2015 HSC Section 1 Book of Articles

Collins and CFM–Goldenhar syndromes. It is unclear why

we observed such a high prevalence of these syndromes rela-

tive to Stickler syndrome, but this may represent a relatively

skewed population of patients who are referred from outside

the local area for tertiary and quaternary care. These syn-

dromes often demonstrate more severe micrognathia than

in isolated Pierre Robin sequence or even other syndromic

forms of micrognathia

and are therefore more likely to have

poorer outcomes.

In our cohort, 4 of the 11 patients with

CFM–Goldenhar syndrome and 2 of the 12 patients with

Treacher-Collins syndrome had Pruzansky grade 3 classifica-

tion with an absent mandibular condyle, and it is possible

that thismayhavealso limited theeffectiveness ofMDO in these

patients. Given thegreater percentageof these syndromes inour

cohort, thismay inpart explainwhy the overall rate of success-

ful MDO was slightly lower than in other published reports.

Whenwe examined thepotential predictors of surgical suc-

cess, the different definitions of success for the 2 subgroups

(decannulation vs avoidance of tracheotomy) necessitated

separate regression analyses based on initial intervention (tra-

cheotomy first vs MDO first). Thus, we cannot draw conclu-

sions regarding predictors of success across both subgroups.

However,we can reasonably conclude that amongpatientswho

required a tracheotomy as an initial procedure, patients with

CFM–Goldenhar syndrome seem to have a far worse chance

of success with subsequent MDO than patients with isolated

Pierre Robin sequence. This association does not seemto hold

among patients who underwent MDO first in the absence of a

tracheotomy.

Compared with patients treated with MDO first, those

treated with tracheotomy first had significantly more syn-

dromic diagnoses andwere older at the time of MDO. Many of

these patients had additional comorbidities, such as multi-

level airway obstruction, neuromuscular compromise, and

other medical comorbidities that necessitated a tracheotomy

as a definitive treatment for relief of their airway obstruction.

Achieving decannulation in this subgroup necessitated sig-

nificantly more adjunct airway procedures, such as laryngo-

tracheoplastyor endoscopic airwayprocedures, comparedwith

the subgroup that underwent MDO first. The finding in uni-

variable regression analysis that patients who underwent tra-

cheotomy first had greater odds of a surgical complication

makes intuitive sense in this context. The fact that this asso-

ciationwas no longer significant in amultivariablemodel that

also adjusted for thenumber of adjunct airwayprocedures sug-

gests that the associationbetween initial tracheotomyandcom-

plication is perhaps mediated by the need for additional pro-

cedures in order to achieve decannulation. Taken together,

these findings are consistent with our hypothesis that pa-

tients selected for tracheotomy rather than MDO as an initial

procedure were more medically complex and required more

airway interventions in order to achieve a stable airway. This

formof selectionbiasmayhave contributed to theirworse rates

of success and complication and also creates an inherent con-

founding by indication when making comparisons between

these 2 subgroups (MDO first vs tracheotomy first).

Limitations to our study include the retrospective nature

of the data collection, lost or missing data, and the inherent

confounding by indication that occurs in comparisons be-

tween the MDO-first subgroup vs the tracheotomy-first sub-

group. In addition, prior to 2002, when neonatal MDO be-

came part of routine practice at our institution, theremay have

been an even stronger selection bias toward tracheotomy as

an initial procedure. To address this possibility, a secondary

analysis was performed with the data set restricted to only

those patients whowere treatedwithMDO after 2002, and the

Figure 3. Proposed Treatment Algorithm for Pediatric Patients With Symptomatic Micrognathia

Severe micrognathia with symptoms

of respiratory distress, unresponsive

to conservative management

• Evaluation by craniofacial surgery,

otolaryngology, genetics, pulmonary

• Swallow evaluation

• Genetic testing if indicated

• Sleep study

• Airway evaluation (bedside flexible

endoscopy, direct laryngoscopy,

bronchoscopy in operating room)

• Maxillofacial computed tomography,

posteroanterior/lateral cephalogram

• Nonsyndromic micrognathia

• No other airway or

respiratory disease

• No dysphagia or aspiration

• Syndromic micrognathia (not

CFM or Goldenhar syndrome)

• No other airway or respiratory

disease

• Syndromic or nonsyndromic

micrognathia

• Other airway/respiratory disease

(eg, laryngomalacia, subglottic

or tracheal stenosis, vocal cord

paralysis, ventilator dependence)

• Any patient with CFM–Goldenhar

syndrome

• No dysphagia or

aspiration risk

• Good neuromuscular

status

Proceed with MDO

as initial treatment

• Persistent aspiration

risk

• Poor neuromuscular

status

Tracheotomy as initial procedure

with correction of other airway

disease before attempting MDO

as final step toward decannulation

The flowchart demonstrates our

current algorithm for workup and

decision making regarding the choice

of mandibular distraction

osteogenesis (MDO) vs tracheotomy

for symptomatic micrognathia.

CFM indicates craniofacial

microsomia.

Research

Original Investigation

Mandibular Distraction Osteogenesis

JAMA Otolaryngology–Head & Neck Surgery

April 2014 Volume 140, Number 4

jamaotolaryngology.com