Management and Outcome of Maxillofacial Trauma in a 9-Week-Old Dog

This case report describes diagnosis, treatment, and outcome of maxillofacial trauma in a 9-week-old shih tzu. In addition to an open left mandibular body fracture and a right condylar process fracture, there were several relatively stable and minimally displaced right maxillary fractures. The torn soft tissues associated with the left mandibular body fracture were sutured closed, and a tape muzzle was placed. Due to sufficient fracture healing at the 2-week recheck examination, the tape muzzle was removed. The 6-week reexamination confirmed continued healing and recovery. Anesthesia was performed at the 5.5-month reexamination when the dog was 8 months old, revealing the presence of persistent deciduous teeth, linguoverted, malformed, and partially erupted permanent teeth, and asymmetric skeletal malocclusion (in addition to the breed-specific mandibular mesioclusion). Persistent deciduous teeth and linguoverted and malformed permanent teeth were extracted to allow for normal opening and closing of the mouth without traumatic occlusion. Long-term follow-up is recommended in juvenile dogs with maxillofacial injuries in order to prevent, recognize, and treat dental complications resulting from the trauma.

The Influence of Post System Design and Material on the Biomechanical Behavior of Teeth with Little Remaining Coronal Structure

PURPOSE

To evaluate the influence of different post systems on the biomechanical behavior of teeth with a severe loss of remaining coronal structure.

MATERIALS AND METHODS

Fifty standardized bovine teeth (n = 10 per group) were restored with: cast post-and-core (CPC), prefabricated metallic post (PFM), parallel glass-fiber post (P-FP), conical glass-fiber post (C-FP), or composite core (no post, CC). The survival rate during thermomechanical challenging (TC), the fracture strength (FS), and failure patterns (FP) were evaluated. Finite element models evaluated the stress distribution after the application of 100 N.

RESULTS

All specimens survived TC. Similar FS was observed among post-containing groups. Groups P-FP and CC presented 100% repairable fractures. The von Mises analysis showed the maximum stresses into the root canal in groups restored with metallic posts. Glass-fiber posts and CC presented the maximum stresses at the load contact point. Glass-fiber groups showed lower stresses in the analysis of maximal contact pressure; CPC led to the highest values of contact pressure. The modified von Mises (mvM) stress in dentin did not show differences among groups. Moreover, mvM values did not reach the dentin fracture limit for any group.

CONCLUSIONS

The type of intracanal post had a relevant influence on the biomechanical behavior of teeth with little remaining coronal structure.

A case of tooth fracture occurred upon medicating bisphosphonate for an elderly person: Preservation therapy and responses for Stage 0 of bisphosphonate-related osteonecrosis of jaw

This case report aimed to report the progress of preservation therapy and response of symptoms and signs for Stage 0 of bisphosphonate-related osteonecrosis of jaw (BRONJ). A 68-year-old female was recognized having a tooth at the left upper first molar fracture upon medicating bisphosphonate (BP) in 2007. At that time, the extraction of the tooth was an absolute contraindication. Therefore, we performed preservation therapy. We observed the symptoms and signs every month. After 5 months, swelling and redness in the entire first molar tooth were seen and fistula formed partly. Bone exposure was not seen. We administrated antibiotics immediately. As a result, symptoms disappeared. On April 10, 2009, the patient visited us as she felt a sense of incongruity in the lower left first and second molar teeth. Clinically, there were no symptoms of pain. However, we observed the radiolucent finding in about 5 mm diameter at apical position by X-ray photography; we considered a possibility of Stage 0 for BRONJ. We immediately administered medicine for 5 days and the symptoms disappeared. At present, no inflammation with signs and symptoms at the upper left first molar and lower left first, second molar parts is shown. We performed preservation therapy for tooth fracture case medicating of BP. Immediate responses for inflammation and symptoms of the Stage 0 of BRONJ have led to success. Hence, dentists should perform regular clinical observation, and enough education to the patient for BRONJ is necessary.

[Not Available]

Zusammenfassung. Etwa jedes zweite europäische Kind erleidet heute einen Zahnunfall. Die Verletzungen reichen von einfachen oder komplexeren Zahnfrakturen über diverse Arten von Dislokationsverletzungen bis hin zu Avulsionen. Während im Milchgebiss maximal ein temporärer Zahnerhalt bis zum physiologischen Zahnwechsel angestrebt wird, fehlen nach schweren Zahnverletzungen oder unfallbedingten Zahnverlusten die entsprechenden Behandlungsmöglichkeiten, die erst Erwachsenen zur Verfügung stehen. Grund ist das noch nicht abgeschlossene Kieferwachstum mit eventuellem Durchbruch weiterer bleibender Zähne, was einen Zahnersatz mit Brücken oder gar Implantaten verbietet. Daher sind richtiges Verhalten unmittelbar nach einem Zahnunfall und eine professionelle zahnärztliche Erstbehandlung essenziell für die Prognose nach einem Zahntrauma.

