Forced eruption in impacted teeth: analysis of failed cases and outcome of re-operation.

BACKGROUND: Forced eruption of an impacted tooth usually requires surgical and orthodontic interventions to successfully bring the tooth into the dental arch. The clinical time required for a forced eruption is difficult to predict before treatment begins and success rates are affected by several factors before and after an eruption. This study was conducted to identify factors that affect the success of forced eruption, the duration of orthodontic treatment of impacted teeth, and the reasons for re-operation and forced eruption failure in a various teeth and cases. METHODS: In this retrospective study, the records regarding the forced eruption of 468 teeth in 371 patients from June 2006 to May 2020 at the Advanced General Dentistry Department of Yonsei University Dental Hospital were initially examined. The records of 214 teeth in 178 patients who completed orthodontic treatment were included in the analysis. Data on patient demographics, tooth characteristics, orthodontic treatment duration, re-operations, and failures were collected from electronic medical records. RESULTS: There was a significant difference in age between the success and failure forced eruption. Factors significantly affecting treatment duration were apex formation, position, rotation, and re-operation. Re-operation had a 96% success rate. The average orthodontic treatment duration was 29.99 ± 16.93 months, but the average orthodontic treatment duration for teeth that undergone re-operation was 20.36 ± 11.05 months, which was approximately 9 months shorter. Additionally, there was an interaction effect between rotation and re-operation on the duration of orthodontic treatment. The causes for failure of forced eruption in 6 cases were ankyloses (3 cases), incomplete alignment with the normal dental arch (2 cases), and a significant deviation in the impacted tooth's location (1 case). CONCLUSIONS: To increase the success rate of forced eruption, age should be considered as a priority, and in order to predict the treatment period, the apex formation status, position in the arch, and rotation should be considered in addition to age. When determining re-operation, considering factors such as ankylosis, root curvature, and apex formation can help in the success of orthodontic treatment.

Long-term prognosis after decoronation of avulsed teeth with replacement resorption: a report of three cases.

The complications of replacement resorption following tooth injury in growing children include infrapositioning of the tooth, tilting of the adjacent teeth, and alveolar ridge deformity. Decoronation is a conservative treatment method that facilitates bone preservation. The current case report focuses on the long-term preservation of alveolar ridge dimension following decoronation in three patients. Decoronation was performed prior to occurrence of the pubertal growth spurt, and the patients' ridge width and vertical apposition were monitored for at least 4 years. Timely intervention and regular monitoring are essential for maximization of the benefits of decoronation, a simple procedure that preserves esthetics and minimizes the need for further treatments. The importance of space management for prosthetic treatment has also been highlighted. The findings of this study show that infrapositioned teeth in growing children can be treated successfully using decoronation.

Effect of ELVAX polymer subgingival implants with echistatin on extracted and reimplanted rats' teeth.

To investigate the effect of ELVAX polymer subgingival implants incorporated with echistatin peptide on incisor reimplanted tooth in rats. Forty-two male Wistars rats were divided into two groups: echistatin-treated rats (E) and control rats (C). The animals had their right maxillary incisors extracted and treated according to the International Association of Dental Traumatology replantation protocol. The extra-alveolar dry period was 30 and 60 min, and the post-surgical experimental periods were 15, 60, and 90 days. The samples were stained with H&E and analyzed for the presence of an inflammatory response, incidence of resorptions, and dental ankylosis. Results were statistically analyzed (p < 0.05). The presence of inflammatory resorption was significantly higher in group C at 30 and 60 min extra-alveolar time, in the 15-day postoperative period as compared with the E group (p < 0.05). Dental ankylosis was significantly more prevalent in group E in 30 min extra-alveolar time and 15 days postoperative period (p < 0.05). However, in 60 min extra-alveolar time and 60 days postoperative period, dental ankylosis was more prevalent in C group (p < 0.05). The use of ELVAX subgingival implants with echistatin demonstrated therapeutic potential in preventing the experimental resorption process after replantation of maxillary incisors in rats.

