Expression of hypoxia-inducible factor 1 alpha in papillary thyroid carcinoma is associated with desmoplastic stromal reaction and lymph node metastasis.

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer, and it early metastasizes into regional lymph nodes. We evaluated immunohistochemically the expression of the hypoxia marker hypoxia-inducible factor 1α (HIF-1α) as well as extracellular matrix protein tenascin C as a marker of stroma remodelling in a cohort of 160 PTCs. Expression of HIF-1α was seen focally accentuated in 100 of the 160 tumours (62.5 %) including 16 cases with equivocal staining (faint staining or only single-cell staining) and 84 cases with unequivocal staining. HIF-1α expression correlated with the degree of desmoplastic stromal reaction as well as with the expression of tenascin C (p < 0.001, Kruskal-Wallis test, respectively). Moreover, expression of HIF-1α was significantly associated with the presence of lymph node metastases (p < 0.001, Mann-Whitney test) as well as signs of invasion, namely, peritumoural and extrathyroidal invasion as well as angioinvasion (p = 0.024, p < 0.001, p = 0.017, Mann-Whitney test, respectively). Additionally, PTC with unequivocal HIF-1α nuclear staining was a larger tumour than PTC with negative (-) or equivocal HIF-1α expression (p < 0.001, Kruskal-Wallis test). Interestingly, the expression of HIF-1α was not significantly associated with BRAF V600E status (p > 0.05, Mann-Whitney test). Our data show that the expression of HIF-1α is associated with stroma remodelling processes within the tumour and, thus, may play an important role in an invasive behaviour of these tumours independent of BRAF mutation status.

Tongue movements in patients with skeletal Class III malocclusions evaluated with real-time balanced turbo field echo cine magnetic resonance imaging.

INTRODUCTION: The aim of this study was to evaluate the position and movements of the tongue in patients with skeletal Class III malocclusion. METHODS: Sixty-six patients (31 male, 35 female) with Class III malocclusion were divided into 3 groups according to cephalometric analysis. The first group comprised 23 patients (13 male, 10 female) with mandibular prognathism, the second group comprised 21 patients (9 male, 12 female) with maxillary retrognathism, and the third group comprised 22 patients (9 male, 13 female) with both maxillary retrognathism and mandibular prognathism. Twenty-two skeletal Class I patients (10 male, 12 female) were also included as the control group. RESULTS: Dentofacial morphology affects the position and the movements of the tongue during deglutition. Contact of the anterior portion of the tongue with the rugae area of the hard palate decreased in the Class III malocclusion groups. The posterior portion of the dorsal tongue was positioned more inferiorly, and the root of the tongue was positioned more inferiorly and anteriorly in patients with Class III malocclusion than in the control group. The tip of the tongue was also in a more anterior position in the Class III groups. When the deglutition stages were evaluated, we observed that the manner of bolus transfer was different in patients with skeletal Class III malocclusion than in those with skeletal Class I malocclusion. CONCLUSIONS: Tongue posture is affected by dentofacial structures, and adaptive changes occur in the tip, dorsum, and root of the tongue. Deglutitive tongue movements in patients with skeletal Class III malocclusion are also different from those with skeletal Class I malocclusion.

Tongue movements in patients with skeletal Class II malocclusion evaluated with real-time balanced turbo field echo cine magnetic resonance imaging.