National Athletic Trainers' Association Position Statement: Preventing and Managing Sport-Related Dental and Oral Injuries

OBJECTIVE

To provide athletic trainers, health care professionals, and all those responsible for the care of athletes with clinical recommendations for preventing and managing sport-related dental and oral injuries.

BACKGROUND

Participation in competitive sports continues to grow at both the interscholastic and intercollegiate levels. Therefore, exposure to, and the incidence of athletic-related injury, including orofacial injury, will also likely increase. At the time of this writing, the leading governing agencies for interscholastic (National Federation of State High School Associations) and intercollegiate (National Collegiate Athletic Association) sports require only protective orofacial equipment (eg, mouthguards) for 5 and 4, respectively, of their sanctioned sports. Although orofacial injuries represent a small percentage of all sport-related injuries, the financial burden associated with these injuries (eg, tooth avulsion) can exceed $15 000 over an adult life. Therefore, effective management of sport-related dental injuries is critical to the long-term financial, physical, and emotional health of people who have experienced dental trauma.

RECOMMENDATIONS

Based upon the current evidence regarding sport-related orofacial injury, we provide recommendations related to planning considerations, education, and mouthguard efficacy, material, fabrication, and care considerations. Additionally, suggested best practices for managing sport-related dental injury are also given for athletic trainers and other health care professionals.

Crown-root fracture with pulp exposure: a case report with 16-year follow-up

A 12-year-old boy presented for dental care 35 days after he fell from his bicycle. Clinical and radiographic examinations revealed a longitudinal crown-root fracture with pulp exposure in the maxillary left central incisor. The radiograph also suggested necrosis of the maxillary right central incisor. Urgent treatment of the left central incisor involved gingivectomy followed by autogenous bonding of the tooth fragment with self-curing composite resin. Immediately after bonding, coronal access was prepared, chemical and mechanical preparation was completed, and a calcium hydroxide intracanal dressing was placed. One week after the initial appointment, endodontic treatment was initiated in the right central incisor. The root canal of the maxillary left central incisor was maintained with calcium hydroxide paste (replaced at 45-day intervals) for 1 year and then definitively obturated. At the 16-year follow-up, satisfactory periodontal, esthetic, and clinical conditions were observed, and a radiograph revealed no resorption or periapical changes.

Common Dental Injury Management in Athletes

CONTEXT

Orofacial and dental trauma continues to be a commonly encountered issue for the sports medicine team. All sports have some risk for dental injury, but "contact sports" presumably incur more risk. Immediate evaluation and proper management of the most common injuries to dentition can result in saving or restoration of tooth structure. Despite the growing body of evidence, mouth guard use and dental protection have not paralleled the increase in sports participation.

EVIDENCE ACQUISITION

A PubMed search from 1960 through April 2012 was conducted, as well as a review of peer-reviewed online publications.

RESULTS

Common dental injuries in sports include tooth (crown) fractures; tooth intrusion, extrusion, and avulsion; and temporomandibular joint dislocation. Mouth guards help prevent most injuries and do not significantly affect ventilation or speech if fitted properly.

CONCLUSION

A working knowledge of the presentation as well as management of commonly encountered dental trauma in sports is essential to the immediate care of an athlete and returning to play. Mouth guard use should be encouraged for athletes of all ages in those sports that incur significant risk.

Effects of pulp capping materials on fracture resistance of Class II composite restorations

OBJECTIVE

The aim of this study was to investigate the effect of cavity design and the type of pulp capping materials on the fracture resistance of Class II composite restorations.

MATERIALS AND METHODS

Sixty freshly extracted, sound molar teeth were selected for the study. A dovetail cavity on the mesio-occlusal and a slot cavity on disto-occlusal surfaces of each tooth were prepared, and the teeth were divided 4 groups which one of them as a control group. The pulp capping materials (TheraCal LC, Calcimol LC, Dycal) applied on pulpo-axial wall of each cavity, and the restoration was completed with composite resin. The teeth were subjected to a compressive load in a universal mechanical testing machine. The surfaces of the tooth and restoration were examined under a stereomicroscope. The data were analyzed using factorial analysis of variance and Tukey's test.

RESULTS

For pulp capping materials, the highest fracture load (931.15 ± 203.81 N) and the lowest fracture load (832.28 ± 245.75 N) were calculated for Control and Dycal group, respectively. However, there were no statistically significant differences among all groups (P > 0.05). The fracture load of the dovetail groups was significantly higher than those of the slot cavity groups (P < 0.05).

CONCLUSION

Dovetail cavity design shows better fracture resistance in Class II composite restorations, independent of used or not used pulp capping materials.