Challenges in Managing Post-Radiation TMJ Pseudoankylosis.

This study demonstrates the outcomes of post-radiation temporomandibular joint (TMJ) pseudoankylosis management and its challenges. A rare maxillary squamous cell carcinoma was treated with subtotal maxillary resection. Subsequent radiation therapy, failure of free flap reconstruction, and 1 year of jaw hypomobility instigated TMJ pseudoankylosis with a maximal mouth opening (MMO) of less than 5 mm. Bilateral coronoidectomy was done simultaneously with maxillary reconstruction, followed up with buccal fibrosis release and extensive jaw exercises. At 16 months of follow-up, the patient's MMO was 20 mm. Although bilateral coronoidectomy released the attachment of the atrophic temporalis muscle, it did not correct the other causes of trismus, specifically the progressive fibrosis of masticatory muscles, loss of elasticity of the TMJ ligaments, and other soft tissue abnormalities. Radiotherapy-induced-trismus refractory to physical exercise may require further management to achieve satisfactory MMO.

Factors Associated With Successful Surgical Exposure of Impacted Maxillary Canines.

PURPOSE: Impacted maxillary canines occur in up to 3% of the population and their eruption is of great importance in establishing, maintaining the shape, aesthetics, and function of the dental arch. Hence, surgical exposure of canines for the purpose of aligning them is a common surgical procedure. This study identifies the frequency and the statistically significant factors associated with successful surgical exposure of impacted maxillary canines and the relative risk factors for repeat surgery. METHODS: This is a retrospective cohort study of 182 patients who underwent surgical exposure of impacted maxillary canines and orthodontic alignment, over a 5-year period between 2014 and 2018. The variables recorded and analyzed included demographics (age and gender), type of surgery (closed or open exposure), grade of surgeon, and radiographic features on orthopantomogram (canine overlap of adjacent tooth root, vertical canine crown height, canine angulation to midline, position of canine root apex). Outcome data recorded were successful surgical exposure and orthodontic alignment and the need for repeat operation or surgical removal due to ankylosis. The data were analyzed to identify the statistically significant correlates of successful surgical exposure and the relative risk factors associated with repeat surgery. RESULTS: A total of 182 patients and 232 bone-impacted maxillary surgical canine exposures were analyzed, as 50 patients had bilateral impaction. Mean age was 15 years (range = 10-38 years), with 122 (67%) female to 60 (33%) male ratio. Total of 222/232 (96%) impacted maxillary canine teeth were successfully surgically exposed and 10/232 (4%) required re-exposure surgery. Correlates of successful surgical exposures were open exposure technique (P < .002) and reduced distance of vertical canine crown height from alveolar bone margin (P < .033). Relative risk factors for repeat surgery were increased age, male, closed surgical exposure, grade of surgeon, central impaction, increased overlap of adjacent root, increased vertical height, increased angulation to midline, canine apex position above second premolar and procedure done under local anesthetics. CONCLUSIONS: This is the largest impacted maxillary canine study to date which has identified the factors that result in successful surgical exposure, hence allow selection of the patients most suitable for this treatment. Secondly, patients with relative risk factors for repeat surgical intervention may be consented appropriately, triaged for a closer orthodontic follow-up and prioritized for surgery to reduce overall treatment time.

Surgical treatment of paediatric fractures of the mandibular condyle: a systematic review of the literature.

