1. Introduction and Literature Review

Orthodontic treatment is a common procedure for patients of all ages, with the aim of achieving proper alignment of the teeth and jaws [1]. Malocclusion not only gives rise to compromised dentofacial esthetics and functional issues but also exerts a psychological impact, significantly influencing the overall quality of life for affected patients [2].

To attain better dental alignment and dentofacial esthetics, many malocclusions demand extractions of teeth particularly premolars [3–6]. Although dental extractions are considered as minor oral surgical procedure, but that also leads to the formation of wound. Patients may suffer symptoms such as pain and swelling and may have disturbed daily routine for few days right after tooth removal [4].

It is a known fact that the placement of a bracket on a tooth and engaging with orthodontic wire exerts force on that tooth that leads to a slight widening of periodontal space due to a localized inflammatory response (regional acceleratory phenomena or RAP) [7]. As a biological response to orthodontic force application, slight increase in tooth mobility is also observed clinically [1, 7]. Mobility of the tooth not only eases the extraction of that particular tooth for the dentist but that also may reduce the postoperative discomfort [1, 7].

It is very important to reduce the factors that contribute to postoperative pain and complications after orthodontic extractions for the improvement in overall patient’s orthodontic treatment experience [8]. This study aims to compare postextraction pain levels in orthodontic patients with and without prior engagement of the tooth in the archwire to assess the effects of early tooth engagement on pain perception.

It was hypothesized that engagement of the tooth with orthodontic archwire is effective in reducing postextraction pain of that tooth.

2. Materials and Methods

This study was a randomized clinical trial with an allocation ratio of 1:1. The research was conducted among Pakistani subjects who were undergoing orthodontic treatment with fixed orthodontic appliance at the Department of Orthodontics at the College of Dentistry. All procedures were performed in compliance with relevant laws and institutional guidelines and have been approved by the appropriate ethical approval committee on August 30th, 2019, and the reference number was BDC/R/101/19. Informed written consent and assent (parent/guardian consent was obtained for participants under the age of 16) were obtained for this research.

Inclusion criteria were as follows: 12- to 18-year-old orthodontic patients needing bilaterally symmetrical extractions of first premolars as a part of orthodontic treatment. Angles Class I with moderate to severe crowding cases, bimaxillary proclination, and Angles Class II Division 1 were included. All the subjects were aware of the study and were willing to participate; informed consent and assent were obtained. Patients with poor oral hygiene, carious or missing premolars, multiple missing teeth, systemic diseases, periodontitis, or patients on analgesics (NSAIDs and corticosteroids) were excluded from the study.

Using these parameters, the software indicated that a total of 44 patients would provide adequate statistical power to detect the specified difference in pain levels between groups. The primary endpoint was pain assessment, measured using the numerical rating scale (NRS). The NRS is a validated tool for pain measurement and has been widely used in dental and oral surgery settings due to its simplicity and reliability [9]. Pain levels were recorded immediately after the extractions at 24 h, and at 7 days posttreatment. This endpoint was chosen to assess the immediate patient-reported outcomes following the standardized surgical procedure.

Based on the timing of the extractions, patients were divided into two groups. Group A comprised patients who needed extractions for the alignment of dentition, with extractions advised before the alignment stage of treatment (Class I crowding cases). Group B consisted of patients who did not need extractions for the alignment but for the retraction of teeth, where extractions were advised after the alignment stage was completed (Class II Division 1 and Class I bimaxillary proclination cases).

Patients belonging to Group A were sent to the surgery department for extractions of both premolars as advised by the orthodontist. Extractions were performed by one surgeon who followed a standardized surgical technique, with two sessions separated by at least 1 week. Surgery was conducted under infiltrative local anesthesia using a maximum of 1.5 cartridges of 1.8 mL of mepivacaine HCl 2% plus epinephrine 1:100,000 (Nova DFL, Jacarepaguá-RJ, Brazil).