Degradation in the fatigue strength of dentin by diamond bur preparations: Importance of cutting direction

The objectives of this investigation were to evaluate the degradation in fatigue strength of dentin by diamond bur preparations and to identify the importance of cutting direction. Three groups of coronal dentin specimens were prepared from unrestored third molars, including a flaw free "control," and two groups that received a diamond bur cutting treatment performed parallel or perpendicular to the specimen length. The specimens were subjected to static or cyclic flexural loading to failure and the results were compared with data for carbide bur cutting. Under static loading diamond bur cutting resulted in significantly lower flexure strength (p ≤ 0.05) than the control for both cutting directions (from 154 to ∼124 MPa). However, there was no significant difference in the strength between the control and carbide bur treated specimens. Similarly, the fatigue strength of the diamond bur treated specimens was significantly lower (p ≤ 0.0001) than that of the control for both cutting directions. Cutting in the perpendicular direction resulted in nearly 60% reduction to the endurance limit (from 44 to 19 MPa). Based on the results, diamond bur cutting of cavity preparations causes a reduction in the fatigue strength of dentin, regardless of the cutting direction. To maintain the durability of dentin, cavity preparations introduced using diamond burs must be performed with appropriate cutting direction and followed by a finishing pass.

The wear and tear of teeth

A review is presented of the mechanical damage suffered by tooth crowns. This has been the subject of much recent research, resulting in a need to revise some of the thinking about the mechanisms involved. Damage is classified here by scale into macro-, meso- and microfracture. The focus is on the outer enamel coat because this is the contact tissue and where most fractures start. Enamel properties appear to be tailored to maximize hardness, but also to prevent fracture. The latter is achieved by the deployment of developmental flaws called enamel tufts. Macrofractures usually appear to initiate as extensions of tufts on the undersurface of the enamel adjacent to the enamel-dentine junction and extend from there into the enamel. Cracks that pass from the tooth surface tend to be deflected by an enamel region of high toughness; if they find the surface again, a chip (mesofracture) is produced. The real protection of the enamel-dentine junction here is the layer of decussating inner enamel. Finally, a novel analysis of mechanical wear (microfracture) suggests that the local toughness of the enamel is very important to its ability to resist tissue loss. Enamel and dentine have contrasting behaviours. Seen on a large scale, dentine is isotropic (behaving similarly in all directions) while enamel is anisotropic, but vice versa on a very small scale. These patterns have implications for anyone studying the fracture behaviour of teeth.

Differential diagnosis of vertical root fractures using reconstructed three-dimensional models of bone defects

OBJECTIVES

The purpose of this study was to evaluate the accuracy of diagnosing vertical root fractures (VRFs) by comparing the volume of bone defects in VRFs with those in non-VRFs on reconstructed three-dimensional (3D) models (TDMs) using CBCT.

METHODS

32 maxillary pre-molars and anterior teeth with radiolucent areas were evaluated on pre-operative CBCT images. Of the 32 teeth, 16 had a fractured root (VRF group) and 16 had a non-fractured root (non-VRF group). The radiolucent area of each tooth was traced in each dimension [mesiodistal, buccolingual and horizontal (the apicoincisal aspect)] by two observers, and 3D images were reconstructed with the Amira(®) software (Visage Imaging Inc., Richmond, Australia). The volume, V, of the TDM was divided into the coronal side and the periapical side at the horizontal slice through the apical foramen, and v was defined as the volume of the coronal side. The values of v/V were calculated for all cases. The Mann-Whitney U test was used to compare values between the VRF group and the non-VRF group (p < 0.05). A receiver operating characteristic (ROC) curve was constructed to select the optimal cut-point.

RESULTS

There was a statistically significant difference in the value of v/V between the two groups (p < 0.05). With a cut-point derived from the ROC curve, and the sensitivity, specificity and accuracy of predicting the VRFs were 1.00, 0.75 and 0.88, respectively.

CONCLUSIONS

Lesions resulting from VRFs can be distinguished from those of non-VRFs on 3D CBCT images with a high degree of accuracy, based on their different 3D shapes.

A temporary filling material used for coronal sealing during endodontic treatment may cause tooth fractures in large Class II cavities in vitro

AIM

To investigate the use of a zinc oxide/zinc sulphate-based cement (Coltosol(®) F, Coltène Whaledent, Cuyahoga Falls, OH, USA) as a temporary filling material during multiple-visit root canal treatments and the occurrence of cracks within the filling material or the tooth.

