Evaluation of Risk Factors for Severe Apical Root Resorption in the Maxillary Incisors Following Fixed Orthodontic Treatment.

OBJECTIVE: The aim of this study was to retrospectively determine the prevalence of severe external root resorption in maxillary inci- sors during fixed orthodontic treatment and to evaluate the possible predisposing factors. METHODS: The treatment records of 7000 patients who had been treated between 1990 and 2019 at the Department of Orthodontics Faculty of Dentistry Marmara University were examined, and a total of 120 patients with severe root resorption in at least one of their upper incisors were identified. The following data were retrieved from the patients' records and radiographs: gender, root morpholo- gy, overjet, overbite, treatment modality (extraction, non-extraction), treatment duration, buccal and palatal alveolar bone thickness for the maxillary incisors, and amount of movement of the incisal root apices and incisal edges. These data from a group of 90 patients with severe root resorption were compared with the data from a control group of 90 patients with minimal root resorption. The Chi- square test, the Mann-Whitney U-test, and the independent t-test were used for statistical analysis. RESULTS: The prevalence of severe external root resorption was 3.23%, and the results demonstrated significant difference between the groups for the variables of treatment modality (extractions), treatment duration, thickness of the alveolar bone, and amount of incisor movement at the end of the treatment. CONCLUSION: It can be concluded that extractions, increased treatment duration, thin alveolar bone, and excessive incisor movement represent risk factors for severe root resorption in maxillary incisors following orthodontic treatment.

The Assessment of Neurosensory Disturbance Following Bilateral Sagittal Split Osteotomy With Subjective and Three-Dimensional Evaluation.

PURPOSE: Inferior alveolar neurosensory disturbance (IAND) is the most common complication of bilateral sagittal split osteotomy (BSSO). The aim of the present study was to evaluate IAND with subjective tests postoperatively and assess the relationship between three-dimensional measurements of the mandibular canal (MC) and IAND. METHODS: Eighteen patients (Mean age: 24.05 ±â€Š5.85 years) treated with BSSO were retrieved from the archive. Subjective tests (light touch, tactile sensitivity, 2-point discrimination, brush-stroke directional discrimination, sharp/blunt discrimination, dental vitality, questionnaire) and three-dimensional measurements related to MC and fixation screws were done postoperatively (on average 20.43 ±â€Š8.76 months after surgery). Statistical significance was set at P  < 0.05. RESULTS: Subjective test results were found compatible with each other except brush-stroke directional discrimination test. According to the questionnaire, IAND was apparent in all patients immediately after surgery, and recovery after 1 to 2 years was statistically significant ( P  < 0.05). Preoperative ramus width, medial and lateral cancellous bone lengths, the decrease in MC length, and the presence of screw in MC were not related to IAND ( P  < 0.05). CONCLUSIONS: There is a high incidence of IAND following BSSO, and the subjective tests are efficient to evaluate the disturbance. Spontaneous recovery of the nerve occurs during the follow-up periods. Instead of preoperative measurements of bone thickness, MC length, and the position of fixation screws, the surgical procedure seems to be more important in IAND occurrence.

Postoperative Positional and Dimensional Changes of Mandibular Canal after Bilateral Sagittal Split Set-Back Osteotomy.

OBJECTIVE: This preliminary study was planned to provide information about preoperative mandibular canal (MC) position and the postoperative positional changes of MC and length in three dimensions, with the purpose of providing some assistance in reducing inferior alveolar neurosensory disturbance (IAND). METHODS: MC was examined on CBCT data using SimPlant Pro Standalone 13.0. MC locations were measured in all dimensions, with respect to mandibular bony borders. RESULTS: The results showed that MC is frequently located in the midthird of the ramus anteroposteriorly and superoinferiorly and in the midthird of the corpus superoinferiorly. Postoperatively, ramus width was increased, ramus length was decreased significantly, and MC was repositioned laterally and inferiorly. MC length was decreased on both sides, non-correlated with the set-back amounts. CONCLUSION: Preoperative results may be beneficial for the prediction of MC position for surgeons, and postoperative results will be used for the following studies to correlate postoperative positional changes with IAND.

