Dental anxiety is one of the major worries in repetitive dental practice, and it should be handled and managed in order to ensure appropriate oral healthcare [48,49]. For this reason, the current study was carried out to assess dental anxiety and fear among undergraduate students at UST University in Yemen by utilizing DAS and DFS questionnaires.
Many questionnaires and scales have been established to investigate dental anxiety and fear [27,28,30,32,35,37]. The DAS is perhaps the most commonly used; it is a four-item, multiple-choice questionnaire that assesses the degree of anxiety. It is very reliable and has established predictive validity [50,51]. It is extensively applied for clinical purposes and surveys; however, it has been criticized for not including all aspects of dental fear and because its response alternatives differ between items . The MDAS contains one more question about dental injection anxiety, with the other 4 questions being identical to those in the DAS. The question on dental injection perhaps also replicates the general phobia of syringes among participants and thus incorporates that phobia with the total score. As the distribution of any kind of phobia is as of yet unidentified in the young Yemeni population, the DAS was considered to be the most appropriate measurement for the current study population of students. This scale has been used in other recent studies . In addition, adaptation tables can be utilized to compare the present results with the MDAS findings of other studies . Moreover, the DFS questionnaire is comprehensive, comprising 26 questions; therefore, we used it in this study. The tool can be routinely used by oral health care professionals on their patients to measure dental fear. The DFS evaluates more stimuli and its increased comprehensiveness may be favourable for research purposes [55,56]. In addition, the DFS is more likely to include items describing specific stimuli that fearful patients may find anxiety-provoking.
The high anxiety levels among students from Yemen might result from a lack of dental health education, which, in turn, might result in poor attitudes and compliance, or such anxiety could be connected to personality features, fear of pain, dentally anxious family members or peers, or earlier traumatic dental experiences, especially in childhood. Highly anxious patients are more difficult to deal with, thus leading to an increase in dental profession-related stress levels [41, 57].
The prevalence of dental anxiety in this study was 55.1%, which suggests that regardless of the technological advancements of modern dentistry, dental anxiety accompanying dental treatment was still widespread in the studied population. These findings are consistent with the results found by Saatchi et al. , who reported that dental anxiety was 58.8%. These figures are still higher than those reported in another study in which dental anxiety was 23% . This difference could be partly due to differences in methods or to geographical variations. The incidence of dental fear in the current study was 96.8%. These findings are consistent with other researchers’ findings, which found the prevalence of dental fear to be 96% .
In the general population and among health care professionals, dental anxiety and fear are considered major, if not commonly encountered, problems. In the current study, we reported relationships between dental anxiety and fear. Many previous researchers have found that earlier unpleasant dental experiences may be the most commonly stated single reason for dental anxiety [59–64]. On the other hand, Davey  suggested that a history of positive or neutral dental experiences may act as a buffer against the development of traumatic associations or experiences. Van Wijk and Hoogstraten  proposed that individuals are likely to exaggerate their fear of dental pain if they have not experienced the specific pain itself. When patients have experienced to the feared pain, they find it less painful than they expected, and this might reduce their anxiety levels.
This study noticed that dental students have less dental anxiety and fear than humanities and social science students. These results are consistent with other reports that dental anxiety in dental students is less prevalent . A lack of dental education might be an unfortunate factor in anxiety, and thus, dental anxiety may be related to the field of study, as dental students have more dental knowledge, education, awareness, professional development and acquired clinical experience dental than students in other fields do .
