Risk factors associated with the occurrence of avulsion in the primary incisors: A case-control study.

BACKGROUND: Identifying factors associated with the occurrence of primary tooth avulsion is essential to promote prevention strategies. AIM: To investigate the risk factors associated with primary incisor avulsion and variables associated with post-avulsion sequelae in the permanent successor. DESIGN: This case-control study comprised 407 children (cases) with primary incisor avulsion and 407 children (controls) with other traumatic dental injuries (TDI). The association between explanatory variables and avulsion was evaluated through logistic regression. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated. Poisson regression analyses between potential explanatory variables and sequelae were run, from which relative risks (RR) and corresponding 95% CI were estimated. RESULTS: TDI caused by moderate falls (OR = 2.20; 95% CI = 1.47 to 3.27), affecting lateral incisors (OR = 10.10; 95% CI = 3.89 to 26.54) and the lower arch (OR = 9.54; 95% CI = 3.15 to 28.85), were associated with primary incisor avulsion. Moreover, children with previous severe TDI, anterior open bite, and anterior crossbite had higher odds of primary incisor avulsion. Children who suffered from any primary tooth avulsion (RR = 2.68; 95% CI = 1.82 to 3.95) had a higher risk of sequelae in the permanent successors. The risk for sequelae in the permanent teeth was significantly greater for younger children under age 2 years than for children ages 3 to 5 years. CONCLUSION: Risk factors for primary incisor avulsion are related to the severity of the fall, tooth position, history of previous TDI, and malocclusion. Furthermore, avulsion increases the risk of sequelae in the permanent successors.

Risk of pulp necrosis and related complications in the permanent anterior teeth with lateral luxation: A systematic review and meta-analysis.

This systematic review aimed to evaluate the evidence related to the occurrence of pulp necrosis and related complications in permanent anterior teeth with lateral luxation. It was envisaged to address the ambiguity related to the recommendation for pulp extirpation in teeth with mature root apex. An a priori protocol was formulated as per the best practices of evidence-based medicine and registered in PROSPERO. A comprehensive search was performed electronically in PubMed, LILACS, Web of Science, EMBASE, Scopus, and Cochrane on July 10,2023 without any restriction of language or year of publication. The screening of titles and abstracts and later the full-text articles were performed. Later, the data extraction was performed by using a self-designed sheet, risk of bias (ROB) assessment was done, meta-analysis was performed, and the GRADE approach was used to assess the quality of evidence. The qualitative synthesis was performed on 13 studies done from 1985 to 2020 in hospital settings. There was variability in the minimum and total observation periods, sample sizes, and characteristics of the sample population. The overall pooled prevalence of pulp necrosis was found to be 57% (95% CI: 42, 72%). It was 12% (95% CI: 8%, 18%, I2 = 0%) in immature teeth, and 58% (95% CI: 42, 73%, I2 = 86%) in mature teeth. The pooled prevalence of EIRR was found to be 11% (95% CI: 4, 27%, I2 = 95%) with greater risk in teeth with mature root apex (RR: 1.26, 95% CI: 1.12, 1.42, I2 = 0%). The ROB was moderate or high in nine studies and the GRADE of evidence was very low in 14 of 15 outcomes. There are greater chances of pulp necrosis in teeth with lateral luxation, especially with mature apex. However, it can still be less than 60% in most cases with the prevalence of EIRR less than 20%. Hence, an absolute recommendation for endodontic intervention in mature teeth with lateral luxation must be interpreted with slight caution.

Risk of ankylosis of avulsed teeth immediately replanted or stored under favorable storage conditions before replantation: A long-term clinical study.