This study aims to review surgical treatment in paediatric condylar fractures and describe different types of techniques performed, along with the results obtained from them. A retrospective review was conducted from records of paediatric patients (from one to 17 years old) who sustained fractures of the mandibular condyle and underwent surgical treatment from 2003 to 2023. The number of patients, age, location, and type of fracture, clinical and imaging examinations, treatment methods, intraoperative/postoperative complications, removal of osteosynthesis material, follow up and outcomes were recorded and analysed. A total of 68 patients with 79 fractures were identified. The most common fracture pattern was condylar neck fracture (61.1%). Of the 68 patients who underwent surgical treatment, one had a complication of minimal temporal paraesthesia and another patient had near-complete resorption of the condyle. A total of 55 patients (81%) reported normal dental occlusion, mouth opening (>35 mm), lateral excursions (7-8 mm), TMJ function, no pain, no deviation of the midline or the jaw, and no ankylosis. Thirteen patients (19%) developed an unsatisfactory result, nine patients (13%) had a jaw deviation on mouth opening, four patients (6%) had mandibular retrusion, and seven patients (10%) had signs of TMJ dysfunction. A total of 59 patients (87%) reported bone completely healed with no signs of bone abnormality; seven patients (10%) had shortening of the condylar neck and/or ramus. Surgical treatment can lead to good or excellent results for severely dislocated and displaced condylar fractures in children and can reduce the unsatisfactory results resulting from closed treatment.

Associations across 22 dental and craniovertebral anomalies or variations, sagittal skeletal relationships, and vertical growth patterns: a comprehensive epidemiological study of 43 dentoskeletal traits.

INTRODUCTION: Despite researchers' recent interest in identifying links between some dental and craniovertebral abnormalities, there are many important, unassessed gaps in our knowledge of this matter. In addition, previous samples were small. This large study aimed to examine, for the first time, the occurrence/severity of numerous dental and skeletal anomalies or variations and their correlations with each other and with growth patterns. METHODS: This epidemiological study was conducted on pretreatment radiographs of 1194 patients from 3 cities (815 females). Skeletal sagittal skeletal relationships and vertical growth patterns were determined. The occurrence/severity were assessed for: cervical vertebral fusion (CVF), atlas posterior arch deficiency (APAD), ponticulus posticus (PP), sella turcica bridging (STB), hypodontia, oligodontia, hyperdontia, missing of maxillary laterals, microdontia, macrodontia, root dilaceration, odontoma, taurodontism, dental fusion, dental gemination, enamel pearl, permanent molar ankylosis, primary molar ankylosis, dens in dente, dens invaginatus, dental impaction, ectopic eruption, and dental transposition. Incidental findings were recorded as well. Concurrent anomalies, sex dimorphism, and correlations across variables were examined statistically, adjusting for the false discovery rate (α = 0.05). RESULTS: Prevalence was calculated for 43 dentoskeletal traits/anomalies (22 abnormalities/variations [plus their severities/types] as well as 21 incidentally found traits/anomalies). Dental impaction may be more common in hyperdivergent and severer cases of sella bridging; also, primary molar ankylosis was associated with missing teeth. Dental impaction was associated only with STB and not with PP, APAD, or vertebral fusion. The only association observed among the four skeletal anomalies was seen between APAD and CVF. Merely the variables 'sagittal skeletal relationships, vertical growth patterns, PP, and APAD' showed sexual dimorphism; of these, only vertical growth pattern and APAD remained sexually dimorphic after adjusting for the FDR; still, the other two remained marginally significant and worth further evaluations. Sex dimorphism did not exist in concurrent abnormalities. The skeletal Class III was associated with the concurrent occurrence of craniovertebral, dental, and dentoskeletal abnormalities. Skeletal Class I was associated with fewer occurrences of concurrent dental anomalies. Vertical growth patterns were not associated with concurrent dental or dentoskeletal anomalies. However, the hyperdivergent pattern was associated with fewer cases of concurrent craniovertebral abnormalities. CONCLUSIONS: STB and hyperdivergent pattern were associated with dental impaction. However, APAD, CVF, or PP were not associated with dental impaction. APAD was associated with CVF. Sexual dimorphism existed conclusively in the case of vertical growth patterns and APAD. Concurrent abnormalities (dental, skeletal, and dentoskeletal) were associated with skeletal Class III.

[Diagnosis of ankylotic deciduous molars using intraoral scans in oligodontic patients]. / Diagnose van ankylotische melkmolaren met intraorale scans bij oligodontiepatiënten.

