Influence of custom-made and stock mouthguard thickness on biomechanical response to a simulated impact.

BACKGROUND/AIMS: Mouthguards (MGs) are devices that can reduce the risks of facial trauma. However, the large variety of MG types and thicknesses raises the question of which type is the most effective and beneficial for the athletes. The aim of this study was to evaluate stress distribution in the skull, teeth, and jaws as a consequence of a direct impact. MATERIAL AND METHODS: Using modeling software, a human skull was modeled and a human jaw was created with all teeth inserted into the respective alveolus. The models were divided according to the MG type (custom-made or stock) and thickness (1, 2, and 4 mm). Two models without MG were evaluated with and without teeth contact. The geometries were exported to analysis software and the materials were considered ideal. Fixation occurred at the base of the foramen magnum. The load (500 N) was applied on the canine tooth with a ball. Maximum principal (MPa) and Von-Mises results were obtained. RESULTS: Without any protection, the generated tensile stress was of greater magnitude causing more damage in the absence of teeth contact. The presence of a MG significantly reduced the generated stress in all structures, and the customized/individualized type was more efficient than stock MGs. CONCLUSIONS: In extreme situations when it is impossible to use a MG, keeping the teeth in maximum intercuspal position is less harmful. Despite this, the use of any MG is beneficial and assists in dampening the generated stress. The thicker the device, the greater the capacity for decreasing the damage in all structures. The use of individual protectors for each patient is even more beneficial for preventing trauma during at-risk activities of impact.

Quantitative analysis of enamel on debonded orthodontic brackets.

INTRODUCTION: Iatrogenic damage to the tooth surface in the form of enamel tearouts can occur during removal of fixed orthodontic appliances. The aim of this study was to assess debonded metal and ceramic brackets attached with a variety of bonding materials to determine how frequently this type of damage occurs. METHODS: Eighty-one patients close to finishing fixed orthodontic treatment were recruited. They had metal brackets bonded with composite resin and a 2-step etch-and-bond technique or ceramic brackets bonded with composite resin and a 2-step etch-and- bond technique, and composite resin with a self-etching primer or resin-modified glass ionomer cement. Debonded brackets were examined by backscattered scanning electron microscopy with energy dispersive x-ray spectroscopy to determine the presence and area of enamel on the base pad. RESULTS: Of the 486 brackets collected, 26.1% exhibited enamel on the bonding material on the bracket base pad. The incidences of enamel tearouts for each group were metal brackets, 13.3%; ceramic brackets, 30.2%; composite resin with self-etching primer, 38.2%; and resin-modified glass ionomer cement, 21.2%. The percentage of the bracket base pad covered in enamel was highly variable, ranging from 0% to 46.1%. CONCLUSIONS: Enamel damage regularly occurred during the debonding process with the degree of damage being highly variable. Damage occurred more frequently when ceramic brackets were used (31.9%) compared with metal brackets (13.3%). Removal of ceramic brackets bonded with resin-modified glass ionomer cement resulted in less damage compared with the resin bonding systems.

Traumatic periapical lesion only identified through cone beam computed tomography: a case report.

This case report describes the diagnosis of a traumatic periapical lesion, caused by parafunctional habits (bruxism) and associated with bone rarefaction, that had not been identified by periapical radiography. Slight edema was observed clinically at the apical region of the maxillary left canine; however, the tooth demonstrated only physiologic mobility, and the results of a pulpal sensitivity test were inconclusive. A cone beam computed tomogram (CBCT) showed the presence of a periapical lesion. After preparation of the root canal, intracanal medication (calcium hydroxide and paramonochlorophenol) was placed and changed once a month for 2 months. After 60 days (at the time of the second medication change), the edema at the apical region was no longer visible. The root canal was filled, and CBCTs obtained 30 days and 24 months after completion of treatment showed that the lesion had regressed with bone repair. Although it is an expensive procedure, CBCT is important in the examination and diagnosis of periapical lesions that may not be seen in periapical radiographs.

