Skeletal and Alveolar Changes in Conventional Rapid Palatal Expansion (RPE) and Miniscrew-assisted RPE(MARPE): a Prospective Randomized Clinical Trial Using Low-dose CBCT

Background: This prospective randomized clinical trial aimed to evaluate the short-term effects of rapid palatal expansion (RPE) and miniscrew-assisted RPE (MARPE) on skeletal, dentoalveolar, and periodontal structures in adolescent and young adult patients. Methods: Thirty-six patients (12 men and 24 women) requiring maxillary expansion were randomly allocated to RPE (n=17) or MARPE (n=19) groups. Upon identical (35 turns) amount of expansion, low-dose cone-beam computed tomography images were taken before treatment (T0), immediately after expansion (T1), and after a 3-month consolidation period (T2). Skeletal, dentoalveolar, and periodontal measurements were performed at each time point. Results: A greater increase in nasal width in the molar region (M-NW) and greater palatine foramen (GPF) was observed immediately after expansion (T1-T0) and consolidation periods (T2-T0) in MARPE group (P<0.05). MARPE and RPE groups showed similar dentoalveolar changes except for the maxillary width (PM-MW, M-MW) (P<0.05). Through the expansion and consolidation periods (T2-T0), lesser buccal displacement of the anchor teeth was observed in the MARPE group (PM-BBPT, PM-PBPT, M-BBPT [mesial and distal roots], and M-PBPT) (P<0.05).Conclusions: Both RPE and MARPE groups exhibited significant triangular basal bone expansion and skeletal relapse during consolidation. Under identical amounts of expansion, the MARPE group showed lower decrease in the skeletal, dentoalveolar and periodontal variables after consolidation. The reinforcement of RPE with miniscrews contributes to the maintenance of the basal bone during consolidation period. This evidence can help clinicians decide the appliance design for maxillary expansion, while preventing periodontal side effects, such as buccal bone dehiscence Trial registration: WHO Institutional Clinical Trials Registry Platform (IRB No. KCT0006871 / Registration Date 27/12/2021)

Analysis of the Changes in Occlusal Plane Inclination in a Class II Deep Bite “Teen” Patient Treated with Clear Aligners: A Case Report

Background: Optimal management of hypodivergent growing patients demands a strict control of vertical dimension and to exploit the growth potential. If a deep bite malocclusion causes a traumatic contact between the upper and lower incisors and affects the facial appearance, an early interceptive treatment is recommended. The aim of this case report is to outline the clinical management of the occlusal plane of a growing Class II division 1 deep bite patient treated with aligners and Class II elastics. Methods: The treatment lasted 11 months and was divided into two phases. Treatment goals included improvement of the soft tissue profile and basal bone relationships through an increase in the mandibular third of the face and a sagittal advancement of the mandible. The correction of the curve of Spee involved intrusion of the mandibular incisors and extrusion of the mandibular premolars. Results: The cephalometric analysis at the end of the treatment displayed significant differences in the skeletal and occlusal pattern along with aesthetic improvements. Conclusion: The final cephalogram showed a consistency between the planned tooth movement and the clinical results. Although definitive recommendations must be withheld until longer follow-up is available, the patient presented here shows that the treatment protocol yielded positive mandibular growth.

The success and effectiveness of miniscrew-assisted rapid palatal expansion are age- and sex-dependent

Objectives This study aimed to assess the success rate and the amount of suture separation after the miniscrew-assisted rapid palatal expansion (MARPE) procedure in relation to the chronological age and sex of the patients. Materials and methods The periapical radiographs of 215 subjects (95 male; 120 female; range, 6–60 years) who had undergone MARPE treatment were retrospectively analyzed. The success of suture separation was determined and, in suture-separated subjects, the amount of suture separation was evaluated by suture separation ratio calculated from the periapical radiograph obtained after active expansion. Association tests were performed using linear-by-linear association, the Jonckheere-Terpstra test, Fisher’s exact test, and the Mann–Whitney U test, and linear regression models were also developed. Results The success rate of suture separation was 61.05% in male, 94.17% in female, and 79.53% in both sexes. There was a statistically significant association between older age and suture nonseparation in male (p < 0.001), but not in female (p = 0.221). In suture-separated subjects, there was a statistically significant trend toward a low amount of suture separation with older age subgroups in both sexes (p < 0.001); however, there was no statistically significant difference in the amount of suture separation between male and female in all age subgroups. Conclusions Older patients treated with MARPE, particularly in male, may have a reduced likelihood of both success in suture separation and sufficient basal bone expansion. Clinical relevance This study demonstrates that clinicians should consider that the success rate of MARPE and the amount of suture separation may depend on chronological age and sex.

