Precise osteotomies for mandibular distraction in infants with Robin sequence using virtual surgical planning

Does Mandibular Distraction Osteogenesis for Robin Sequence Create Altered Craniofacial Morphology and Disrupt Tooth Development?

BACKGROUND

Robin Sequence (RS) infant patients may require mandibular distraction osteogenesis (MDO) to improve airway. The distracted mandible may grow vertically and the developing dentition may be disrupted.

PURPOSE

The study purpose was to measure the association of MDO on craniofacial morphology and tooth development in RS subjects.

STUDY DESIGN, SETTING, SAMPLE

This was a retrospective cohort study of RS infants treated with/without MDO. Inclusion criteria were RS diagnosis, complete imaging, and treatment at our pediatric regional hospital. Exclusion criteria were treatment elsewhere and insufficient imaging.

EXPOSURE VARIABLE

Exposure was airway management; subjects were grouped by use of MDO or not. Subjects were compared to age-matched normal infants presurgically and to age-matched normal controls at follow-up.

MAIN OUTCOME VARIABLES

Main outcome variables were craniofacial morphology measured using cephalometric gonial angle and ramus height to mandibular body length ratio presurgically (T1), postsurgically (T2), and at the mixed dentition (T3). Disrupted tooth development was assessed by absence/abnormality of teeth on radiographs at T3.

COVARIATES

Covariates were age, sex, body mass index, comorbidities, and cephalometric measurements.

ANALYSES

Appropriate univariate, bivariate, and regression models were computed, and significance level was set at P < .05.

RESULTS

The sample contained 14 RS-MDO subjects with median age of 1.1 months and 10 (71.4%) were female. Presurgery, RS-MDO subjects had significantly more obtuse gonial angles (145° vs 137°, P = .04) and shorter mandibular bodies (32 vs 41 mm, P < .01) than the 37 unaffected controls. Increased ramus height (P < .01) and mandibular body length (P < .01) and forward rotation of the mandible were seen in 12 subjects with post-MDO imaging compared to their presurgical condition. At mixed dentition, 12 post-MDO subjects had more obtuse gonial angles (P < .01) and steeper mandibular planes (P < .01) than 19 non-MDO RS subjects. Both RS groups had different cephalometric values and more vertical measures than matched cephalometric norms. Thirty-one percent of 12 RS-MDO subjects had ≥1 teeth with abnormal development compared to none of 19 RS subjects without MDO (P = .02).

CONCLUSION AND RELEVANCE

MDO increased mandibular size in infants but can disrupt the developing dentition. Postdistraction growth may result in more vertical mandibular morphology with large gonial angles.

Computerized Surgical Planning for Mandibular Distraction Osteogenesis

Mandibular distraction osteogenesis is a technically challenging procedure due to complex mandibular anatomy, especially in the treatment of Pierre-Robin Sequence due to variable bone thickness in the infant mandible and the presence of tooth buds. Computerized surgical planning (CSP) simplifies the procedure by preoperatively visualizing critical structures, producing cutting guides, and planning distractor placement. This paper describes the process of using CSP to plan mandibular distraction osteogenesis, including discussion of recent advances in the use of custom distractors.

Artificial Intelligence and Pediatric Otolaryngology

Artificial intelligence (AI) studies show how to program computers to simulate human intelligence and perform data interpretation, learning, and adaptive decision-making. Within pediatric otolaryngology, there is a growing body of evidence for the role of AI in diagnosis and triaging of acute otitis media and middle ear effusion, pediatric sleep disorders, and syndromic craniofacial anomalies. The use of automated machine learning with robotic devices intraoperatively is an evolving field of study, particularly in the realms of pediatric otologic surgery and computer-aided planning for maxillofacial reconstruction, and we will likely continue seeing novel applications of machine learning in otolaryngologic surgery.