Mandibular incisor extraction: a 5-year follow-up.

This case report presents the mandibular incisor extraction treatment of a patient with dental Class I malocclusion and lower crowding, in whom one mandibular incisor extraction was selected as the treatment of choice to improve the dental occlusion. A 19-year-old male patient's chief complaint was the crowding of lower incisors. He had a straight profile with normal upper and lower lip projection. Upper and lower dental midlines were coincident with the facial midline. The patient had Class I molar and canine relationships on both sides. He had Class I skeletal relationship, low angle vertical pattern, and proclined upper and lower incisors. The treatment plan included the extraction of lower right central incisor to resolve the crowding. At the end of 16-month active fixed treatment, lower dental crowding was resolved. At the 5-year follow-up, the patient had a stable occlusion, with the results of the orthodontic treatment maintained.

Surgically assisted rapid maxillary expansion: cone-beam computed tomography evaluation of different surgical techniques and their effects on the maxillary dentoskeletal complex.

INTRODUCTION: The aims of this study were to evaluate and compare skeletal, dentoalveolar, dental, and periodontal changes in surgically assisted rapid maxillary expansion (SARME) patients with and without pterygomaxillary disjunction. METHODS: The records of 20 patients who underwent SARME in the clinics of the dental school at Marmara University in Turkey were collected and divided into 2 groups of 10 patients each, according to the surgical protocol followed. Cone-beam computed tomography images before the operation and 3 to 6 months after the end of active expansion were analyzed by 20 linear and 7 angular measurements. The reliability of the 3-dimensional analysis was investigated. RESULTS: All transversal measurements in the dentoalveolar and dental levels increased after expansion in both the SARME with pterygomaxillary disjunction and the SARME without pterygomaxillary disjunction groups with no significant differences between them. In the SARME without pterygomaxillary disjunction group, more pronounced buccal alveolar bending and buccal tipping of the posterior teeth were found, but the difference did not reach statistical significance. SARME reduces buccal alveolar width in the premolar region significantly when pterygoid disjunction is not performed. CONCLUSIONS: SARME with or without pterygomaxillary disjunction is an effective technique to treat maxillary transverse deficiency in adolescent and adult patients. Pterygomaxillary disjunction is advised in periodontally compromised patients. Cone-beam computed tomography scanning is a reliable method for studying the dentoskeletal effects of SARME.

[Surgically assisted rapid maxillary expansion. An evaluation of different surgical techniques and their effect on maxillary dentoskeletal complex based on cone-beam computed tomography. Preliminary report]. / Expansion maxillaire rapide assistée chirurgicalement. Évaluation de différentes techniques chirurgicales et de leur effet sur le complexe dento-squelettique maxillaire par tomographie volumique à faisceau conique (CBCT). Rapport préliminaire.

AIM: To evaluate and compare the dentoskeletal effects associated with surgically assisted rapid maxillary expansion (SARME) performed with (+) and without (-) pterygomaxillary disjunction (PD), utilizing cone beam computed tomography (CBCT). MATERIALS AND METHODS: A retrospective study of 9 patients (1 male, 8 females, mean age 18.9 years) undergoing SARME who were divided into two groups. In group (-PD) the surgical technique followed involved bilateral LeFort I type of osteotomy plus midline osteotomy. In group (+PD) same protocol was followed and pterygoid disjunction was performed additionally. Three-dimensional CBCT scans were obtained preoperatively and 3-6 month postretention. A Hyrax type acrylic bonded expander was used. MIMICS 14.0 (Materialise Europe, Belgium) software was used to evaluate transverse expansion at skeletal, dentoalveolar and dental level. Additionally dental inclinations, alveolar bending and the pattern of expansion sagittally were assessed. Wilcoxon's and Mann Whitney U tests were used for comparisons. RESULTS AND DISCUSSION: All linear transverse measurements at dental and dentoalveolar level were found to have a statistically significant increase (P < 0.05) in both treatment groups. No statistically significant differences were found between the two groups as well as within groups on skeletal level (except of the anterior expansion of maxilla between piriform rims bilaterally). In -PD group significant buccal tipping of the 1(st) premolar was observed as well as increased buccal bending of the alveolar crest. CONCLUSION: This study confirms that SARME is an effective treatment of maxillary transverse deficiency. CBCT is an adequate tool to assess dentoskeletal treatment effects.

