Rationale for the lingual approach to mandibular osseous surgery

The definitive treatment of periodontitis for pocket elimination and the establishment of periodontal architecture that can be effectively maintained with daily personal oral hygiene techniques is sometimes an elusive goal. Performing osseous reduction, primarily from the lingual aspect of the posterior mandible, definitely helps in accomplishing such a goal. This paper should not be interpreted to mean that osseous correction of bony defects should be approached strictly from the lingual, since almost all cases require some buccal recontouring if a satisfactory soft and hard tissue architectural form is to be achieved. Clinical observation and experience have shown that the anatomical patterns, seen in relation to the mandible, have a powerful effect on normal periodontal architecture as well as the types and locations of bony defects encountered. Tooth to bone relationships deserve attention. The buccal housing of the alveolar bone is frequently thin in the premolar region and occasionally on the first molar, while the external oblique ridge causes thicknened bone over the second molar. The vestibular depth on the buccal of the molars is often quite shallow, meaning that only a very limited amount of osteoplasty-osteoectomy can be performed from the buccal. The lingual housing of the alveolar bone is normally thickened and shelf-like from the distal of the third molars to the mesial aspect of the premolar region. Because the posterior teeth are inclined lingually from the second premolar distally, the buccal marginal bone height is higher occlusally than the lingual bone margins, with the interproximal bone therefore sloping somewhat apically and lingually. Interdental craters are the most common defect seen with the onset of periodontitis. Such defects in the lower arch tend to occur beneath the contact areas of the teeth, which are much further to the lingual than in the maxilla. The highest percentage of interproximal craters are shallow and not amenable to grafting techniques in the hands of most clinicians. These shallow craters are prime candidates for osseous reduction techniques. With the progression of periodontitis, the interproximal defects frequently extend to include infrabony lingual defects. Although obtaining lingual access for osseous reduction techniques is often difficult, osteoectomy-osteoplasty techniques performed primarily from the buccal of the posterior mandible frequently result in compromise of the lingual and over treating the buccal in terms of osteoectomy procedures. The lingual embrasure spaces are usually wider than on the buccal, and with adequate reduction of the mylohyoid ridge, greater access for oral hygiene procedures is provided.