Histologic analysis of resorbable blasting media surface implants retrieved from humans: a report of two cases.

The purpose of this study is to evaluate the degree of osseointegration of resorbable blasting media (RBM) surface implants retrieved from humans. Three implants in the mandibular molar region that were surface-treated with RBM were retrieved from two patients. The implants were used to manufacture specimens in order to measure the bone-implant contact (BIC) ratio. The BIC ratios of the three implants were found to be an average of 69.0%±9.1%. In conclusion, that RBM surface implants are integrated into the host environment with histological significance and the BIC ratio of the RBM surface-treated implant was not significantly different from that of other surface-treated implants.

Evaluation of Soft Tissue Changes Around the Lips After Mandibular Setback Surgery With Minimal Orthodontics Using Three-Dimensional Stereophotogrammetry.

PURPOSE: Most reports on the surgery-first approach in skeletal Class III malocclusion have focused on the skeletal changes. The present study evaluated the soft tissue changes around the lips over time after mandibular setback surgery (MS) with minimal orthodontics (MO) using 3-dimensional (3D) stereophotogrammetry. MATERIALS AND METHODS: We performed a retrospective study of patients with mandibular prognathism who had undergone MS-MO. Lateral cephalograms and 3D photographs were taken before (T0) and 1 (T1) and 6 months (T2) after surgery and were superimposed. A paired t test, independent t test, and simple linear regression analysis were used to evaluate the hard and soft tissue changes and their correlation. RESULTS: The sample included 15 patients (7 males and 8 females). The soft tissue landmarks on the X-axis (left-right) showed no significant positional changes. The landmarks of the lips and oral commissure on the Y-axis (vertical) moved downward until T2; however, most of these changes did not differ significantly over time (T1 compared with T0 and T2 compared with T0). The landmarks in the lower lip, oral commissure, and soft tissue chin on the Z-axis (anterior-posterior) showed posterior movement at T1 and T2. In contrast, the lower lip (labiale inferius, 1.67 mm) and soft tissue chin (soft tissue B point, 1.28 mm; soft tissue pogonion, 1.61 mm) moved significantly forward from T1 to T2, but had no correlation with the anterior relapse of the mandible. CONCLUSIONS: Protrusion of the lower lip and soft tissue chin with forward and upward relapse of the mandible during postoperative orthodontics was observed. The results from the present study suggest that 3D stereophotogrammetry can be useful for evaluating the perioral soft tissue changes over time in orthognathic surgery patients.

Evaluation of soft tissue changes around the lips after bracket debonding using three-dimensional stereophotogrammetry.

OBJECTIVE: To evaluate the changes in soft tissue around the lips after orthodontic bracket debonding using three-dimensional (3-D) stereophotogrammetry. MATERIALS AND METHODS: 3-D facial images of 20 subjects (10 men and 10 women; mean age, 26.81 ± 7.23 years) were taken with a white light scanner before and after debonding the labial brackets. Two images acquired from each subject were superimposed, and 15 soft tissue landmarks around the lips were plotted and analyzed. Statistical analysis was performed using both paired and independent t-tests (P < .05). RESULTS: There were no significant changes in position of any landmark on the x (left-right)- or y (vertical)-axes after removal of the brackets. However, the landmarks in the oral commissures and lower lip (LLP, -0.55 mm; Li, -0.44 mm; Ch-L, -0.56 mm, all P < .05) on the z (anteroposterior)-axis showed statistically significant differences. There were no significant positional changes of most landmarks on the x-, y-, or z- axes after bracket removal among the various genders and lip thicknesses. CONCLUSIONS: There was a slight retrusion in the oral commissure and lower lip areas after debonding, but no changes were found in the upper lip area. This study showed that 3-D stereophotogrammetry can be useful in evaluating facial soft tissue changes in orthodontic patients.

Influence of the changes in arch width on postsurgical relapse after mandibular setback surgery with minimal orthodontics.

PURPOSE: Most reports on the surgery-first approach in patients with skeletal Class III malocclusion have focused on skeletal changes and treatment efficacy. This study sought to evaluate the association between the transverse changes of arch dimension and postsurgical relapse of the mandible after mandibular setback surgery (MS) with minimal orthodontic preparation (MO) without extractions (N). MATERIALS AND METHODS: This was a retrospective cohort study. The sample consisted of patients with skeletal Class III malocclusion who underwent MS-MO/N. Primary outcome variables were horizontal, vertical, and angular changes of the mandibular position (mandibular relapse). Predictor variables included changes in the transverse width of the upper and lower arches. Lateral cephalograms and study models were obtained and measured before (T0) and 1 month (T1), 3 months (T2), and 6 months (T3) after surgery. Descriptive, paired t test, repeated measures analysis of variance, and a generalized estimating equation with Bonferroni correction were computed. RESULTS: The sample consisted of 12 patients (7 female and 5 male; mean age, 19.83 ± 2.37 yr). Significant anterior and superior movements and counterclockwise rotation of the mandible were noted from T1 to T3. Despite dental decompensation from T1 to T3, there were no significant postsurgical changes in arch width. In addition, there was no correlation between the forward and upward movements of the mandible and changes of arch width. However, the counterclockwise rotation of the mandible was correlated with the changes in the upper inter-first premolar width (UIP1W) and lower inter-first molar width (LIM1W) over time. CONCLUSION: The changes in arch width had no association with horizontal and vertical relapses of the mandible. Only changes in UIP1W and LIM1W showed an association with angular relapse of the mandible.

Postsurgical stability after mandibular setback surgery with minimal orthodontic preparation following upper premolar extraction.

PURPOSE: To compare patterns of surgical change and postsurgical relapse between patients with mandibular setback surgery with minimal orthodontic preparation (MS-MO) and those with sufficient orthodontic preparation (MS-SO) after upper premolar extraction (UPE). MATERIALS AND METHODS: Twenty-six patients were allocated to 2 groups based on the duration of presurgical orthodontic preparation: MS-MO/UPE (n = 15; 5.53 ± 3.14 months) and MS-SO/UPE (n = 11; 13.00 ± 5.33 months). Lateral cephalograms were taken during the initial examination (T0), at splint removal (4 weeks after surgery; T1), and immediately after debonding (T2). To evaluate the surgical changes (T1 vs. T0) and relapse (T2 vs. T1), linear, angular, and dental measurements were used and analyzed using paired t test and independent t test. RESULTS: Although there was no significant difference in skeletodental patterns at T0 between the 2 groups, the MS-MO/UPE group showed a significantly larger amount of mandibular setback than the MS-SO/UPE group from T0 to T1. The 2 groups exhibited significant anterior and superior movement of the mandible from T1 to T2. However, the MS-MO/UPE group manifested greater counterclockwise rotation and forward movement of the mandible than the MS-SO/UPE group. Owing to such relapse of the mandible, the MS-MO/UPE group exhibited limited retraction of the upper incisors, whereas the MS-SO/UPE group showed slight labioversion of the upper incisors. CONCLUSION: Compared with the MS-SO/UPE group, the MS-MO/UPE group showed a larger amount of surgical setback and greater postsurgical counterclockwise rotation and forward movement of the mandible.