Non-extraction Orthodontic Treatment Research Articles

The Impact of Non-Extraction Orthodontic Treatment on the Oral-Health-Related Quality of Life between a Modified Aligner Appliance with Ni-Ti Springs and the Traditional Fixed Appliances: A Randomized Controlled Clinical Trial.

Background and Objectives: To compare the oral-health-related quality of life (OHRQoL) outcomes between patients treated with modified Ni-Ti spring-based alignment appliances or conventional fixed appliances using the Oral Health Impact Profile 14 (OHIP-14), as well as the levels of satisfaction with the appliance appearance, treatment progress, and outcomes. Materials and Methods: Thirty-six patients (11 males, 25 females) were randomly divided into two groups: either the modified aligner appliance with Ni-Ti springs group (MAA) or the traditional fixed appliances group (FA). The allocation ratio was 1:1, and the randomization process was carried out by an independent investigator not involved in this study. Mild crowding cases were included in this study. The OHRQoL of patients was evaluated using the short-form Oral Health Impact Profile (OHIP-14) at five time points: before the treatment commencement (T0); 2 weeks (T1), 1 month (T2), and 2 months (T3) after the treatment initiation; and post-treatment (T4). The visual analog scale (VAS) was used to evaluate the patient satisfaction. Blinding was performed only during the outcomes assessment. Results: This randomized controlled trial had no dropouts, and the demographic characteristics of the groups were comparable. The MAA group experienced significantly greater functional limitations compared with the FA group at all three evaluation time points (T1, T2, and T3), as evidenced by the statistically significant p-values (p = 0.004, p = 0.001, and p < 0.001, respectively). The psychological disability in the MAA group was significantly lower than in the FA group at both T2 (p = 0.005) and T3 (p = 0.003). The patient satisfaction with the appliance appearance was significantly higher in the MAA group than in the FA group (p = 0.002). Conclusions: The OHRQoL improved in both the modified aligner appliance with Ni-Ti springs and fixed appliance groups after the treatment. Moreover, the functional limitations during the treatment were less severe in the FA group, while the psychological disability was lower, and the patient satisfaction with the appliance appearance was higher in the MAA group.

A clinical evaluation of low-level laser therapy for pain reduction in early treatment stages: A pilot study

Objectives: This study aimed to clinically evaluate the efficacy of low-level laser therapy (LLLT) in reducing pain associated with orthodontic movement during the early stages of treatment. Material and Methods: A randomized controlled trial was conducted with 20 participants undergoing non-extraction orthodontic treatment. The laser group (LG, n = 10) received LLLT (808 nm, 100 mW) immediately after appliance installation, while the control group (CG, n = 10) received no pain control intervention. Pain levels were assessed using a visual analog scale (VAS) at 6, 24, 48, and 72 h till 7 days with an interval of 24 h. Statistical analyses included Chi-square tests and Mann–Whitney tests. Results: The LG consistently demonstrated significantly lower pain scores during chewing and at rest compared to the CG. After 6 h post-treatment, the median pain score on chewing in the LG was markedly lower than the CG (P &lt; 0.001), a trend observed at each subsequent interval till 7 days. The comparison of spontaneous pain also favored the LG at various time points. Lower median VAS scores for pain on chewing among the LG and CG were zero and two, respectively, with a significant difference. The maximum median VAS scores for pain on chewing among the LG and CG were five and seven, respectively, with a significant difference. Conclusion: This study provides robust evidence supporting the effectiveness of LLLT in reducing orthodontic pain during the early stages of treatment. The sustained and significant reduction in pain scores, coupled with rigorous statistical analyses, emphasizes the potential of LLLT as a valuable adjunctive therapy in orthodontic practice.

Third Molar Comparison in Class I and II Extraction and Non-extraction Orthodontic Treatment: A Retrospective Longitudinal Study.

