	0.145	0.107	0.151	0.129	0.274
cigarette	0.120	−0.094	0.396	0.314	−0.248	0.260
alcohol	0.373	0.162	0.613	0.107	0.442	0.538
v4a	0.093	0.210	0.165	0.395	−0.428	0.176
v4b	0.373	0.162	0.060	0.107	−0.329	0.136
v5	0.814	0.194	0.557	0.245	−0.019	0.406
v6t	0.064	0.028	0.452	−0.004	0.033	0.202
v14a	0.061	−0.323	0.156	−0.032	0.099	0.319
v14b	−0.139	0.094	−0.046	−0.035	0.167	−0.101
v14c	0.156	0.460	−0.071	0.242	0.047	−0.099
v14d	−0.046	−0.001	−0.097	−0.087	−0.286	−0.217
v15	−0.214	−0.028	0.080	0.358	−0.292	0.611
v16	0.733	0.647	0.144	0.367	0.144	0.019
v18	−0.073	−0.514	−0.518	−0.406	−0.011	−0.126

v = variable, a/b/c/d/e/f = the first/second/third/fourth/fifth/sixth choice. All the correlation coefficients range from −1 to 1, with positive values indicating positive correlations and vice versa. We coded “YES” as 1, “No” as 0.

Table 7. P values of the univariate analysis.

	v9a	v9b	v9c	v9d	v9e	v9f
gender	0.662	0.271	0.518	0.805	0.518	0.997
age	0.400	0.414	0.541	0.389	0.462	0.175
cigarette	0.679	0.806	0.170	0.286	0.386	0.543
alcohol	0.178	0.646	0.024	0.717	0.107	0.996
v4a	0.741	0.550	0.555	0.169	0.121	0.683
v4b	0.178	0.646	0.829	0.717	0.231	0.753
v5	0.023	0.687	0.121	0.543	0.960	0.997
v6t	0.715	0.874	0.018	0.984	0.851	0.276
v14a	0.727	0.097	0.373	0.853	0.571	0.118
v14b	0.431	0.595	0.791	0.840	0.350	0.564
v14c	0.376	0.035	0.685	0.177	0.787	0.572
v14d	0.791	0.993	0.578	0.617	0.114	0.279
v15	0.396	0.821	0.828	0.169	0.208	0.111
v16	0.005	0.996	0.598	0.209	0.598	0.965
v18	0.700	0.180	0.090	0.181	0.822	0.736

v = variable, a/b/c/d/e/f = the first/second/third/fourth/fifth/sixth choice.

We utilised a hierarchical regression model to predict the dental pain and gum problem based on snacks taking and alcohol consuming. In Table 8, age and gender were routinely included in models who thought they were not that relevant to toothache. Daily snack consuming could significantly augment the risk of toothache, accounting for 0.217 of variance together with age and gender. Similar to Table 8, age and gender only explained a tiny variance (R2 = 0.015). Alcohol consumption seemed to be a risk factor for the gum problem, accounting for 0.132 of the total variance together with age and gender (Table 9).

Table 8. Hierarchical regression model of snacks taking.

	Estimate	Std. Error	z value	Pr(>|z|)	Resid.Dev	Df	R^2	Pr(>Chi)
Model 1
(Intercept)	−0.96	2.149	−0.447	0.655	44.377	2	0.024	0.578
age	0.041	0.044	0.934	0.35
gender	−0.778	1.306	−0.596	0.551
Model 2
(Intercept)	−1.967	2.508	−0.784	0.433	35.619	1	0.217	0.003
age	0.032	0.05	0.632	0.528
gender	−0.365	1.526	−0.239	0.811
snacks taking	2.293	0.841	2.727	0.006

Estimate=coefficients of variables, Std.Error=standard error of estimate, Z values=statistics for Wald-test, Pr(>|Z|)=Significance of Wald-test, Resid.Dev=Residual deviance, Df=degree of freedom, R2=coefficient of determination, Pr(> Chi)=Significance of the model compared with the previous model. The first model was compared with the NULL model.

Table 9. Hierarchical regression model of alcohol taking.

	Estimate	Std. Error	z value	Pr(>|z|)	Resid.Dev	Df	R^2	Pr(>Chi)
Model 1
(Intercept)	−1.57	2.134	−0.735	0.462	45.02	2	0.015	0.706
age	0.022	0.043	0.503	0.615
gender	0.715	1.298	0.551	0.581
Model 2
(Intercept)	0.378	2.447	0.155	0.877	39.678	1	0.132	0.021
age	−0.026	0.052	−0.505	0.614
gender	0.142	1.332	0.106	0.915
snacks taking	2.016	0.944	2.134	0.033

Estimate = coefficients of variables, Std.Error = standard error of estimate, Z values = statistics for Wald-test, Pr(>|Z|) = Significance of Wald-test, Resid.Dev = Residual deviance, Df = degree of freedom, R2 = coefficient of determination, Pr(> Chi) = Significance of the model compared with the previous model. The first model was compared with the NULL model.

Discussion

The article is the first known study about the Chinese doctors dental care experience in Antarctic stations. The clinic visit frequency recalled by doctors showed dental visits ranked second high, which are coincide with other countries’ records we mentioned in introduction [2–5], proving the high morbidity of dental problems in Chinese Antarctic stations.