Match of the Bimaxillary Basal Bone Arches and Its Variations among Individuals

Introduction. This study is aimed at illustrating the bimaxillary basal bone contours, to clarify the match of the basal bone arches of the upper and lower, especially the posterior segments, including the second molar and retromolar region. Methods. Based on 100 cone-beam computed tomography (CBCT) images (50 males and 50 females), we obtained 100 pairs of basal bone arches, which were the horizontal inner cortex contours passing the furcation of the first molar paralleled to the lower occlusal plane. The Generalized Procrustes Analysis (GPA) was applied to depict average contours and calculate the ratio and difference width of both upper and lower dental arches in different positions. Variations of the basal bone morphology among individuals were revealed using Principal Component Analysis (PCA). Results. The width discrepancy occurred at 7-7 segment (male: upper 65.62 mm and lower 68.81 mm and female: upper 62.98 mm and lower 68.38 mm) and the retromolar region (male: upper 64.67 mm and lower 71.96 mm and female: upper 62.34 mm and lower 71.44 mm). The ratio ( p = 0.006 ) and difference value ( p = 0.009 ) of 7-7 segment and the ratio of retromolar region ( p = 0.044 ) differed in genders. Setting 2 mm overjet, the upper basal bone arch was wider than the lower by approximate 2 mm on both sides, except the second molar and retromolar region. According to PCA, the variation of basal bone arches appeared mainly at terminal segments. Conclusions. For both male and female, the bimaxillary basal bone matched except terminal segments. Mismatch of female bimaxillary posterior basal bone was more pronounced than male. The basal bone arches of male were wider and longer than that of female.

Dental Aesthetic Index (Dai) Score Among Patients with Antero-Posterior Basal Bone Discrepancy

Aim: To determine the mean Dental Aesthetic Index (DAI) malocclusion score among patients with Antero-posterior basal bone discrepancy (APBBD) and to assess the treatment need of the patients with horizontal jaw deformities as calculated by DAI guidelines. Methodology: The descriptive cross sectional study was conducted in the Orthodontic department, University College of Dentistry, The University of Lahore. Lateral cephalograms of the patients were analyzed for anteroposterior basal bone discrepancy by measuring angle ANB. Two hundred and thirty one subjects were included in the study having ANB >4° or <1° through non probability consecutive sampling technique. Study casts were obtained and malocclusion parameters for Dental Aesthetic Index (DAI) were calculated. Results: The mean Dental Aesthetic Index (DAI) score in APBBD was 37.10 ± 7.62, in skeletal class II (37.14 ± 7.90) and in skeletal class III (36.98 ± 6.68), (p-value 0.75). Moderate positive correlation existed between DAI score and ANB in skeletal class II subjects (R 0.49, p <0.001). Conclusion: The mean DAI score in APBBD showed mandatory treatment need in patients with Antero-posterior basal bone discrepancy. Moderately positive correlation existed between ANB and DAI score in skeletal class II patients. Keywords: Malocclusion, Dental Aesthetic Index, Jaw disharmony

Influence of bone anatomical morphology of mandibular molars on dental implant based on CBCT

