The effects of orthodontic treatment type, depression, and treatment need on perceived pain intensity

INTRODUCTION

The aim of modern orthodontics is to offer patients treatment with as little pain as possible that results in a more comfortable life. However, orthodontic treatment inevitably has various side effects, such as pain.^[1,2] Pain associated with orthodontic treatment is caused by inflammatory mediators such as cytokines and prostaglandins and occurs as a result of pressure put on the periodontal ligament and bone.^[1] During orthodontic treatment, pain signals are sensed by nociceptors in the periodontal regions and sent to the trigeminal ganglia, trigeminal nucleus, ventroposterior nucleus, and then the sensory cortex.^[3] Orthodontic pain typically begins 4 h after the application of orthodontic force, is at its highest intensity around 24 h, gradually decreases after 5–7 days, and returns to baseline after 14 days.^[3,4]

Orthodontic applications such as separator placement, fixed orthodontic appliances, and debonding procedures can cause discomfort and pain.^[5] Pain is a subjective response and is different for each individual.^[6] However, as a procedure becomes more difficult, it is possible that the patient feels more pain. Many patients stated that pain started 24 h after the placement of fixed orthodontic appliances and caused more pain than removable appliances.^[7] Studies have evaluated the perceived pain intensity (PPI) after the attachment of different types of brackets. Miles et al.^[8] revealed that self-ligating brackets were more comfortable than conventional twin brackets.

Various indices are used to evaluate malocclusion. The Index of Orthodontic Treatment Need (IOTN) is a scoring system that was developed by Brook and Shaw.^[9] The malocclusion severity can have an effect on the occurrence of pain. In one study, a significant correlation was reported between the orthodontic treatment need and oral pain.^[10]

Depression is a complex disorder that manifests in different ways.^[11] People suffering from depression tend to feel a greater sense of hopelessness or anger. Depression is characterized by the inability to cope with challenging life events.^[12] Individuals with dentofacial deformities might be more prone to depression and experience work and social adjustment difficulties.^[13,14] One study examined how depression affected the quality of life of patients with dentofacial deformity.^[14] Another study examined biomarker levels in saliva in patients undergoing orthognathic surgery, and these parameters were associated with quality of life and psychological symptoms like depression.^[15] To the best of our knowledge, no study has explored the relationship between depression and PPI during orthodontic treatment. The aim of this study is to determine the correlation of pain with treatment type, orthodontic treatment need, and depression.

MATERIAL AND METHODS

Study design, participants, and sample size

The Sivas Cumhuriyet University Non-Interventional Clinical Trials Ethics Committee approved the study and verbal and written consent was obtained individually from patients and their legal guardians (decision no: 2021-05/14).

The sample size was calculated assuming alpha of 0.05, beta of 0.20, and 80% power of the study, with a minimal relevant difference in the groups and variability of the outcome.^[16] The minimum sample size was calculated as 120. This prospective study included 190 patients chosen at random from 300 applicants who met the inclusion criteria, then admitted to the orthodontic clinic between June and September 2021. Patients who did not receive orthodontic treatment before, had no missing teeth, no mucosal or periodontal disease, and had good oral hygiene were included in the study. Patients with any mental or physical illness were excluded from the study. Patients who used analgesics on the day of the pain assessment were also excluded from the study (n = 18).

The patients were evaluated in three groups as fixed orthodontic treatment (group 1), twin block (group 2), and rapid maxillary expansion and reverse headgear (RME/RH) (group 3). Patients in the fixed orthodontic treatment group had <7 mm crowding and non-extraction treatment was planned for them. The MBT 0.022” bracket system (Mini Master American Orthodontics, USA) was used for the fixed orthodontic treatment group. A 0.013” round nickel titanium arch wire (Tanzo Cu-Niti, American Orthodontics, USA) was used as the initial arch wire [Figure 1]. Additional appliances such as molar band, transpalatal arch, headgear, and miniscrew that could be an unpredictable pain source were excluded from the study. In the following sessions, 0.016,” and 0.014” × 0.025” nickel titanium wires were inserted, respectively. The arch wires were replaced every 2 months. Descriptive data of the treatment groups are given in [Table 1].

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Figure 1:

Fixed orthodontic appliance.

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Patients used twin blocks for at least 16 h/day and were examined at 4-week intervals by the same clinician (T.Ö.K.). Labial bows and Adams clasps were used on the lower part of the twin blocks. Slow expansion screws were installed in the upper portion of the appliances by keeping relative maxillary narrowness [Figure 2]. The expansion screw was used by the patients twice a week.

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Figure 2:

Twin block appliance used in the study.

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Table 1: Descriptive data of the treatment groups.

Treatment groups	Gender		Total
	Female	Male
FOT	29	35	64
Twin block	28	37	65
RME/RH	23	20	43

FOT: Fixed orthodontic treatment, RME/RH: Rapid maxillary expansion and reverse headgear

RME/RH developed by Baccetti et al.,^[17] was used. To suspend the elastics between the canine and lateral teeth, two hooks were attached to the fully bonded RME appliance, which included a HYRAX screw (Leone Orthodontics and Implantology, Firenze, Italy; [Figure 3]). The screw was rotated two turns per day until the occlusal aspect of the maxillary first molar’s lingual cusp came into occlusion with the facial cusp of the mandibular first molars. Following the completion of the expansion, the use of RH was started.^[18] The procedure started with unilateral 8oz force and was increased to 14oz after the 2^nd month. A Petit face mask was used to achieve maxillary protraction.

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Figure 3:

The full coverage rapid maxillary expansion appliance used in the study.