The Influence of Force Direction on the Fracture Pattern and Fracture Resistance of Canine Teeth in Dogs.

Biomechanical studies of the elongated canine tooth of animals are few, and thus our understanding of mechanical and physical properties of animal teeth is limited. The objective of the present study was to evaluate the influence of force direction on fracture resistance and fracture pattern of canine teeth in an ex vivo dog cadaver model. Forty-five extracted canine teeth from laboratory beagle dogs were standardized by hard tissue volume and randomly distributed among 3 force direction groups. The teeth were secured within a universal testing machine and a load was applied at different directions based on testing group. The maximum force to fracture and the fracture pattern classification were recorded for each tooth. After correcting for hard tissue cross-sectional area in a multivariate analysis, no significant difference in the amount of force required for fracture was apparent between the different force direction groups. However, the influence of force direction on fracture pattern was significant. The results of this study may allow the clinician to educate clients on possible causal force directions in clinically fractured teeth and, thus, help prevent any contributing behavior in the future.

Unusual Spontaneous Mandibular Regeneration of a Large Defect Followed by Orthodontics, Alveolar Distraction, and Dental Implant Rehabilitation: A 10-Year Follow-Up.

This report describes an atypical case of spontaneous mandibular regeneration of a large size bony defect after resection of an aseptic osteonecrotic area near the symphysis and parasymphyseal area. The patient underwent orthodontic therapy, vertical osteogenic distraction of the alveolar bone, and oral rehabilitation with an implant borne prosthesis. This case study also describes the 10-year follow-up of comprehensive multidisciplinary treatment and successful recovery of a patient's esthetic and functional aspects.

Cross-sectional Study of Dental Trauma and Associated Factors Among 9- to 14-year-old Schoolchildren in Isfahan, Iran.

PURPOSE: To assess the prevalence of dental trauma (DT) and its associated factors in 9- to 14-year-olds. SUBJECTS AND METHODS: A cross-sectional survey was carried out through clinical examination of the permanent incisors and canines of 907 schoolchildren (9 to 14 years old, average age = 11 ± 0.5 [SD] years, 55% female and 45% male) enrolled in 20 public schools in Isfahan, Iran. The demographic data, history and cause of trauma were recorded during patient interviews and with a structured questionnaire filled in by their parents. The overjet, lip coverage, and visible signs of DT (permanent incisors only, similar to the classification used by the US National Health and Nutrition Examination Survey 1988-1994, NHANES III) were recorded. DT in permanent canines were also recorded. RESULTS: Approximately 36% (n = 325) recalled the occurrence of dental trauma, but only 23.8% (n = 216) of children had visible signs of dental trauma to the permanent incisors (girls [18.8%], boys [29.9%], OR = 0.54; 95% CI 0.40- 0.74; p = 0.000). The maxillary central incisors were commonly injured (69.5%). The most frequent types of injuries were the enamel fracture (59.0%), craze lines (16.3%), and enamel and dentin fracture (13.4%). Tooth avulsion was seen in 0.7%. No significant association was found between dental trauma and increased overjet of > 3 mm (p = 0.328), but a tendency was identified for overjet > 5 mm (OR = 1.51; 95% CI 0.89-2.58; p = 0.060). The relationship between DT and lip coverage was statistically significant (OR = 1.63; 95% CI 1.18-2.25; p = 0.003). Violence (30%) and fall (22.7%) were the main causes of DT. CONCLUSION: The prevalence of DT in permanent incisors was high (23.8%) and significantly lower in girls. The association between DT and lip coverage was significant. There was no association between DT and increased overjet of > 3 mm.

Post-traumatic complications of severe luxations and replanted teeth.

