Glossary

The mandibular canal is an important inner structure of the mandible, or lower jaw. It is a small canal that contains the inferior alveolar artery and vein, as well as the alveolar nerve. In the ramus, it runs obliquely forward and downward, and in the body, it runs horizontally forward. The mandibular canal rests underneath the alveoli, which it is able to communicate with via tiny openings. Since this canal contains a nerve and both a vein and an artery, it’s important for dental professionals to determine its location in proximity to the desired procedure site. In root canal therapy of the second molar, a dentist must take care not to extend past the tooth root with either the reamer tool or root canal filling material. If an implant is being placed in this area, the attending surgeon must be sure that the placement of implant hardware does not interfere with the mandibular canal.

Mandibular flexure is a complicated deformation process that can occur in the lower mandible. This can result in a change in the shape and width of the mandible arch, as well as protruding mandibular movements. These are caused by the contraction of various masticatory muscles, particularly the lateral pterygoid muscles. There are generally four types of deformation patterns recognized in mandibular flexure: corporal rotation, anteroposterior shear, dorsoventral shear, and symphyseal bending related to medial convergence. These patterns of deformation can result in excess stress on the bone tissue of the mandible. How the stress is distributed throughout the mandible depends on the shape of the mandible, the quality and quantity of bone, and the amount of force the masticatory muscles exert. Mandibular flexure is important for dental implant surgeons to consider, since excess occlusal loads, such as in cases of bruxism, can potentially result in long-term implant failure.

The mandibular foramen is the opening into the mandibular canal. It is located on the medial surface of the ramus of the mandible providing a passage to the inferior alveolar nerve, artery, and vein. The mandibular foramen thus allows these structures to supply the lower jaw, teeth, and part of the chin with blood, nutrients, gas exchange, and sensation. For oral procedures, the dentist or oral surgeon must be aware of the location and size of the mandibular foramen in order to administer a nerve block to numb the teeth and tissues that will be involved. Since a cranial nerve is involved with the mandibular foramen, it’s location must also be known before placing a dental implant to prevent damage to this nerve. The size and placement of the mandibular foramen can differ between patients since factors such as age, skull shape, and facial dimensions can affect its location.

Mandibular movement refers to the muscle- and ligament-activated border and/or intraborder movements of the lower jaw. There are five types of mandibular movements including rotational, horizontal axis, frontal axis, sagittal axis, and translational. Mandibular movement is affected by several factors such as the muscles used in suspending the jaw, mandibular articulation, and the synovial joint system. Study of this movement is important for the fields of dentistry and orthodontics as it describes the concepts related to dental occlusion and the masticatory processes of the jaw. A detailed understanding of each patient’s unique mandibular movement is also required for the proper design and creation of a customized prosthesis. It provides information regarding their occlusal habits and angle of dentition so a truly functional prosthesis can be formed. Information on mandibular movement is also an important part of dental and medical research pertaining to oral health, mandibular issues, and prosthesis design.

A mandibular ramus is a quadrilateral process projecting upward and backward from the posterior part of the body of the mandible and ending on the other side at the temporomandibular joint in a saddle-like indentation (called the sigmoid notch) between the coronoid and condylar processes. It may serve as a source for bone grafting. The lateral surface of the mandibular ramus is the attachment site of the masseter muscle. In bone grafting, the mandibular ramus provides a good source of autogenous cortical graft best suited for the correction of ridge deficiencies prior to the placement of an implant. Grafts from this location generally require shorter periods of healing, show low levels of resorption, and maintain their density. Obtaining graft bone from the mandibular ramus over other possible facial sources also creates less noticeable facial scars or alterations and is less likely to cause nerve or sensory issues or discomfort.

The mandibular staple implant, also known as the transmandibular implant, is a form of transosseous dental implant in which a plate is fixed at the inferior border of the mandible. Retentive pins are placed partially into the inferior border with two continuous screws going transcortically and penetrating into the mouth in the canine areas and used as abutments. A mandibular staple implant is a good choice in patients who have experienced severe atrophy of the alveolar bone and allows for the attachment of a lower denture. The mandibular staple implant has high rates of success as well as high rates of patient approval and satisfaction. However, the nature of the implant and the procedure required for its placement do not always make it a first choice among practitioners. There are other, less-complex procedures that are often capable of achieving the same results and are therefore used more often.

The mandibular symphysis is the line of fusion of the lateral halves of the body of the mandible which splits inferiorly to form the mental protuberance. It may serve as a source for bone grafting. The mandibular symphysis is usually formed sometime during the first two years of life as the two halves of the mandible come together. It has been shown to be a reliable source of bone graft material for both maxillofacial reconstructive and oral reconstructive procedures. It is considered to be a safe location for bone harvesting as enough bone can be obtained without damaging the mental nerve, causing injury to the nearby teeth, or disturbing the patient’s facial contours. In addition, the mandibular symphysis provides a bone grafting source that yields bone with good density and that can be harvested in the necessary volume. The use of high-resolution scanners provides details of the bone’s vasculature so injury can be avoided during surgery.