In this retrospective study, 2 intraoral scans with an interval of at least 1 year were superimposed in 25 oligodontic patients. The differences in vertical eruption (mm) were measured and the orthopantomograms were analyzed for the presence of ankylotic deciduous molars with no successor. The mean eruption of deciduous molars with and without successor was significantly lower than the mean eruption of permanent molars. The eruption of permanent molars was a predictive variable for the eruption of deciduous molars. The number of agenetic elements and the presence of a successor were strongly associated with the eruption of deciduous molars. Also, the mean eruption of deciduous molars with ankylosis was significantly lower than that of deciduous molars without ankylosis. This study showed a strong relationship between the diagnosis of ankylotic deciduous molars and the measurement of negative vertical eruption when monitored by intraoral scans.

Assessment of bony changes in temporomandibular joint in patients using cone beam computed tomography - a cross sectional study.

BACKGROUND AND AIM: The aim of this study is to evaluate the changes in the temporomandibular joint (TMJ) in patients with temporomandibular disorder (TMD) and the relationship between age, sex, and types of TMJ change using Cone Beam Computed Tomography (CBCT). METHODS AND MATERIAL: CBCT records of 200 patients (123 women and 67 men) were retrieved and assessed. Right and left TMJs were evaluated separately, resulting in a total of 400 TMJs. The images were analyzed using On demand 3D Application The radiographic findings were classified as erosion, proliferative changes mainly, including flattening and osteophytes of the condyle, sclerosis, Ely cyst, hypoplasia and hyperplasia of the condyles, ankylosis, and joint cavity. Data analysis was performed using descriptive statistics, paired T-tests, and repeated measure ANOVA (Analysis of Variance) in SPSS Software. RESULTS: The most prevalent types of condylar bony changes observed was osteophyte (63.5%) followed by flattening of the articular surface (42%), erosion (40%), ankylosis (10%) and sclerosis (10%). 7.5% of joints showed hyperplastic condyles but only 2% showed hypoplasia. The least prevalent change observed was Ely Cyst (1%). Osteophyte was the most prevalent change observed in all age groups and both sexes except for men aged 31 ~ 50, where flattening was more frequent. A statistically significant difference was found between sex and prevalence of erosion in the age group of 10 ~ 30 (P = 0.001); as well as between sex and condylar hyperplasia in the same age group. CONCLUSION: Based on the findings of this research, the prevalence of bony changes of TMJ from highest to lowest is as follows: osteophyte, flattening of the articular surface, erosion, ankylosis, sclerosis, hyperplastic condyles, hypoplastic condyles and Ely Cyst. CBCT is an accurate 3 dimensional imaging modality for assessment of TMJ bony structures.

Management of ankylosed teeth using the decoronation technique: integrative literature review and case report.

INTRODUCTION: The decoronation technique has been described in literature since 1984 and, based on the available results, it can lead to considerable benefits for the repair and rehabilitation of ankylosed teeth. Based on these reports, one could expect that this procedure would be well known by the dental community. However, this fact does not seem to be true, and this procedure is not widely used. METHODS: The objective of this paper is to present appropriate literature that discusses decoronation and evaluate the perspectives of the procedure, both in relation to the technique and the long-term benefits for the patient. An integrative literature review at PubMed, ScieELO, and Lilacs databases was performed using the keywords "decoronation", "ridge preservation decoronation", "decoronation ankylosis". In addition, a case report will be presented to demonstrate the technique in a systematic and detailed manner. RESULTS: Considering the inclusion criteria, 27 articles that present consistency regarding decoronation were selected. CONCLUSION: There is scarce availability of scientific works related to the topic, to corroborate and discuss the technique. The present paper reinforces the benefits of this procedure, and revisit decoronation, attempting to provide a possible treatment for ankylosed teeth in growing patients.

Conventional avulsion versus less traumatic extraction of ankylosed roots with a magnetoelectric device in anterior maxillary areas.