AIM: The aim of this study was to evaluate the main post-traumatic complications of severe luxation and replanted teeth using clinical and radiographic analyses. MATERIALS AND METHODS: Eighty-three patients aged between 7 and 55 years old presenting 180 traumatized teeth that suffered extrusive luxation (n=67), lateral luxation (n=69), intrusive luxation (n=10) and tooth avulsion (n=34) followed by replantation were evaluated. The follow-up period was 24 months. The complications examined were: pulp canal obliteration, pulp necrosis and root resorption (infammatory and replacement). Furthermore, the relationship between time elapsed before receiving dental attendance and development of infammatory resorption was observed. RESULTS: Pulp necrosis was the main complication, occurring in 147 teeth (82.7%). All of the teeth that suffered intrusive luxation and tooth avulsion were diagnosed with pulp necrosis, with significant difference in comparison with another traumas (p<0.001/Fisher's exact test). Infammatory root resorption was observed in 20.5% of the cases and replacement resorption was more related to tooth replantation (94.1%), showing significant prevalence among tooth luxations (p<0.001/Fisher's exact test). In addition, it was noted that patients who seek treatment 9 weeks after the trauma episode presented 10 times more chance of developing infammatory resorption when compared with patients who seek treatment soon after dental trauma (Odds ratio test). CONCLUSION: It may be concluded that pulp necrosis was the main post-traumatic complication observed in traumatized teeth and that delay in seeking treatment may damage the prognosis of severe luxation and replanted teeth. CLINICAL SIGNIFICANCE: Clinical studies describing the main complications that may affect traumatized teeth present great relevance to make the population aware of the importance of seeking immediate treatment and to alert the professional to the need for follow-up. When traumatic injuries are diagnosed and treated early, post-traumatic complications may be controlled, allowing conservation of the tooth in oral cavity.

Socio-economic indicators and predisposing factors associated with traumatic dental injuries in schoolchildren at Brasília, Brazil: a cross-sectional, population-based study.

BACKGROUND: This study assessed the prevalence of traumatic dental injuries (TDI) and its association with sociodemographic and physical characteristics in the anterior permanent teeth of 12-year-old schoolchildren at the city of Brasília - DF, Brazil. METHODS: A cross-sectional, population-based study was conducted on a sample of 1,389 boys and girls aged 12 years, enrolled in public and private fundamental schools at the Administrative Region (RA) of Brasília, Brazil, from October 2011 to September 2012. The demographic details were achieved by a structured questionnaire. The study recorded the type of damage, the size of incisal overjet, and whether lip coverage was inadequate. Sociodemographic data included sex, income and educational level of the parents or caretakers. RESULTS: A total of 1118 schoolchildren were examined, yielding a response rate of 80.48%. The prevalence of TDI was 14.63% in public schools and 23.40% in private schools. The students did not differ according to sex, income and educational level of the parents or caretakers concerning the occurrence of traumas in permanent anterior teeth. Increased overjet and inadequate lip coverage were found to be important contributing factors for TDIs. CONCLUSION: In conclusion, this study showed an expressive prevalence of TDI in 12-year-old in schoolchildren at Brasília DF, Brazil. Sex and educational level of the parents were not associated with trauma. The increased overjet and inadequate lip coverage were significantly associated with dental trauma.

Effect of preparation surface area on the clinical outcome of full veneer crowns in dogs.

Crown therapy is commonly used in veterinary medicine to provide support to teeth which have previously fractured, received root canal therapy, have significant wear, or experienced other detrimental removal of tooth substance. As with several aspects of veterinary medicine, many of the recommendations or guidelines for crown therapy originate from human dentistry, which are then transferred to veterinary patients. Due to the significant difference in the anatomy of teeth and function of the oral cavity between humans and dogs, these guidelines need to be studied to determine the appropriateness of their use in veterinary patients. This article evaluates the relationship between surface area of the preparation and clinical outcome of full veneer crown therapy of the canine tooth in dogs. Although there appeared to be a positive relationship between preparations with greater surface area and successful clinical outcome, it was not found to be statistically significant.

