Skeletal and dental stability of segmental distraction of the anterior mandibular alveolar process. A 2-year follow-up

Abstract

Clinical Paper Orthognathic SurgerySkeletal and dental stability of segmental distraction of the anterior mandibular alveolar process. A 2-year follow-up Abstract. 33 patients (27 females; 6 males) were retrospectively analysed for skeletal and dental relapse before distraction osteogenesis (DOG) of the mandibular anterior alveolar process at T1 (17.0 days), after DOG at T2 (mean 6.5 days), at T3 (mean 24.4 days), and at T4 (mean 2.0 years). Lateral cephalograms were traced by hand, digitized, superimposed, and evaluated. Skeletal correction (T3 À T1) was mainly achieved through the distraction of the anterior alveolar segment in a rotational manner where the incisors were more proclined. The horizontal backward relapse (T4 À T3) measured À0.8 mm or 19.0% at point B (p < 0.001) and À1.6 mm or 25.0% at incision inferior (p < 0.001). Age, gender, amount and type (rotational versus translational) of advancement were not correlated with the amount of relapse. High angle patients (NL/ML 0 ; p < 0.01) and patients with large gonial angle (p < 0.05) showed significantly smaller relapse rates at point B. Overcorrection of the overjet achieved by the distraction was seen in a third of the patients and could be a reason for relapse. Considering the amount of skeletal relapse the DOG could be an alternative to bilateral sagittal split osteotomy for mandibular advancement in selected cases.

Soft tissue stability after segmental distraction of the anterior mandibular alveolar process: a 5.5 year follow-up

“…13 In addition, the interface of the surgical section of the anterior aspect of the symphysis was more susceptible to resorption and bony remodelling. 2,14 In conclusion, this long-term follow-up of 5.5 years found that further change in soft tissues occurred between 2.0 and 5.5 years postoperatively regarding point B 0 and labrale inferior. The physiological process of ageing and loss of soft tissue elasticity should be considered as possible reasons.…”

“…It is interesting to note that the amount and type (rotational vs. translational) of advancement in the same patient population examined earlier were not correlated with the amount of skeletal relapse measured at incision inferior or point B. 2,14 An important short-term effect of maxillofacial surgery and a confounding variable is postoperative swelling (oedema from retraction, irritations, and inflammation). For this reason, the immediate shortterm soft tissue profile changes measured on lateral cephalograms always include swelling and thickness of the orthodontic brackets.…”

“…2,13 The initial patient sample consisted of 33 Caucasian patients (27 females and six males) aged 16.5-56.0 years (mean age 30.3 years, SD 10.7). Of these 33 patients, 17 patients could be re-examined.…”

“…2,13,14 The net effect of the soft tissue at point B 0 was 100% of the advancement at point B while the lower lip (labrale inferior) followed the advancement of incision inferior to 46% examined 2.0 years postoperatively. 13 Skeletally, 5.5 years after DO the horizontal backward relapse measured À0.3 mm or 8.3% at point B and À1.8 mm or 29.0% at incision inferior.…”

Neurosensory and functional evaluation in distraction osteogenesis of the anterior mandibular alveolar process

“…5,6 Recently, changes in skeletal stability, and soft tissue profile were analysed after DO of the anterior alveolar process. 7,8 Besides the clinical benefits of DO, complications such as neurosensory disturbances of the inferior alveolar nerve are possible. Neurosensory changes in the alveolar nerve were evaluated mainly in animal studies after DO of the whole mandible.…”