BACKGROUND/AIM: There are few long-term clinical follow-up studies on human teeth replanted immediately or after storage in a suitable storage medium prior to replantation. This study aimed to assess the risk of ankylosis in avulsed human teeth replanted immediately or after storage in physiological media for a short time. MATERIAL: Data from 116 patients with 145 replanted avulsed permanent teeth were selected from a comprehensive dental trauma database in Copenhagen University Hospital. The following teeth were selected: Group 1 comprised 36 teeth replanted immediately (dry time <6 min; wet time <6 min). Group 2 comprised 61 teeth replanted after physiologic storage media (saliva and saline) (dry time <6 min; wet time >5 min; wet time ranged from 7 to 170 min, and mean wet time was 59 min). Group 3 (control) included 48 teeth replanted after dry storage (dry time > 60 min). METHOD: Clinical and radiographic registrations were carried out according to a standardized protocol; follow-up ranged from 7 months to 23 years. Ankylosis was diagnosed by percussion test and radiographs and related to the conditions prior to replantation and stage of root development. RESULTS: The overall risk of ankylosis was 17.2% [95% CI: 4.61; 29.79] for immediately replanted teeth, 55.3% [95% CI: 42.54; 68.00] for teeth stored in physiologic media before replantation, and 85.7% [95% CI: 75.70; 95.73] for teeth stored dry more than 1 h. Mature teeth showed a significantly higher risk of ankylosis than immature teeth. CONCLUSION: This clinical long-term study has verified earlier experimental studies showing that immediate reimplantation has the lowest risk of ankylosis. Physiologic storage media are good alternatives that also reduce the risk of ankylosis compared to dry storage, where ankylosis is more likely although not always seen. Mature teeth are significantly more likely to develop ankylosis.

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.

A pilot study comparing optical coherence tomography, radiography, clinical photography, and polarisation microscopy for studies of hypomineralisation disturbances in enamel.

Aim: To investigate the use of optical coherence tomography (OCT) as a tool to assess general and localised hypomineralisation defects in the enamel. Design and Materials: Ten extracted permanent teeth (four teeth with localised hypomineralisation, four teeth with general hypomineralisation, and two healthy controls) were used in this study. In addition, four participants who underwent OCT served as living controls for the extracted teeth. Methods: The OCT results were compared with clinical photographs, digital radiographs, and polarising microscopy images of tooth sections (considered the gold standard) to determine the method with the most accurate information regarding the extent of enamel disturbances: 1) visibility of enamel disturbance (visible yes/no); if yes, 2) extent of the disturbance in the enamel; and 3) determination of the plausible involvement of the underlying dentin. Results: OCT was more accurate than digital radiography and visual assessment. OCT could provide information about the extent of localised hypomineralised disturbances in the enamel that was comparable to that with polarisation microscopy of the tooth sections. Conclusion: Within the limitations of this pilot study, it can be concluded that OCT is suitable for investigating and evaluating localised hypomineralisation disturbances; however, it is less useful in cases with generalised hypomineralisation of the enamel. In addition, OCT complements radiographic examination of enamel; however, more studies are necessary to elucidate the full extent of the use of OCT in case of hypomineralisation.

Dental Implants in Patients with Osteogenesis Imperfecta - Clinical and Radiographic Outcome in Six Patients.

PURPOSE: To investigate the survival rate of dental implants in patients diagnosed with osteogenesis imperfecta (OI). MATERIALS AND METHODS: The study is a retrospective analysis of six individuals (2 males, 4 females) with OI (type I, III and IV) with a total of 25 dental implants. Clinical examination included plaque index, gingival index, periodontal pocket depth for each implant, presence of pus, and loosening of the implant(s). Marginal bone loss was measured on radiographs. The observation period ranged from 2-17 years (mean:7.5 years, median: 5 years). RESULTS: The overall implant survival rate was 80%. One patient with OI type III lost five implants. However, four out of five lost implants functioned for 11 years. CONCLUSION: Dental implant treatment seems to be a valid option for replacing missing teeth in OI patients. It is recommended that patients diagnosed with OI undergo the same preoperative evaluation as regular dental implant patients with special emphasis on a healthy periodontal status and ideal oral hygiene.

Regression modelling of interval censored data based on the adaptive ridge procedure.

