Three-dimensional evaluation of upper airway changes following rapid maxillary expansion: A retrospective comparison with propensity score matched controls

Background The aim of this study is to evaluate upper airway changes three-dimensionally following rapid maxillary expansion (RME) and compare the changes with matched controls. Materials and methods Seventeen patients (mean age 12.6 ± 1.8 years) with maxillary transverse deficiency were treated with RME. Using the propensity score matching method, 17 patients (mean age 12.3 ± 1.5 years) were selected from a non-RME control group of 33. Case-control matching was performed based on 5 covariates: age, gender, CBCT scan interval, sagittal skeletal pattern, and tongue posture. Airway volumes of nasopharynx and oropharynx and minimum cross-sectional areas (MCA) of oropharynx were measured and compared between the case and control groups in CBCT scan images. Results In the case group, significant increases from before to after RME were found in all measurements except MCA of the retroglossal segment of oropharynx. Before treatment, there were no significant differences between case group and control group. While comparing the case group with the control group after treatment showed overall greater increases in the case group. In particular, MCA of retropalatal segment showed statistically significant differences. Conclusion The results of this study indicate that RME causes an increase in upper airway dimensions.

Effects of Class II elastics during growth on the functional occlusal plane according to skeletal pattern and extraction vs nonextraction

ABSTRACT Objectives To investigate the effect of Class II intermaxillary elastics on the functional occlusal plane (FOP) of growing patients. Materials and Methods A total of 50 participants aged 11 to 16 years were selected from a university clinic archive >1-year after treatment and after undergoing 6 months of Class II elastic wear, taking pretreatment (T0) and posttreatment (T1) lateral cephalometric radiographs, and consenting to participate at recall (T2). Participants were divided into 3 groups according to skeletal pattern or into 2 groups according to treatment with extraction (E) or nonextraction (NE). Angular changes of FOP relative to the Sella-Nasion (SN), mandibular plane (MP), and Frankfort horizontal (FH) were compared within and between groups. Results A statistically significant reduction of FOP-SN/FH, but not of FOP-MP, was found from T0–T1–T2 when all patients were grouped together. FOP-SN/MP/FH was significantly the largest in the patients with a hyperdivergent skeletal pattern, but lowest in the patients with a hypodivergent skeletal pattern at T0, T1, and T2 (P < .032). FOP-MP at T0–T2 was statistically larger in group E than in group NE (P < .02). No differences were found for FOP changes (change before treatment minus after treatment and change after treatment minus 1 year after treatment) between different skeletal patterns (P > .433) and treatment groups (P > .193). Conclusions Use of Class II elastics during the growth period was not found to show adverse effects on FOP rotation. Neither skeletal pattern nor treatment modality differed in the response to Class II elastics with regard to FOP changes. Individual patient growth pattern must be taken into consideration when treatment planning the use of Class II elastics. Orthodontists should take into account individual skeletal and growth patterns while using Class II elastics.

Evaluation of tongue posture & dimensions in relation to skeletal Class I and Class II patterns- A cephalometric study

Association of tongue posture with dental and facial skeletal pattern have been suggested in past. This study was undertaken to assess tongue posture and dimensions in Class I and Class II Dentoskeletal patterns to determine whether any correlation exists between tongue posture and skeletal pattern of an individual. Cephalograms of 150 individuals (aged 18-23 years), taken in Natural Head Position (NHP) and tongue at rest were divided into three groups i.e. Group 1 – Class I Normal occlusion, Group 2 – Class II Division 1 Normodivergent and Group 3 – Class II Division 1 Hypodivergent, consisting of 50 samples each. To ensure the rest position of tongue, patient was asked to relax for 30 seconds after coating the tongue with barium sulphate in midline and then to swallow, and the X-ray was taken at the end of swallowing. Each group was divided into two subgroups according to sex. Groups were constituted according to the Frankfort mandibular plane angle (FMA) angle. The subjects who had skeletal Class II pattern due to mandibular retrusion and not due to maxillary prognathism were only included in the study group. Statistical analysis was done using the software SPSS version 21.0. The statistical tests used were unpaired t-test and One-way ANOVA test with post-hoc bonferroni test. The p-value was considered significant if less than 0.05.The dorsum of the tongue was higher at back and lower in front in Class II Division 1 Hypodivergent group as compared to Class I Normal occlusion group (P<.05). Tongue height and tongue length were significantly reduced in Class II Division 1 Normodivergent and Class II Division 1 Hypodivergent malocclusion groups when compared to Class I control group (P<.05).The study supports the existence of a relationship between posture & dimensions of the tongue with Class I and Class II skeletal patterns.

