A CBCT Evaluation of Esthetic Preference Regarding the Perceived Facial Attractiveness of Young Korean Female Adults with a Normal Skeletal Pattern.

The aim of this study was to determine the factors that affect esthetic preference regarding the perceived facial attractiveness of young Korean female adults with a normal skeletal pattern using cone-beam computed tomography (CBCT). After reorienting the CBCT images of 40 young Korean female adults, three-dimensional (3D) measurements were analyzed, and five 3D facial images were digitally constructed. A computer-based questionnaire was used to determine perceived facial attractiveness by scoring from 1 (very unattractive) to 10 (very attractive). Esthetic perception and the most influential facial view and component were examined and compared by orthodontists, general dentists, and laypeople to evaluate facial attractiveness. Compared to the unattractive group, the attractive group had significantly greater values for Pog-NB, L1SI-FH, U lip thickness, L lip-U lip, and Nasolabial angle, along with significantly lower values for U1SI-FH and Cant of U lip; the attractive group also had a more retruded U1MP (p < 0.01), L1MP (p < 0.01), U lip (p < 0.05), and L lip (p < 0.01) relative to N, as well as a more retruded U lip (p < 0.05) and L lip (p <0.001) relative to esthetic lines. Orthodontists and general dentists were more likely to consider the profile view. When evaluating facial attractiveness, orthodontists and laypeople more often focused on the lips and chin. When evaluating facial attractiveness, all evaluators showed a high esthetic preference for retroclination and retrusion of the incisors and lips, but there were some differences in how they perceived facial attractiveness. Therefore, the ultimate perception of facial attractiveness needs to be based on the esthetic perceptions of laypeople.

Three-dimensional surgical accuracy between virtually planned and actual surgical movements of the maxilla in two-jaw orthognathic surgery.

OBJECTIVE: To investigate the three-dimensional (3D) surgical accuracy between virtually planned and actual surgical movements (SM) of the maxilla in twojaw orthognathic surgery. METHODS: The sample consisted of 15 skeletal Class III patients who underwent two-jaw orthognathic surgery performed by a single surgeon using a virtual surgical simulation (VSS) software. The 3D cone-beam computed tomography (CBCT) images were obtained before (T0) and after surgery (T1). After merging the dental cast image onto the T0 CBCT image, VSS was performed. SM were classified into midline correction (anterior and posterior), advancement, setback, anterior elongation, and impaction (total and posterior). The landmarks were the midpoint between the central incisors, the mesiobuccal cusp tip (MBCT) of both first molars, and the midpoint of the two MBCTs. The amount and direction of SM by VSS and actual surgery were measured using 3D coordinates of the landmarks. Discrepancies less than 1 mm between VSS and T1 landmarks indicated a precise outcome. The surgical achievement percentage (SAP, [amount of movement in actual surgery/ amount of movement in VSS] × 100) (%) and precision percentage (PP, [number of patients with precise outcome/number of total patients] × 100) (%) were compared among SM types using Fisher's exact and Kruskal-Wallis tests. RESULTS: Overall mean discrepancy between VSS and actual surgery, SAP, and PP were 0.13 mm, 89.9%, and 68.3%, respectively. There was no significant difference in the SAP and PP values among the seven SM types (all p > 0.05). CONCLUSIONS: VSS could be considered as an effective tool for increasing surgical accuracy.

[Orthodontic tooth movement through the maxillary sinus in an adult with multiple missing teeth]. / Mouvements dentaires orthodontiques au travers du sinus maxillaire chez une patiente adulte présentant des édentements multiples.

This case report describes the successful orthodontic tooth movement through the maxillary sinus in an adult patient. A 41-year-old Asian woman had severe lip protrusion and multiple missing posterior teeth. Her orthodontic treatment included the extraction of two teeth, maximum retraction of the incisors using the extraction spaces and the existing spaces from the missing molars, and closure of all remaining spaces. Even though the treatment time was extended because of the anatomic and biologic challenges associated with moving posterior teeth over a long distance through the maxillary sinus, a successful outcome was obtained, with significant bone modeling of the maxillary sinus. The results demonstrate that a carefully selected force system can overcome the anatomic limitations of moving tooth against the cortical bone of the maxillary sinus wall in adult patients.

