Does Subspinal Le Fort I Osteotomy Reduce Nasolabial Soft Tissue Changes Compared to the Conventional Technique?

BACKGROUND

Le Fort I osteotomy (LFIO) may lead to nasolabial changes. Therefore, several techniques have been proposed to minimize these effects, including the subspinal osteotomy, which can preserves perinasal structures.

PURPOSE

The purpose of this study was to compare the associations between conventional and subspinal LFIO and changes in the nasolabial soft tissues.

STUDY DESIGN, SETTING, SAMPLE: A retrospective cohort study was conducted at the residency program of the João XXIII Hospital in Belo Horizonte (2019 to 2023). The sample included subjects who underwent conventional or subspinal LFIO without segmentation. Exclusion criteria included a history of facial trauma or previous facial surgery, such as surgically assisted rapid maxillary expansion, as well as the presence of symptomatic or unhealthy temporomandibular joints.

PREDICTOR VARIABLE

The predictor variable was the surgical technique, categorized into conventional and subspinal LFIO.

MAIN OUTCOMES

The outcome variables were the changes in nasolabial soft tissues, including interalar width, alar base width, upper lip dimensions, and nasolabial angle, measured preoperatively and at least 6 months postoperatively.

COVARIATES

The covariates consisted of maxillary movement, sex, age, and type of dentofacial deformity.

ANALYSES

Descriptive statistics and group comparisons evaluated nasolabial changes, while correlation and regression analyses assessed relationships between maxillary movements and soft tissue changes (P < .05).

RESULTS

The sample included 96 subjects: 48 underwent conventional LFIO with alar cinch suture, and 48 underwent subspinal LFIO with alar cinch suture. The sample had a mean age of 31.2 ± 8.16 years, and most participants were female, comprising 66.7% (n = 64). The conventional group showed a significantly greater increase in alar base width than the subspinal group (1.85 ± 2.14 and 0.55 ± 0.02 mm, respectively; P = .03). No significant differences were found in interalar width or nasolabial angle (P = .2; P = .4). The conventional group also showed a significantly greater increase in upper lip length than the subspinal group (1.26 ± 1.62 and 0.3 ± 1.63 mm, respectively; P = .01). Interalar widening was correlated with maxillary impaction (P = .01), and upper lip lengthening with maxillary advancement (P = .04). In the conventional group, interalar widening was predicted by both impaction and advancement (P = .02; P = .03).

CONCLUSION AND RELEVANCE

Compared to conventional LFIO, subspinal osteotomy was associated with less alar base widening and reduced upper lip lengthening.