METHODOLOGY

Root canals of one hundred and twenty-two extracted human molars were prepared using ProTaper instruments up to size F2. After root canal preparation, standardized mesial-occlusal-distal cavities were prepared. The buccal-lingual/palatal width of the cavities was 4.5 mm), so that the remaining cavity walls had a mean thickness of 3.5 mm. Teeth were checked for cracks and fracture lines using a stereomicroscope with 10× magnification. A calcium hydroxide slurry was used as an intracanal dressing. The teeth were divided into three groups. In the Coltosol group, the cavity was filled with Coltosol(®) F. In the Coltosol-Clearfil group, a 2-mm layer of Coltosol(®) F was placed into the coronal pulp chamber, the remaining cavity was filled with Clearfil(™) . In the Clearfil group, a foam pellet was placed onto the orifices of the root canals, the remaining cavity was filled with Clearfil(™) . In the control group, the cavities were left without any filling material. The teeth were stored in water at 37 °C for 14 days and examined every 24 h under a stereomicroscope for fracture lines occurring on the tooth surface or in the filling material.

RESULTS

In the Coltosol group, fractures within the filling material were observed in 28 (85%) of 33 teeth. 13 (39%) teeth had tooth fractures. Amongst these teeth, 8 (61%) had root fractures, 1 (8%) had a crown fracture and 4 (31%) had a root-crown fracture.

CONCLUSION

Coltosol(®) F, when used alone as a restorative material, led to tooth fractures in Class II cavities in teeth undergoing root canal treatment. Tooth fractures may occur 4 days after placement of the filling.

Horizontal root fracture accompanied by luxation of coronal fragment in a maxillary central incisor: a case report

Root fracture injuries affect up to 7% of permanent teeth. This type of injury is rarely seen in teeth with open apices and depending on the fracture site, the prognosis is good. This case report describes a horizontal intra-alveolar root fracture in the middle third of a maxillary central incisor associated with an extrusive luxation of the coronal segment and its treatment in a 6-year-old girl. The patient was observed under a regular follow-up regime. After 2 years, clinical examination showed normal tooth color and position, with a positive response to the pulp test.

Fracture resistance and stress distribution of simulated immature teeth after apexification with mineral trioxide aggregate

AIM

To evaluate the effect of adhesive restorations on fracture resistance and stress distribution in teeth with simulated immature apices and apical plugs of mineral trioxide aggregate (MTA).

METHODOLOGY

Sixty bovine incisors were sectioned 8 mm above and 12 mm below the cemento-enamel junction (CEJ). The root canal was enlarged using a diamond bur, resulting in remaining root canal walls with 0.1-0.2 mm of thickness. A 5-mm apical plug of MTA was placed and the teeth were restored according to the following groups: GP--the root canal was filled with gutta-percha and endodontic sealer; CR--the root canal was filled with light-cured composite resin inserted incrementally; FP--a fibre post was cemented into the root canal; and RFP--the fibre post was relined with composite resin prior to the cementation into the root canal. A load was applied on the crown of all teeth at 135° to their long axis until fracture. Data was analysed by one-way anova and SNK tests (α = 0.05), whilst the fracture pattern was evaluated according to the position of the fracture. Stress distributions in the restored teeth were verified by finite element analysis.

RESULTS

Teeth restored with fibre posts and relined fibre posts were associated with the highest fracture resistance, whilst the GP group had the lowest values. GP and RC groups had similar fracture resistance values (P = 0.109). All fractures types involved the cervical and middle thirds of roots. The GP model had high levels of stress concentration in the cervical and middle thirds of roots. No difference was found amongst the stress concentration in the RC, FP and RFP models.

CONCLUSION

Restorative protocols alter the fracture resistance and stress distribution of immature teeth after placement of MTA apical plugs.

Effect of storage environment on the bond strength of reattachment of crown fragments to fractured teeth

Aim:

The aim of this study was to examine various storage environments for storing fragments before being bonded to the remaining teeth and also estimate the required force to fracture the restored teeth.

Materials and Methods:

Sixty mandibular incisor teeth were fractured on the incisal one-third and were divided into five groups of 12 each to be stored in normal saline, water, milk, saliva and dry environments for 24 hours. All the fractured parts in each group were bonded to their relevant apical parts by an etch and rinse bonding system and a flowable composite resin. The fracture resistance was measured by a universal testing machine, and the results were analyzed using one-way ANOVA and Tukey statistical tests.

Results:

The results revealed that the difference among the five groups was statistically significant (P<0.001). Tukey tests showed that the force required for fracturing fragments kept in the milk and saliva environments were significantly higher than those for the normal saline, water and dry environments (P<0.05 ).

Conclusions:

It was concluded that keeping the fractured parts in milk and saliva environments can increase the required force for fracturing teeth more than the other environments.

A single visit, reattachment of fractured crown fragment

“Minimal intervention with maximum dentistry” The immediate restorative technique resolving the acute problem of traumatic tooth fracture with pulpal involvement–An immediate fracture fragment reattachment using pre-fabricated fiber post with dual cure cement–A challenging, conservative, aesthetics, rehabilitating, functionally, and economically viable single visit procedure.