Patient-specific distractors for customized mandibular distraction osteogenesis to relieve upper airway obstruction in infants with Pierre Robin sequence

The purpose of this article is to report the author's technique for using patient-specific distractors for customized distraction osteogenesis of the mandible in patients with Pierre Robin sequence and upper airway obstruction. The advantages of virtual planning and patient-specific plates in other aspects of craniomaxillofacial surgery, such as orthognathic and reconstructive surgery, have been reported previously. Similar to patient-specific plates, the theorized advantages of patient-specific distractors in infants with Robin sequence and upper airway obstruction include increased accuracy, decreased operating time, and less morbidity to vital anatomic structures such as the inferior alveolar nerve and developing tooth buds. This technique is novel in using patient-specific distractors in the craniomaxillofacial skeleton.

Is a Difficult Airway Team Needed for Intubation at Removal of Mandibular Distraction Devices for Infants With Robin Sequence?

PURPOSE

Difficult airway teams (DATs) are typically present to assist intubation at the initial mandibular distraction osteogenesis (MDO) operation for infants with Robin sequence (RS). In some institutions, the RS diagnosis triggers a "difficult airway" label for the infant, requiring DAT presence for future operations. By the time of distractor removal, however, breathing and airway anatomy are significantly improved. The objective of this study was to measure intubation difficulty and perioperative respiratory complications at MDO device removal as a proxy for the necessity for coordination with a DAT.

METHODS

This is a retrospective study including infants with RS from 2013 to 2021 who had MDO during infancy. Patients were excluded if they had a tracheostomy or MDO device failure. Predictor variables included demographic data, comorbidities, and apnea-hypopnea indices (AHIs) from pre- and immediate post-MDO polysomnograms. The primary outcome measures were number of intubation attempts, laryngoscopy grade, and perioperative respiratory events at the distractor removal operation. Descriptive statistics were computed including Fisher's exact, paired sample t-tests, and Wilcoxon rank tests, and P < .05 was considered statistically significant.

RESULTS

The sample included 47 (60% male) patients with a mean age at MDO of 12.0 ± 15.7 weeks. Significant improvement in AHI was seen after MDO (pre-MDO: 26.8 ± 18.4 events/hour; post-MDO 2.78 ± 2.66 events/hour; P < .001). Average number of intubation attempts decreased from 2.09 ± 1.36 to 1.30 ± 0.75 (P < .001) and the most common post-MDO laryngoscopy grade was 1 (69%). There were no intraoperative and 2 (4%) minor postoperative respiratory events, both in patients with repaired congenital cardiac disease and not related to traumatic intubation.

CONCLUSION

Neither difficult intubations nor perioperative respiratory events associated with intubation trauma were seen at distractor removal, suggesting that specialty airway assistance is not routinely needed after successful MDO. DAT presence should be determined on a case-by-case basis based on specific patient risk factors.

Dental outcomes after neonatal mandibular distraction

PURPOSE OF REVIEW

The aim of this study was to understand dental complications associated with neonatal mandibular distraction and subsequent dental outcomes.

RECENT FINDINGS

Dental injury is often associated with neonatal mandibular distraction osteogenesis. Newer technology offers safer techniques to minimize this risk. Long-term follow up and dental outcomes in permanent dentition are needed to better understand the actual risk associated with the procedure.

SUMMARY

Surgeons performing neonatal mandibular distraction osteogenesis need to understand the associated risks to deciduous and permanent dentition as well as techniques to mitigate this risk.

Mandibular Distraction Osteogenesis in Robin Sequence Using Three-Dimensional Analysis and Planning

SUMMARY

The optimal management of patients with Robin sequence may include neonatal mandibular distraction osteogenesis, which has been used to achieve excellent functional and aesthetic outcomes in appropriate patients. This article and video vignette depict the treatment of micrognathia and airway obstruction secondary to Robin sequence, demonstrating the planning and surgical approach of the senior author (D.M.S.) using mandibular distraction osteogenesis.

Safety of Mandibular Osteotomies in Infants with Pierre Robin Sequence: Computer-Aided Modeling to Characterize the Risks of Various Techniques

BACKGROUND

Mandibular distraction osteogenesis is effective for the correction of severe tongue-based airway obstruction in infants with Pierre Robin sequence. Involved osteotomies may damage developing tooth buds and/or the inferior alveolar nerve. The authors evaluated the theoretical safety of various osteotomy techniques to better define infantile mandibular anatomy using computer-aided modeling.