Periodontal status of ectopic canines after orthodontic treatment.

OBJECTIVE: To evaluate the periodontal health and tooth vitality of palatally impacted and buccal ectopic maxillary canines after completion of orthodontic treatment. MATERIALS AND METHODS: Fifteen patients who had unilateral, palatally impacted canines and 15 patients who had unilateral, buccal ectopic canines comprised the subjects of the study. Clinical and radiographic data was collected by recalling the patients in both groups after a mean period of 3.82 ± 1.54 years following completion of their orthodontic treatment. In both groups, the contralateral, normally placed canines served as controls. RESULTS: Palatally impacted canines had greater pocket depths, higher gingival levels, higher electric pulp testing scores, and reduced bone levels compared to their contralaterals. Buccal ectopic canines had increased plaque and gingival bleeding index, greater pocket depths, reduced attached gingival width, higher gingival levels, increased clinical crown lengths, and higher electric pulp testing scores compared to their contralaterals. Buccal ectopic canines had lower electric pulp testing scores and higher bone levels compared to palatally impacted canines. CONCLUSION: All ectopic canines had increased plaque and gingival bleeding index, greater pocket depths, reduced attached gingival width, higher gingival levels, increased crown lengths, higher electric pulp testing scores, and reduced bone levels compared to their contralaterals.

Dimensional changes of maxillary sinuses and pharyngeal airway in Class III patients undergoing bimaxillary orthognathic surgery.

OBJECTIVE: To evaluate the pharyngeal airway and maxillary sinus volume changes after mandibular setback surgery combined with maxillary advancement and/or impaction surgery. MATERIALS AND METHODS: Seventeen Class III skeletal patients (11 females, 6 males) who required bimaxillary orthognathic surgery were selected. Volumetric measurements were performed using cone beam computed tomography (CBCT) scans preoperatively and 3.9 ± 0.87 months postoperatively. All the CBCT scans were assessed and analyzed using MIMICS 14.0 software. Preoperative and postoperative volumes of pharyngeal airway and maxillary sinuses and the relationship between the amounts of surgical movement of the jaws and the above volumes were statistically evaluated. RESULTS: The pharyngeal airway area presented no significant change except for the lower and total pharyngeal airway volumes in males, in whom a significant decrease was observed (4196.27 ± 2061.11 mm(3) and 3375.53 ± 3624.67 mm(3), respectively). No significant change was observed in the minimal cross-sectional area of the pharyngeal airway. There was a significant decrease in the volume of the maxillary sinuses after the surgery by 3448.09 ± 3315.56 mm(3). No correlation was found between the amount of skeletal movement and the change in the volume of pharyngeal airway or maxillary sinuses. CONCLUSION: There was a significant decrease only for lower and total pharyngeal airway volumes in males and a significant decrease in the volume of the maxillary sinuses.

A review of early displaced maxillary canines: etiology, diagnosis and interceptive treatment.

Impaction of maxillary canines is a frequently encountered clinical problem the treatment of which usually requires an interdisciplinary approach. Surgical exposure of the impacted tooth and the complex orthodontic mechanisms that are applied to align the tooth into the arch may lead to varying amounts of damage to the supporting structures of the tooth, not to mention the long treatment duration and the financial burden to the patient. Hence, it seems worthwhile to focus on the means of early diagnosis and interception of this clinical situation. In the present article, theories related with the etiology of impacted canines and predictive variables of canine impaction in the mixed dentition are reviewed with an insight into current interceptive treatment modalities.

Evaluation of facial soft tissue parameters for Palestinians using Holdaway analysis.

