What changes in maxillary morphology from distraction osteogenesis maxillary expansion (DOME) correlate with subjective and objective OSA measures?

OBJECTIVES: To correlate skeletal and airway measures on imaging with polysomnographic and self-reported measures after distraction osteogenesis maxillary expansion (DOME), in the effort to identify clinically relevant sites of expansion to guide treatment for adult patients with obstructive sleep apnea (OSA). MATERIALS AND METHODS: This is a retrospective study reviewing subjects who underwent DOME and had the complete set of the following data: peri-treatment cone-beam computed tomography (CBCT) scans, polysomnography (PSG), Epworth Sleepiness Scale (ESS), and nasal obstruction symptom (NOSE) scores. RESULTS: Of 132 subjects who underwent DOME, 35 met inclusion criteria (71% men, mean age 27.7 ± 6.5 years, mean BMI 26.0 ± 6.4 kg/m2) and were enrolled in the study. There was a significant reduction in the NOSE score from 11.4 ± 5.5 to 3.6 ± 3.1, in the ESS score from 12.0 ± 4.6 to 7.1 ± 4.7, and in the apnea-hypopnea index (AHI) from 17.1 ± 15.8 to 7.01 ± 6.2 (p < 0.0001), after DOME. Nasal floor width at the nasopalatine canal level showed a statistically significant correlation with AHI reduction (p < .0001). CONCLUSIONS: DOME is significantly associated with reduction of nasal obstruction, sleepiness, and severity of OSA. The findings suggest that expansion at the anterior third of the bony nasal passage, specifically where the nasopalatine canal is located predicts its clinical efficacy. This site may be a useful target anatomically via imaging.

Three-dimensional digital applications for implant space planning in orthodontics: A narrative review.

In the digital dentistry era, new tools, algorithms, data science approaches, and computer applications are available to researchers and clinicians. However, there is also a strong need for better knowledge and understanding of multisource data applications, including three-dimensional imaging information such as cone-beam computed tomography images and digital dental models for multidisciplinary cases. In addition, artificial intelligence models and automated clinical decision systems are rising. The clinician needs to plan the treatment based on state-of-the-art diagnosis for better and more personalized treatment. This article aimed to review basic concepts and the current panorama of digital implant planning in orthodontics, with open-source and closed-source tools for assessing cone-beam computed images and digital dental models. The visualization and processing of the three-dimensional data allow better implant planning based on bone conditions, adjacent teeth and root positions, and the prognosis of the case. We showed that many tools for assessment, segmentation, and visualization of cone-beam computed tomographic images and digital dental models could facilitate the treatment planning of patients needing implants or space closure. The tools and approaches presented are toward personalized treatment and better prognosis, following the path to a more automated clinical decision system based on multisource three-dimensional data, artificial intelligence models, and digital planning. In summary, the orthodontist needs to analyze each patient individually and use different software or tools that better fit their practice, allowing efficient treatment planning and satisfactory results with an adequate prognosis.

Automated landmark identification on cone-beam computed tomography: Accuracy and reliability.

OBJECTIVES: To evaluate the accuracy and reliability of a fully automated landmark identification (ALI) system as a tool for automatic landmark location compared with human judges. MATERIALS AND METHODS: A total of 100 cone-beam computed tomography (CBCT) images were collected. After the calibration procedure, two human judges identified 53 landmarks in the x, y, and z coordinate planes on CBCTs using Checkpoint Software (Stratovan Corporation, Davis, Calif). The ground truth was created by averaging landmark coordinates identified by two human judges for each landmark. To evaluate the accuracy of ALI, the mean absolute error (mm) at the x, y, and z coordinates and mean error distance (mm) between the human landmark identification and the ALI were determined, and a successful detection rate was calculated. RESULTS: Overall, the ALI system was as successful at landmarking as the human judges. The ALI's mean absolute error for all coordinates was 1.57 mm on average. Across all three coordinate planes, 94% of the landmarks had a mean absolute error of less than 3 mm. The mean error distance for all 53 landmarks was 3.19 ± 2.6 mm. When applied to 53 landmarks on 100 CBCTs, the ALI system showed a 75% success rate in detecting landmarks within a 4-mm error distance range. CONCLUSIONS: Overall, ALI showed clinically acceptable mean error distances except for a few landmarks. The ALI was more precise than humans when identifying landmarks on the same image at different times. This study demonstrates the promise of ALI in aiding orthodontists with landmark identifications on CBCTs.

Condylar degeneration in anterior open bite patients: A cone beam computed tomography study.

OBJECTIVES: The purpose of this study was to investigate the prevalence of condylar degeneration in patients with anterior open bites (AOB). STUDY DESIGN: Cone beam computed tomography (CBCT) scans of 194 patients with AOB (108 with skeletal open bites and 86 with dental open bites) and 100 patients serving as controls were included in this retrospective study. Two oral and maxillofacial radiologists categorized each of the 588 condyles as normal, degenerative-active, or degenerative-repair. The χ2 analysis with Bonferroni adjustment was used to evaluate the relationship of condylar status (normal vs degenerative) to anterior open bites. RESULTS: Of the 103 degenerative condyles, there were 59 in the group with skeletal open bites, 14 in the group with dental open bites, and 30 in the control group. Condylar degeneration occurred twice as frequently in patients with skeletal open bites as it did in the control group (P < .0001). Conversely, a greater frequency of normal condyles was found in the group of patients with dental open bites (P = .0002). The group with skeletal open bites also showed a significantly higher frequency of bilateral degenerative condyles (P = .0001). The frequency of condylar degeneration did not differ significantly between female and male individuals. CONCLUSIONS: Degenerative condylar change was significantly more likely in patients with skeletal open bites and less likely in patients with dental open bites.