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RESULTS

Eighty female and 92 male patients with a mean age of 14.32 ± 1.57 were included in the present study. [Table 2] shows DHC and mean pain over time. [Table 3] shows pain changes in terms of gender. In the 2^nd week, the VAS score of male patients was significantly higher than the score of their female counterparts (P = 0.005). Pain changes between the genders within the groups are presented in [Table 4]. There was a significant difference in 2^nd week pain levels between boys and girls, in the twin block (P = 0.008) and RME/RH (P = 0.011) groups. For the RME/RH group, there was a significant difference in pain levels in the 1^st month, between boys and girls (P = 0.016).

[Table 5] shows pain changes in terms of treatment groups. The changes observed in the 1^st (P = 0.036), 2^nd (P = 0.012), ^3rd (P = 0.000), and 6^th (P = 0.006) months were statistically significant. In terms of pain change over time, there was no significant difference between treatment groups (P>0.05; repeated measures two-way analysis of variance; [Figure 4]).

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Figure 4:

Pain changes in treatment groups over time.

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[Table 6] shows data on the descriptive and internal consistency of CDS. The Cronbach’s alpha value, which indicates the internal consistency of the CDS, was 0.754.

[Table 7] shows the correlation values between DHC, depression, and pain changes. The correlation between DHC and VAS in the 2^nd (r = 0.182; P = 0.000), 3^rd (r = 0.161; P = 0.03), and 6^th (r = 0.189; P = 0.000) months was statistically significant. There was no statistically significant correlation between depression, the need for orthodontic treatment, or PPI.

DISCUSSION

Pain is a complex feeling that differs from one individual to another, therefore making it difficult to assess objectively. More than one instrument is required to assess pain intensity.^[22] When an appropriate device is given, children as young as 3 years and older have been shown to understand the concept of pain and the varying degrees of severity.^[23] VAS was used to determine pain in this study, and as with Almasoud^[24] and Kaur et al.,^[25] overall, we reported PPI was low–to-moderate in all three treatment groups. The pain level decreased over time, reaching its lowest point in the 6^th month. This finding is consistent with studies by Wiedel and Bondemark.^[7]

The studies have revealed that gender is not a significant factor in reporting pain.^[26,27] The present study’s data show that boys had significantly higher rates of pain than girls in ^2nd week. According to Campos et al.,^[28] the level of pain differed significantly by gender. Contrary to this study, women have been shown to be more prone to pain.^[29]

In the present study, pain levels were measured after the activation of the orthodontic appliances. Long et al.^[2] examined pain levels after initial arch wire engagement. Similarly, Campos et al.^[28] assessed pain levels following orthodontic appliance activation. Pain levels in the treatment groups decreased over time in the present study. The highest pain intensity in orthodontic treatments was reported 24 h after orthodontic activation.^[30] The fact that the measurements were taken after activation could explain the decrease in pain levels.

The type of appliance used can have an impact on the PPI. According to a previous review, fixed appliances cause more pain, because they apply constant force, whereas removable appliances cause less pain because the force application is more intermittent.^[31] In the present study, there was no significant difference between fixed orthodontic treatment and the twin block in terms of pain levels, but pain levels of the twin block group were lower in the beginning and increased from the 2^nd month compared to the fixed treatment group. One study found minor changes in PPI between fixed orthodontic treatment and removable treatment options.^[7] This finding was refuted by Kavaliauskiene et al.,^[32] who claimed that fixed and functional appliances produced more PPI than removable appliances. The RME/RH group experienced the most pain in this current study. It has been reported that the majority of RME patients experience pain, particularly during the early stages of expansion.^[26] Here, we observed that the highest level of pain was detected during the 1^st week of expansion and gradually decreased over time.

Individuals with a high need for orthodontic treatment have a lower quality of life.^[33] Here, we found that as the need for treatment increased, so did the PPI. Keshavarz et al.^[34] found no significant difference between the severity of pain and the degree of crowding during orthodontic treatment. Marković et al.^[35] reported that despite the use of different orthodontic arch wires, there was no significant relationship between the severity of pain and the severity of crowding after initiation of orthodontic treatment, but there was a clinical correlation between these two variables. Age, racial differences, treatment protocols, and evaluation criteria may have affected the results of the studies.

The amount of pain reported by patients is largely determined by the individual’s psychological well-being as well as the magnitude of the applied force.^[36] Orthodontic pain is reported to have an effect on the psychosocial and behavioral aspects of a patients’ life.^[28] Depression is common in the general population. Depressed adolescents, unlike adults, are often agitated, very active, and prone to risk-taking, while constantly devaluing themselves.^[37] In one study, people who were uncooperative during orthodontic treatment were more depressed.^[38] De Ávila et al.^[14] concluded that in patients with dentofacial deformity, depression significantly interferes with vitality, social aspects of the individual, and mental health. They also reported that individuals with depression and dentofacial deformity had a poorer quality of life.^[14] Beck et al.^[39] discovered that those with high dental anxiety and pain catastrophizing, which is considered a maladaptive coping strategy that intensifies the experience of pain and depression, had greater pain levels during orthodontic treatment. In one study, a low level of positive correlation was found between pain and depression, and it was concluded that dental anxiety was more effective on pain than depression.^[40] In contrast, the present study found no correlation between depression and PPI. While some studies have shown that depressed patients have a lower pain threshold,^[41,42] others have found the opposite.^[43,44] These mixed findings suggest the need for more detailed evaluations.

CONCLUSION

RME/RH treatment is more painful than other types of orthodontic treatment. Boys reported significantly more pain than girls in 2^nd week. In the 2^nd, 3^rd, and the 6^th months, there was a positive and significant relationship between DHC and PPI. Comprehensive studies are needed to further determine the relationship between depression and PPI.