Orthodontic tooth movement through the maxillary sinus in an adult with multiple missing teeth.

This case report describes the successful orthodontic tooth movement through the maxillary sinus in an adult patient. A 41-year-old Asian woman had severe lip protrusion and multiple missing posterior teeth. Her orthodontic treatment included the extraction of 2 teeth, maximum retraction of the incisors using the extraction spaces and the existing spaces from the missing molars, and closure of all remaining spaces. Even though the treatment time was extended because of the anatomic and biologic challenges associated with moving posterior teeth over a long distance through the maxillary sinus, a successful outcome was obtained, with significant bone modeling of the maxillary sinus. The results demonstrate that a carefully selected force system can overcome the anatomic limitations of moving tooth against the cortical bone of the maxillary sinus wall in adult patients.

Effect of rigid fixation on orthodontic finishing after mandibular bilateral sagittal split setback: the case for miniplate monocortical fixation.

PURPOSE: This report reviews the diagnosis and management of patients with Class III skeletal patterns and discusses the rationale for monocortical plate fixation after bilateral sagittal split osteotomy for surgical precision, stability, and postsurgical management of patients with setback. MATERIALS AND METHODS: Two cases with significant Class III sagittal skeletal discrepancies were identified. The cases, which required maxillary advancement and mandibular setback surgery, are presented to describe the rationale and advantages for the monocortical rigid fixation method. CONCLUSIONS: Monocortical plate fixation after bimaxillary surgery for the correction of Class III skeletal malocclusions has the advantages of excellent stability and latent postsurgical adjustability, qualities that are essential for favorable treatment outcomes.

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.

Long-term stability of surgical mandibular setback.

OBJECTIVE: To test the relationship between positional changes of the proximal segments during surgery and the positional rebound of the mandible during the postsurgical period of orthodontic treatment. MATERIALS AND METHODS: The sample included records for 34 patients who had received sagittal split surgery for the correction of mandibular prognathism. Data were collected from standardized cephalometric radiographs taken immediately prior to surgery (T2), immediately following surgery (T3), and following the completion of orthodontic treatment (T4). Linear and angular changes in the orientation of the posterior border of the ascending ramus between time points T2, T3, and T4 were measured relative to superimposition on the anterior cranial base. In addition, linear changes in the position of pogonion between T3 and T4 were measured. RESULTS: The magnitude of linear displacement of the posterior border of the proximal segment during surgery (T2 to T3) was statistically significantly correlated (r=.61) with the magnitude of linear displacement of pogonion during the postsurgical phase of orthodontic treatment (T3 to T4). There was a strong relationship between the magnitude of angular (r=.67) displacement of the posterior border of the proximal segments during surgery (T2 to T3) and the magnitude of angular rebound of the posterior border of the proximal segments that occurred during the postsurgical phase of orthodontic treatment (T3 to T4). CONCLUSIONS: When rigid fixation procedures alter the position of the proximal segments during sagittal split osteotomy of the mandible, the proximal segments tend to go back toward their presurgical positions following surgery.

Clinical applications of mini-implants as orthodontic anchorage and the peri-implant tissue reaction upon loading.

Orthodontic tooth treatment depends on anchorage for improved results. There are many different sources of orthodontic anchorage. Segments of teeth or the entire arch have been the most common type of orthodontic anchorage. But in challenging situations, orthodontists frequently need extra-dental supplements of anchorage such as headgear, face mask, and intermaxillary elastics. Most of them require the patient's compliance. Recently, temporary mini-implants placed within the bone tissue have been used as orthodontic anchorage. It has been proven in many studies and case reports that the mini-implant is a very reliable anchorage source clinically and histologically. The purpose of this article is to introduce the basic clinical application of mini-implants as orthodontic anchorage and to discuss basic concepts about the tissue reaction of peri-implant bone upon placement and loading either from orthodontic mechanics and/or function in the orthodontic treatment of the patients. It is possible for mini-implants to supply absolute anchorage even though they may move slightly within the bone tissue without losing clinical stability. The primary application of mini-implants as orthodontic anchorage will be cases that need absolute anchorage for desired tooth movement.