This study compared third molar angulation and eruption status in Class I and II malocclusions after orthodontic treatment with and without first premolar extractions. The sample comprised 93 patients divided into four groups: Group 1, Class I malocclusion treated with first premolar extractions; Group 2, Class I malocclusion treated without extractions; Group 3, Class II malocclusion treated with first premolar extractions; and Group 4, Class II malocclusion treated without extractions. Panoramic radiographs were used to evaluate the third molar mesiodistal angulations at T1 (pretreatment), T2 (posttreatment), and T3 (long-term posttreatment). Third molar eruption status was assessed in dental casts. Intergroup angulations and eruption status comparisons were performed using one-way analysis of variance (ANOVA), followed by Tukey's test and Kruskal-Wallis test, respectively. Significantly greater mesial angulation and percentage of erupted right maxillary third molars were observed in the Class I extraction group. Significantly greater eruption status of the right mandibular third molars was observed in the Class I and Class II malocclusion extraction groups. Class I and II malocclusion extraction treatment exhibited more favorable angulations and a greater number of erupted third molars than non-extraction treatment. The non-extraction groups exhibited a greater percentage of unerupted third molars.

Extraction vs nonextraction orthodontic treatment: a systematic review and meta-analysis.

To compare four first premolar extraction and nonextraction treatment effects on intra-arch width, profile, treatment duration, occlusal outcomes, smile aesthetics and stability. An electronic search of the literature to June 2, 2023 was conducted using health science databases, with additional search of gray literature, unpublished material, and hand searching, for studies reporting nonsurgical patients with fixed appliances regarding sixteen sub-outcomes. Data extraction used customized forms, quality assessed with ROBINS-I (Risk Of Bias In Non-randomized Studies-of Interventions) and Cochrane RoB 2 (risk-of-bias) tool. GRADE (Grading of Recommendations Assessment, Development and Evaluation) assessed certainty of evidence. Thirty (29 retrospective studies, 1 randomized controlled trial) studies were included. Random-effect meta-analysis (95% CI) demonstrated maxillary (MD: -2.03 mm; [-2.97, -1.09]; P < .0001) and mandibular inter-first molar width decrease (MD: -2.00 mm; [-2.71, -1.30]; P < .00001) with four first premolar extraction; mandibular intercanine width increase (MD: 0.68 mm; [0.36, 0.99]; P < .0001) and shorter treatment duration (MD: 0.36 years; [0.10, 0.62]; P = .007) in the nonextraction group. Narrative synthesis included three and five studies for upper and lower lip-E plane, respectively. For American Board of Orthodontics Objective Grading System and maxillary/mandibular anterior alignment (Little's irregularity index), each included two studies with inconclusive evidence. There were no eligible studies for UK Peer Assessment Rating (PAR) score. Class I subgroup/sensitivity analyses favored the same results. Prediction interval indicated no significant difference for all outcomes. Four first premolar extraction results in maxillary and mandibular inter-first molar width decrease and retraction of upper/lower lips. Nonextraction treatment results in mandibular intercanine width increase and shorter treatment duration. There was no significant difference between the two groups regarding maxillary intercanine width, US PAR score, and posttreatment smile esthetics. Further high-quality focused research is recommended.

Nonextraction Orthodontic Treatment of Severely Impacted Maxillary Canines through Transalveolar Transplantation in a 10-Year-Old Patient: A Case Report with a 6-Year Follow-Up Period

Objective: This case report describes the interdisciplinary treatment of a 10-year-old girl with asymmetric Class III malocclusion, severe maxillary crowding, and bilaterally impacted maxillary canines. Clinical considerations: The clinical decision-making factors regarding treatment alternatives and the final treatment plan are discussed. A two-phase nonextraction therapy was implemented to relieve severe crowding, eliminate the maxillary canine impactions, and compensate for skeletal Class III malocclusion. The first treatment phase involved aligning the left canine through conventional orthodontic traction, while the more deeply horizontally impacted right canine was corrected through transalveolar transplantation. In the second phase, the Class III dental relationship was corrected through mandibular molar retraction. The effective use of various temporary skeletal anchorage devices such as modified c-palatal plates and mini-implants was illustrated. Conclusions: At the end of the treatment, esthetic dental alignment was achieved, along with improved facial balance. The transplanted maxillary right canine showed good health and a favorable long-term prognosis over six years after the procedure.

