Evaluation of enamel surface integrity after orthodontic bracket debonding: comparison of three different system.

OBJECTIVE: This study aimed to evaluate enamel surface integrity and time consumed during residual cement removal after bracket debonding using different adhesive removal burs with and without a dental loupe. MATERIAL AND METHODS: Sixty human-extracted premolars were collected, cleaned, mounted, and prepared for orthodontic bracket bonding. Teeth were randomly divided into three main groups (n = 20) based on the adhesive removal method: tungsten carbide system (TC), sof-lex discs system (SD), and diamond system (DB) groups. Then, each group was subdivided into two subgroups (naked eye and magnifying loupe subgroups). The brackets were bonded and then debonded after 24 h, and the Adhesive Remnant Index (ARI) was assessed. The adhesive remnants were removed by different systems, and the final polishing was performed by Silicone OneGloss. The enamel surface roughness was evaluated before bracketing (T0), after residual cement removal (T1), and finally after polishing (T2) using surface Mitutoyo SJ-210 profilometry and Scanning Electron Microscopy (SEM) to determine the Enamel Damage Index (EDI) score. The time consumed for adhesive removal was recorded in seconds. RESULTS: The Kruskal Wallis test showed a statistically significant difference in roughness values at T1 compared to T2 between subgroups (p < 0.001). When comparing EDI at T1 and T2, the Kruskal-Wallis H-test showed statistically significant differences in all subgroups. The pairwise comparisons revealed that EDI scores showed a statistically significant difference at T1 and T2 between DB vs. TC and SD (p = 0.015) but not between TC vs. SD (p = 1.000), indicating the highest roughness value observed in the DB group. The time for cement removal was significantly shorter in the magnifying loupe group than in the naked eye group and was shortest with the TC group, whereas the time was the longest with the DB group (p < 0.05). CONCLUSION: All three systems were clinically satisfactory for residual orthodontic adhesive removal. However, TC system produced the lowest enamel roughness, while the DB system created the greatest. The polishing step created smoother surfaces regardless of the systems used for resin removal.

Evaluation of maxillary sinus changes following molar distalization using clear aligners: A three-dimensional study.

OBJECTIVE: To evaluate the impact of molar distalization with clear aligners (CAs) on maxillary sinus parameters and its proximity to the root apices of maxillary molars using Cone Beam Computed Tomography (CBCT). METHODS: The study involved pre- and post-treatment CBCT images of 27 adult patients. MIMICS 21.0 software was used to measure maxillary sinus volume and surface area, while Invivo Dental 6.0 program was used to measure the sinus diameters and proximity of the maxillary molar root apices to the sinus floor. RESULTS: Post-treatment, there was a marked increase in the average volume and surface area of the maxillary sinus on both sides; however, changes in dimensions were not statistically significant. Sinus proximity to the root apices of the maxillary molars showed statistically significant differences, particularly on the left side for all roots. Gender and age impacted the outcomes, with males and younger individuals showing more pronounced changes. No significant differences were observed between the left and right sinuses in all parameters. CONCLUSION: Molar distalization with CAs increases maxillary sinus parameters, more notably in younger and male patients. All molar teeth roots moved toward the sinus, particularly the mesiobuccal root of the maxillary second molar protruded to the sinus.

Impact of molar teeth distalization by clear aligners on maxillary alveolar bone thickness and root resorption: a three­dimensional study.

OBJECTIVE: This study aimed to evaluate the impact of molar teeth distalization movement by clear aligners on changes in the alveolar bone thickness and orthodontically induced inflammatory root resorption (OIIRR) in maxillary molars using conebeam computed tomography (CBCT). MATERIALS AND METHODS: Three-dimensional CBCT scans of 35 adult patients (one hundred forty maxillary molars) with pre-designed selection criteria and a mean age of 24.4 ± 7.1 years were included. The measured parameters, including alveolar bone thickness for maxillary molars and root resorption (OIIRR), were analyzed using pre-and post-treatment CBCT (T0 and T1, respectively) with Invivo 6.0 software. RESULT: Post-treatment, relevant statistically significant changes included deposition of bone in the average palatal surface of the 1st molars. The reduction of bone was seen in the average buccal surface of the first molars and both surfaces of the second molars. Regarding root length after treatment, the average maxillary 1st molar roots showed significant OIIRR (p < 0.001). CONCLUSION: Clear aligner treatment could effectively reduce the incidence of alveolar bone thickness reduction and OIIRR in treating Class II malocclusions compared to conventional braces, as shown in previous studies. This research will aid in fully grasping the benefits of clear aligners.

Radial and ulnar forearm free flaps: A critical comparison of donor site morbidity and its impact on quality of life.