INTRODUCTION: The aim of this study was to evaluate the deglutitive tongue movements in patients with skeletal Class II malocclusion. METHODS: Fifty-nine patients (26 male, 33 female) with skeletal Class II relationship were divided into 3 groups according to cephalometric analysis. Group 1 (n = 19) had mandibular retrognathism, group 2 (n = 20) had maxillary prognathism, and group 3 (n = 20) had both mandibular retrognathism and maxillary prognathism. Twenty-two skeletal Class I patients (10 male, 12 female) were also included as the controls. RESULTS: In the mandibular retrusion group, the posterior portion of the dorsal tongue moved downward at stage 2 and upward at stage 3; the root of the dorsal tongue was in an inferior and anterior position at stage 2. In patients with both mandibular retrognathism and maxillary prognathism, the middle portion of the dorsal tongue was positioned superiorly at stage 3 relative to stage 1; the tongue tip was retruded at stage 3 relative to stages 1 and 2. In the control group, the middle portion of dorsal tongue was positioned superiorly at stage 3 relative to stages 1 and 2; the posterior portion of the tongue moved upward at stage 2 and downward at stage 3, and tongue-tip retrusion was observed at stage 2 relative to stage 1. Contact of the anterior portion of the tongue with the rugae area of the hard palate decreased in the Class II malocclusion groups relative to the control group. The middle portion of the dorsal tongue was positioned more superiorly in patients with Class II malocclusion during all stages of deglutition. The root of the tongue was more inferior and anterior, and the tongue tip was retruded in patients with Class II malocclusion compared with the control group. The posterior portion of the dorsal tongue was more inferiorly positioned in patients with mandibular retrusion than in the other Class II groups or the controls. In the third stage of deglutition, this portion of the tongue had a superior position in groups 2 and 3 relative to the control group. CONCLUSIONS: Dentofacial morphology affects the position and movements of the tongue during deglutition, and adaptive changes occur in the tip, dorsum, and root of the tongue. Deglutitive tongue movements in patients with a skeletal Class II relationship are different from those with a skeletal Class I relationship.

Cephalometric comparison of pharyngeal airway in snoring and non-snoring patients.

OBJECTIVES: To compare the skeletal and the airway structures of the non-snoring individuals with simple snoring and patients with obstructive sleep apnea (OSA). METHODS: The first group consisted of 20 simple snoring cases (mean age: 37.5±8.05 years; max: 50 years, min: 21 years), the second group consisted of 20 OSA cases (mean age: 40.0±8.28 years; max: 54 years, min: 27 years) and the third group consisted of 20 individuals without any respiration problems (mean age: 29.6±3.20 years; max: 35 years, min: 24 years). In the cephalometric films, 4 skeletal and 14 airway space measurements were done. The control group and the study groups were compared using the Dunnett t test, and the groups with snoring problems were compared using the Bonferroni test. RESULTS: No statistically significant differences were found between the three groups in skeletal measurements. The OSA and simple snoring groups showed no significant differences in airway measurements. The OSA group showed significantly increased soft palate angulation when compared with the control group (P<.05). Soft palate length, soft palate thickness and soft palate height were significantly higher in the OSA samples than in the control group (P<.001). Pharyngeal spaces in the soft palate area had the significantly lowest values in the OSA group. Inferior pharyngeal space distances in the control group were greater than in both study groups. The OSA group showed the most inferiorly positioned hyoid bone and the difference between OSA and control groups was significant (P<.01). CONCLUSIONS: The decreased airway dimension in the soft palate area due to increased soft palate volume must be taken into consideration in treatment planning of OSA patients.

Measurement accuracy of a computer-assisted three-dimensional analysis and a conventional two-dimensional method.

OBJECTIVE: To determine the differences between manual and cephalometric measurements on different sections of the human skull, which were obtained using computer-assisted three-dimensional (3D) analysis and conventional two-dimensional (2D) techniques. MATERIALS AND METHODS: Measurements were carried out on 13 dry human skulls, then 2D cephalograms and 3D computed tomographic (CT) images were obtained. Anatomic landmarks were determined and marked with clay before CT images were taken, and the same landmarks were marked with the help of metallic balls and pins for lateral and frontal cephalograms. Manual, lateral/frontal cephalometric, and computer-assisted 3D cephalometric measurements were compared statistically. One-way analysis of variance and Tukey Honestly Significant Difference tests were used to compare the results among the groups. RESULTS: All measurements were statistically insignificant between the computer-assisted 3D and manual measurements. On the other hand, the differences between the conventional 2D and the manual measurements were statistically significant. The greatest amount of magnification was found at the Nasion-Menton distance (14.6%), which was located at the farthest distance from the central x-ray beam in the lateral cephalogram (P < .01). For the same reason, the greatest enlargement (16.2%) was observed in the distance between the zygomaticomaxillary sutures on the conventional frontal cephalogram (P < .01). CONCLUSIONS: The computer-aided 3D cephalometric measurements were found to be more accurate than the conventional cephalometric measurements. The results revealed that 3D cephalometric measurements were consistent with the manual measurements. In addition, the magnification and distortion might limit the results of conventional cephalometric measurements.

Effects of hyperbaric oxygen during experimental tooth movement.

