Evaluation of prosth-orthodontic treatments for maxillary protrusion in elderly adults

Objectives: Maxillary protrusion is a common class of malocclusion in China. Usually the patients with maxillary protrusion are treated using a combination of orthognathic surgery and orthodontics, which includes a general approach of tooth extraction followed by retraction of the incisors. However, the oral diseases established in some elderly adults with maxillary protrusion are among contraindications to routine therapies, which, together with the fact that some patients would not accept to wear fixed appliances for 1-2 years, increases the demand for an alternative therapy. The proposed study is aimed to evaluate the esthetic effects of prosth-orthodontic therapy on maxillary protrusion in these elderly adults.

Methods: Totally 16 female and 2 male patients with maxillary protrusion (with an average age of 45.6 years old) were treated with the prosth-orthodontic therapy. Briefly, a post-and-crown prosthesis was prepared after root canal therapy. Cephalometric analyses before and after the treatment were performed to evaluate the esthetic effects of the treatment. The following angular measurements were performed: angulation of upper incisors (UI-FH), angulation of lower incisors (LI-MP) and inter-incisal angle (II). Linear measurements including horizontal distance measurements and vertical distance measurements were also performed.

Results: The angular measurements of U1-FH were significantly decreased after prosth-orthodontic therapy (p<0.05). In contrast, the measurements of II were increased after the therapy (p<0.01). The linear measurements of OB (p< 0.05), OJ (p<0.01), Uls-AB (p<0.01), LLs-AB (p<0.05), and C-St (p<0.05) were also significantly decreased after the prosth-orthodontic treatment. The overbite and overjet values also reduced to a normal level. These results indicated a significant lingual proclination of upper incisors and a normal occlusal guidance in anterior movement after the prosth-orthodontic therapy.

Conclusion: Prosth-orthodontic therapy could serve as an alternative therapy to maxillary protrusion in some elderly patients.