A new method for the analysis of time to ankylosis complication on a dataset of replanted teeth is proposed. In this context of left-censored, interval-censored and right-censored data, a Cox model with piecewise constant baseline hazard is introduced. Estimation is carried out with the expectation maximisation (EM) algorithm by treating the true event times as unobserved variables. This estimation procedure is shown to produce a block diagonal Hessian matrix of the baseline parameters. Taking advantage of this interesting feature in the EM algorithm, a L 0 penalised likelihood method is implemented in order to automatically determine the number and locations of the cuts of the baseline hazard. This procedure allows to detect specific areas of time where patients are at greater risks for ankylosis. The method can be directly extended to the inclusion of exact observations and to a cure fraction. Theoretical results are obtained which allow to derive statistical inference of the model parameters from asymptotic likelihood theory. Through simulation studies, the penalisation technique is shown to provide a good fit of the baseline hazard and precise estimations of the resulting regression parameters.

Temporomandibular disorders, bite force and osseous changes of the temporomandibular joints in patients with hypermobile Ehlers-Danlos syndrome compared to a healthy control group.

BACKGROUND: Ehlers-Danlos syndrome (EDS) is a hereditary disorder that affects the connective tissue and collagen structures in the body characterised by joint hypermobility, skin hyperextensibility and tissue fragility. OBJECTIVE: The aim was to investigate temporomandibular disorders (TMD), bite force, teeth in occlusal contact and osseous changes of the temporomandibular joints (TMJs) in 26 patients with hypermobile EDS (hEDS), differentiated by a genetic test, compared to 39 healthy controls. METHODS: Clinical examination according to Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), radiological examinations of the TMJs by cone-beam-computed tomographic (CBCT) scans, registration of bite force and teeth in occlusal contact was performed. Statistical analyses included Fisher's Exact Test, multiple logistic and linear regression models adjusted for age, gender and Body Mass Index (BMI). RESULTS: Single symptoms and signs of TMD occurred significantly more often in hEDS (p = .002; p = .001; p = .003; p = <.0001; p = .012) and maximum mouth opening was significantly smaller in hEDS compared to controls (p = <.0001). The DC/TMD diagnosis myalgia, myofascial pain with referral, arthralgia, headache attributed to TMD, disc displacement disorders and degenerative joint disease occurred significantly more often in hEDS compared to controls (p = .000; p = .008; p = .003; p = .000; p = <.0001; p = .010, respectively). No significant differences were found in bite force and in teeth in occlusal contact between the groups (p > .05). On CBCT of the TMJs, subcortical sclerosis occurred significantly more often in hEDS compared to controls (p = .005). CONCLUSION: Symptoms and signs of TMD and osseous changes of the TMJs occurred significantly more often in hEDS. Bite force and teeth in occlusal contact were comparable to controls.

Impact of avulsion of the primary incisors on the occurrence of sequelae in the permanent teeth: A retrospective cohort study.

OBJECTIVES: The purpose of this retrospective cohort study was to investigate the occurrence of sequelae in the permanent teeth after avulsion of their primary antecessors and to evaluate the factors associated with this occurrence. METHODS: We screened 2922 records of patients with photographic and radiographic images who attended a reference centre for dental trauma in the primary teeth from 1998 to 2019. Among them, 240 were eligible records of children who had suffered avulsion of the primary incisors and were followed up until complete eruption of the permanent successors. Multilevel Poisson regression analyses were conducted between the explanatory variables related to children and avulsed teeth; outcome variables were occurrences of any type of sequelae in the permanent teeth, opacities, hypoplasia and malformation. Relative risks (RRs) and respective 95% confidence intervals (95% CIs) were calculated. RESULTS: Among the 240 children's records, 194 fulfilled the inclusion criteria. Finally, we found 266 primary avulsed teeth and 115 (43.2%) permanent teeth presenting with sequelae. Avulsion occurring when children were older than 4 years (RR = 0.48; 95% CI = 0.24-0.95) had lower risks for developing sequelae than children aged 0-2 years of age. Additionally, when avulsion occurred in the lower dental arch (RR = 1.45; 95% CI = 1.06-1.99) and when three or more teeth were affected (RR = 1.57; 95% CI = 1.02-2.41), the occurrence of sequelae in the permanent teeth was more probable than if avulsion occurred in the upper arch and affected only a single tooth. Age older than 3 years was a protective factor for the occurrence of hypoplasia and age older than 4 years protective for the occurrence of opacities. CONCLUSIONS: The risk of sequelae in the permanent teeth after avulsion of their antecessor is higher when the trauma occurs in young children (<2 years) and in patients with avulsions of greater magnitude, such as when it affects the lower jaw, and more teeth are involved.