Camel bite injury to the maxillofacial region: unusual cause and uncommon location.

Animal bite injuries are prevalent worldwide, but the causative animal and the spectrum of injuries are dependent on the kind of animals cohabitating with the human population. Camel bites as a cause are relatively rare. Camels are particularly aggressive, especially during the mating season, when conflicts between the males occasionally lead to dangerous fights resulting in the death of one or both of the combatants. We present a case of camel bite injury to the maxillofacial region inducing an uncommon fracture and the management of both soft and hard tissue injuries, especially addressing the literature for this uncommon bite injury. Because of the unique mode of injury, the ramus was horizontally fractured and displaced. The fracture was also compound because of the deep intraoral bite wounds. The ramal fracture itself is a rare entity. The issue of primary or delayed closure in such cases is addressed.

Retrospective study of extensive heat-pressed ceramic veneers after 36 months.

STATEMENT OF THE PROBLEM: The clinical performance of ceramic veneers is influenced by various clinical and material-related factors. PURPOSE: Retrospective evaluation of extensive anterior ceramic veneers in the upper and lower jaw 36 months after placement in a private practice. MATERIALS AND METHODS: Thirty-seven patients (21 female, 16 male) were restored with adhesively luted extensive ceramic veneers made from a heat-pressed ceramic (Cergo, DeguDent, Hanau, Germany). One dentist restored a total of 130 teeth (maxilla N = 76, mandible N = 54). Adhesive cementation was performed with an etch-and-rinse adhesive (Optibond FL, Kerr Hawe, Karlsruhe, Germany) and a dual-curing composite cement. RESULTS: After 36 months, the survival rate (in situ criteria) according to Kaplan-Meier was 95.1% (95% confidence interval [CI]: 0.88; 1). Reasons for failure were four ceramic fractures and one biological failure in five restored teeth. Of the restorations, 92.8% (95% CI: 0.86;1) were in service without any clinical intervention and rated successful after 36 months. Interventions were necessary in five cases (three recementations, two endodontic treatments). Clinical performance was not influenced by the veneer position (maxillar/mandibular, survival p = 0.3/success p = 0.4). Veneers with more than 50% of exposed dentin demonstrated a significantly increased risk (hazard ratio 10.6, p = 0.026) for a clinical intervention (recementation, endodontic treatment), whereas no effect on the survival rate could be detected (p = 0.17). CONCLUSIONS: After 36 months of clinical service, extensive veneer restorations made of a pressable ceramic showed a comparable survival and success rate in the upper and lower jaw. Large areas of exposed dentin (>50%) were associated with lower success rates. CLINICAL SIGNIFICANCE: Mandibular ceramic veneers made using a heat-pressed ceramic offer the same clinical reliability as do veneers on anterior maxillary teeth. Dentin exposure significantly affects the clinical performance of heat-pressed ceramic veneers.

Radiological evaluation of single implants in maxillary anterior sites with special emphasis on their relation to adjacent teeth: a 3-year follow-up study.

AIM: The aim of this study was to measure, in adults, changes in crest bone level around single dental implants in the anterior maxilla and continuous eruption of adjacent teeth. MATERIAL AND METHODS: In this prospective study, 50 patients received single-implant-supported crowns in the maxillary anterior region. Enrolled patients lacked maxillary anterior teeth as a sequel to trauma or agenesis in the maxillary anterior region. Participants were followed during a 3-year period. Baseline radiographs were taken at the time of loading and then repeated at one- and 3-year recalls. Radiographic parameters were recorded to assess changes in the skeletal bone structure and crest bone level. RESULTS: Twenty-six patients attended for all recalls. Three patients were excluded owing to difficulties related to identifying the same radiographic landmark on the radiographs throughout the recall period. All implants were successfully integrated with no sign of peri-implantitis. The mean crest bone loss was 0.45 mm at the mesial aspect of the implant and 0.56 mm at the distal aspect. In smokers, there was significant bone loss on the distal aspect. Mean change between reference points on implant and adjacent tooth (continuous eruption of adjacent tooth) over the 3-year period was 0.67 mm. In women, mean change (0.79 mm) was statistically insignificantly higher, compared with men (0.59 mm). CONCLUSIONS: Radiographic evaluation of crest bone level showed slight bone loss after 3 years of functional loading. Some changes in the eruption of neighbouring teeth were seen. Being a smoker was associated with significant negative changes related to the crest bone level.

