Factors Influencing on Gingival Recession in Class III Surgery Patients

Objectives: Periodontal problem around mandibular incisors has been reported in skeletal Class III patients following combined orthodontic and orthognathic treatment. The objective of this study was to investigate possible factors related to gingival recession in skeletal Class III patients for long period time.
Methods: This study consisted of 39 Korean skeletal Class III adult patients with vertical facial pattern who received LeFort I and bilateral sagittal split ramus osteotomy. Among them, 24 patients received genioplasty in addition. For measurement of alveolar bone changes, cone beam computed tomography (CBCT) images before and after surgery were analyzed using InVivo Dental software (Anatomage, San Jose, California). For evaluation of gingival recession, clinical crown length of mandibular incisors was measured at pre-, post- treatment and retention. For possible relation with periodontal biotype, sum of the clinical papillary length of the mandibular incisors was measured using Rapidform software (INUS Technology and Rapidform Inc, Seoul, Korea).
Results: Clinical crown length in mandibular incisors increased with an average of 0.34±0.27 mm at post-treatment. 6 patients (4 patients received with genioplasty) exhibited between 0.5 and 1.0 mm recession on mandibular incisors at posttreatment. At retention, however, continuous recession was not observed in all participants. Genioplasty caused insignificant changes in both alveolar bone level and clinical crown length in skeletal Class III patients. Periodontal biotype was not associated with the changes of clinical crown length.
Conclusions: It is known that genioplasty and thin gingiva type may have a detrimental effect on gingiva around mandibular incisors in skeletal Class III patients, however, this study shows that these affect insignificant changes on periodontal complex over the period of the observation.