Computed tomography-aided descriptive analysis of maxillary and mandibular atrophies

The aim of the present retrospective chart review was to analyze by Computed Tomography (CT) scan technique the degree of maxillomandibular atrophies, searching for differences between totally- and partially-edentulous subjects, and possibly identify and classify maxillomandibular atrophy staged patterns for implant planning in both totally- and partially- edentulous jaws.

CT scans of 89 mandibles and 77 maxillae from 111 patients were classified according to six different patterns of residual ridge resorption and to two different groups of edentulism (totally- and partially-edentulous). Maxillomandibular absolute linear dimensions were calculated and results compared for statistically significant differences by Wilcoxon tests.

Maxillomandibular CT cross-section interpretation showed different patterns of linear bone remodelling (height values) between the two groups of edentulism joined with specific positions in the maxilla or mandible. The judgment of the investigator was uncertain in the analysis of the mandibular posterior areas with similar percentages for both totally- and partially-edentulous groups (12.5% and 11.5%, respectively).

The 3D analysis is self-explanatory and easy to apply, aided by CT scans. The measurements between the referring planes and inviolable anatomical structures (nasal floor NFD, lower border of mandible LBD, inferior alveolar nerve AND, and sinus floor SFD), showed that class III may not guarantee an optimal implant placement, especially in the totally-edentulous group, due to a major degree of pneumatisation.