Abstract
Congenital retrognathia and glossoptosis characterize isolated Pierre Robin sequence (iPRS); the small mandible and its retracted position cause retrodisplacement of the tongue and reduction of the oropharyngeal airway. These neonates may be affected by airway obstruction, feeding difficulties, failure to thrive, and chronic hypoxaemia. To solve the respiratory problems secondary to glossoptosis, various treatments have been described including prone positioning, a nasopharyngeal tube, glossopexy, and mandibular distraction. Over the last 28 years, the authors have treated 118 neonates and infants affected by iPRS by carrying out traction of the mandible using two parasymphyseal wires, positioned under local anaesthesia. All the procedures were successful, with no major complication. The patients’ respiratory problems and apnoea disappeared suddenly after beginning traction.
Pierre Robin sequence (PRS) identifies a group of neonates affected by congenital retrognathia/micrognathia and glossoptosis, which may or may not lead to airway obstruction . A cleft palate may be present but it is not a required for a diagnosis of PRS . Most of these neonates affected by micrognathia and glossoptosis have isolated PRS (iPRS). The most frequent syndromes involving PRS are, in decreasing frequency, Stickler syndrome, velocardiofacial syndrome and Treacher Collins syndrome.
Neonates affected with iPRS develop different degrees of respiratory distress, feeding difficulties, or both, immediately after birth or during the following weeks of life . Left untreated, many of these infants would suffer significant complications , including failure to thrive, chronic hypoxaemia, and cor pulmonale. The mortality rate may be as high as 14%.
Regardless of the aetiopathogenesis of the mandibular retrognathia/micrognathia, in more than 90% of neonates, the point of obstruction of the airway is at the base of the tongue in proximity to the posterior pharynx . The small size of the mandible, and its retracted position causes a ‘corresponding back displacement of the tongue and associated reduction in the oropharyngeal airway lumen’ . Several treatments are described to manage the respiratory problems secondary to glossoptosis, including prone positioning treatment (PPT), nasopharyngeal tube (NPT), glossopexy, tracheotomy and mandibular distraction; each has benefits and morbidities .
In an attempt to minimize morbidity, some authors have proposed different classifications of PRS severity and algorithms of treatment. The minimal invasive treatments have been considered first. PPT has been shown to resolve 47–72% of cases . NPT has resolved 72–100% of cases . Despite the favourable results, the conservative treatments and some surgical techniques do not address the critical component of isolated PRS which is characterized by mandibular deficiency .
The cutting-edge approach to the maxillary–mandibular discrepancy is represented by mandibular distraction osteogenesis , by means of external or internal bone distraction devices . This technique offers an immediate solution to mandibular growth deficiency, solving the respiratory problems of PRS.
Considering the potential morbidities associated with bone distraction devices and the need for general anaesthesia, the authors have considered whether there are any other surgical techniques that could solve the respiratory problems. They think that their approach to this problem (i.e. early mandibular traction by means of wires) may provide a partial answer. In the past 28 years, the authors have treated 118 neonates and infants with mandibular traction.
A high incidence of temporomandibular joint (TMJ) ankylosis has been described: this complication has been reported as the primary reason why the first attempts at using mandibular traction by wires were abandoned. The authors would like to illustrate their work on mandibular traction by wires, applying a technique reported by S tellmach & S chettler in 1968. The authors describe and present the results of their simple and low cost method to treat severe breathing distress (respiratory crisis) with no major complications. They consider this technique an alternative to other surgical techniques.
Materials and methods
This study reviews 246 consecutive neonates with iPRS referred to the authors’ centre between January 1980 and June 2008 ( Table 1 ). 147 were female (60%) and 99 male (40%). 216 babies (88%) had cleft palate. The mean age of the neonates at admission was 15 days (range 3–40 days). Four patients arrived with a tracheostomy.
| 246 neonates admitted | At admission, it was decided to treat 159 patients conservatively | At admission, it was decided to treat 87 patients with mandibular traction |
| 147 females (60%) | In 31patients clinical evidence of respiratory distress was clear in the 12–24 h following admission | 31patients, ultimately required mandibular traction |
| 99 males (40%) | 128 patients were treated only with conservative methods | 118 of the 246 neonates admitted underwent wire traction |
| 216 babies (88%) were affected by cleft palate |
128 patients (52%) were treated with conservative methods ( Table 1 ), including PPT, NPT and nasogastric tube (NGT). Owing to respiratory problems, the other 118 neonates (48%) were subjected to mandibular traction; no other surgical techniques were used in these patients. The follow-up period ranged from 5 months to 10 years, with a mean period of 7 years, focusing on the efficiency of the technique to solve the respiratory problems.