The analysis aimed to compare two different single-tooth extraction surgical approaches in anterior maxillary areas of the ankylosed teeth: less traumatic magneto-electrical (mag) versus conventional tooth extraction (con) in minimizing the adverse effects on post-extractive sockets. Parameters of clinical interest such as intra-surgical fracture of the buccal bone plate, presence of postoperative inflammation, and application of stitches were acquired from medical records. The data were subjected to Pearson's χ2 analysis or to Fisher's exact test with significance at 0.05. Sixty-six hopeless maxillary permanent ankylotic teeth were extracted in the same number of patients. In the mag group 2 incisors suffered a fracture. Two patients out of 40 had signs and symptoms of inflammation that resolved completely within 3 days. In the con group 18 out of 26 patients suffered from buccal alveolar fracture. Six of these patients experienced signs of inflamed tissue. The two groups showed significant differences with p-values ≤0.0009 with regards to fracture (2/38 vs. 18/8) and tissue inflammation variables (2/38 vs. 10/16). A significantly different distribution about the presence of sutures was registered between the mag (4/36) and the con (18/8) group with a p-value <0.0001. Mag group seemed to have reduced frequency of fractured and infected post-extractive sites.

Puricelli biconvex arthroplasty: an experimental study in sheep.

BACKGROUND: The aim of this study was to establish a sheep model of the Puricelli biconvex arthroplasty (ABiP) technique in sheep for evaluating its functional, biological and histological parameters. METHODS: Ten Corriedale black sheep were submitted to TMJ total reconstruction with poly(methyl methacrylate) (PMMA) using ABiP and euthanized after 45 (n = 5) or 90 (n = 5) days. Control animals (n = 2) underwent sham operations and were euthanized after 45 days. Variables were assessed before the surgery (T0), immediately after (T1) and at 45 or 90 postoperative days (T2). RESULTS: Histological analyses showed regression of inflammatory cells over the follow-up period. PMMA showed reduced porosity and roughness in the articular contact area. PMMA temporal components showed linear and volumetric wear in comparison to control, but no foreign body reaction was observed. The reconstructions were stable in all animals. The amplitude of mouth opening and left lateral movements were maintained, except for a reduction in the range of right lateral movements at day 90 in the experimental group. Clinical, macroscopic and radiographic observations showed that the reconstructions were stable. CONCLUSIONS: The analysis of functional, biological and histological parameters in sheep submitted to ABiP showed stable results of the procedure, with maintenance of body weight and all mandibular movements, save contralateral mandibular movement, suggesting that joint function was completely maintained following the procedure. This experimental study provides support for clinical results previously reported of the ABiP technique in TMJ reconstruction procedures.

The diagnostic accuracy of cone-beam computed tomography and two-dimensional imaging methods in the 3D localization and assessment of maxillary impacted canines compared to the gold standard in-vivo readings: A cross-sectional study.

BACKGROUND: Although the widespread cone-beam computed tomography (CBCT) is a diagnosing tool for impacted canines, the surgical exposure-based diagnostic accuracy of this 3D imaging modality has not been established yet. Therefore this study aimed to (1) compare the accuracy of CBCT- and 2D-based interpretations of impacted canine and its relationships with the neighbouring structures with the gold standard (GS) readings, (2) and calculate the diagnostic accuracy, sensitivity, and specificity values of the variables assessed using CBCT and 2D methods. MATERIAL AND METHODS: Patients with unilateral impacted maxillary canines (IMCs) planned for surgical extraction between 2016-2018 were checked in-depth to include in this cross-sectional study. For each patient, 2D and 3D radiographic records were obtained and assessed by eight postgraduate orthodontic students. These assessments were compared with the GS readings based on surgical exposure and direct vision of the IMCs. To compare 2D- and CBCT-based assessments with the GS values, Cochran's Q tests, Friedman's tests, McNemar's, McNemar-Bowker's, and Wilcoxon tests were applied. RESULTS: A total of 17 patients (6 males, 11 females; mean age: 20.52±3.98 years) were randomly selected and included in this study. Significant differences were found between the CBCT-based assessments and the GS only concerning shape and bony coverage of the IMC (P=0.001 and P<0.001, respectively). On the contrary, there were significant differences between the 2D-based assessments and the GS regarding all the assessed variables except for the ankylosis and the proximity to the adjacent teeth (P=0.424, and P=0.080, respectively). CBCT-based assessments had remarkably higher values of diagnostic accuracy, sensitivity, and specificity compared to 2D-based ones. CONCLUSIONS: The diagnostic accuracy of CBCT outperformed 2D radiography in localizing the IMC (labiopalatal, mesiodistal, and vertical location), detecting root apex development of the IMCs, and the resorption of the adjacent incisors. Although both 2D and 3D techniques showed the same ability in the diagnosis of IMCs ankylosis, the diagnostic accuracy of CBCT was superior. However, both techniques inaccurately determined the shape of the impacted canine and the bony coverage.