BACKGROUND: A poor evidence basis exists regarding direct comparing objective and subjective donor site morbidity associated with forearm flap. The authors evaluated the postoperative donor-site complications and quality of life outcomes between radial forearm free flap (RFFF) and ulnar forearm free flap (UFFF). METHODS: All patients undergoing RFFF or UFFF harvest were included. Grip strength, pinch strength, wrist range of movement, and testing skin sensitivity were assessed with the appropriate scales at different time intervals. In addition, cosmetic and quality of life were assessed using the Patient and Observer Scar Assessment Scale (POSAS) and Disability of Arm, Shoulder, and Hand (DASH) score. RESULTS: Eighty patients were enrolled (40 RFFF and 40 UFFF). The results showed a short-term reduction in grip strength, fine motor skills (tip pinch, key pinch, palmar pinch), and range of motion was observed for RFFF and improved over time. None of the patients in either group experienced functional disturbance in grip strength, wrist motion, fine motor skills, or sensation to light touch at 1 year. Nine patients experienced partial skin graft loss (RFFF = 6; UFFF = 3). There was a significantly higher incidence of temporary numbness in the RFFF group (p=0.040). Persistent numbness occurred in 3 cases in RFFF. Cold intolerance was significantly lower in UFFF (2.5 %) than in RFFF (22.5%). Moreover, the mean POSAS and DASH score reduced at 12 months compared to 6 months, significantly superior for UFFF. CONCLUSION: Objective function limitations are reversible short-term effects after forearm flap and do not affect daily routines in the long term. Additionally, UFFF appears to be preferred over RFFF for subjective outcomes, which emphasizes the UFFF should be considered an alternative to RFFF for reconstructing soft-tissue defects.

Alveolar bone changes following bi-maxillary vertical molars' movements using clear aligners.

OBJECTIVE: This study aimed to assess the alveolar bone changes following maxillary and mandibular molars' intrusion and extrusion movements using Clear Aligners using Cone-Beam Computed Tomography (CBCT). MATERIALS AND METHODS: This is a retrospective clinical study in which 24 adult patients with pre-designed selection criteria and a mean age of 31.1 + 9.9 years were enrolled. The alveolar bone changes around one hundred thirty-three maxillary and mandibular molars intruded or extruded by Clear Aligners therapy were analyzed from CBCT using Invivo 6.0 software. Intra- and inter-examiner reliability analysis was performed using the intra-class correlation coefficient (ICC) and Cronbach's Alpha statistics. The paired t-test was used to analyze significant differences before and after treatment (T0-T1). The significance level was considered at P < 0.05. RESULT: The patients were divided into two groups: extrusion (48.9%, n = 65 molars' root) and intrusion (51.1%, n = 68 molars' root) group. There was a significant decrease in the alveolar bone changes in the buccal surface of the mandibular right and left 1st molars in the extrusion group (-1.05 ± 0.97, -0.76 ± 1.12 mm, respectively) and the maxillary left 2nd molars in intrusion group (-0.42 ± 0.77 mm), and the lingual surface of intrusion of the mandibular left 1st molar (-0.64 ± 0.76 mm). Comparing the mean maxillary and mandibular changes (T0-T1) of both studied groups showed that the buccal alveolar bone changes for the left 1st and right 2nd molars showed a significant difference in extrusion and intrusion groups, respectively. CONCLUSIONS: The buccal alveolar bone changes is considered the most affected surface following maxillary and mandibular molars' intrusion and extrusion movements using clear aligners, with mandibular molars being more affected than the maxillary ones.

Lower lip reconstruction using McGregor fan technique with or without depressor anguli oris chimeric flap. Is there a difference in function and aesthetic outcomes?

BACKGROUND: Lower lip reconstruction aims to maintain facial subunit function and aesthetics. We present a minor modification of the McGregor flap technique, in which depressor anguli oris (DAO) muscle is separately elevated as a chimeric flap together to investigate the outcomes for reconstructing lower lip defects using various functional parameters. METHODS: The study included patients who underwent surgical repair of lower lip defects using a McGregor fan flap with or without DAO muscle chimeric flap between January 2018 and May 2021. The patients were divided into our modified technique with DAO chimeric flap (study group) and conventional McGregor (control group). The primary outcomes were functional evaluation of oral competency, speech intelligibility, and tactile sensation of reconstructed lip outcomes. The functional satisfaction and Patient and Observer Scar Assessment Scale (POSAS) were analyzed. RESULTS: A total of 20 patients were enrolled (10 patients for each group). Excellent oral competence was present in 12 patients, favorably significant in patients with DAO chimeric flap (n = 8/10, p = 0.018). All patients had intelligible speech with insignificant differences between the two groups. No patients demonstrated differences to light touch from baseline sensation at 1 year. Patients in the study group reported more lip function satisfaction (p = 0.049). The POSAS score indicates satisfaction with the appearance of all patients. CONCLUSION: McGregor fan technique combined with DAO muscle chimeric flap offers a good choice by maintaining sensory and motor functions. Our minor modification can ensure the integrity of the oral sphincter, leading to improved lower lip function.

Influence of inflammation on bleeding and wound healing following surgical extraction of impacted lower third molars.

