Comprehensive Long-Term Outcomes Following Mandibular Distraction Osteogenesis

OBJECTIVE

To describe long-term outcomes and complications following mandibular distraction osteogenesis (MDO) in a diverse patient cohort.

DESIGN

Cross-sectional study.

SETTING

Single tertiary-care pediatric center.

PATIENTS

Forty-eight patients previously undergoing MDO with minimum 4-year follow-up.

MAIN OUTCOME MEASURES

Respiratory outcomes, feeding patterns, dental development, motor/sensory nerve function, temporo-mandibular joint function, and postsurgical scarring.

RESULTS

Forty-six patients with a median age of 7 years were evaluated. Of 20 nonsyndromic patients, none required additional airway procedures, none required continuous positive airway pressure (CPAP) during sleep, and 19 (95%) fed exclusively by mouth. Among 26 syndromic patients, 7 (27%) required CPAP and 8 (31%) were tube fed. Permanent first molar differences were seen in the majority of subjects; patterns of damage interfering with function were more common in syndromic (13/28, 46%) compared to nonsyndromic (5/24, 21%; P = .014) subjects. MDO prior to age two was associated with more frequent and worse dental damage (P = .001). Inferior alveolar nerve and marginal mandibular nerve function were fully intact in 37 (80%) and 39 (85%) of patients, respectively. Three patients (6%), all with associated genetic syndromes, demonstrated severe nerve impairment. By the Vancouver scar scale, ≥ 80% of surgical scars were rated in the most favorable category for each quality assessed. Temporomandibular joint dysfunction was rare.

CONCLUSIONS

MDO shows highly favorable long-term respiratory, feeding, nerve, and scar outcomes in nonsyndromic patients, although permanent molar changes not precluding tooth viability are commonly seen. Patients with associated syndromes demonstrate respiratory and feeding benefits, but higher rates of dental and nerve abnormalities.

Imaging characteristics of the mandible and upper airway in children with Robin sequence and relationship to the treatment strategy

Some patients with Robin sequence (RS) may respond to conservative therapy, while others require surgery; however, there are currently no objective anatomical criteria to gauge surgical indication. The purpose of this study was to explore the imaging characteristics of the mandible and upper respiratory tract in children with RS and examine how individual morphometric parameters influence the treatment strategy. Cone beam computed tomography (CBCT) images were obtained from 57 children with RS. Twenty parameters were measured as potential surgical indicators. The children were divided into two groups according to surgical requirement: a non-surgical group (26 children) and a surgical group (31 children who underwent mandibular osteodistraction). Differences in the imaging parameters were compared between the groups. The mandibular ramus was shorter bilaterally (left, P = 0.047; right, P = 0.027) and the mandibular body was longer bilaterally (left, P = 0.030; right, P = 0.025) in the surgical group when compared to the non-surgical group. In addition, the mandibular angle bilaterally (left, P = 0.023; right, P = 0.003) and the cross-sectional area at the epiglottis tip (P = 0.010) were smaller in the surgical group. Compared to RS patients receiving conservative treatment, children requiring surgery have specific anatomical features of the mandible and upper airway that can be used as surgical indications.

Distraction osteogenesis in the treatment of temporomandibular joint ankylosis with mandibular micrognathia

AIMS

The aims of the study were to evaluate the efficacy of simultaneous interpositional arthroplasty with distraction osteogenesis (DO) as a single procedure and to give the patient acceptable functional rehabilitation with correction of the gross facial asymmetry.

MATERIALS AND METHODS

Nine patients of temporomandibular joint (TMJ) ankylosis with micrognathia were treated with interpositional arthroplasty and simultaneous DO and followed for a period of minimum 3 years. Preoperative, immediate postoperative, at the end of distraction, at 6 months and 3 years postdistraction consolidation radiographs were taken along with the clinical examination for mouth opening, deviation, length of the mandible and ramus, midline shift, occlusal cant, and occlusion.

RESULTS

The results showed an increase in the mouth opening, length of the mandible and ramus height, correction of deviation, occlusion, and midline shift. Relapse was not seen in any case, rather one patient developed infection at the distractor site and two patients had fracture of the roots of the teeth at the osteotomy site. There was an overall improvement in the facial asymmetry.

CONCLUSION

Simultaneous interpositional arthroplasty with DO should be used to correct TMJ ankylosis associated with facial asymmetry/micrognathia, as it reduces the need for second surgery, thereby saving the trauma of a second surgery and difficulty in intubation, increases the length of the mandible, corrects the deformity, thereby resulting in an acceptable facial esthetics and function.

Appropriate Tongue Blade Length of the Dingman Mouth Gag for Japanese Pediatric Patients With Cleft Palate and Mandibular Micrognathia

Objective Our objective is to determine appropriate specifications for smaller tongue blade for Japanese pediatric patients with cleft palate (CP) and mandibular micrognathia. Patients We investigated 59 patients who underwent palatoplasty. Patients were divided into two groups: the micrognathia (MG) group consisted of 11 patients and the normognathia (NG) group consisted of 48 patients. Interventions The following five items were investigated retrospectively: (1) gender, (2) cleft type, (3) age at the time of surgery, (4) weight at the time of surgery, and (5) distance from the tongue blade base to the posterior pharyngeal wall (Dis). Results There was a significant difference (P < .01) in age at the time of surgery and in Dis between groups, but not in weight. The minimum values were 55 mm for the MG group. As for correlations between age and weight at the time of surgery, the P values for the MG and NG groups were .993 and .052, respectively. As for correlations between weight at the time of surgery and Dis, the P values for the MG and NG groups were .987 and .099, respectively. Conclusions It was difficult to predict Dis on the basis of the patient's age and weight measured preoperatively. The minimum Dis was 55 mm, equal to the length from the base to the tip of the Dingman Mouth Gag tongue blade currently in use, suggesting that a tongue blade of approximately 50 mm in length, shorter than the current minimum specifications, may be appropriate.