Gingival response to mandibular incisor extrusion.
BACKGROUND
The aims of the study were to evaluate the rate of accompanying gingival movement and changes in the widths of the attached gingiva (AG) and the keratinized gingiva (KG) after orthodontic extrusion of the mandibular incisors.


METHODS
The study was carried out with 10 subjects whose mandibular incisors were orthodontically extruded to correct a dental open bite. Periodontal indices and the widths of the AG and the KG were recorded before and after treatment. The gingival movement in relation to orthodontic extrusion was determined by radiopacity with a specially designed metal device indicating the position of the gingival margin (GM) and the mucogingival junction (MGJ) on the cephalograms before and after extrusion.


RESULTS
The widths of the AG and the KG, and the clinical crown length increased significantly after treatment (P <0.05). The GM and the MGJ moved in the same direction as the teeth by 80% and 52.5%, respectively. The sulcus depth decreased significantly (P <0.05).


CONCLUSIONS
Orthodontic extrusion leads to increases in the widths of the AG and the KG. The gingiva moves in the same direction as the tooth, but less. Clinically, increased gingival width can lead to a gummy smile in patients with a low lip line. Gingival corrective procedures cannot be performed in such cases due to risk for root exposure. Nevertheless, long-term follow-up is suggested to determine the final sulcus depth and the position of the GM and the MGJ.
Pikdoken
Levent
L
Section of Periodontics, Department of Dentistry, Gulhane Military Medical Academy, Haydarpasa Training Hospital, Istanbul, Turkey. ml_pikdoken@yahoo.com
Erkan
Mustafa
M
Usumez
Serdar
S
D000222:Adaptation, Physiological; D000293:Adolescent; D005260:Female; D005881:Gingiva / Q000033:anatomy & histology* / Q000502:physiology; D006801:Humans; D007180:Incisor; D008297:Male; D008334:Mandible; D009811:Odontometry; D016382:Orthodontic Appliance Design; D050793:Orthodontic Extrusion / Q000379:methods*; D009971:Orthodontics, Corrective / Q000379:methods*; D010512:Periodontal Index; D014087:Tooth Movement Techniques / Q000379:methods*; D016896:Treatment Outcome