However, patients belonging to Group B went through banding and bonding procedures. Preadjusted edgewise McLaughlin–Bennett–Trevisi (MBT) prescription brackets (Ortho Organizers, Carlsbad, California, USA) of 0.022-in slot were bonded using a light cure bonding kit, i.e., Transbond XT Light Cure Adhesive (3M Unitek, Monrovia, California, USA), and curing was done with a light-emitting diode (Dentsply International, York, Pennsylvania, USA). Alignment and leveling were initiated with 0.014-in heat-activated nickel–titanium (NiTi) wire (3M Unitek, Minnesota, USA), and later sequences of wires were 0.016-in NiTi, 0.017 × 0.025-in NiTi, and 19 × 25-in NiTi. After completion of the first stage of alignment and leveling, a final working wire of 0.019 × 0.025 SS was placed. After 21 days, patients were sent to the surgical department for extractions of required premolars.

For pain assessment, the NRS was used. An 11-point NRS was used to formulate a questionnaire to record the pain intensity associated with extraction, where 0 indicated “no pain” and 10 indicated “an intolerable pain” [9]. Questionnaires were given to all the patients to fill out at home and bring back on their next visit.

Patients were told to record their pain intensity at 2, 4, 8, 12, and then 24 h after the procedure and then after every 24 h for the next 7 days. Reminders to fill the questionnaire were also given to the patients daily by phone calls. Patients were not discouraged to take analgesics as rescue medicine “ibuprofen 600 mg” (Brand: Brufen, Abbott Laboratories, Karachi, Pakistan) to relieve pain if required due to its efficacy [10]. However, they were advised to note it whenever taken.

SPSS Version 20.0 (IBM, Armonk, New York, USA) was used to record and analyze the data, which is a widely used statistical software for dental research [11]. The normality of the data was assessed using the Shapiro–Wilk test and Kolmogorov–Smirnov test to determine whether the data followed a Gaussian distribution [12]. Since the data did not meet the criteria for normal distribution, the Mann–Whitney U test, a nonparametric test suitable for ordinal data, was applied to compare pain levels between groups [12]. A p value less than 0.05 was considered statistically significant. Although pain levels were recorded at multiple time points, no formal statistical analysis was performed to assess changes across different time points. This could be a limitation of the study, as the trend of pain progression over time was not quantitatively analyzed.

3. Results

In this study, 44 patients were divided into two groups, Group A (extraction done before the alignment of the teeth) and Group B (extraction done after the alignment of the teeth). One male and female patients were dropped from Group A as they used NSAIDs to relieve the postextraction pain. After dropouts, the total number of patients in Group A were 20 (10 females, 10 males), and in Group B, there were 22 (11 males, 11 females). The mean age of the patients in Group A was 15.05 ± 2.51 years, while in Group B, it was 14.68 ± 2.16 years.

A nonparametric Mann–Whitney U test was used to compare the level of pain perception between males and females. The results showed that there was a significant difference (p < 0.05) in the pain perception between males and females in Group A at 2, 4, 8, 12, and 24 h, 2nd and 3rd day, after extraction. Females had greater pain as compared to males, while there was no gender dimorphism in Group B (Figure 1).

The subjects from Group A reported more pain after extraction when compared with Group B. The Mann–Whitney U test showed a significant difference in the pain experienced by patients among Groups A and B, at 2, 4, 8, and 12 h after extractions (Table 1). Table 2 highlights the differences in procedure sequences between Groups A and B, specifically focusing on the timing of the bilateral premolar extraction in the maxilla and the prior engagement of the tooth, emphasizing variations in their treatment approaches.

4. Discussion

Orthodontic treatment involves the use of various fixed and removable appliances to correct malalignment of the teeth and improve oral functions and dentofacial aesthetics [13]. In many cases, orthodontists prefer extraction of teeth (mostly premolars) to create sufficient space for the remaining teeth to be aligned and occlude properly [14]. However, any dental treatment procedure increases patient’s anxiety especially extraction of teeth, which provokes the most stress [15]. Additionally, extractions may be associated with complications, postoperative pain, and discomfort for orthodontic patients [16].

One technique that may positively influence postextraction pain in orthodontic patients is the engagement of the destined tooth with orthodontic appliances prior to extraction. When a tooth is subjected to orthodontic forces, it initiates an inflammatory reaction in the periodontal ligament which causes an increase in tooth mobility of the tooth that has been engaged with orthodontic appliances [17, 18]. As a result, the extraction of that tooth becomes less traumatic and easier for the surgeon to extract and also causes less postoperative pain [7].