Craniofacial Morphology and Upper Airway Dimensions in Patients with Hypermobile Ehlers-Danlos Syndrome Compared to Healthy Controls.

OBJECTIVES: The aims of the present case-control study were to compare craniofacial morphology, airway minimum cross-sectional area and airway volume between patients with hypermobile Ehlers-Danlos syndrome and healthy controls. MATERIAL AND METHODS: The sample comprised 18 hypermobile Ehlers-Danlos syndrome (hEDS) patients (16 females, 2 males, mean age 34.1 [SD 10.35] years), clinically diagnosed and genetically tested in order to exclude other types of EDS, and 16 controls (14 females, 2 males, mean age 37.9 [SD 10.87] years) with neutral occlusion and normal craniofacial morphology. Craniofacial morphology was assessed on lateral cephalograms. Minimum cross-sectional area and upper airway volume were assessed on cone-beam computed tomography and analysed by standard and well-validated methods. Differences were tested by logistic regression analysis adjusted for age, gender and body mass index (BMI). RESULTS: No significant differences in craniofacial morphology were found between hEDS patients and controls. Airway minimum cross-sectional area (P = 0.019) and airway volume (P = 0.044) were significantly smaller in hEDS patients compared to controls. When adjusted for age, gender and BMI no significant differences were found. However, minimum cross-sectional area was almost significant (P = 0.077). CONCLUSIONS: The craniofacial morphology and airway dimensions of hypermobile Ehlers-Danlos syndrome patients were comparable to controls, with a tendency towards a smaller minimum cross-sectional area in the hypermobile Ehlers-Danlos syndrome group. The results may prove valuable for understanding the effect of hypermobile Ehlers-Danlos syndrome on craniofacial morphology and the upper airways.

Reprint of: Jens Ove Andreasen, 1935-2020 Father of Dental Traumatology.

The life and professional contributions to dental traumatology of Dr Jens Ove Andreasen are described in terms of his research, writing, teaching, and leadership.

The risks of ankylosis of 89 avulsed human teeth stored in saliva prior to replantation-A re-evaluation of a long-term clinical study.

BACKGROUND/AIM: The survival of an avulsed tooth highly depends on the emergency management. The aim of this study was to evaluate the risk of ankylosis for avulsed human teeth stored in saliva preceded by various dry storage conditions prior to replantation. MATERIAL AND METHODS: Data include 74 patients (54 male and 20 female) with 89 avulsed and replanted teeth (16 immature teeth, 73 mature teeth). Patient ages ranged from 6 to 36 years (median: 13.0 years). All teeth were stored in saliva before replantation. Treatment and follow-up were performed according to a standardized procedure. Follow-up periods ranged from 7 months to 20 years (mean 5.3 years). The risk of ankylosis over time was estimated by the Aalen-Johansen method in relation to the length of dry storage and the stage of root development. The effect of risk factors (root development and length of dry time) on the risk of ankylosis was analysed by Cox regression analysis. RESULTS: For mature teeth, dry storage for 5 min or less before saliva storage resulted in a 47.4% (95% confidence interval (CI): 32.8-60.7) ankylosis rate. When dry storage was >5 min and <20 min, the risk of ankylosis was 76.8% (95% CI: 45.7-91.5). When dry storage exceeded 20 min prior to saliva storage, ankylosis increased to 89.3% (95% CI: 68.0-96.7). Ankylosis also increased with increasing saliva storage time. Specifically, one additional minute of wet time increased the ankylosis hazard rate (HR) by approximately 1% (CI = [0%, 2%], p = .052). Teeth with mature root development were significantly more frequently affected by ankylosis than teeth with immature root development (HR: 2.4 (95% CI: 1.0-5.5), p = .04). CONCLUSION: Temporary storage in saliva should be encouraged if an avulsed permanent tooth cannot be immediately replanted or a suitable storage medium such as milk or saline is not immediately available at the place of the accident.