OBJECTIVE: To determine the effects of hyperbaric oxygen (HBO) on bone remodeling during orthodontic tooth movement. MATERIALS AND METHODS: Twenty-four male, adult Sprague Dawley rats were randomly divided into two groups. HBO was administered in the first group, and the second group served as a control. The mandibular first molars were moved mesially by means of Ni-Ti closed coil springs in all groups. RESULTS: Results were evaluated histomorphometrically and the parameters of trabecular bone volume (BV/TV), trabecular bone number (Tr.N), and trabecular separation (Tr.Sep) were evaluated at the interradicular bone area of the mandibular first molars. Increases in BV/TV and Tr.N and decreases in Tr.Sep revealed the osteoblastic activity of HBO. HBO application caused an increase in bone apposition and osteoblastic activity or a decrease in osteoclastic activity. CONCLUSIONS: HBO enhanced the bone formation during experimental tooth movement. Therefore, the findings of this study support our hypothesis that osteoblastic activity might be modulated by changes in the environmental oxygen tension.

Cephalometric evaluation of patients treated by maxillary anterior segmental distraction: a preliminary report.

OBJECTIVE: The aim of this study was to evaluate the cephalometric results of distraction osteogenesis in patients with premaxillary deficiency. MATERIAL AND METHODS: In this study, an individual tooth-borne distraction device was used for advancement of the maxillary anterior segment. Unilateral or bilateral distraction was performed for 7 patients, according to the specific requirements of the individuals. Cephalometric radiographs were taken before treatment (T0), after distraction (T1), and after consolidation for 8 weeks (T2). RESULTS: Cephalometric analysis revealed that the premaxilla was moved forward and upward and the length of palatal plane increased. CONCLUSION: These alterations improved the soft tissue profile and solved the space deficiency of the maxilla by increasing the arch perimeter.

Multitomographic evaluation of the dental effects of two different rapid palatal expansion appliances.

Rapid palatal expansion (RPE) is widely used in the treatment of transverse maxillary deficiencies. Generally, there are two types of RPE appliances: banded and bonded expanders. The purpose of this prospective study was to compare the dental effects of banded and bonded appliances. The study consisted of 23 patients (13 females and 10 males) with a bilateral maxillary deficiency. Twelve patients (seven females and five males) with a mean age of 14.8 +/- 0.3 years were treated with banded RPE and 11 patients (six females and five males) with a mean age of 15.1 +/- 0.7 years with bonded RPE. Multitomographic radiographs were taken before (T0) and at the end (T1) of expansion while the patients were wearing an acrylic mandibular appliance in which ball bearings and bars were embedded. Statistical analyses of the measurements at T0 and T1 were undertaken with a paired t-test, and the difference between the groups assesed with a Student's t-test. In both groups, the angle between the radiographic image of the bar and the axial inclination of the upper first premolar and molar teeth was (5.34 and 2.73 degrees for the right premolars, 5.17 and 2.28 degrees for the left premolars, 11.83 and 3.73 degrees for the right molars, and 9.75 and 5.64 degrees for the left molars in the banded and bonded groups, respectively. The distance from the vestibular cortical plate to the palatal root of these teeth (1.17 and 1.23 mm for the right premolars, 2.46 and 1.09 mm for the left premolars, 2.75 and 0.64 mm for the right molars, 2.23 and 0.96 mm for the left molars in the banded and bonded groups, respectively) increased (both P < 0.01). These increases indicated buccal tipping of the teeth. Comparison of the two groups showed that tipping of the first molar and premolar teeth in the banded group was significantly more than in the bonded group (P < 0.01 and P < 0.001, respectively).

Distraction osteogenesis in a severe mandibular deficiency.

OBJECTIVE: Distraction osteogenesis is an alternative treatment method for the correction of mandibular hypoplasia. In this case report, distraction with a multidirectional extraoral device was performed to gradually lengthen the corpus and ramus of a patient who had a severe hypoplastic mandible. MATERIALS AND METHODS: The patient underwent bilateral extraoral ramus and corpus distraction osteogenesis. After seven days of latency period, distraction was performed 0.5 mm twice a day. Subsequent consolidation period was 12 weeks. RESULTS: The patient's mandible was elongated successfully. Cephalometric analysis revealed that ANB angle decreased from 13 degrees to 6 degrees , overjet of 15 mm decreased to 4 mm, corpus length increased from 49 mm to 67 mm, and ramus length increased from 41 mm to 43 mm. Posterior airway space (PAS) also increased due to advancement of the mandible. In stereolithographic model evaluation it was determined that the distances from condylion to gonion and from gonion to pogonion increased. CONCLUSION: Satisfactory results from both aesthetic and functional standpoints were obtained by distraction osteogenesis of the ramus and corpus.

