OBJECTIVE

To perform a comparative morphometric analysis of mandibular body length and ramus height in adolescents with unilateral mandibular underdevelopment, and to develop a classification of severity grades and an algorithm for surgical treatment planning.

MATERIALS AND METHODS

The study included 50 patients (27 boys and 23 girls) aged 9 to 17 years (mean age 13.4 ± 2.1 years) with unilateral underdevelopment of the mandible of various etiologies. All patients underwent multisection CT of the maxillofacial region with morphometric analysis of key parameters (Go—Me, Co—Go). The obtained values were compared with the normative age indicators identified according to literature data and CT scans of 10 healthy children, and the shortening in millimeters and percentages was calculated.

RESULTS

A quantitative classification of unilateral underdevelopment of the mandible has been developed. With grade I underdevelopment, shortening of the body and/ or branch is less than 10% of the age norm; with grade II, a decrease in size in the range of 10-30%, grade III corresponds to severe underdevelopment with a shortening of more than 30%. A clear relationship between the morphometric degree of shortening and clinical manifestations was established: at grade I, distal bite was observed without pronounced functional disorders.; Grade II revealed a pronounced malocclusion (Angle class II) with deep incisor overlap and crowding of teeth; grade III showed gross changes in the profile of the face with pronounced asymmetry, distal bite and severe functional disorders — impaired chewing, swallowing and speech

CONCLUSION

The morphometric classification made it possible to quantify three degrees of underdevelopment of the mandible — mild, moderate and severe — based on shortening of body length and/or height of the branch relative to the age norm. Taking into account the prevailing type of shortening (horizontal, vertical, or combined) provides a more accurate reflection of the clinical picture. Based on the classification, a treatment algorithm has been developed. The proposed approaches standardize the planning and implementation of surgical correction of mandibular underdevelopment in adolescents.