Size and anatomical thickness, as well as depressions and prominences are presence and vary to a great extent from mandible to mandible. A depression called retromolar area is located between the internal lateral border of the retromolar triangle and the external oblique ridge. Bone prominences or exostoses are found in different locations of the mandible. The root apices of canine and first bicuspid are inclined lingually, while the posterior teeth are inclined buccally. The buccal bony plate is higher than the lingual plate.
Alveolar crest is convex in the bicuspid area and flat in the molar area.
Lower molars and premolars are the teeth most affected by osseous defects in the mouth. Reverse architecture is a common finding in the mandible after interproximal craters are eliminated and can be easily eliminated without furcation compromise if ostectomy is performed. It should be remembered that bone should be conserved in the buccal because it is supporting bone. The fact that the buccal furca is situated further coronal than the lingual one is another reason to do osseous from the lingual.