|Year : 2020 | Volume
| Issue : 4 | Page : 190-194
Evaluation of the soft-tissue changes in orthodontic patients treated using traditional versus miniscrew-supported anchorage
Tarulatha Revanappa Shyagali, Pushpraj Kesharwani, Sarvraj Kohli, Abhishek Gupta, Tanvee Tiwari, Ruchi Jha
Department of Orthodontics and Dentofacial Orthopedics, Hitkarini Dental College and Hospital, Jabalpur, Madhya Pradesh, India
|Date of Submission||20-Aug-2020|
|Date of Acceptance||19-Nov-2020|
|Date of Web Publication||05-Feb-2021|
Dr. Tarulatha Revanappa Shyagali
Department of Orthodontics and Dentofacial Orthopedics, Hitkarini Dental College and Hospital, Jabalpur, Madhya Pradesh
Background and the Purpose: Soft-tissue paradigm shift clearly indicates the soft-tissue orientated treatment plan in orthodontics. Hence, the current study was undertaken with the aim to analyze the soft-tissue changes in orthodontic patients who have undergone upper and lower first premolar extractions followed by en masse retraction with conventional anchorage and mini-implant-supported anchorage. Materials and Methods: A retrospective study was done on 32 orthodontic patients with a mean age of 17.5 ± 3.2 years. All the patients had undergone upper and lower first premolar extractions followed by fixed orthodontic treatment and a friction type of orthodontic retraction to close the extraction spaces using NiTi coil springs. All the cases belonged to high anchorage category. The sample was divided into groups, namely Group I (20) treated using conventional anchorage system and Group II (12) treated using implant-supported anchorage. The pre- and posttreatment lateral cephalograms were traced for different soft-tissue parameters such as mentolabial angle, nasolabial angle, liner measurements from E line, H line and Burstone's subnasale to pogonion line. Results: Significant changes were seen between the pre- and posttreatment soft-tissue parameter values for both Group I and Group II. However, Group II showed more changes in relation to superior sulcus to E line (SS-E line), Ls-E line, Li-E line, mentolabial angle, Ls-SnPg, Li-SnPg, Li-H line, and H line to nose tip, and the changes were statistically significant (P ≤ 0.05). The comparison of Group I and Group II showed that there existed a significant difference for the parameters such as nasolabial angle, mentolabial angle, and H line to nose tip (P ≤ 0.05). Conclusion: Facial soft-tissue changes were to a greater extent in patients who have undergone implant-supported orthodontic retraction of anterior teeth in comparison to the conventional retraction method.
Keywords: Anchorage, conventional anchorage, extraction, implant-supported anchorage, orthodontics, soft tissue
|How to cite this article:|
Shyagali TR, Kesharwani P, Kohli S, Gupta A, Tiwari T, Jha R. Evaluation of the soft-tissue changes in orthodontic patients treated using traditional versus miniscrew-supported anchorage. SRM J Res Dent Sci 2020;11:190-4
|How to cite this URL:|
Shyagali TR, Kesharwani P, Kohli S, Gupta A, Tiwari T, Jha R. Evaluation of the soft-tissue changes in orthodontic patients treated using traditional versus miniscrew-supported anchorage. SRM J Res Dent Sci [serial online] 2020 [cited 2021 Mar 2];11:190-4. Available from: https://www.srmjrds.in/text.asp?2020/11/4/190/308787
| Introduction|| |
Orthodontic treatment is aimed to achieve functional efficiency, structural balance, and esthetic harmony. Esthetic harmony is brought about not only by the changes in the position of the teeth but also by the changes in the soft-tissue facial contours, and to achieve this, most often premolars are extracted. Literature is explicit with the details about the favorable changes produced in soft tissue due to the orthodontic treatment in terms of change related to the upper and lower lips (3.4 and 3.6 mm, respectively, in relation to E line). Many of the researchers have highlighted positive changes in the nasolabial angle and the facial profile, and it also is noted that the final position of upper and lower incisor positions influences the posttreatment position of the upper and lower lips., Although there is sufficient literature positively correlating the soft-tissue changes and the extraction treatment, very few studies have compared the soft-tissue changes produced by conventional anchorage-supported retraction versus implant-supported retraction. Thus, the current study was undertaken with the objective to compare the soft-tissue changes seen in orthodontic patients treated using the conventional anchorage and implant-supported anchorage system in Group A anchorage cases.