Adult patient expectations and satisfaction: Can they be influenced by viewing the three-dimensional predicted outcome before fixed orthodontic treatment of dental crowding?

Investigating the possible changes in patients' expectations of and satisfaction with the orthodontic treatment outcomes when they were given the three-dimensional digital prediction of their teeth alignment before the beginning of treatment. A prospective non-controlled single-group clinical trial was conducted on 28 (18 females, 10 males, mean age: 20.68 ± 1.91 years) patients with Class I malocclusion and moderate dental crowding who required a nonextraction orthodontic treatment. Patients were given the expectations questionnaire on their first visit (T0). Then, patients were shown a three-dimensional digital setup-created by Orthoanalyzer software (3Shape, Copenhagen, Denmark)-of the proposed treatment results before orthodontic treatment (T1) and received two questionnaires, the second expectations questionnaire and the satisfaction with the proposed changes questionnaire. Treatment was then initiated using the fixed appliances and completed. After debonding, a question about patients' satisfaction with the achieved changes was completed (T2). Patients' expectations level significantly increased after watching the predicted alignment of teeth compared with the initial levels in terms of chewing (x¯=5.54 and x¯= 6.71), speech (x‾ =5.93 and x¯= 6.93), and oral hygiene improvement (x‾= 7.93 and x¯=8.61 ± 1.06; at T0 and T1, respectively). The remaining items showed no significant differences between the two assessment times. Patients had a higher level of satisfaction at the end of treatment than after watching the proposed outcome. There were significant statistical differences in the items related to teeth appearance (x¯= 9.12 and x¯= 9.60 at T1 and T2, respectively), and teeth engagement (x¯= 8.92 and x¯= 9.40 at T1 and T2, respectively) CONCLUSIONS: Watching the predicted alignment outcome increased patients' expectations of chewing, speech, and oral hygiene improvement compared with the initially recorded levels. Patients were more satisfied with the final result than what was recorded after viewing the predicted plan. However, these results were not clinically significant.

Non-Surgical Non-Extraction Orthodontic Treatment Of An Adult With Facial Asymmetry

Non-Surgical Non-Extraction Orthodontic Treatment Of An Adult With Facial Asymmetry

Three-dimensional evaluation of a virtual setup considering the roots and alveolar bone in molar distalization cases

We aimed to evaluate root parallelism and the dehiscence or fenestrations of virtual teeth setup using roots isolated from cone beam computed tomography (CBCT) images. Sixteen patients undergoing non-extraction orthodontic treatment with molar distalization were selected. Composite teeth were created by merging CBCT-isolated roots with intraoral scan-derived crowns. Three setups were performed sequentially: crown setup considering only the crowns, root setup-1 considering root alignment, and root setup-2 considering the roots and surrounding alveolar bone. We evaluated the parallelism and exposure of the roots and compared the American Board of Orthodontics Objective Grading System (ABO-OGS) scores using three-dimensionally printed models among the setups. The mean angulation differences between adjacent teeth in root setups-1 and -2 were significantly smaller than in the crown setup, except for some posterior teeth (p < 0.05). The amount of root exposure was significantly smaller in root setup-2 compared to crown setup and root setup-1 except when the mean exposure was less than 0.6 mm (p < 0.05). There was no significant difference in ABO-OGS scores among the setups. Thus, virtual setup considering the roots and alveolar bone can improve root parallelism and reduce the risk of root exposure without compromising occlusion quality.

Predicted overbite and overjet changes with the Invisalign appliance: a validation study.