Effects of interferon-gamma on bone remodeling during experimental tooth movement.

OBJECTIVE: To determine the effects of interferon-gamma (IFN-gamma) on bone remodeling during orthodontic tooth movement. MATERIALS AND METHODS: Thirty adult male Sprague Dawley rats were randomly categorized into five groups. IFN-gamma was administered in three different doses (0.01, 0.02, and 0.05 microg/20 microL) and the remaining two groups served as control. Mandibular first molars were moved mesially by means of Ni-Ti closed coil springs in all groups. The results were evaluated histomorphometrically, and parameters of trabecular bone volume (BV/TV), trabecular bone number (Tr.N), and trabecular separation (Tr.Sep) were observed at the interradicular bone area of the mandibular first molars. RESULTS: Increases in BV/TV and Tr.N and decreases in Tr.Sep revealed the antiosteoclastic activity of IFN-gamma. CONCLUSION: IFN-gamma administration may be useful clinically for anchorage control.

Dynamic MRI evaluation of tongue posture and deglutitive movements in a surgically corrected open bite.

Tongue thrust usually develops in the presence of anterior open bite in order to achieve anterior valve function. In the literature, tongue thrust is described both as the result and the cause of open bite. If it is an adaptation to malocclusion, then tongue posture and deglutitive tongue movements should change after treatment. In this case report, an adult who had skeletal open bite and Class II malocclusion caused by mandibular retrusion was treated surgically. The mandible was advanced in a forward and upward direction with a sagittal split osteotomy. The open bite and Class II malocclusion were corrected and an increase in the posterior airway space (PAS) was observed. Pretreatment and posttreatment dynamic magnetic resonance imaging (MRI) revealed that tongue tip was retruded behind the incisors and contact of the tongue with the palate increased. It was also determined that the anterior and middle portions descended, whereas the posterior portion was elevated at all stages. Advancement of the mandible, correction of open bite, and an increase in PAS affected not only the tongue posture and deglutitive movements, but also the breathing pattern of the patient.

Forsus Nitinol Flat Spring and Jasper Jumper corrections of Class II division 1 malocclusions.

OBJECTIVE: To compare the effects of Forsus Nitinol Flat Spring (FNFS) and Jasper Jumper (JJ) in the correction of Class II division I malocclusions. MATERIALS AND METHODS: Our research was conducted on 48 adolescents, who had a normal or horizontal growth pattern and retrognathic mandible. The patients were divided into three equal groups randomly. First group was treated with FNFS, and the second group was treated with JJ appliances, whereas the third group was the control group. Lateral cephalograms and study models were obtained after the leveling phase and at time of the removal of the appliances. RESULTS: Cephalometric analysis revealed that both the appliances stimulated mandibular growth, increased the anterior face height because of the lower face, and elongated the posterior face height because of the growth of temporomandibular joint. Maxillary central incisors were extruded, retruded, and distally tipped. Contrarily, intrusion, protrusion, and labial tipping were observed in the mandibular central incisors. Distal movement and intrusion of the maxillary first molars and mesial movement and extrusion of the mandibular first molars were the other dental alterations. Overjet and overbite were decreased, and a Class I molar relationship and improvement in the profile were attained in both treatment groups. Cast model analysis showed expansion in the maxillary and mandibular dental arches. CONCLUSIONS: Both the appliances were effective in the treatment of Class II malocclusion and revealed nearly same alterations in the skeletal, dental, and soft tissue parameters.

Initial effects of the tongue crib on tongue movements during deglutition: a Cine-Magnetic resonance imaging study.