A CBCT Evaluation of Midpalatal Bone Density in Various Skeletal Patterns

The purpose of this study was to evaluate midpalatal bone density (BD) by using cone-beam computed tomography (CBCT) according to gender, age, and vertical and horizontal skeletal patterns. CBCT images from 126 subjects (64 females and 62 males) were reoriented and analyzed in order to attain BD values at the midpalatal suture. Four age groups were used for classification (adolescence, 10 ≤ early < 14 years, 14 ≤ middle ≤ 17 years, and 17 < late ≤ 21 years; adult > 21 years). Vertical skeletal pattern categories were differentiated by the Frankfort horizontal line to mandibular plane angle (hypodivergent < 22°, 22° ≤ normovergent ≤ 28°, and 28° < hyperdivergent). Horizontal skeletal pattern differentiation was defined by ANB angle (Class III < 0°, 0° ≤ Class I ≤ 4°, and 4° < Class II). Females showed significantly higher BD than males (p < 0.001). As age increased, BD increased significantly (p < 0.001). There were no significant differences between vertical skeletal patterns. Class II showed significantly less BD than Class III (p < 0.05). With this information, clinicians can better understand BD trends of the midpalatal suture and, thus, better understand our patient’s anatomy and potential hurdles in successful treatment.

Management of a complete 180° rotation of bilateral maxillary canines

Background: Dental anomalies usually lead to complicated decisions having to be made in terms of the orthodontic treatment of permanent dentition; tooth rotation is the most common of these irregularities. The prevalence rate of this phenomenon is 2.1–5.1% in patients who have not received orthodontic treatment. Purpose: This case report aimed to manage the complete bilateral rotation of maxillary canines with couple force by using a Nance appliance modification. Case: A 17-year-old male patient came in wanting to straighten his teeth. He complained about his bilateral canines, which were not in a normal position. There was an impacted left maxillary second premolar and an ectopically erupted right maxillary first premolar. He also had protrusions in the upper and lower anterior teeth and crowding in the lower anterior teeth as well as upper and lower midline deviations. Case Management: A clinical examination showed a class I relationship between the dental and cephalometry measurements and highlighted a class I skeletal pattern. The upper right first premolar was extracted and the left second premolar had undergone an odontectomy to allay protrusion and correct crowding. Bilaterally rotated upper canines were derotated using a modified Nance appliance and an elastomeric chain with couple force. Conclusion: The success of the orthodontic treatment was influenced by the specific nature of the patient’s dental and medical history, extraoral and intraoral examination, diagnosis and treatment planning, which was followed by a systematic approach to treatment. The Nance appliance modification reduced the total treatment time by achieving controlled anchorage and derotation of the canines.