Dental pain is one of the two common dental troubles in China Antarctic, which is usually caused by deep caries or pulpits/apical periodontitis. According to the latest China oral health epidemiology survey, dental caries is one of the two major diseases affecting oral health, even the tooth filling ratio increases in last decades, it is still extremely low compared to developed country [7]. Hence, pre-departure dental check is quite crucial. On the one hand, it helps dentist to evaluate one’s oral condition and do caries filling or root canal therapy to prevent the painful experience in the near future. On the other hand, candidates with high risk or lack of sufficient time to treat can be rejected to avoid future medical burden in Antarctic base. For the people who has not got pre-departure screen, dental check after-departure is still useful. It helps the medical staff in Antarctic stations to make individual dental related life behaviour intervention plan [8], e.g. evaluating the erosive potential of snacks, adding alkaline ionised water to high-risk person to reverse the PH lowered by snacks [9], consumption more milk and yoghurt [10]. Unfortunately, in our study, the number of doctors who got pre-departure screen was low and none of them got any dental check after-departure. The neglect of dental care before departure was a result of low dental awareness and behaviour in China. Even though people have started recognising the essential role of oral health in general health in recent years, there is still much room to improve. From two surveys conducted in 2020, only 19% of 5230 older Chinese had dental care in the last 12 months [11]. Overall, 50% of 153 dentists did not do professional dental cleaning in the last 12 months, 7.84% of them never had it before [12]. The situation mentioned above plus the fact that there is no dentist in China Antarctic station is the possible reasons for the zero dental screening after-departure. Last but not least, dental pain is sometimes caused by food impaction, doctors in Antarctic eat much more meat than the standard diet, although most of them had good habits of brushing teeth twice a day, but their brushing method and whether they use dental floss are unknown. As a matter of fact, medical doctors’ awareness and behaviour of oral hygiene health is no better than others, they have the same misunderstanding about dental hygiene as non-medical staffs and their periodontal condition is only slightly better than the latter [12]. This coincides with the situation observed in Chinese medical students [13] and the low answer accuracy of the 8 questions we set to in our study. As the result that eating snacks is the strongest predictor of dental pain, we suggest the more tightly control about snacks consumption and more efforts in dental knowledge education, e.g. stressing the importance of using dental floss/floss water.

Gum problem (periodontal diseases) is the other major dental problem in China Antarctic station and drinking alcohol is the strongest predictor. Even though the study about the relationship between alcohol with periodontitis is not as well as tobacco use, more and more evidence showed alcohol definitely contributes to periodontal disease, after excluding the influence of other life pattern factors [14]. For example, drinking alcohol leads to malabsorption of micronutrients, like Vitamin C, D and E. A small portion of the lack of micronutrient can lead to gingival bleeding [15–17], which are already insufficient in China Antarctic stations because the shortage of fresh vegetables and fruits. Moreover, periodontal lesion caused by alcohol consumption is related with gender and race, Asian male have higher risk than female and Caucasian [18]. According to our results, most of the Antarctic doctors are males, at the same time, half of them are over 45 years old. Considering the fact that the severity of periodontal disease increases with age, the doctors in China Antarctic station are under high risk of being affected by periodontal disease.

Although the medical level in Antarctic increased in the last decades, it is still a lack of specialists and facilities. It is reported that the medical care the US Antarctic base can provide is just similar to a rural place in the US [18]. The situation in China is no better. As we know, there is no dentist in China Antarctic station, according to our result, most dental problems were treated by non-dentist with no essential equipment. We do not know what kind of treatment they did as there is no relevant published report, but it should be limited to medicine prescription (e.g. antibiotics), pericoronitis mouthwash and loose teeth extraction, etc. It is true that patients can get better dental treatment after evacuation to near island where is better equipped, but when the weather condition is not allowed, clinicians in the stations must take actions. In fact, trained clinicians can do some dental treatments, like dental radiographs taking, simple dental extraction and adjust occlusal, and most got successful results [19]. The high outcome satisfaction in our study also prove this. Moreover, a list without medical jargon can help base clinicians to evaluate the situation and communicate with a licenced dentist through telemedicine, which allows real time painful site examination and instruction, making sure the medicine quality [20,21].

In our study, in the uneasiness caused by dental issues, most people complained about the trouble of eating food. At the same time, we noticed emotion and sleeping ranked the second and third high. Psychological symptoms and sleep problem have always been hot study topics in Antarctic, because the polar day/polar night, dry air, geography and social isolation make depression common in there [22,23]. Physical condition can also be affected by the harsh environment, worsening the quality of sleep and leading to a consequence of low physical and cognitive performance [24]. In the 30th Chinese Antarctic Research Expedition, psychological problem visits accounts for 20% of the total visits, among them, most were complaints about sleep disruption [1]. Hence, the uneasiness caused by dental issues worsen life quality and work efficiency in Antarctic.

In conclusion, this study first focus on the doctor group in Chinese Antarctic station and proved the common existence of dental problem and the weakness of dental care. Those findings make it possible to improve dental knowledge education, update the content of dental screen, select the right candidates, prepare a proper diet, equip essential equipment and train clinicians.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/22423982.2023.2179453

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China (81870808) and Shanghai East Hospital research grant (DFRC2022002). Thanks for the participation of the doctors in our study.