Background To apply CBCT to investigate the anatomical relationship between the mandibular molar and alveolar bone, aimed to provide clinical guidelines for the design of implant restoration. Methods 201 CBCT data were reevaluated to measure height of the alveolar process (EF), width of the alveolar process (GH), width of the basal bone (IJ), the angle between the long axis of the first molar and the alveolar bone (∠a) and the angle between the long axis of the alveolar bone and basal bone (∠b). The angle and width were measured to determine the implant-prosthodontic classification of the morphology in the left lower first molar (36) and right lower first molar (46). All measurements were performed on the improved cross-sectional images. Results EF, GH and IJ were measured as (10.83 ± 1.31) mm, (13.93 ± 2.00) mm and (12.68 ± 1.96) mm for 36, respectively; and (10.87 ± 1.24) mm, (13.86 ± 1.93) mm and (12.60 ± 1.90) mm for 46, respectively. No statistical significance was observed in EF, GH, IJ, ∠a and ∠b between 36 and 46 (all P > 0.05). The morphology was divided into three categories including the straight (68.7–69.2%), oblique (19.9–20.4%) and concave types (11%). Each type was consisted of two subcategories. Conclusions The proposed classification could provide evidence for appropriate selection and direction design of the mandibular molar implant in clinical. The concave type was the most difficult to implant with the highest risk of lingual perforation. The implant length, width, direction required more attention.

Basal Implant: A Remedy to Restore Resorbed Alveolar Ridges

The conventional crestal implants are used only when there is adequate jawbone height and width. Results of conventional implants are good in patients with healthy bone at the time of treatment, but prognosis gets deteriorated when surgical augmentation of bone is included with implant placement. These augmentation procedures have surgical risks and are costlier to the patients. Patients with atrophied jawbones are given no treatment, until crestal implants are seen as the last option. In this article, the indications for basal implants and functional differences between basal implants and crestal implants have been discussed.Patients with extreme jawbone atrophy do not benefit from crestal implants. The basal bone is the (cortical) osseous tissue of the mandible and maxilla, and lies below the alveolar process, which has a relatively strong and no resorbing framework.Basal osseointegrated and basal cortical screw (BCS) are two types of implants designed to take anchorage from the cortical bone of the jaw. BCS implants have long shafts and can be placed immediately in the socket after extraction and provided with immediate loading within 72 hours of implant placement. Basal implants are also called bicortical or cortical implants as they utilize the cortical portion of the jawbones for anchorage and implant stability. The basal bone has better quality and quantity of cortical bone for retention of these unique and highly advanced implants. The other names for these implants are lateral implants or disk implants.

Computed tomography assessment of maxillary bone density for orthodontic mini-implant placement with respect to vertical growth patterns

Objective: To quantitatively measure and report bone density of maxilla in the interradicular (alveolar and basal bone) and infrazygomatic crest (IZC) region in various growth patterns among Dravidian individuals. Design: This was a retrospective spiral computed tomography (CT) study. Setting: The study was conducted at the Department of Orthodontics, Saveetha Dental College and Hospital, Tamil Nadu, India. Methods: Sixty CT scans (24 men, 36 women; mean age = 25.3 years and 23.8 years, respectively) divided equally into three groups based on vertical facial proportions were included. Bone density measurements in Hounsfield units (HU) were performed using Philips and RadiAnt DICOM viewers. Buccal cortical, palatal cortical and cancellous bone regions were analysed in a Philips DICOM viewer and IZC region was analysed in a RadiAnt DICOM viewer. Statistical analysis with one-way ANOVA and post-hoc Tukey HSD test was done. Results: The hypodivergent group had a significantly higher bone density at the buccal cortex in posterior region ( P < 0.05) when compared to the normodivergent and hyperdivergent groups. Buccal basal bone was denser than buccal alveolar bone ( P < 0.05) in all three groups. In the IZC region, hypodivergent groups had significantly higher density values when compared to the normodivergent and hyperdivergent groups ( P < 0.05). Conclusion: The present study concluded that cancellous bone density in the interradicular regions was greatest in the anterior sites and was not influenced by growth pattern. Hypodivergent groups tend to have higher density in the posterior regions (buccal and palatal cortical bone) and at the IZC region compared to normodivergent and hyperdivergent groups.