The risk of healing complications in primary teeth with root fractures: A retrospective cohort study.

BACKGROUND/AIM: Primary teeth are frequently affected by traumatic dental injuries. Root fractures are rare and have a reported incidence of 2% in the primary dentition. Hence, there is limited evidence on this topic. This study aims to evaluate the risk of healing complications in primary teeth with root fracture and to identify possible sequelae in the permanent dentition following root fracture in the primary dentition. MATERIALS AND METHODS: A retrospective analysis of a cohort of 53 patients with 74 root fractured primary teeth. The standard follow-up program included clinical and radiographic examination after 4 weeks, 8 weeks, 6 months, and 1 year after the trauma and when the patient was 6 years of age. The following complications were registered: pulp necrosis (PN), pulp canal obliteration (PCO), ankylosis with replacement root resorption (ARR), infection-related root resorption (IRR), premature tooth loss (PTL), and repair-related resorption (RRR). STATISTICS: The Kaplan-Meier and Aalen-Johansen estimators were employed. The level of significance was 5%. RESULTS: A total of 74 teeth were included. 42 teeth were extracted at the initial examination. Risks estimated after 3 years: PTL 45.9% [95% CI: 28.8-63.0], PCO 12.9% [95% CI: 2.3-23.4], PN 14.9% [95% CI: 3.9-25.9], RRR 2.6% [95% CI: 0.0-7.5]. No teeth showed ARR or IRR. All complications were diagnosed within the first year. Most common sequelae in the permanent dentition was demarcated opacities, with an estimated risk of 20% [95% CI: 8.2-41.3]. CONCLUSIONS: There is a low risk of healing complications following a root fracture in the primary dentition. Root fractures often result in early extraction of the coronal fragment. The remaining apical fragment will undergo a physiological resorption. Aside from opacities, there is a low risk of sequelae in the permanent dentition.

Combined orthodontic and prosthodontic treatment in an adolescent patient with traumatically ankylosed incisors: A case report.

Symmetric extraction of premolars is a frequently used orthodontic treatment for dental crowding and protrusion. However, when a patient has incisors with ankylosis, the establishment of a treatment protocol often plagues orthodontists. An adolescent patient with a history of incisor trauma sought treatment for dental protrusion and crowding. Upon percussion of his infrapositioned maxillary central incisors, characteristic dull metallic sounds were noted, and a lack of normal mobility of these teeth under the application of external forces was detected. Follow-up radiographs after the trauma showed replacement root resorption of the maxillary central incisors. Based on clinical and radiological findings, ankylosis of the maxillary central incisors was tentatively diagnosed. A combination of orthodontic and prosthodontic treatment options involving extraction of the maxillary central incisors and mandibular first premolars was chosen to resolve the functional and esthetic problems. After treatment, well-aligned dentition, improved smile esthetics, and a more harmonious facial profile were achieved, and these outcomes remained stable during the follow-up period. This case report illustrates a viable treatment strategy for tackling predicaments caused by ankylosed incisors, which is unusual in the literature.

"Does the Exploration of the Temporomandibular Joint Using a Deep Subfascial Technique Result in a Superior Operative Outcome?"