The objective of this study was to investigate the initial effects of a tongue crib on tongue movements during deglutition by using real time balanced turbo field echo (B-TFE) Cine-MR imaging. A total of 21 patients were evaluated in this study. The open-bite group (OBG) consisted of 11 patients (seven girls, four boys) who had a mean age of 11.09 +/- 2.02 years and a mean overbite of -5.14 +/- 1.83 mm. These patients were evaluated initially (T1) and while wearing a tongue crib (T2). A total of 10 patients (five girls, five boys) with a mean age of 14.5 +/- 2.6 years and with a mean overbite of 1.6 +/- 0.5 mm served as controls (CG), and only initial records were obtained from these patients. T2 was compared with T1 and CG. T1 was also compared with CG. We evaluated deglutition during three stages matching oral (1), pharyngeal (2), and esophageal (3) stages. Our results indicated that the tongue's tip positioned more posteriorly when the crib was in place (T2) compared with both T1 and CG; the anterior portion of the tongue's dorsum was at a lower position in T2 compared with both T1 and CG at stage 3; the midportion of the tongue's dorsum was at a lower position in T2 than in T1 and CG at stages 1 and 2. To compensate for the posterior position of the tongue's tip (caused by the tongue crib), adaptive changes occurred in the anterior and midportions of the dorsum of the tongue.

Use of zygomatic anchors during rapid canine distalization: a preliminary case report.

Rapid canine distalization is a technique involving periodontal ligament distraction. The primary aim of this technique is to distalize the canines without anchorage loss and to shorten the duration of orthodontic treatment. After the rapid canine distalization, the healing process of the periodontal ligament is similar to rapid palatal expansion and requires a consolidation period. The long consolidation period of the technique conflicts with the second aim. Skeletal anchorage systems seem to compensate for this conflict because they can be also used for retraction of incisors during consolidation period. This case report presents the orthodontic treatment of a 16-year-old female, who had a bimaxillary retrusion and a dental Class II division I malocclusion. Upper first premolars were extracted and, while the canines were being distalized rapidly by periodontal ligament distraction, the incisors were retracted using a zygomatic anchorage system. The treatment of the patient was completed in five months without any anchorage loss.

Real-time balanced turbo field echo cine-magnetic resonance imaging evaluation of tongue movements during deglutition in subjects with anterior open bite.

INTRODUCTION: The aim of this study was to evaluate tongue movements in subjects with anterior dental open bites during deglutition by using real-time balanced turbo field echo cine-magnetic resonance imaging. METHODS: The study included 28 subjects. Two groups were formed according to the presence of anterior open bite (at least 2 mm). The open-bite group (OBG) consisted of 18 patients (14 girls, 4 boys) with a mean age of 14.5 +/- 2.7 years. The control group (CG) consisted of 10 patients (5 girls, 5 boys) with a mean age of 14.5 +/- 2.6 years. We evaluated deglutition during 3 stages: oral (stage 1), pharyngeal (stage 2), and esophageal stage (3). RESULTS: Results indicated that (1) in the OBG, from stage 2 to stage 3, the anterior portion of the tongue dorsum was elevated [corrected] whereas its midportion was lowered [corrected]; (2) in the CG, its posterior portion was lowered [corrected] from stage 2 to stage 3; (3) in the CG, the tongue tip was positioned more posteriorly [corrected] at stage 2 than at stage 1; (4) in the OBG, the tongue tip moved more anteriorly in all stages of deglutition than in the CG. CONCLUSIONS: Compensatory tongue functions occur in patients with anterior dental open bites. Dynamic MRI is a promising tool for evaluating swallowing patterns in these patients.

Effects of a segmented removable appliance in molar distalization.

The aim of the present investigation was to evaluate the skeletal and dentoalveolar treatment effects of a segmented removable appliance [removable molar distalizer (RMD)] for molar distalization. The study was conducted on 28 patients (12 females and 16 males), with a mean age of 11.8 years. All presented with a skeletal Class I malocclusion and a bilateral dental Class II molar relationship. The pre- and post-distalization records included lateral head films, study models and standard photographs. The findings were evaluated with a paired samples t-test. The average maxillary first molar distalization with the RMD was 3.98 mm, with 4.61 degrees of distal tipping. The maxillary second premolars drifted distally 2.13 mm on average with 1.54 degrees of distal tipping, while the maxillary first premolars showed 1.23 mm of mesial movement and 1.98 degrees of mesial tipping. The incisors protruded 1.09 mm with 1.27 degrees of labial tipping. The RMD was effective in distal molar movement and all patients attained a bilateral Class I molar relationship in an average period of 4.5 months. Hygiene problems and mucosal irritations, frequently found with fixed intraoral distalization techniques, were not observed during the distalization period.

