Anatomical relationship of the mandibular canal to its surrounding structures in mature mandibles.

A lack of agreement exists in the literature regarding the anatomical relationship of the mandibular canal to its surrounding structures such as the root apices. The purpose of this investigation was to study the spatial relationship of the mandibular canal to the posterior teeth in dried human mandibles. Twenty-two mature dried mandibles were sectioned through the root apices of the first and second premolars and molars. Second premolars and second molars had the closest distances to the canal with a mean of 4.7 mm and 3.7 mm, respectively. With a mean of 6.9 mm, the apices of the mesial roots of the first molars were farthest from the canal. The canal pathway in mature mandibles followed in S-shaped curve in 31% of the cases. In 41% of the cases it was located lingual (19%), buccal (17%), or directly inferior (5%) to the apices of the posterior teeth. In 28% of the cases the canal could not be identified clearly in the second premolar and first molar regions. In a typical S-shaped configuration the canal was located buccal to the distal root of the second molar, crossed to the lingual below the second molar mesial root, ran lingual to the first molar, and crossed back to the buccal apical to the apex of the second premolar. Based on our results it appears that the mandibular second premolar and second molar are the most likely teeth to be involved in accidental damage to the mandibular canal during root canal therapy.

Healing of horizontal root fractures.

The roots of six anterior maxillary and mandibular teeth were intentionally fractured in three monkeys. The teeth were then rigidly splinted for 12 wk. The healing of the fractured roots was examined clinically, radiographically, and histologically for a period of 6 months. Five of six fracture sites healed by either dense connective tissue or mineralized hard tissue which appeared to enter the fracture sites from the periodontal ligament. The canal spaces in these teeth were reduced substantially by calcific deposits. The remaining pulp tissue appeared vital histologically, but with areas of odontoblastic layers absent. The fractured root which failed to heal showed presence of necrotic pulp in both apical and coronal segments and the fracture site was infiltrated by inflammatory cells.

Traumatic dental injuries: current treatment concepts.

In an overview of traumatic injuries in the permanent dentition, the authors describe the classification of, assessment of and treatment strategies for managing such injuries. They explore pulpal and periodontal considerations, as well as methods of minimizing complications. In addition, they suggest preventive strategies and future directions for trauma management.

Using mineral trioxide aggregate as a pulp-capping material.

This study examined the dental pulp responses in monkeys to mineral trioxide aggregate, or MTA, and a calcium hydroxide preparation when used as pulp-capping materials. After the pulps of 12 mandibular incisors were exposed with a No. 1 round bur, they were capped with either MTA or the calcium hydroxide preparation. After five months, the authors noted no pulpal inflammation in five of six samples capped with MTA, and all six pulps in this group had a complete dentin bridge. In contrast, all of the pulps capped with the calcium hydroxide preparation showed pulpal inflammation, and bridge formation occurred in only two samples. Based on these results, it appears that MTA has the potential to be used as a pulp-capping material during vital pulp therapy.

Root resorption.

Several types of resorption affect teeth: internal, external, invasive, pressure, and idiopathic resorption. Diagnosis depends on an accurate medical and dental history, and radiographic and clinical examination. Because trauma appears to be a major factor associated with resorption, questions regarding past traumatic events may provide good leads to a likely cause. Treatment is determined based on a correct diagnosis. Root canal therapy is very beneficial in cases of internal resorption and external, inflammatory resorption. In cases of invasive resorption, it may or may not be necessary, whereas in replacement and pressure resorption, root canal therapy is not indicated at all (unless unrelated pulpal conditions necessitate endodontic intervention). Prevention of resorption includes appropriate treatment of traumatically injured teeth with frequent evaluation visits during the first year following an injury. Early detection of pressure-producing agents such as cysts, tumors, and impacted teeth can allow timely treatment to minimize the resorptive destruction.

Treatment of endodontic urgent care cases.

This article describes treatment for urgent care cases involving the dental pulp and periradicular tissues: acute pain of pulpal or periradicular origin, acute pain from endodontic procedures, and management of traumatically injured teeth.

Trauma to the oral cavity.

Sports events, particularly those in which mouth protectors are not commonly used, can be associated with injuries to the oral structures. While the incidence of sports-related orofacial injuries is not as high as for other traumatic events, the incidence could be reduced further by increased use of mouth and face protection. When injuries occur, quick action by primary health care providers can significantly improve the final outcome of the definitive treatment. Also important is appropriate follow-up evaluation and care since the effect of trauma on teeth is not always immediately apparent. Destructive resorption, unnecessary tooth loss, and possible alveolar infections may be prevented by referral to appropriate health care providers for evaluation following the initial urgent care of trauma patients.

Management of traumatically injured pulps in immature teeth using MTA.

Maintaining pulpal health during tooth development is an important goal in managing traumatic injuries in the immature dentition. The introduction of mineral trioxide aggregate has offered an improved method for pulp protection in such cases. This article describes a technique using MTA for vital pulp therapy on teeth with crown fractures that have resulted in pulp exposure.

Examination of the dentally traumatized patient.

A thorough examination of the dentally traumatized patient is the first step in arriving at the correct diagnosis and subsequent treatment plan. A medical history and evaluation is part of the initial examination along with an oral exam during which detailed information is recorded.

Treatment of crown fractures.

A crown fracture with or without pulpal involvement presents a significant problem to the patient and dentist alike. The management of the crown fracture with pulpal involvement often involves a multitude of possible clinical presentations and, therefore, many treatment options.