PURPOSE: The literature is replete with various approaches for the temporomandibular joint (TMJ), each with its own distinct advantages and disadvantages. None of these approaches, however, have been associated with superior operative outcomes. The purpose of this study was to measure the efficacy of three operative approaches to TMJ, namely superficial, subfascial, and deep subfascial approaches. The aim was to contrast selected intraoperative and postoperative outcomes among these surgical approaches. METHODS: This was a prospective randomized clinical trial of subjects presenting to outpatient department. The primary predictor variables were three dissection planes of TMJ: Group-I (superficial), Group-II (subfascial), and Group-III (deep subfascial). The primary outcome variables were quality of surgical field employing fromme scale, dissection time in minutes, amount of blood loss in milliliters, and facial nerve function (FNF) using House-Brackmann scale. The secondary outcome variables were postoperative pain using visual-analog scale and swelling in millimeters measured on 1st, 3rd, and 7th postoperative days and quality of life using facial clinimetric evaluation questionnaire at 6-month follow-up. Age, gender, side, diagnosis, and type of surgery were the covariates. The data were analyzed using descriptive, comparative, and regression analysis. A P value of less than .05 was considered statistically significant. RESULT: The study included thirty subjects (8 males and 22 females) with various TMJ disorders ranging in age from 8 years to 65 years (mean 27.83 ± 10.52). On evaluation of intraoperative parameters, subfascial approach had statistically significant superior quality of surgical field (Group-I: 1.90 ± 0.57; Group-II: 1.10 ± 0.32; Group-III: 1.40 ± 0.52; P value = .006), statistically significant shortest dissection time (Group-I: 18.30 ± 3.74 min; Group-II: 13.240 ± 1.96 min; Group-III: 16.20 ± 1.99 min; with P value = .03), and statistically significant lower amount of blood loss compared with other groups (Group-I: 92.40 ± 4.74 ml: Group-II: 82.30 ± 3.77 ml; Group-III: 84.60 ± 3.06 ml; P value<.001). On assessment of postoperative parameters, only FNF of temporal branch showed statistically significant difference from 24 hours till 3 months with better outcome in deep subfascial approach. Mean scores of FNF at 24 hours and 1-week (Group-I: 4.20 ± 2.39; Group-II: 2.40 ± 2.27; Group-III: 1.50 ± 1.58 P = .02) and 1-month and 3-month (Group-I: 2.70 ± 1.82; Group-II: 1.20 ± 0.63; Group-III: 1.00 ± 0.00 P = .04). CONCLUSIONS: The subfascial approach significantly improved intraoperative outcomes and deep subfascial approach was comparatively safe with fewer incidence of facial nerve injury.

Biomechanical Evaluation of a Standard Temporomandibular Joint Prosthesis and Screw Arrangement Optimization: A Finite Element Analysis.

BACKGROUND AND OBJECTIVE: Artificial total joint replacement is an important method of temporomandibular joint (TMJ) reconstruction, which has been advocated for TMJ osteoarthrosis, ankylosis, tumors, and other diseases. We designed one type of standard TMJ prosthesis fit for Chinese patients. This study aimed to explore the biomechanical behavior of the standard TMJ prosthesis using finite element analysis and selects an optimal screw arrangement scheme for clinical application. MATERIALS AND METHODS: A female volunteer was recruited for a maxillofacial computed tomography scan, then the Hypermesh software was used to establish a finite element model of a mandibular condyle defect repaired with an artificial TMJ prosthesis. An advanced universal finite element program software was used to calculate the stress and deformation under a simulated maximum bite force loading. Also, the forces of screws under different numbers and arrangements were analyzed. Meanwhile, we designed an experiment to verify the calculation model. RESULTS: The average maximum stress of the fossa component of the standard prosthesis model was 19.25 MPa. The average maximum stress of the condyle component was 82.58 MPa, mainly concentrated near the top row hole. The fossa component should be fixed with at least 3 screws, and the optimal number of screws was 4. The condyle component should be fixed with at least 4 screws, and its optimal number was 6. The best scheme of screw arrangement was determined. The results of the verification experiment showed that the analysis was reliable. CONCLUSIONS: The stress distribution of the standard TMJ prosthesis is uniform, meanwhile, the number and arrangement of the screws significantly affect the contact force of the screws.