METHODS

Seven mandibular osteotomy techniques (oblique, inverted-L, multiangular, walking stick, high oblique, vertical/high inverted-L, and horizontal) were simulated using computed tomography studies from infants with Pierre Robin sequence and without other associated conditions. Software was used to manually segment the mandibular bone, inferior alveolar nerve, and tooth buds.

RESULTS

Sixty-five computed tomography scans were included, yielding 130 hemimandibles. The horizontal osteotomy pattern had significantly lower theoretical risk of tooth bud (p < 0.001) and inferior alveolar nerve involvement (p < 0.001) than all other patterns. Osteotomies with high vertical components (i.e., vertical, walking stick, and multiangular) had lower theoretical tooth bud involvement than the more proximal oblique and inverted-L osteotomies (p < 0.001). Average lingula location was measured at a point 65 percent of the mandibular width from anterior mandibular border and 63 percent of the mandibular height from the inferior mandibular border.

CONCLUSIONS

Surgical planning with computed tomography scans can help evaluate an infant's mandibular anatomy to select an osteotomy that reduces morbidity risks. Regardless of technique, tooth buds and the inferior alveolar nerve are often included in osteotomies. The lingula location in this study demonstrates a position more superior and posterior than that previously described.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Conformity of the Virtual Surgical Plan to the Actual Result Comparing Five Craniofacial Procedure Types

BACKGROUND

The "accuracy" of virtual surgical planning across multiple procedure types is not known. The authors aimed to compare the planned outcome from virtual surgical planning to the actual postoperative outcome for five craniofacial procedure types performed by a single surgeon: implant cranioplasty, cranial vault remodeling, orthognathic surgery, mandible reconstruction, and mandibular distraction.

METHODS

Stereolithography formats were obtained from virtual surgical planning and compared to postoperative computed tomographic scans for consecutive patients who underwent one of the five procedure types. Volumetric renderings of the operated bony region of interest were overlaid and compared using a Boolean operation to compute conformity (as a percentage of the region of interest). Conformity across procedure type was analyzed using analysis of variance and post hoc Bonferroni analysis, where appropriate.

RESULTS

One hundred thirty patients were included (51.5 percent male and 49.5 percent female; mean age, 27 years; 59 orthognathic surgery, 32 cranial vault remodeling, 16 mandible reconstruction, 12 mandibular distraction, and 11 implant cranioplasty patients). The highest tier of conformity was obtained for implant cranioplasty (median, 76.8 ± 10.3 percent) and mandible reconstruction (mean, 69.4 ± 11.2 percent), followed by orthognathic surgery (mean, 55.0 ± 7.3 percent) and mandibular distraction (median, 41.9 ± 20.3 percent), followed by cranial vault remodeling (mean, 22.2 ± 12.1 percent) (p < 0.001 between tiers and p > 0.05 among tiers).

CONCLUSIONS

Virtual surgical planning resulting in custom permanent implants and intraoperative guides provides more predictable results compared to virtual surgical planning used for procedures involving higher degrees of skeletal repositioning and postoperative movement (i.e., mandibular distraction and nonrigid cranial vault remodeling). In cases with expectedly lower conformity, excellent outcomes can be achieved with sound intraoperative judgment.

Three-dimensional printing in medicine: a systematic review of pediatric applications

BACKGROUND

Three-dimensional printing (3DP) addresses distinct clinical challenges in pediatric care including: congenital variants, compact anatomy, high procedural risk, and growth over time. We hypothesized that patient-specific applications of 3DP in pediatrics could be categorized into concise, discrete categories of use.

METHODS

Terms related to "three-dimensional printing" and "pediatrics" were searched on PubMed, Scopus, Ovid MEDLINE, Cochrane CENTRAL, and Web of Science. Initial search yielded 2122 unique articles; 139 articles characterizing 508 patients met full inclusion criteria.

RESULTS

Four categories of patient-specific 3DP applications were identified: Teaching of families and medical staff (9.3%); Developing intervention strategies (33.9%); Procedural applications, including subtypes: contour models, guides, splints, and implants (43.0%); and Material manufacturing of shaping devices or prosthetics (14.0%). Procedural comparative studies found 3DP devices to be equivalent or better than conventional methods, with less operating time and fewer complications.