Over the past 28 years the guidelines for assessing babies affected by iPRS have been modified. Consequently, the inclusion criteria for traction treatment have changed, but the authors always tried to detect neonates who had experienced even a single episode of desaturation or respiratory obstruction, and babies with feeding difficulties. Regarding the monitoring of desaturation, pulse oximetry devices became available in 1999. Before then, monitoring of oxygen saturation was mainly clinical, seldom utilizing blood gas examination. The other inclusion criterion, if it was present with clinically observed desaturation, was a maxillo-mandibular discrepancy of 7 mm or more.
The present guidelines and inclusion criteria for traction treatment, according to the guiding principles stated by S chaefer et al. in 2004, are as follows. First, all the neonates are monitored immediately after admission with pulse oximetry for at least 24 h. In older children, oxygen saturation is monitored during sleep. Second, the patients are considered to have desaturation when the oxygen saturation value is <90% for 5% or more of the observation time. Neonates with a single recorded value of oxygen saturation <80% and who experienced even a single episode of desaturation or respiratory obstruction are defined as being affected by desaturation during the ‘following activities of early life: sleeping, feeding, or wakefullness’ . Third, regarding micrognathia, the so-called maxillo-mandibular discrepancy, the maxillary overjet is measured with a ruler positioned between the alveolar ridges ‘with the patient in an upright position’ . In the authors’ series, 7 mm or more of maxilla overjet is considered one of the indications for surgery, when breathing difficulties are also present. Fourth, feeding difficulties are always considered as an inclusion criterion for traction procedure. Feeding difficulties are identified , such as a desaturation event during feeding (oxygen saturation less than 80%).
When the children match the criteria for inclusion, mandibular traction is accomplished by the positioning, under local anaesthesia, of two circum-mandibulary wires on both sides of the symphysis ( Fig. 1 a–d ). The senior author (B.U.) performed approximately 90% of all the surgical procedures. No antiobiotics were given to the patients before or after surgery.
The parents of all the neonates were instructed by the nursing staff about the proper care techniques for their infants. The parents were trained to change the position of the neonate so as to modify the position of the pulley ( Fig. 1 e–f). The patients are neonates so they sleep for several hours during the day, which means constant supervision by the parents during the traction phase is unnecessary.
Discontinuing traction was based on the evaluation of oxygen saturation values and on the degree of correction of the mandibular deficiency. The oxygen saturation values had to be stable and >96% in room conditions for 72 h without traction while mantaining the circum-mandibular wires. The maxillo-mandibular discrepancy had to be less than 3 mm. The authors reviewed the oxygen saturation values in all patients before and immediately after traction ( Fig. 2 ).
If a cleft palate was present, a palatal plate was applied to avoid the tongue intruding into the cleft and to train the tongue to resume its correct position.
Over the last 28 years, the authors have used the traction technique of the mandible reported by S tellmach & S chettler . The traction was performed under local anaesthesia in the operating room in the presence of a paediatric anaesthesist. Two circum-mandibular wires were applied in the parasymphyseal area of the lower jaw ( Fig. 1 a–d). The two traction wires were passed through two drilled holes in a plate made of rigid plastic ( Fig. 1 d). The wires were tied together. This plate (acting as a spacer) was used to keep the wires parallel to each other, thus maintaining the direction of traction symmetric, parallel and equal for both wires. A loop was made by bending the two wires, which had been previously joined. This loop served as a point for hanging the weight, through an apparatus of hangers and an orthopaedic pulley attached to the neonate’s bed. The weight applied was approximately 95 g, ranging between 90 and 100 g.
Immediately after applying the wires, the traction of the mandible started and it was continuous. The nurses taught the parents to alternate the position every 2 h ( Fig. 1 e and f). The traction was discontinued only if the neonate appeared to be very nervous or to suffer pain. Traction was discontinued during feeding time. The parents were given a questionnaire to collect their opinions and to grade their satisfaction.
Results
Over the last 28 years, of the 246 neonates examined, the authors treated 128 patients with conservative methods ( Table 1 ) and the other 118 (48%) underwent mandibular traction ( Table 1 , Figs. 3–5 ). At admission, the authors had decided to treat 159 infants conservatively, but 31 of these patients required a surgical procedure to resolve their problem ( Table 1 ). Clinical evidence of respiratory distress was clear in the 12–24 h following admission.
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