Prosthetic reconstruction of broken canine teeth in dogs with use of cast metal posts.

Prosthodontic treatment, especially restorations of fractured teeth in small animals, has been the subject of many veterinary dental analyses in relation to techniques of endodontic treatment, preparation and cementation, as well as the general principles of prosthodontic treatment. The purpose of this paper is to present a previously undescribed method of all-in-one crown and root prosthetic restoration of fractured teeth in large dogs, together with a thorough analysis of the drawbacks, which may help veterinary dentists to use an evidence-based approach when deciding on the type of treatment for their patients with tooth fractures.

The multidisciplinary conservative management of a vital crown root fracture.

UNLABELLED: This case study reports on the multidisciplinary management of a maxillary canine which sustained an unusual labial crown root fracture, resulting in a large veneer-like fragment.The canine was extruded orthodontically and the fragment was re-attached using adhesive materials.This multidisciplinary solution prevented impingement on the biological width, loss of vitality and loss of tooth structure, leading to an optimal soft and hard tissue aesthetic result. Successful clinical and radiographic results after three years were observed, despite canine protected occlusion. CLINICAL RELEVANCE: Multidisciplinary management can result in an improved prognosis of the tooth and, in time, may be the most cost-effective solution for the patient. When discussing treatment options with the patient, utilization of all dental specialties should be considered and offered to the patient.

Severe complication of a bonded mandibular lingual retainer.

Bonding a flexible spiral wire retainer to the lingual surfaces of all 6 anterior mandibular teeth is a commonly used type of retention. Complications are rare but can be serious enough to produce biologic damage. This article presents a serious complication of a lingual flexible spiral wire retainer. Four years after the orthodontic treatment, a 20-year-old man sought treatment for a broken flexible spiral wire retainer. The clinical examination showed about 35° of buccal root torque of that tooth. A cone-beam computed tomography image showed that the root and the apex of the tooth were almost completely out of the bone on its buccal side. Surprisingly, the tooth's vitality was preserved. The tooth was moved back, nearly to its original position; clinically, only a gingival recession remained. Orthodontists and dentists should be aware of possible complications of bonded retainers. Patients should be clearly informed how to detect problems at an early stage.

Success of Feather Margin Preparation for Full Metal Prosthodontic Crowns in the Canine Teeth in 84 Pet and Working Dogs (2005-2017).

Medical and dental records of Veterinary Dental Specialties and Oral Surgery were searched to identify dogs that received full metal prosthodontic crowns on canine teeth, using a feather or knife edge preparation between 2005 and 2017. A total of 160 teeth in 84 dogs were included in the study. Current follow-up by telephone, electronic mail, or electronic messaging was conducted, in addition to thorough record review for in-person recheck examinations. Treatment was considered successful if the prosthodontic crown was in place and no further or additional injury to the tooth had occurred at the time of reexamination, owner contact, or patient death. Tooth fracture apical to the prosthodontic crown occurred in 2 (1.25%) cases, bond failure between the tooth and the cement or the cement and the crown occurred in a single case (0.625%), and one metal crown required replacement after 3 years due to wear (0.625%), for an overall failure rate of 2.5%. These results suggest that feather preparation of the margin is at least as, if not more, successful as the more commonly accepted and performed chamfer margin, and thus is a successful, practical and durable option for prosthodontic crown treatment in dog canine teeth.