To investigate whether the predicted changes in overbite (OB) and overjet (OJ) in Align Technology's (Santa Jose, Calif) digital treatment plan for the prescribed course of treatment with the Invisalign appliance were consistent with those same changes in OB and OJ measured with the Geomagic Control X (Geomagic US, Research, Triangle Park, NC) metrology software system. Geomagic Control X software was used to determine OB and OJ differences between the pretreatment and predicted outcome. STL files for patients satisfying inclusion criteria and undergoing nonextraction orthodontic treatment with the Invisalign appliance. The differences were compared, using the Bland-Altman analysis, to the corresponding data provided by Align Technology's digital treatment-planning interface, ClinCheck. Data regarding 76 adult patients who satisfied strict inclusion criteria were assessed. The Shapiro-Wilks test indicated normality (P > .05). The Bland-Altman analysis showed high levels of agreement between the two measurements, with a bias range of -0.131 to 0.111 for OB and -0.393 to 0.03 for OJ recorded. Clinicians and researchers can be confident that measurement data provided by Invisalign's ClinCheck digital treatment-planning facility concerning OB and OJ changes from the initial to the predicted treatment outcome are valid.

Maxilomandibular changes in patients with Class I maloclusion – A cephalometric study

Maxillomandibular analysis relates the upper and lower jaw. The anteroposterior relationship of the maxilla and mandible through both angular and linear measurements is used to assess the sagittal jaw relationship. To evaluate skeletal maxillomandibular changes in patients with class I malocclusion after extraction and non-extraction orthodontic treatment in the Solan population. Cephalometric radiographs before and after treatment of 50 orthodontic patients were used in the study. The sample was divided into 2 groups, Group I (Class I, N=25, extraction cases) and Group II (Class I, N=25, non-extraction cases). Maxillomandibular parameters (ANB, Wits Appraisal, Harvold unit length difference, plane angle AB, convexity angle and MKG angle) were measured in both groups. When comparing the two groups, significant changes were observed in the ANB angle (p=0.05), AO-BO (p=0.00), MKG angle (p=0.03) and convexity angle (p=0, 00). Conversely, Harvold (p=0.70) and AB plane angle (p=0.75) were found to be insignificant. The result of the above study indicated that bone maxillomandibular changes in ANB angle, AO-BO, MKG angle and convexity angle can be observed in patients after extraction and non-extraction orthodontic treatment.

Keep it simple: correction of anterior cross bite – an ortho-perio interdisciplinary approach

This case report explores the treatment of a 13-year-old male patient with severe dental crowding and periodontal issues using non-extraction orthodontic treatment combined with a root coverage procedure. The patient presented with a skeletal class 1 base malocclusion, and multiple anterior crossbites, along with a compromised lower central incisor and gingival recession. Despite the option of extraction, the patient declined this approach, and the final goal was to achieve stable class 1 occlusion and an improved smile.The treatment plan utilized pre-adjusted edgewise appliance (MBT 0.022 inch slot), distalization of the canine, inversion of the maxillary right lateral bracket, and the cautious use of open coil spring in the upper and lower anterior segments. After alignment was completed, a root coverage procedure was performed on the lower right central incisor. The treatment lasted for 20 months, and the results showed successful alignment of both arches, canine protected occlusion, and improved periodontal health.Overall, this case report highlights the complex relationship between orthodontic treatment and periodontal health and the importance of careful treatment planning and patient communication to achieve successful and stable results. The non-extraction approach combined with root coverage procedure proved to be an effective treatment option for this patient, leading to an improved occlusion, smile, and periodontal health.

Comparative evaluation of smile attractiveness in various orthodontic treatment modalities- A cross-sectional study