Management of Crown-root Fracture with 180-degree Rotation Replantation: a Report of 2 Cases.

Intentional replantation involves a combination of periodontics, endodontics, prosthodontics and oral surgery. Crown-root fracture management is still complicated nowadays. A fracture line extending longitudinally to the subgingival area and intruding bioogical width could affect infection control, gingival health and crown restoration. In the present study, we present two cases. Case 1 involved a 23-year-old man who presented at our hospital with crown-root fracture of the maxillary left central incisor. A radiographic image of the tooth revealed a fracture line under the alveolar crest. The fractured tooth was treated with intentional replantation with 180-degree rotation, root canal treatment and veneer restoration. The patient was followed up for 60 months. The replanted tooth functioned well, and no symptoms of resorption or ankylosis were observed by radiographic examination. Case 2 involved a 20-year-old woman who was referred to our hospital for crown-root fracture of her maxillary teeth. A radiographic examination revealed complicated crown-root fracture of the maxillary right lateral incisor and both maxillary central incisors. The central incisors were treated with intentional replantation with 180-degree rotation. At the 48-month follow-up, the fractured teeth were found to have regained normal function based on clinical and radiographic examination. Limited case reports are available on a long-term follow-up of intentional replantation with 180-degree rotation. These two cases, particularly case 2, presented optimal healing after 4 years with unideal crown-root ratios. This case report suggests that this old method of preserving teeth with crown-root fractures can be used as a last resort to save teeth owing to its timesaving and microinvasive procedure.

The effect of intentionally perforating the floor of the pulp chamber on pulpal healing after tooth replantation in mice.

OBJECTIVES: Shortening the root of a mouse molar prior to tooth replantation results in early revascularization in the pulp cavity and activation of the dental pulp quiescent stem cells. This study aimed to validate the effects of pulp chamber floor perforation on pulpal healing after tooth replantation as a strategy to promote early revascularization into the pulp. METHODS: The maxillary first molars of three-week-old Crlj:CD1 mice were extracted and repositioned into the original socket: the left teeth were immediately replanted (control group: CG), whereas the floor of the pulp chamber of the right teeth was perforated with a tungsten carbide bur before tooth replantation (experimental group: EG). The samples were collected from three days to eight weeks postoperatively. In addition to the TUNEL assay, immunohistochemistry for Nestin, CK14, and Ki-67 was conducted. RESULTS: In the EG, early revascularization occurred with a decrease in apoptosis and an increase in cell proliferation, facilitating pulpal healing, compared with the CG. The rate of Nestin-positive perimeter in the distal root significantly increased on days 5 and 14 and the amount of Nestin-positive hard tissue increased on day 14. However, on day 7, the number of epithelial cell rests of Malassez in the EG significantly decreased, making the EG susceptible to ankylosis at the floor. CONCLUSIONS: Intentionally perforating the floor of the pulp chamber provides a route for early revascularization, resulting in better pulpal healing after tooth replantation.

Intentional replantation and management of avulsion related ankylosis and external cervical resorption. A 10-year follow up case report.

Replantation is the treatment of choice for avulsed permanent teeth; ankylosis and cervical root resorption are among survival complications. A 9.5-year-old boy presented with an avulsed maxillary permanent central incisor with an open root apex following a school accident. The tooth was kept in milk, after a dry time of 15-20 min. Its replantation was performed 60 min after the accident. At 8 months, apexification with apical plug was attempted upon radiographic evidence of apical periodontitis. Ankylosis sound with infraocclusion and radiographic evidence of external cervical root resorption (ECR) were evident at 3 years and 3 months. At the patient's return one year later with esthetic concerns (2 mm infraocclusion) there was a 5 mm diameter ECR cavity. After intentional atraumatic extraction the resorptive cavity was debrided and restored with Biodentine; subsequently the tooth was reimplanted and splinted at an extruded position. At the 10-year follow up since the first avulsion the tooth remains esthetically pleasing, asymptomatic, non-ankylotic and functional. The present case supports intentional replantation as an option in managing infraoccluded teeth with advanced ECR.