Evaluation of Supporting Bony Tissue
Examination of the supporting bone should include visual inspection, palpation, radiographic ‘examination, and in some cases evaluation of models. Abnormalities of the remaining ‘bone can often be assessed during the visual inspection; however, because of bony resorption and location of muscle or soft tissue attachments, many bony abnormalities may be obscured. Palpation of all areas of the maxilla and mandible, including both the primary denture-bearing area and vestibular area, is necessary ..
Evaluation o f the denture-bearing area of the’ maxilla includes an overall evaluation of the bony ridge form. No bony. undercuts or gross bony protuberances that block he path of denture insertion should be allowed to
remain in the area of the alveolar ridge, buccal vestibule, or palatal vault. Palatal tori that require modification should be noted. Adequate posttuberosity notchrng must exist for posterior denture stability and peripheral seal. . The remaining mandibular ridge should be evaluated
visually for overall ridge fonn and contour, gross ridge irregularities, tori, and buccal exostosis. In cases of moderate-to-severe resorption of alveolar bone, ridge contour canriot be adequately assessed by visual inspection of t”_ .ldge may obscure underlying bony anatomy, particuiarlv if! the an » r ihe posteric, mandible, where a depression can I••..•. :.tly be palpated between the external v~:ique :••.••.wllU mylohyoid ridge areas. The location of the mental foramen and mental neurovascular bundle can be palpated in relation to the superior aspect of the mandible, and eurosensory’ disturbances tan be noted. Evaluation of the interarch relationship of the maxilla and the mandible is extremely important and includes an examination of the anteroposterior a nd vertical relationships,
as well as any possible skeletal asymmetries that may exist between the maxilla and mandible. In partially edentulous patients, the presence of hypererupted or malpositioned teeth or segments should also be noted. The
anteroposterior relationship must be evaluated with the patient in the proper vertical dimension .•Overclosure of the mandible may result in a class III skeletal relationship but may appear normal if evaluated with the mandible in the proper postural position. Lateral and post eroanterior
cephalometic radiographs with the jaws in proper postural position may be helpful in confirming a skeletal discrepancy. Careful attention must be paid to the interarch distance, particularly in the posterior aras, where vertical
excess of the tuberosity, either bony tissue or soft tissue may impinge on space necessary for placement of a proshesis that is properly constructed (Fig. 13-2). Proper radiographs are an important part of the initial
diagnosis and treatment plan. Panoramic radiographic techniques provide an excellent overview assessment of underlying bony structure and patnologtc conditions.” Radiographs should disclose bony pathologic lesions, impacted teeth or portions of remaining roots, the bony
pattern of the alveolar ridge, and the size and pneumatization of the maxillary sinus (Fig. 13-3).
Cephalometric radio graphs may also be helpful in evaluating the cross-sectional configuration of the anterior mandibular ridge area and ridge relationships (Fig. 13-4,A). To evaluate the ridge relationship in the vertical and anteroposterior dimensions, it will be necessary to obtain the cephalometric radio graph in the appropriate vertical dimension. This may’ require adjusting or reconstructing dentures to this position or making properly adjusted bite rims to be used for positioning at the time the radio graph is taken. . More sophisticated radio graphic studies, such as
tomography’ or computerized tomography (CT) scans, may provide further information. CT scans are particularly helpful in evaluating the cross-sectional anatomy of the maxilla, including ridge form and sinus anatomy (Fig. 13-4, B). The cross-sectional anatomy of the mandible can be more precisely evaluated by including the location ‘of the inferior alveolar nerve