Jens Ove Andreasen, 1935-2020 Father of Dental Traumatology.

The life and professional contributions to dental traumatology of Dr. Jens Ove Andreasen are described in terms of his research, writing, teaching, and leadership.

Treatment Strategies for Patients with Regional Odontodysplasia: A Presentation of Seven New Cases and a Review of the Literature.

PURPOSE: Regional odontodysplasia (RO) is a rare dental anomaly affecting primary and/or permanent dentition, and leads to comprehensive treatment need. The purpose of this study was to present a larger consecutive sample with RO, discuss treatment strategies for patients with RO, and review the literature. MATERIALS AND METHODS: A consecutive, retrospective sample of seven children with RO (6 males, 1 female) including all patients diagnosed with RO in the eastern part of Denmark was conducted over a period of 15 years. The evaluation included gender, localisation and treatment outcome. A review of the literature and cases published within the last 15 years was conducted. RESULT: Referral age was 2-12 years (mean: 7.3 years). The gender ratio was 1:6 (female:male), and the right:left ratio was 3:4. 71% of the patients had RO in the mandible and 29% in the maxilla. 43% had RO in the permanent dentition, while both primary and permanent dentition were affected in 57%. Typically, RO affected incisors and canines. In some patients, RO also affected more distal tooth types. Treatment included early multiple extractions and subsequent combined orthodontics, surgery and prosthetics. A search on RO cases published within the last 15 years was conducted and included 44 cases. The review showed a male and maxillary preponderance. The most common treatment of RO is extraction. CONCLUSION: Treatment of RO should take place in interdisciplinary, specialised teams, and individual treatment plans should be designed. Fewer but more extensive treatment sessions under general anesthaesia may minimise the burden of care for the patients.

International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 1. Fractures and luxations.

Traumatic dental injuries (TDIs) of permanent teeth occur frequently in children and young adults. Crown fractures and luxations of these teeth are the most commonly occurring of all dental injuries. Proper diagnosis, treatment planning, and follow up are important for achieving a favorable outcome. Guidelines should assist dentists and patients in decision making and in providing the best care possible, both effectively and efficiently. The International Association of Dental Traumatology (IADT) has developed these Guidelines as a consensus statement after a comprehensive review of the dental literature and working group discussions. Experienced researchers and clinicians from various specialties and the general dentistry community were included in the working group. In cases where the published data did not appear conclusive, recommendations were based on the consensus opinions of the working group. They were then reviewed and approved by the members of the IADT Board of Directors. These Guidelines represent the best current evidence based on literature search and expert opinion. The primary goal of these Guidelines is to delineate an approach for the immediate or urgent care of TDIs. In this first article, the IADT Guidelines cover the management of fractures and luxations of permanent teeth. The IADT does not, and cannot, guarantee favorable outcomes from adherence to the Guidelines. However, the IADT believes that their application can maximize the probability of favorable outcomes.

International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth.

Avulsion of permanent teeth is one of the most serious dental injuries. Prompt and correct emergency management is essential for attaining the best outcome after this injury. The International Association of Dental Traumatology (IADT) has developed these Guidelines as a consensus statement after a comprehensive review of the dental literature and working group discussions. It represents the current best evidence and practice based on that literature search and expert opinions. Experienced researchers and clinicians from various specialties and the general dentistry community were included in the working group. In cases where the published data did not appear conclusive, recommendations were based on consensus opinions or majority decisions of the working group. They were then reviewed and approved by the members of the IADT Board of Directors. The purpose of these Guidelines is to provide clinicians with the most widely accepted and scientifically plausible approaches for the immediate or urgent care of avulsed permanent teeth. The IADT does not, and cannot, guarantee favorable outcomes from adherence to the Guidelines. However, the IADT believes that their application can maximize the probability of favorable outcomes.