Dentofacial effects of asymmetric headgear and cervical headgear with removable plate on unilateral molar distalization.

Cervical headgear (CHG) is used widely in the treatment of Class II anomalies. Asymmetric headgear (AHG) is an alternative treatment for the correction of unilateral Class II dental relationships. The purpose of this investigation was to compare the effects of AHG with those of a CHG combined with a removable plate in unilateral first molar distalization. The study consisted of 20 patients with unilateral Class II molar relationship (12 girls and eight boys). One group of 10 patients was treated with an AHG, and a second group of 10 patients was treated with a CHG and a removable plate. Lateral cephalograms and basilar radiographs were taken before and after molar distalization. It was found that distalization and distal tipping of molar on the passive side was less in the CHG and removable plate (CHG-RP) group. Distalization and distal tipping of the second premolar on the distalization side was also reduced in this group. Incisors were retruded in both groups but were retruded more in the CHG-RP group.

Mandibular distraction with MD-DOS device.

Distraction osteogenesis is an alternative treatment method for the correction of mandibular hypoplasia. In this case report, mandibular distraction with a dynamic osteosynthesis system (MD-DOS) was performed to gradually lengthen the mandible of a patient who had a severe hypoplastic mandible. The patient underwent intraoral bilateral mandibular distraction osteogenesis. The latency period after the operation was seven days. The distraction was performed three times daily for 14 days at the rate of 0.33 mm each time. Subsequent retention was nine weeks. The patient's mandible was elongated successfully and a satisfactory profile and occlusion was achieved.

Effects of nitric oxide in orthodontic tooth movement in rats.

The purpose of this study was to evaluate the role of nitric oxide (NO) in orthodontic tooth movement in rats. Nomega-nitro-L-arginine methyl ester (L-NAME) was used as NO synthase (NOS) inhibitor, and nitro-L-arginine (NLA) was used as NOS precursor. Fifty-four Sprague-Dawley rats were divided into 3 equal groups, and each group was divided into 3 subgroups. In the first 8 subgroups, 20 g of force was applied to the maxillary incisors with a spring. NLA was administered in the first 3 subgroups at 10(-4), 10(-5) and 10(-6) mol/L (20 microL/12 hours), respectively. L-NAME was administered in the next 3 subgroups with the same order, amount, and prescription. The last 3 subgroups were evaluated as control groups; in the seventh subgroup, 0.9% NaCl (saline solution) was injected (20 microL/12 hours). Only the force was administered in the eighth subgroup, and no chemical solution or orthodontic force was used in the last subgroup. The rats were killed on the fifth day of the experiment. Their premaxillae were dissected, and tissue sections were obtained from the coronal, middle, and apical thirds of the incisor roots. Multinuclear osteoclasts, Howship's lacunae, capillary vascularization, and orthodontic tooth movement were significantly increased in the NLA groups compared with the L-NAME and control groups.

Initial intrusion of the molars in the treatment of anterior open bite malocclusions in growing patients.

The treatment of the hyperdivergent phenotype and/or anterior openbite is one of the common problems facing orthodontists. The purpose of this study is to present a new appliance (Molar Intruder) for molar intrusion and to determine its effects in the treatment of anterior openbite. The study group comprised 14 patients (eight girls and six boys), with a mean age of 10 years and 7 months. All presented anterior open bite malocclusions between the second premolars. The study was carried out on lateral head films taken before (T1) and after (T2) molar intrusion. Periapical radiographs, study models, and standard photographs of all the patients were also obtained before and after molar intrusion. The paired sample t-test was used to determine the differences between the parameters. The average treatment time with the Molar Intruder was five months. The mean intrusion of maxillary and mandibular molars was 1.86 mm and 1.04 mm, respectively. Maxillary incisors extruded 0.54 mm with a labial tipping of 1.46 degrees and overbite increased by 4.00 mm. The mandibular plane angle was decreased by 1.57 degrees, and the anterior face height was decreased by 1.86 mm on average. The mandible showed a counterclockwise rotation, the chin moved forward, and the posterior facial height/anterior facial height ratio was increased. Anterior openbites of the patients were significantly rehabilitated at the end of the intrusion period, simplifying further orthodontic treatment.