Teeth fracture among visually impaired and sighted children of 12 and 15 years age groups of Udaipur city, India--a comparative study.

AIM: To compare the prevalence of anterior teeth fracture among sighted and visually impaired children of 12 and 15 years ages in Udaipur city, India. MATERIALS AND METHODS: A cross sectional study was carried out among 508 children (83 visually impaired and 425 sighted children), which comprised of 55 males and 28 females among visually impaired and 348 females and 77 males among sighted. The survey was carried out using Andreasen's classification for teeth fracture. Data was analyzed using chi-square test, with keeping level of significance at P < 0.05. RESULTS: It was found that, visually impaired children (32.5%) had significantly higher percentage of teeth fracture than that of sighted children (9.6%) (P = 001). Males had significantly higher percentage of teeth fracture than females in both groups (P = 0.001). It was observed that overjet of more than 3.5 mm had significantly increased risk of sustaining traumatic dental injuries among visually impaired (70.4%) than that of sighted individuals (46.3%) (P = 0.043). However, fracture of teeth was independent of age groups and lip coverage. CONCLUSION: Prevalence of traumatic dental injuries in a group of individuals with visual impairment was higher than that of sighted. This should alert caregivers to carry out a profound investigation of the events and suggest methods to reduce this type of morbidity.

Treatment of multiple traumatized anterior teeth associated with an alveolar bone fracture in a 15-year-old school boy: a 2.5-year follow up.

We report a case of multiple dental traumas in a 15-year-old school boy who was hit by a stone. Clinical examinations revealed the avulsion of teeth 21, 22, and 23, an uncomplicated crown fracture of tooth 41, and a complicated crown fracture (CCF) of teeth 11, 31, and 33. An alveolar bone fracture and a root fracture in the apical third of tooth 23 were as well noted on radiographs. The avulsed teeth were replanted and rigidly splinted after an extraoral dry time of 90 min. Endodontic treatments were performed on teeth with CCFs. The dental morphology was restored using polyethylene fiber-reinforced composite resin. Endodontic obturations were performed on replanted teeth after the arrest of external root resorptions by a long-term calcium hydroxide dressing. Esthetics and function were recovered with a 2.5-year follow-up period.

Effects of traumatic dental injuries to primary teeth on permanent teeth--a clinical follow-up study.

AIM: This study evaluated the prevalence of developmental sequelae to permanent teeth (DSP) after traumatic dental injuries to primary teeth (TDI-1) and their association with age, gender, type of injury, recurrence of injury and post-traumatic damage to primary teeth. MATERIALS AND METHODS: Dental records of 2725 children treated from February 1993 to December 2008 in a private pediatric dental clinic were examined. A total of 308 records had 412 primary teeth that sustained traumatic injuries. Age at the time of injury ranged from 4 months to 7 years. A chi-squared test and logistic regression were used for statistical analyses. RESULTS: One hundred forty-eight children (241 teeth) were followed up until the eruption of the permanent successor. The prevalence of DSP was 22.4%. Discoloration and hypoplasia were the most frequent abnormalities (74.1%), followed by eruption disorders (25.9%). Age at the time of TDI-1 was the only variable significantly associated with DSP. Sequelae were most prevalent among children who suffered an injury between 1 and 3 years of age. CONCLUSIONS: Children who sustain traumatic dental injuries should be followed up regularly for an early diagnosis and treatment of possible DSP.

Management of multiple trauma avulsion of anterior primary teeth: a three-year follow-up.

Dental trauma can cause physical, esthetic, and psychological problems. This paper presents the case of a 2-year-old boy who suffered multiple avulsions of the maxillary anterior teeth. Treatment consisted of fixed orthodontic appliances with artificial anterior teeth. The clinical follow-up lasted for three years. The procedure for the re-establishment of esthetic and dental function was based on a simple, low-cost therapeutic solution. The child and parents were satisfied with the treatment results.