| Materials and Methods|| |
A retrospective study was done on a sample of 32 patients with a mean age of 17.5 ± 3.2 years. The sample was divided into two groups, namely Group 1 (G1), which contained cases treated using conventional method of anchorage preparation, and Group 2 (G2), which contained the cases treated using mini-implants as anchor units. Group 1 had 20 patients and Group 2 had 12 patients. Ethical clearance for the study was obtained by the institutional ethical committee. The sample was selected after thorough evaluation for the inclusion criteria such as all the selected cases who had Class I bimaxillary protrusion malocclusion, requiring extraction of all four first premolars (upper and lower), and who required Group A anchorage preparation. The anterior space closure was done in both the groups using frictional en masse retraction with NiTi closed coil spring with 150 g of force per side. In Group 1 cases, as a part of anchorage preparation, transpalatal arch in the maxilla and lingual arch in the mandible were given. Along with this, anchorage reinforcement was done by bonding the second molars in both the arches. In Group II cases, mini-implants were used to conserve the anchorage.
Pre- and posttreatment lateral cephalograms were retrieved from the departmental record room. All the cephalograms were taking using a standardized protocol using the same cephalometric machine. The retrieved lateral cephs were traced by a single orthodontist. Tracing was done on a lead acetate tracing sheet of 0.003-mm thickness using a 0.5 lead pencil. [Table 1] represents the cephalometric points, lines taken for measuring the soft-tissue changes. The linear and angular measurements are shown in [Figure 1],[Figure 2],[Figure 3],[Figure 4]. The final soft-tissue value was quantified by subtracting pre- and posttreatment cephalometric values.
|Figure 1: Cephalometric landmarks and four of the measurements used in this study (to the Ricketts E line) to evaluate changes in the soft-tissue profile: Ss to E line, Ls to E line, Li to E line, and Si to E line|
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|Figure 2: Angular measurements: (1) Nasolabial angle, (2) labiomental angle|
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|Figure 3: Measurements used from the Burstone Sn-Pg line to evaluate changes in the protrusion of the lips: Ls to Sn-Pg and Li to Sn-Pg|
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|Figure 4: Measurements from the Holdway's H line to evaluate changes in the soft-tissue facial profile: Ss to H line, Li to H line, Si to H line, and H line to nose tip|
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Data collected were entered in Microsoft Excel and were amended to statistical analysis using SPSS software version 10 (SPSS, Chicago, IL, USA). For all the cephalometric parameters, mean and standard deviation were calculated. To know the difference between pre- and posttreatment cephalometric variables, paired t-test was used for both the groups. Moreover, to evaluate the difference between the two groups, unpaired t-test was used. The landmarks of 10 lateral cephs were traced twice within a gap of week. Moreover, the intra-examiner variability was evaluated using a kappa statistic, and the same was accounted for 90% of accuracy.
| Results|| |
The intragroup comparison of the soft-tissue parameters for Group 1, i.e., conventional anchorage group, is shown in [Table 2]. There were many positive changes in the soft-tissue parameters indicating improvement in the soft-tissue profile of the patients. However, none of the parameters showed a statistically significant difference between pre- and posttreatment soft-tissue measurements except for labrale superius to E line (Ls-E line) (P ≤ 0.05).
|Table 2: Differences between pre- and post-cephalometric soft-tissue measurement in Group 1|
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[Table 3] shows the pre- and posttreatment soft-tissue parameter difference in Group 2. A statistically significant difference was noted for the measurements such as superior sulcus to E line (SS-E Line), Ls-E line, Li-E line, mentolabial angle, Ls-SnPg, Li-SnPg, Li-H line, and H line to nose tip (P ≤ 0.05).
