Major anomalies of jaw size

M26.00 identifies a major anomaly of jaw size that has not been further specified as affecting the maxilla or mandible, and does not indicate whether the anomaly involves hyperplasia, hypoplasia, macrogenia, microgenia, or excessive tuberosity.

Abnormal overgrowth of the maxillary bone resulting in a disproportionately large upper jaw relative to the mandible or cranial base.

M26.02 identifies underdevelopment of the maxilla (upper jaw) as a major anomaly of jaw size, classified under dentofacial anomalies in ICD-10-CM Chapter 13.

Overgrowth of the mandible (lower jaw) classified as a major anomaly of jaw size, reported under the dentofacial anomalies section of ICD-10-CM.

Underdevelopment of the mandible (lower jaw) resulting in a smaller-than-normal jaw structure, classified as a major anomaly of jaw size under the dentofacial anomalies category.

M26.05 identifies macrogenia — abnormal enlargement of the chin (the bony symphyseal region of the mandible) classified as a major anomaly of jaw size under the dentofacial anomalies block.

M26.06 identifies microgenia — an abnormally small or underdeveloped chin (symphysis menti region of the mandible) classified as a major anomaly of jaw size under the dentofacial anomalies category.

M26.07 identifies an abnormal overgrowth of the maxillary tuberosity — the bony prominence at the posterior end of the upper jaw — classified as a dentofacial anomaly under the musculoskeletal chapter.

M26.09 captures jaw size anomalies that are documented and clinically specified but do not match any of the individually named codes within the M26.0 category — such as agenesis of the jaw, jaw hyperplasia not classified as maxillary or mandibular, or other discrete size deformities without a dedicated subcategory.