Background: Smile plays a significant role in facial attractiveness and social interactions. The present study aimed to evaluate the smile attractiveness in subjects treated with extraction or non-extraction orthodontic treatment modality. Materials and Methods: Frontal smiling photographs of 100 orthodontically treated subjects with an age range of 16-25 years were taken and divided into two groups each having 50 subjects. Group I (ANB 0° to 4° ) was subdivided into cases treated with extraction (group la) and without extraction (group lb). Similarly, Group II (ANB &gt; 4°) was subdivided into cases treated with extraction (group lla) and without extraction (group lib). Smile esthetics and esthetic scores were assessed on frontal smile photographs by using different smile variables objectively and with the help of raters (10 laypersons,10 dental graduates, and 10 orthodontists) subjectively. Results: In extraction cases, the esthetic scores of dental practitioners and orthodontists were higher than in cases of non-extraction. Between extraction and non-extraction cases, laypeople had no esthetic preference. In Skeletal class I, smile variables such as the arch form index, smile arc and maxillary incisor show had a higher value in extraction cases however, the buccal corridor was more in non-extraction cases. In Skeletal Class II, smile variables such as the maxillary incisor show and arch form index were more in extraction cases and exposure of mandibular teeth was more in non-extraction cases. Judgement given by the raters was mainly based on maxillary incisor show, number of teeth displayed, and buccal corridor ratio. In orthodontic patients treated with and without the extraction, statistically non-significant variations in smile esthetics and esthetic scores were found. Conclusion: Thus, a decision regarding the extraction of teeth in orthodontic patients should not be solely based on smile esthetics but other factors which determine extraction should be considered.

Non-Extraction Orthodontic Treatment with Sequential Distalization Strategy of Clear Aligner

Orthodontic treatment with clear aligners has become an increasingly common choice because of the growing number of patients that ask for esthetic and comfortable alternatives to conventional fixed appliances. Using clear aligners, anterior crowding with lack of adequate space in the dental arch can be solved by molar distalization, which is common strategy applied in the non-extraction treatment of Class II molar relation, and to resolve crowding. This case report describes orthodontic treatment of two patients with moderate crowding using clear aligners. Molar distalization in the manner of sequential distalization, and arch expansion was accomplished with clear aligner therapy. The patients achieved improved facial profile with favorable occlusion.

Evaluating the Accuracy of Automated Orthodontic Digital Setup Models

Orthodontic tooth setup provides the orthodontist an insight into the possibilities and limitations of treatment and enables visualization of the final goal of treatment. Lately, artificial intelligence techniques have been applied to the digital setup software to automate the process of tooth segmentation and alignment. The purpose of this study was to evaluate the accuracy and efficiency of automated digital setup software. The diagnostic digital impression data of 30 patients (mean age, 29.8 ± 14.4 y) who underwent non-extraction orthodontic treatment from 2020 to 2022 were collected. Three automated digital setup software programs, Autolign (Diorco, Yongin, Korea), Outcome Simulator Pro (Align Technology, Inc., Arizona, USA), and Ortho Simulation (Medit, Seoul Korea) were tested and compared to the manual setup model using the Maestro 3D Dental Studio software (AGE Solutions S.r.l., Pontedera, Italy). The linear and angular transposition with respect to six dimensions of tooth movements, including occlusal-gingival, facial-lingual, and mesial-distal bodily movement, as well as crown rotation, mesial-distal crown tip, and facial-lingual crown torque, were calculated. The mean error for linear and angular movement ranged 0.39 – 1.40 mm and 3.25 – 7.80 °, respectively. The effectiveness of automated digital setup systems varies among software, tooth type, and the dimension of movement. Although the setup results have shown improvement in the occlusion indices, further manual adjustments may be needed for clinical use, such as indirect bonding and clear aligner therapy.

Changes in masticatory performance during the retention period following 4-premolar extraction and non-extraction orthodontic treatment.

To evaluate changes in masticatory performance (MP) during the retention period after extraction and non-extraction treatment and compare it with MP in individuals with normal occlusion. Adult patients who had completed orthodontic fixed appliance treatment comprised the extraction and non-extraction treatment groups, and those with normal occlusion comprised the control group. Their mixing ability (MA), maximum bite force (MBF), and occlusal contact area (OCA) were recorded immediately after the fixed appliance was removed and at 1month, 6months, and 1year post-treatment. The MA was measured via the two-color chewing gum MA test using ViewGum software, and the MBF and OCA were measured using Dental Prescale II system. MA immediately after orthodontic treatment was lower than that in the normal group but showed a time-dependent gradual increase during a 1-year retention period (P < 0.01). The MA at 1month post-treatment was not significantly different between the three groups (P > 0.05). The MA revealed a significant correlation with the MBF and OCA (P < 0.01). The MP immediately after orthodontic treatment was lower than that in the normal group but increased gradually, with levels comparable to those of the normal occlusion group at 1month post-treatment. Further, extraction did not affect the recovery of the MP after orthodontic treatment. No other study has evaluated the changes in MP during the retention period after orthodontic treatment. The findings show that compared with MBF and OCA, the patients' MP improved faster to levels found in normal occlusion.