International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 3. Injuries in the primary dentition.

Traumatic injuries to the primary dentition present special problems that often require far different management when compared to that used for the permanent dentition. The International Association of Dental Traumatology (IADT) has developed these Guidelines as a consensus statement after a comprehensive review of the dental literature and working group discussions. Experienced researchers and clinicians from various specialties and the general dentistry community were included in the working group. In cases where the published data did not appear conclusive, recommendations were based on the consensus opinions or majority decisions of the working group. They were then reviewed and approved by the members of the IADT Board of Directors. The primary goal of these Guidelines is to provide clinicians with an approach for the immediate or urgent care of primary teeth injuries based on the best evidence provided by the literature and expert opinions. The IADT cannot, and does not, guarantee favorable outcomes from strict adherence to the Guidelines; however, the IADT believes their application can maximize the probability of favorable outcomes.

Phenotypic presentations of Hajdu-Cheney syndrome according to age - 5 distinct clinical presentations.

We present five Danish individuals with Hajdu-Cheney syndrome (HJCYS) (OMIM #102500), a rare multisystem skeletal disorder with distinctive facies, generalised osteoporosis and progressive focal bone destruction. In four cases positive genetic screening of exon 34 of NOTCH2 supported the clinical diagnosis; in one of these cases, mosaicism was demonstrated, which, to our knowledge, has not previously been reported. In one case no genetic testing was performed since the phenotype was definite, and the diagnosis in the mother was genetically confirmed. The age of the patients differs widely from ten to 57 years, allowing a natural history description of the phenotype associated with this ultra-rare condition. The evolution of the condition is most apparent in the incremental bone loss leading to osteoporosis and the acro-osteolysis, both of which contribute significantly to disease burden.

Risk of ankylosis of 400 avulsed and replanted human teeth in relation to length of dry storage: A re-evaluation of a long-term clinical study.

BACKGROUND/AIMS: Ankylosis and subsequent tooth loss is a serious complication following tooth avulsion and replantation. The aim of the study was to evaluate the risk of ankylosis of human teeth replanted after various periods of dry storage prior to replantation. The material originates from a previously reported clinical study of 400 replanted teeth. METHODS: Initial treatment, clinical and radiological examination and follow-up were conducted according to a standardized protocol. PDL was not removed. Follow-up periods ranged from 0.2 to 20 years (mean 5.1 years). The risk of ankylosis was analysed using the Cox regression model including stage of root development, length of dry time and age > 20 years. RESULTS: The risk of ankylosis significantly increased with increasing length of dry time (hazard ratio: 1.22, P = .002) and was significantly higher for teeth with mature root development than for teeth with immature root development (hazard ratio: 2.1 P < .0001). The estimated risks of ankylosis after 900 days for teeth with immature root development were: dry time < 20 minutes: 33.9% (95% confidence interval (CI): 25.4-42.7), dry time 20-40 minutes: 49.6% (95% CI: 37.5-64.8), dry time 40-60 minutes: 54.4% (95% CI: 37.1-71.3) and dry time > 60 minutes: 60.0% (95% CI: 45.0-75.8). The risks for teeth with mature root development were: dry time < 20 minutes: 59.4% (95% CI: 51.6-66.5), dry time 20-40 minutes: 78.3% (95% CI: 69.5-86.2), dry time 40-60 minutes: 81.9% (95% CI: 67.2-92.4) and dry time > 60 minutes: 86.4% (95% CI: 79.7; 92.9). CONCLUSION: The risk of ankylosis rose with increasing length of dry time. However, some teeth may heal without ankylosis even after 60 minutes of dry time. Immature teeth have a lower risk of developing ankylosis. Replantation should therefore always be considered for avulsed teeth.