|Table 3: Differences between pre- and postcephalometric soft-tissue measurement in Group 2|
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The difference between Group 1 and Group 2 for the soft-tissue measurement changes before and after treatment is shown in [Table 4]. Nasolabial angle, mentolabial angle, and H line to nose tip showed a significant difference between Group 1 and Group 2 (P ≤ 0.05).
|Table 4: Difference between Group 1 and Group 2 for the soft-tissue parameters before and after treatment|
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| Discussion|| |
The study was intended to analyze and compare the soft-tissue treatment changes in orthodontic cases treated using implant-supported retraction mechanism and the conventional retraction mechanism in all four first premolar extraction, Group A anchorage cases.
According to the soft-tissue paradigm shift, soft tissue plays an essential role in deciding the orthodontic treatment plan. It is a well-known fact that the skeletal and dental positions determine the soft-tissue contour of each face, and it is a unique visual tension between comforting harmony and compiling balance.,,,, Although the previous research is explicit on the soft-tissue changes produced due to extraction treatment, none of the studies evaluated the difference in soft-tissue facial changes in premolar extraction cases between absolute anchorage-aided retraction and conventional retraction mechanics.
In the current study, when the comparison was done between the pre- and posttreatment cephalometric soft-tissue parameters in Group 2, it is seen that implant-supported anchorage cases showed favorable changes in soft-tissue parameters. The amount of change was more in relation to the measurements such as nose tip to H line indicating reduction in the convexity of the face. Similarly, parameters related to the upper and lower lips such as superior sulcus to E line, labrale superius to E line, labrale inferius to E line, labrale superius to Sn-Pg, labrale inferius to SnPg, and labrale inferius to H line indicated positive changes in lip position, thus bringing about reduction in the protrusion of the upper and lower lips. Earlier studies of similar nature also showed similar results. In an article by Upadhyay et al., it is reported that the upper and lower lips were retracted by 2.41 mm and 2.73 mm, respectively, and the convexity angle reduced by over 2 degrees in the implant-supported orthodontic cases. These findings were in accordance with the results of the current study.,
When we consider traditional and temporary anchorage devices, we see that the soft-tissue changes produced by implant-supported orthodontic cases were more favorable in comparison to orthodontic cases treated with conventional orthodontic appliances. There was a significant reduction in nasal prominence, nasolabial angle, and mentolabial angle in case of absolute anchorage cases in comparison to the conventional anchorage cases. These results were in accordance with recent systemic review, which states that mini-implants facilitated favorable soft-tissue profile than the conventional anchorage devices.,, Results were also in accordance with the previous study done by Xu and Xie, who reported that a significantly higher nasolabial angle was achieved in the mini-implant group. The reason behind this increased efficiency in case of implant-supported orthodontics is the nature of correction achieved. They are known to produce skeletal alteration, thus bringing about the advantageous soft-tissue changes. Reports of similar nature were cited in the literature.,,,,
The study compared only the pre- and posttreatment changes pertaining to the said groups, however, the question remains unanswered whether the changes so brought are for long term or will there be any relapse in the changes brought forth, so the study carries the scope to explore the possibilities of relapse in the cases treated using implant-supported anchorage and conventional anchorage over a period of time. Further, the unequal sample size in the current study might have caused the variation in the reported results, so future studies with increased sample size can bring about the concrete evidences in relation to soft-tissue changes pertaining to implant-supported anchorage cases. The research in this area is the need of the hour.
| Conclusion|| |
The soft-tissue response was variable for both the implant-supported and traditional anchorage treated cases. Nasal tip drop, mentolabial angle, and nasolabial angle had greater changes in implant-supported anchorage. Not only is the implant supported retraction good in terms of managing the anchorage, but it also brings about the more desirable soft tissue changes in comparison to conventional retraction mechanics.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2], [Table 3], [Table 4]