Non-extraction orthodontic treatment for severe dental crowding using miniscrew-assisted rapid maxillary expansion.

Malocclusion is caused by an incorrect relationship between the teeth and jaws, which leads to an abnormal variation of normal occlusion. Crowding is an increasingly common type of malocclusion caused by a discrepancy in tooth-jaw size that leads to twisted and misaligned teeth. Two methods to treat this malalignment are tooth material reduction and arch width expansion. Of these two treatment options, the latter is preferred because it enables orthodontists to avoid extractions and increase the dental arch perimeter by widening the jaws; this resolves crowding and accommodates existing teeth. This case report describes a unique approach in the treatment of a patient with severe crowding by an orthopaedic widening of the dental arches using a skeletally anchored rapid palatal expander. Under favorable circumstances, this approach can serve as a robust method to treat patients with severe crowding and may be used as an alternative to extraction.

Hispanic adolescent lip response to extraction and nonextraction orthodontic treatment

In orthodontics, treatment aims to improve the patient's occlusion and overall facial appearance. Extraction of 4 first premolars may improve the occlusion, but it may negatively impact a patient's facial harmony and create a "dished-in" appearance. Although many studies in orthodontic literature reviewed Caucasian patient soft-tissue change throughout extraction treatment, there is a void in the literature regarding Hispanic patients, who have different soft-tissue characteristics and may respond differently to extraction therapy. This study aimed to determine the influence of first premolar extractions on soft-tissue profile in Hispanic adolescents and whether there is a correlation between pretreatment lip strain and lip movement throughout treatment. Lateral cephalograms and study models of 60 Hispanic patients were evaluated at pretreatment and posttreatment stages. Patients were divided into nonextraction and extraction groups and further subdivided on the basis of pretreatment lip strain. Cephalometric analyses were compared between the groups and subgroups, and a correlation analysis was conducted. There was a significant difference in lip position change between nonextraction and extraction groups. There was a significant increase in upper vermillion lip thickness in the extraction group. There was no significant difference in lip position change between the minimal and moderate-severe lip strain extraction groups. There was no significant correlation between pretreatment crowding or lip strain and lip position change. Hispanic patients' lips may retract less than Caucasian patients' lips in response to extraction treatment. Pretreatment lip strain and crowding may have less effect on retrusive lip movement than in Caucasian patients.

Evaluation of pharyngeal airway dimensions and cephalometric changes after premolar extraction and nonextraction orthodontic treatment in adolescent and adult patients

PurposeThe purpose of this study was to investigate the effects of premolar extraction and non-extraction for orthodontic treatment on the skeletal, dentoalveolar and pharyngeal airway. Material and MethodThe study was carried out with the radiographs of a total of 130 patients at the ages of 14 to 25, including 59 male and 71 female patients. The cases were divided into two groups as the “extraction” group(2 upper premolar teeth) (n = 66) and the “non extraction” group (n = 64). ResultsExtraction Group:In both age groups, there was a statistically significant increase in the mean interincisal angle (U1xL1) and lower anterior facial height (ANS-Me) values(p < 0.05). In the 14-18 age group, there was a significant increase in the mean upper airway thickness, inferior airway space, hyoid position, soft palate length(PNSP) and upper pharynx values(p < 0.05). In both sexes, while the mean U1xL1 and ANS-Me values significantly increased, the mean upper incisors inclination values decreased significantly(p < 0.05).Non Extraction Group:In both age groups, the mean ANS-Me values increased significantly from T0 to T1(p < 0.05). In the 14-18 age group, the increase in the mean upper adenoid thickness, tongue length,PNSP, softpalate thickness and vertical airway length values was significant(p < 0.05). In the male patients, the mean U1xL1 value decreased significantly(p < 0.05). ConclusionThe premolar teeth extraction performed in the patients receiving orthodontic treatment did not affect airway dimensions to a high extent.It was determined that the position of the hyoid bone and tongue length was not affected in the patients with premolar extraction and non extraction.