In this study, the dental students who were in their last two years of study (clinical class) had lower dental anxiety than those in their first three years (preclinical class). These findings support those of other investigators who argued that dental fear and anxiety are reduced as years of study increase [12, 25, 28]. During university study, dental students begin practical training with artificial teeth models in their third year. Much later in the same year, students move on doing simple treatment procedures on each other, such as administering anaesthesia. This gives them a gradual level of experience in dental treatment that the other student group obviously lacks. Some studies have found that behavioural techniques that contain exposure for patients are most frequently applied to treat patients with phobias. The treatment decreases the fear of the frightening stimuli by removing avoidance behaviours, and thereby, recurrent exposure helps patience experience reduced anxiety in situations they formerly feared [68,69]. This is significant because avoidance behaviours can be seen as a critical mechanism in maintaining phobias. As in exposure techniques, dental students are gradually be exposed to a hierarchy of potentially anxiety-provoking situations. This might begin with reading dental anatomy and training with dolls and end with performing dental examinations and administering anaesthesia on other students (including being exposed to such events). Other reasons for dental anxiety differences might be that dental students from the preclinical class are more susceptible to stress and anxiety because they are dealing with unfamiliar study situations. Students who are just beginning their studies can experience extra stress because of the transitioning challenge from high school to university. Earlier reports have shown that students in earlier years of study have been found to have higher stress responses than those in later years [41, 70]. Decreasing stress because of settling into university life could be a nonspecific reason that anxiety is reduced.
Many investigators have stated that dental anxiety is more common in women [6, 33, 71–73]. Our study results agree with recent studies showing that women exhibit more dental anxiety than men. Both faculties’ female students displayed greater DAS scores than did male students. These results are in agreement with those of previous reports [27, 30–37]. This may be attributed to the fact that women are less emotionally stable than men [74–76]. It has been suggested that women are more vulnerable to observed danger or threats and that they might express their fears more openly, but men may be more emotionally tolerant and may hide their anxieties . Nevertheless, some studies have found no differences regarding sex [27,34,35] and have mentioned that a possible explanation is cultural characteristics . The reason behind this difference may be that women are more capable of expressing their feelings of fear. In addition, physiological conditions such as panic, stress, depression, social phobia, and fear are more common in women, and dental anxiety may be related to such emotions .
Noticeably, the stimuli for fear vary because every individual has unique fear responses because of different stimuli during dental treatments. Local anaesthesia injection was found to be the most fearful situation among all dental events, followed by the drilling of teeth. This study revealed that seeing the anaesthetic needle and feeling the needle injection and drilling were the most common fears out of all dental procedures. In the case of local anaesthesia injections, the incidence of extreme anxiety among students was 56.6%. For the drilling of teeth, however, 49.1% of all students were extremely anxious. Normally, the phobia of needles is related to age, but it should be considered a separate phenomenon  that is not particular to dental anxiety and is associated with other painful treatments . The results of our study are in agreement with previous studies that have reported these two procedures as the most feared by all respondents worldwide [80–82]. The third and fourth most-feared items in the present study were pain during dental treatment and having instruments in the mouth, respectively.
Undesirable and unsupportive clinician behaviour has been found to be a substantial issue in anxiety development , and more empathic behaviour has been related to reduced anxiety . Students from dental colleges with dental anxiety are acquainted with the undesirable concerns of unfortunate clinician behaviour, which might motivate them to work towards a more patient-centred style [85–87].
There are some limitations of this study that should be considered. The present work is a cross-sectional study; therefore, no causal relationships in the relationship between dental anxiety or fear and the factors investigated or trends in the frequency of dental anxiety and fear over time can be determined. However, the present findings could show that educational programme structure can be an important aspect in reducing fear and anxiety. Moreover, the study used a self-administered questionnaire study, and thus, the participants might have hidden their true feelings and underreported their dental anxiety and fear or the unpleasantness they associate with seeking and receiving dental care. Furthermore, the current study may be limited by the fact that only university students from the UST contributed in this study, which makes it challenging to generalize our findings to the young Yemeni population. Therefore, further research on the subject is needed. Although Arabic versions of the DAS and DFS questionnaires were tested several times by language experts for clarity in the translated version and then verified for face validity by the college members, a more thorough testing of the instrument’s reliability and validity is necessary. In addition, oral diseases are significant public health worries, and their occurrence is increased due to dental anxiety, thus affecting quality of life. These findings highlight the necessity for population-based studies to identify the associations of dental and fear anxiety for better dental health in Yemen. Furthermore, it is suggested that the university syllabus be adjusted to comprise sufficient dental education for various fields. Additionally, the implication of oral health education at the school level can be very supportive in this issue.