CONCLUSION

Patient-specific applications of Three-Dimensional Printing in Medicine can be elegantly classified into four major categories: Teaching, Developing, Procedures, and Materials, sharing the same TDPM acronym. Understanding this schema is important because it promotes further innovation and increased implementation of these devices to improve pediatric care.

IMPACT

This article classifies the pediatric applications of patient-specific three-dimensional printing. This is a first comprehensive review of patient-specific three-dimensional printing in both pediatric medical and surgical disciplines, incorporating previously described classification schema to create one unifying paradigm. Understanding these applications is important since three-dimensional printing addresses challenges that are uniquely pediatric including compact anatomy, unique congenital variants, greater procedural risk, and growth over time. We identified four classifications of patient-specific use: teaching, developing, procedural, and material uses. By classifying these applications, this review promotes understanding and incorporation of this expanding technology to improve the pediatric care.

Dental 3D-Printing: Transferring Art from the Laboratories to the Clinics

The rise of three-dimensional (3D) printing technology has changed the face of dentistry over the past decade. 3D printing is a versatile technique that allows the fabrication of fully automated, tailor-made treatment plans, thereby delivering personalized dental devices and aids to the patients. It is highly efficient, reproducible, and provides fast and accurate results in an affordable manner. With persistent efforts among dentists for refining their practice, dental clinics are now acclimatizing from conventional treatment methods to a fully digital workflow to treat their patients. Apart from its clinical success, 3D printing techniques are now employed in developing haptic simulators, precise models for dental education, including patient awareness. In this narrative review, we discuss the evolution and current trends in 3D printing applications among various areas of dentistry. We aim to focus on the process of the digital workflow used in the clinical diagnosis of different dental conditions and how they are transferred from laboratories to clinics. A brief outlook on the most recent manufacturing methods of 3D printed objects and their current and future implications are also discussed.

Robotics in Pediatric Otolaryngology-Head and Neck Surgery and Advanced Surgical Planning

Robotic surgery has been shown to be feasible and successful in several areas of pediatric head and neck surgery. However, adoption has been limited. Robotic surgery may be better integrated into practice with advanced preoperative surgical planning and the design of new robotic platforms with instrumentation specific for the application. With continued investigations, computer-aided surgical planning techniques including three-dimensional printing, virtual reality, multiobjective cost function for optimization of approach, mirror image overlay, and flexible robotic instruments may demonstrate value and utility over current practice.

Is Intensive Care Unit Admission Necessary After Removal of Mandibular Distraction Devices in Infants With Robin Sequence?

OBJECTIVE

Intensive care unit (ICU) care is routinely required after the operation to initiate mandibular distraction osteogenesis (MDO) in infants with Robin sequence (RS). Many patients are also managed in the ICU after subsequent device removal. It is uncertain if ICU care, which is expensive and limited, is necessary after this second operation. The objective of this study was to evaluate the incidence of respiratory events following device removal. We hypothesized that respiratory events would be infrequent and non-ICU inpatient monitoring would be adequate.

DESIGN

This is a retrospective study of patients with RS from 2013 to 2018.

PATIENTS

Patients were included if they had MDO and distractor removal during the first year of life. Patients were excluded if they had a tracheostomy or remained intubated after distractor removal.

MAIN OUTCOME MEASURE

Postoperative respiratory events.

RESULTS

Twenty-five (60% male) patients were included. Mean age and weight at distractor removal were 142 ± 79 days of life and 5.5 ± 1.1 kg. Mean apnea-hypopnea index after completion of distraction was 1.1 ± 1.5 events/hour. Two (8%) patients experienced postoperative respiratory events that required intervention. In 1 (4% of sample) of these, the event was deemed to have benefited from ICU-level care. Two variables were significantly associated with these events: congenital heart disease (P = .020) and concomitant procedure performed during the same operation (P = .020).

CONCLUSIONS

Intensive care unit-level care is rarely needed after distractor removal in infants with RS. Intensive care unit admission should be considered in patients with congenital cardiac disease and when having multiple operations during the same anesthetic.