OBJECTIVE: The aims of this study were to evaluate soft-tissue measurements for a Palestinian sample population with normal occlusion by Holdaway's analysis, and to check the applicability of Holdaway values to the Palestinian population. Normal Holdaway values for Palestinians will be established if their parameters do not match those of Holdaway. MATERIAL AND METHODS: Cephalometric radiographs of 93 Palestinian university students with normal occlusion (63 women, mean age: 20.1 ± 2.1 years; 30 men, mean age: 20.2 ± 2.4 years) were traced and evaluated. Cephalometric landmarks were located according to Holdaway analysis. Ten linear and two angular measurements were produced on each radiograph. RESULTS: The soft-tissue measurements for the Palestinians were similar to the Holdaway norms, except for the soft-tissue convexity angle and soft-tissue chin thickness, which were larger than the Holdaway averages. The Palestinian sample had a narrower range for normal nose prominence, as well as thicker lips, deeper superior and inferior sulci, and thicker soft-tissue chins than the Holdaway values. CONCLUSIONS: We determined normal values for the Holdaway soft-tissue analysis for Palestinians, which are appropriate for use in orthodontic practices in these territories.

Molar distalization with a pendulum appliance K-loop combination.

SUMMARY: The aim of this study was to evaluate the dentoalveolar effects of a pendulum appliance supported buccally by a K-loop, and to compare these with a cervical headgear (CHG) group. The records of 30 patients with skeletal Class I and dental Class II malocclusions were divided in to two groups: Patients in group 1 (seven females and eight males; mean age, 15.0 +/- 3.4 years) were treated with a pendulum appliance supported with a K-loop buccally, while in group 2 (10 females and 5 males; mean age, 14.2 +/- 2.9 years), the patients were treated with CHG. Standardized lateral cephalograms and study models were taken at the beginning of treatment (T0) and at the end of distal molar movement (T1). T0-T1 changes within the groups were analysed with a paired t-test, and between the groups with a t-test. The mean amount of distalization was 4.53 +/- 1.46 mm in group 1 and 2.23 +/- 1.68 mm in group 2. The mean amount of distal tipping for group 1 was 5.13 +/- 4.90 degrees; the mean amount of mesial tipping for group 2 was 0.80 +/- 2.27 degrees. Intrusion and mesiobuccal rotation of the maxillary molars were achieved in both groups. In group 1, the amount of labial protrusion and tipping of the maxillary incisors was not statistically significant. In group 2, palatoversion and retrusion of the maxillary incisors was statistically significant (P < 0.01 and P < 0.001, respectively). The two major disadvantages of intraoral appliances, which are distal tipping of molars and loss of anchorage at the anterior teeth, were significantly decreased with the use of a pendulum appliance K-loop combination.

Morphologic changes of the nasal cavity induced by rapid maxillary expansion: a study on 3-dimensional computed tomography models.

INTRODUCTION: The aim of this study was to evaluate the effect of rapid maxillary expansion on the volume of the nasal cavity by using computed tomography. METHODS: The sample consisted of 24 patients (10 boys, 14 girls) in the permanent dentition who had maxillary constriction and bilateral posterior crossbite. Ten patients had skeletal Class I and 14 had Class II relationships. Skeletal maturity was assessed with the modified cervical vertebral maturation method. Computed tomograms were taken before expansion and at the end of the 3-month retention period, after active expansion. The tomograms were analyzed by Mimics software (version 10.11, Materialise Medical Co, Leuven, Belgium) to reconstruct 3-dimensional images and calculate the volume of the nasal cavities before and after expansion. RESULTS AND CONCLUSIONS: A significant (P = 0.000) average increase of 11.3% in nasal volume was found. Sex, growth, and skeletal relationship did not influence measurements or response to treatment. A significant difference was found in the volume increase between the Class I and Class II patients, but it was attributed to the longer expansion period of the latter. Therefore, rapid maxillary expansion induces a significant average increase of the nasal volume and consequently can increase nasal permeability and establish a predominant nasal respiration pattern.

Soft tissue profile after distal molar movement with a pendulum K-loop appliance versus cervical headgear.