Vertical Skeletal Changes after Extraction and Nonextraction Orthodontic Treatment.

Due to the constant battle regarding the controversial topic of orthodontic extraction, this study aims to assess the changes in vertical dimensions of patients treated with premolar extractions compared with nonextraction orthodontic patients. A sample of 60 borderline patients were recruited and divided into extraction and nonextraction groups. Eleven pretreatment cephalometric measurements were recorded using WebCeph and patients were followed-up until the completion of treatment. Intragroup and intergroup comparisons were made using paired t-test and two-sample independent t-test, respectively. The joint significance of differences was measured using F-tests. The intragroup comparison revealed that in the extraction group, the vertical dimension was significantly increased posttreatment for four cephalometric measurements, that is, mandibular plane angle (p < 0.05), palatal plane angle (p < 0.05), Frankfort mandibular plane angle (p < 0.05), and y-axis (p < 0.05). In the comparison of the posttreatment values of both groups, the mean differences of the posttreatment values for sella nasion (SN)-gonion (Go)-gnathion (Gn) angle (p = 0.008), the total anterior (p = 0.050), and lower anterior facial heights (AFH; p = 0.011) were significantly higher. At the same time, the Jarabak ratio was significantly (p = 0.006) lower in the extraction group than in the nonextraction group. The increase in vertical dimension is significantly higher in the extraction group than in the nonextraction group which indicates a significant impact of orthodontic extraction on the vertical dimensions.

Gingival Recessions and Periodontal Status after Minimum 2-Year-Retention Post-Non-Extraction Orthodontic Treatment

The objectives of this study were to assess gingival recessions (GR) and periodontal status in patients previously treated with non-extraction orthodontic treatment and retention at a follow-up of a minimum of two years after the end of treatment. Data from patients aged between 16 and 35 years with a previous non-extraction orthodontic treatment and at least 2 years of retention and full records before and after treatment were collected. The casts were digitalized using the 3Shape TRIOS® intraoral scanner and the Viewbox4 software was used for the measurements. The following parameters were scored: inclination of the lower and upper incisors (IMPA and I^SN) and anterior crowding (Little index). The included patients were recalled for a clinical periodontal follow-up examination and the following parameters were evaluated: buccal and lingual GR (mm) of incisors and canines, bleeding of probing score, plaque score, and gingival phenotype. The digital cast analysis showed a mean Little index of 7.78 (SD 5.83) and 1.39 (SD 0.79), respectively, before and after treatment. The initial and final cephalometric analyses showed an I^SN of 103.53° and 105.78° (SD 7.21) and IMPA of 91.3°and 95.1°, respectively. At the follow-up periodontal visits, the patients showed an overall low oral hygiene with bleeding at probing in 66.6% and plaque in the anterior area in 76.2% of patients. From the total examined 240 teeth of the frontal sextants, three patients had GR (from 1 to 6.5 mm): in the upper arch two at canines and one at central incisor, whereas in the lower arch two at central and one at lateral incisors. The gingival phenotype was thick in 55% of cases. The lingual-to-lingual retainers at follow-up were present in 61.9% of patients. A slight increased risk for buccal GR development was found only in correlation with the presence of fixed retainer and thin gingival phenotype mainly in patients with gingivitis. Thus, non-extraction orthodontic treatment performed with controlled forces and biomechanics seems to not affect the development of GR or the periodontal health after retention.