In this study, all those subjects, who needed extractions of maxillary premolars for the treatment of their malocclusions, were recruited. However, they were divided into two groups based on the timings of their extraction within the sequence of the treatment. This is a well-known fact that teeth move much faster in the recent extraction socket compared to the healed socket because of alveolar bone atrophy and mature lamellar bone formation in the healed sockets, which may decelerate the tooth movement [19]. Furthermore, there is a greater risk of gingival invagination, if the tooth movement is delayed even by 12 weeks after the extraction [20].

Therefore, extraction should ideally be carried out when the adjacent tooth is ready to move in the fresh extraction socket. Moreover, when there is a greater amount of malocclusion and crowding, even a heat-activated NiTi wire of the smallest diameter is severely deflected during the alignment stage, which may exert heavier and undesirable force with side effects such as root resorption and proclination of incisors (round tripping) [21, 22].

Therefore, in this study, Group A, which comprised patients with Angle’s Class I crowding, underwent premolar extraction first before the alignment stage, so that the anterior teeth had fresh extraction space for aligning movements. However, Group B included patients with well-aligned teeth who did not need premolar extraction for alignment but for the retraction of anterior teeth at later stage (on a heavy working wire i.e. 19 × 25 SS). Consequently, premolars destined for extraction were subjected to the orthodontic forces before extractions in Group B, unlike Group A.

Rai also carried out similar research in 2016. The study design in his investigation was a split-mouth design, and just one premolar destined to extraction on the control side was excluded from bonding, while the rest of the teeth were bonded and subjected to orthodontic forces. This may introduce bias in the research because orthodontic forces on the adjacent teeth may also cause bending of the alveolar bone and trauma at a microscopic level initiating RAP. This reaction (RAP) always occurs regionally around the injury, subsequently causing osteopenia and reducing bone density in the whole region, which may ease the extraction and reduce the postsurgical pain of the tooth that was never subjected to orthodontic force [23, 24]. However, in this study, there were parallel groups, which introduce the possibility of variability in individual pain thresholds among participants. This variation may have influenced the results, as pain perception is inherently subjective and differs from one individual to another [25, 26].

Premolars in Group A were extracted before the bonding and banding procedure; therefore, none of the teeth in Group A were subjected to orthodontic force.

In this study, maximum pain was reported among females in Group A, which was significantly greater than males belonging to the same group at 2, 4, 8, 12, and 24 h, as well as 2nd and 3rd day, after extraction. Although the intensity of pain at any time of the day was less than that in other studies [27, 28].

It has been reported that females are generally more anxious about pain when compared to males [29, 30]. However, there was no gender dimorphism in Group B. The reason could be the level of intensity of pain in Group B, which was of significantly low intensity perceived by both the genders.

There was significantly lesser pain at 2, 4, 8, and 12 h after extraction in Group B as compared to Group A. This result is in agreement with Rai, who also reported lesser postextraction pain when the tooth (premolar) was subjected to orthodontic force prior to the extraction.

In this study, there was no significant difference in the pain levels between both the groups at 24, 48, 72, and 96 h after extractions. The reason could be the significant reduction in the levels of pain after 12 h in Group A as well. This finding was slightly inconsistent with the previous research which observed rapid decline in the pain at 4 h after extraction [28]; however, Chaushu reported a decline in the levels of pain and consumption of analgesics significantly on the second day after extraction of healthy premolars before the start of the orthodontic treatment [27].

5. Conclusion

Early engagement of teeth with orthodontic appliances may potentially reduce postextraction pain in patients. Early engagement of teeth with orthodontic appliances could potentially reduce postextraction pain in patients up to 12 h post-op. Orthodontists should consider a range of factors when assessing the risks and benefits of tooth extraction for each individual patient and work to provide appropriate pain management to minimize any postoperative discomfort, so that the patient could have an overall pleasant orthodontic treatment experience.

Conflicts of Interest

The authors declare no conflicts of interest.

Author Contributions

All authors contributed significantly to this research and agreed to be accountable for the content and conclusions of the article.

Conceptualization, methodology, and project administration: Meenaz Karim, Irfan Qamruddin, and Adam Husein.

Investigation and data collection: Danish Ali and Sarvaich Kumar.

Reviewing, editing, and refining the manuscript: Meenaz Karim, Liszen Tang, and Mohammad Khursheed Alam.

All authors have reviewed and approved the final version of the manuscript.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.