OBJECTIVE: To evaluate the soft tissue changes associated with the pendulum appliance that was supported with a K-loop buccally and to compare these treatment changes with a cervical headgear group. MATERIALS AND METHODS: The records of 30 patients having skeletal Class I, dental Class II malocclusions were divided to two groups. Group 1 consisted of 7 girls, 8 boys (mean age, 15.0 +/- 3.4 years), and Group 2 consisted of 10 girls, 5 boys (mean age 14.2 +/- 2.9 years). The first group was treated with a pendulum appliance that was supported with a K-loop buccally, and the second group was treated with cervical headgear. Lateral cephalograms were taken at the beginning of treatment and at the end of distal molar movement. Treatment changes within the groups were analyzed using the paired t-test, and between group changes were analyzed with the independent t-test. RESULTS: The results showed that the pendulum/K-loop appliance had no significant effect on skeletal and dental variables and soft tissue A point, upper lip thickness, and sagittal upper lip position relative to the E plane. A significant difference for the change in Vp-Ls distance was found in patients in the pendulum/K-loop group (P < .05). Patients in the cervical headgear group showed significant retrusion in skeletal, dental, and soft tissue measurements (P < .05). CONCLUSIONS: The pendulum/K-loop appliance produces distal molar movement without causing any significant changes in the sagittal or vertical positions of either the jaw or the soft tissue profile.

Zygomatic anchorage for en masse retraction in the treatment of severe Class II division 1.

An adult female patient who presented with a severe Class II division 1 malocclusion was treated by en masse retraction of upper anterior teeth against zygomatic anchorage. This case report describes the surgical and orthodontic procedures followed during the treatment. En masse retraction of the six anterior teeth by using zygomatic bone anchorage proved to be an efficient method for the correction of a severe overjet problem.

Comparison of metal release from new and recycled bracket-archwire combinations.

Most orthodontic brackets and archwires made from stainless steel or nickel (Ni)-titanium (Ti) alloys can release metal ions into the saliva. This study measures the amounts of metal released from simulated fixed orthodontic appliances. Sixty simulated fixed orthodontic appliances were manufactured in different ways and divided into four equal groups as follows: new brackets and new archwires (group 1 controls), new brackets and recycled archwires (group 2), recycled brackets and new archwires (group 3), and recycled brackets and recycled archwires (group 4). The bracket bases coated with adhesives were heated at 350 degrees C for 30 minutes. Recycled archwires were sterilized by autoclaving. Each appliance was soaked in artificial saliva of pH 7 at 37 degrees C for 45 days. At the end of this period, a sample of the artificial saliva was collected for analysis. Concentrations of Ni, chromium (Cr), iron (Fe), manganese, copper (Cu), and Ti ions were measured by atomic absorption and recorded in micrograms per liter. Analysis of variance and the Duncan multiple-range test indicated significant differences among the groups (P < .001). The study revealed the following: (1) group 4 released higher amounts of Cr, Fe, and Ti than any of the other three combinations; (2) Ni release was similar in groups 1 and 2 and in groups 2, 3, and 4; (3) the amounts of Cu, Cr, and Ti ions released from groups 3 and 4 were significantly greater than the amounts released from the other two combinations.

Evaluation of the relationship between the anterior component of occlusal force and postretention crowding.

The aim of this study was to investigate whether a relationship exists between the anterior component of occlusal force (ACF) and postretention crowding in the mandibular incisor area. The study group comprised 32 adults who had undergone fixed orthodontic treatment in the department clinic at Marmara University in Istanbul, Turkey. In 13 subjects, the mandibular arch was treated without extractions; in 19, it was treated with bilateral first premolar extractions. The average postretention period was 3.5 years. The ACF created in the left side of the mandibular dentition was determined by measuring interdental frictional forces at each contact point mesial to the first molar and distal to the canine. Anatomic contact point displacements between the left mandibular anterior teeth (lateral incisor-canine, central incisor-lateral incisor, and central incisor-central incisor) were measured on plaster casts and summed to provide the irregularity index for these teeth. Correlation analysis was used to assess the relationship between the ACF values at each contact and the irregularity index. In the nonextraction group, statistically significant positive correlations were observed between the ACF and the irregularity index at the 3 contact points that were measured. The strongest correlation was found at the canine-first premolar contact (r = 0.65). In the extraction group, a positive correlation was found between the ACF and the irregularity index (r = 0.49, P <.05) at the second premolar-first molar contact, but no correlation was found at the canine-second premolar contact.