Airway and cephalometric changes in adult orthodontic patients after premolar extractions.

OBJECTIVE: To examine changes in the airway and cephalometric measurements associated with orthodontic treatment of adults with and without premolar extractions. The study investigated whether extractions had a direct or indirect effect on the airway and examined selected skeletal and dental features. MATERIALS AND METHODS: This retrospective study used pre- (T1) and posttreatment (T2) cone-beam computed tomography scans of 83 adult patients matched for age and sex. A total of 15 airway and 10 skeletal and dental measures were analyzed by means of repeated-measures analysis of variance. RESULTS: There were no results showing that extractions affected airway dimensions that could not be accounted for as reflections of measurement error. There was no evidence that extractions affected the airway indirectly through skeletal and dental changes. There were strong and consistent findings that patients with small airways showed larger ones after treatment and that patients with large airways showed smaller ones later. These effects were independent of whether or not extractions were part of treatment. The measurement phenomena of regression toward the mean and of differential unfolding of natural changes over time could have accounted for the results observed. CONCLUSIONS: There was no evidence that extractions in nongrowing patients have negative consequences on the size of various airway measures in the nasopharynx, retropalatal, or retroglossal regions.

Reliability of 3D dental and skeletal landmarks on CBCT images.

OBJECTIVES: To quantify reliability of three-dimensional skeletal landmarks and a comprehensive set of dental landmarks in cone-beam computed tomography (CBCT) and to determine the shapes of envelope of error. MATERIALS AND METHODS: Three judges located 31 skeletal landmarks and 60 dental landmarks on the pre- and posttreatment CBCT images of 22 patients. Landmark error was determined by calculating the distance of deviation of landmark locations around their average. Standard deviation and mean radial spherical error were calculated. Scatterplots were constructed to characterize envelope of error. RESULTS: The midline landmarks of the cranial base were highly reliable. Bilateral skeletal landmarks tended to have larger error than midline landmarks. Among the nonconventional landmarks, fronto-zygomatic suture, condyle, and mental foramen showed relatively high reliability. However, foramen spinosum and temporal fossa showed larger errors. Gonion was the least reliable landmark. Most dental landmarks were located more reliably than skeletal landmarks. The highest reliability was found at incisal edges. Mesiobuccal cusp of first molars also showed high reliability. CONCLUSIONS: There were differences in the size and shape of the distributions of errors of different landmarks. Most landmarks showed elongated envelopes. Bilateral structures tended to show greater errors than midline structures. Most dental landmarks were more reliable than skeletal landmarks.

Parameters affecting mechanical and thermal responses in bone drilling: A review.

Surgical bone drilling is performed variously to correct bone fractures, install prosthetics, or for therapeutic treatment. The primary concern in bone drilling is to extract donor bone sections and create receiving holes without damaging the bone tissue either mechanically or thermally. We review current results from experimental and theoretical studies to investigate the parameters related to such effects. This leads to a comprehensive understanding of the mechanical and thermal aspects of bone drilling to reduce their unwanted complications. This review examines the important bone-drilling parameters of bone structure, drill-bit geometry, operating conditions, and material evacuation, and considers the current techniques used in bone drilling. We then analyze the associated mechanical and thermal effects and their contributions to bone-drilling performance. In this review, we identify a favorable range for each parameter to reduce unwanted complications due to mechanical or thermal effects.

Three-dimensional evaluation of interradicular spaces and cortical bone thickness for the placement and initial stability of microimplants in adults.

INTRODUCTION: The objective of this retrospective study was to measure interradicular space, thickness of cortical bone, and alveolar process width at prospective microimplant placement sites in order to understand both safety and stability aspects of microimplant placement by using cone-beam 3-dimensional volumetric images. METHODS: Initial 3-dimensional images of 60 adult patients (30 men, 30 women; mean age, 27.1 years) were reoriented by using a standardized protocol. Interradicular space, cortical bone thickness, and alveolar process width were obtained at the alveolar processes from canine to second molar at 3 different vertical levels from the cementoenamel junction (CEJ). Palatal bone thickness was measured along the midpalate at 5 different distances from the distal edge of the incisal foramen. Peripheral palatal bone thickness was also measured at analogous locations, and cortical bone thickness of the retromolar pad was measured. RESULTS: Maxillary interradicular distances ranged from 1.6 to 3.46 mm and tended to increase from the CEJ to the apex. They were the greatest between the second premolar and the first molar. Mandibular interradicular distances ranged from 1.99 to 4.25 mm and tended to be greater than maxillary interradicular spaces. Maxillary and mandibular buccal cortical bone thicknesses were 1.12 to 1.33 mm and 1.25 to 2.98 mm, respectively. In both jaws, buccal cortical bone thickness tended to increase from the CEJ to the apex. Alveolar process widths were 3.74 to 5.78 mm in the maxilla and 3.11 to 7.84 mm in the mandible. Along the midpalate, palatal bone 20 to 25 mm from the incisive foramen had 7.04 mm and 6.99 mm thickness, respectively. The retromolar pad areas showed 1.96 to 2.06 mm thicknesses of cortical bone. CONCLUSIONS: In the alveoloar process, 1 mm or more cortical bone thickness can be expected in the posterior dentition area. Safe locations for microimplant placements with adequate interradicular space are between the second premolar and the first molar in the maxillary buccal alveolar bone, between the molars in the maxillary palatal alveolar bone, and interradicular spaces from the first premolar to the second molar in the mandibular buccal alveolar bone. The midpalatal area and the retromolar pad area are also excellent locations for microimplant placement. Because of limited interradicular spaces, the recommended diameter of a microimplant is 1.2 to 1.6 mm for placement in the alveolar bone, and the recommended length is 6-7 mm.