OBJECTIVE: This study aimed to investigate the effect of inflammatory states following impacted lower third molar (ILTM) surgery regarding postoperative bleeding and wound healing. METHODS: The study included patients who underwent extraction of ILTMs associated with or without inflammatory conditions. Post-extraction bleeding and wound healing were assessed. In addition, mean grey values (MGVs) of alveolar bone and bone height using an orthopantomography radiograph were analyzed. RESULTS: A total of 376 patients were enrolled; 171 pericoronitis, 51 pulpitis, 44 chronic periapical periodontitis, 36 chronic periodontitis, and 74 control. The bleeding score in the control group was significantly lower than in the periapical periodontitis and periodontitis groups. Excellent wound healing for control, pericoronitis, pulpitis, periapical periodontitis, and periodontitis groups was (78.38%, 35.67%, 70.59%, 70.45%, and 33.33%, respectively). Patients with pericoronitis and periodontitis had significantly poorer wound healing (P < 0.01). The MGV in periapical periodontitis and periodontitis was considerably lower than in the control group. CONCLUSIONS: The inflammatory conditions associated with ILTMs increase the risk of bleeding. So suturing with the placement of local hemostatic agents over a pressure pack alone is recommended. The poorest wound healing was in localized gingival inflammation. Furthermore, MGV was affected by age and was lower with periapical periodontitis.

Proximity of upper central incisors to incisive canal among subjects with maxillary dentoalveolar protrusion in various facial growth patterns.

OBJECTIVE: To investigate the position of the upper central incisor roots (U1) relative to the incisive canal (IC) among subjects with maxillary dentoalveolar protrusion in various facial growth patterns. MATERIALS AND METHODS: 240 cone beam computed tomography images of skeletal Class I and II maxillary or bimaxillary protrusive subjects with a mean age of 23.74 ± 3.73 years were enrolled according to their facial growth pattern. The IC volume was measured using Mimics 21 software (Materialise, Leuven, Belgium). The U1 inter-root distance, width of IC, and their proximity were estimated using Invivo6 software (Anatomage, San Jose, CA). RESULTS: The IC volume was slightly greater among the high angle facial group and female patients than the other groups. Overall, the IC width was greater than the U1 inter-root distance in 55.65%, 57.6%, and 65% among the average, low, and high angle facial groups, respectively, and in 56.5% and 62.9% of males and females, respectively. The overall anteroposterior (sagittal) distances between the U1 roots and IC were 4.36 ± 1.18, 4.78 ± 1.17, and 3.83 ± 0.90 mm among the average, low, and high angle facial groups, respectively. CONCLUSIONS: The high angle facial group and female patients showed slightly greater IC dimensions than the other groups. The overall maximum sagittal distances between the U1 and IC were around 5.5, 6, and 4.7 mm among the average, low, and high angle facial groups, respectively. The low angle facial group and male patients tended to have greater sagittal distances. Therefore, the present findings could serve as a guideline when a considerable amount of upper incisor retraction is planned for Class I or II maxillary or bimaxillary dentoalveolar protrusion patients.

Acellular dermal matrix for prevention of Frey's syndrome after superficial parotidectomy of benign tumors.

PURPOSE: To evaluate: 1) the efficacy of acellular dermal matrix (ADM) to prevent Frey's syndrome (FS) after superficial parotidectomy of benign tumors. 2) the effect of different follow-up intervals on the incidence of FS. METHODS: Fifty-five patients with benign parotid gland tumors underwent superficial parotidectomy were divided into two groups: Non-ADM group (n = 31, 56.3%) and ADM group (n = 24, 43.6%). The primary outcomes measure was the incidence of FS. The secondary outcomes were surgical site depression, infection, salivary sialocele, and salivary fistula. Subjective FS was evaluated using a clinical questionnaire submitted via WeChat at 3, 6, 12, 18, 24, and 32 months postoperatively. Objective FS was evaluated using Minor starch-iodine test at 6 and 12 months postoperatively. RESULTS: There was a statistically significant difference in the incidence of subjective and objective FS when ADM compared with Non-ADM groups (P<0.05). The respective incidence of subjective FS at 3, 6, 12, 18, 24, and 32 months was 4.2%, 8.3%,20.8%, 20.8%, 20.8%, 20.8% in ADM group and 3.2%, 9.7%, 29%, 38.7%, 45.2% in Non-ADM group. The incidence of objective FS after 6 and 12 months was 4.2%, 8.3% in ADM group and 8.3% (2/24), 38.7% (12/31) in Non-ADM group respectively. Five patients in ADM group and 1 patient in Non-ADM group developed sialocele, and all patients resolved with conservative management. Surgical site depression was significantly higher in the Non-ADM group (15/31) compared with (5/24) in ADM (P=0.049). No cases of immune rejection, infection, hematoma, or salivary fistula were observed in ADM group. CONCLUSIONS: The current study demonstrated that 1) ADM could reduce the incidence of FS in the patients undergoing superficial parotidectomy. 2) the peak onset of about 18 months appear to be acceptable follow-up for the development of FS.