Interradicular distance and alveolar bone thickness for miniscrew insertion: a CBCT study of Persian adults with different sagittal skeletal patterns

Background This study aimed to assess the interradicular distance and alveolar bone thickness of Persian adults with different sagittal skeletal patterns for miniscrew insertion using cone-beam computed tomography (CBCT). Methods This cross-sectional study was conducted on maxillary and mandibular CBCT scans of 60 patients (18–35 years) in three groups (n = 20) of class I, II and III sagittal skeletal pattern. Anatomical and skeletal parameters were measured at 2, 4 and 6 mm apical to the cementoenamel junction (CEJ) by one examiner. The intra- and inter-class correlation coefficients were calculated to assess the intra, and interobserver reliability. Data were analyzed by ANOVA and Tukey’s test (alpha = 0.05). Results The intra- and interobserver reliability were > 0.9 for all parameters. The largest inter-radicular distance in the maxilla was between the central incisors (1–1) in classes I and III, and between premolars (4–5) in class II patients. The largest inter-radicular distance in the mandible was between molar teeth (6–7) in all three classes. The buccal cortical plate thickness was maximum at the site of mandibular first and second molars (6–7). The posterior maxilla and mandible showed the maximum thickness of cancellous bone and alveolar process. Wide variations were noted in this respect between class I, II and III patients. Conclusions The area with maximum inter-radicular distance and optimal alveolar bone thickness for miniscrew insertion varies in different individuals, depending on their sagittal skeletal pattern.

Skeletal Divergence and Condylar Asymmetry in Patients with Temporomandibular Disorders (TMD): A Retrospective Study

Introduction. This study was aimed at evaluating the association between vertical skeletal patterns, condylar height symmetry, and temporomandibular disorders in adults. Methods. The study sample consisted of 200 patients (ages 18–30 years old) retrospectively recruited: 100 with temporomandibular disorders (TMD) and 100 without TMD (control), diagnosed by Diagnostic Criteria for the Temporomandibular Disorders (DC/TMD). For each subject, skeletal divergence was assessed on lateral cephalograms, and condylar height symmetry was evaluated by orthopantomography (Habets’ method). Results. Subjects with temporomandibular disorders showed a strong association with condylar asymmetry ( p < 0.0001 ) and, for the skeletal pattern variables, hyperdivergence ( p < 0.001 ). A correlation with the female sex was also found ( p < 0.04 ), while there was no difference in terms of age in the 2 groups ( p > 0.29 ). Conclusions. Although it does not imply a direct cause-and-effect relationship, the present study suggests condylar asymmetry and hyperdivergent skeletal pattern are more likely to be associated with a higher risk of temporomandibular disorder joint diseases in adult patients.

Evaluation of Salivary Leptin Levels and Its Correlation with Class I, Class II, and Class III Facial Skeletal Pattern: A Prefatory Study

Materials and Methods A sample of 62 patients were selected prior to the orthodontic treatment from a population that attended the International Islamic University Malaysia Specialist Orthodontic Clinic. Based on the lateral cephalometric analysis, the subjects were grouped into Class I, Class II, and Class III facial skeletal patterns, according to Eastman and Wits appraisal. Subsequently, unstimulated saliva samples were taken and purified to undergo leptin enzyme-linked immunosorbent assay analysis to determine the levels of leptin hormone. Statistical analysis using the Kruskal–Wallis test was used to analyze the data obtained. Results The results showed that there was a significant difference between the levels of leptin hormone between Class I and Class II skeletal patterns and between Class I and Class III facial skeletal patterns. No statistical difference was noted between the levels of leptin of Class II and Class III facial skeletal patterns. Conclusion Salivary leptin hormone levels are higher in patients with Class II and Class III facial skeletal patterns compared with Class I.

TAD’s for the Derotation of 90° Rotated Maxillary Bicuspids

It is undeniable that the advent of extra-alveolar mini-implants for anchorage purposes has revolutionized the field of Orthodontics. This case report sheds light on an innovative anchorage plan using TADs, to carry out treatment for a 15-year-old female patient. The patient reported to the clinic with a chief complaint of rotated second premolars, crowding, and a deep bite. On examination, it was seen that the patient had a Class I skeletal pattern, Class II subdivision molar relationship, 90-degree maxillary second premolar rotations, crowding in both the arches, and a deep bite. In this case, the clinicians decided to use TADs for premolar derotation as it not only provides a pure rotational couple without any deleterious effects on the adjacent teeth but also helps shorten the overall treatment time. The total treatment time for this case was 10 months.