2015 HSC Section 1 Book of Articles

3.4 [95%CI, 1.4-8.4]) comparedwith patients with 0 or 1 other

procedure. In a multivariable regression model adjusting for

all these variables, only length of follow-up (OR, 1.2 [95% CI,

1.0-1.3]) and number of other airway procedures (OR, 3.2 [95%

CI, 1.2-8.6]) remained significantly associated with occur-

rence of a complication.

Figure 2

demonstrates the modeled

probabilities of a complication withMDO in the 2 initial treat-

ment subgroups as a function of these 2 independent predic-

tors. One can see that in both theMDO-first subgroup and the

tracheotomy-first subgroup, the probability of a complica-

tion increases with length of follow-up time. In addition, for

any given follow-up duration, there is a greater probability of

a complication when 2 or more other airway procedures are

required.

Discussion

The application of distraction osteogenesis to themandible for

the treatment of symptomatic micrognathia was first de-

scribed by McCarthy et al

in 1992, and since that time there

have been increasing reports of the outcomes of this interven-

tion in the pediatric population. Owing to the heterogeneous

nature of the patient population that experiences sympto-

matic micrognathia severe enough to warrant surgical inter-

vention, definitions of success have varied depending on the

specific study. Given this context, success rates forMDO in im-

proving or relieving airway obstruction due to micrognathia

have been reported to range from 63% to 100% depending on

the definition of success used.

8-11,17-20

In a recent meta-

analysis, Ow and Cheung

found a 91% rate of prevention of

tracheotomy among neonates undergoing MDO as an initial

procedure and a 78% rate of decannulation among patients

with existing tracheostomies who underwent MDO.

This study reports the outcomes ofMDO in one of the larg-

est cohorts of patients treated for symptomatic micrognathia.

The relatively large cohort provided greater statistical power

thanmost previous reports and facilitated the investigation of

potential predictorsof surgical success andcomplications.Over-

all, we found a high rate of surgical success among patients

undergoingMDO, especially among those undergoingMDO as

an initial procedure to treat symptomatic micrognathia. The

Table 3. Adjusted Associations Between Potential Predictors

and Surgical Success in the Tracheotomy-First Subgroup

Variable

OR (95% CI)

Value

Male

0.31 (0.09-1.10)

.07

Diagnosis

Treacher-Collins syndrome

0.45 (0.06-3.60)

.45

CFM–Goldenhar syndrome

0.05 (0.005-0.43)

.007

Other

0.27 (0.06-1.20)

.09

Age at distraction, y

1.15 (0.93-1.40)

.20

Abbreviation: CFM, craniofacial microsomia.

Reference diagnosis was isolated Pierre Robin sequence.

Figure 1. Predicted Probabilities for Surgical Success (Tracheotomy-First Subgroup)

0.0

1.0

0.8

Probability of Surgical Success

Age, y

0.6

0.4

0.2

0.0

1.0

0.8

Probability of Surgical Success

Age, y

0.6

0.4

0.2

Isolated Pierre Robin sequence

Treacher-Collins syndrome

Goldenhar syndrome or

craniofacial microsomia

Other

Diagnosis

Females

Males

Predicted probabilities of surgical success among patients who had a tracheotomy prior to mandibular distraction osteogenesis. A, Females; B, males. The colored

dotted lines indicate differences in the probability of success for each diagnosis. Open circles represent the observed values.

Research

Original Investigation

Mandibular Distraction Osteogenesis

JAMA Otolaryngology–Head & Neck Surgery

April 2014 Volume 140, Number 4

jamaotolaryngology.com