Effect of a syndromic diagnosis on mandibular size and sagittal position in Robin sequence.

Full Abstract

PURPOSE: Despite its pathogenic heterogeneity, it is often assumed that the small mandible in a neonate with Robin sequence will not grow normally. The purpose of this study was to determine mandibular length and position in patients with nonsyndromic versus syndromic Robin sequence. PATIENTS AND METHODS: Lateral cephalograms of 51 children with Robin sequence were analyzed. Group I consisted of nonsyndromic (NS) subjects and group II consisted of subjects with the 4 most common syndromic (S) diagnoses. Cephalometric measurements included sella-nasion-A point (SNA), sella-nasion-B point (SNB), sella-nasion-pogonion (SNPg), articulare-gonion-pogonion (ArGoPg), temporomandibular joint-pogonion (TmPg), articulare-gonion (ArGo), and gonion-pogonion (GoPg). Differences between groups and subgroups were compared using t test. RESULTS: There were 26 NS patients (mean age, 6.8 yrs) and 25 S patients (mean age, 8.7 yrs); mean age was statistically different between groups (P = .04); therefore, cephalometric measurements were compared with age-matched normal values. Syndromes included Stickler (n = 10), bilateral facial microsomia (n = 8), velocardiofacial (n = 4), and Treacher Collins (n = 3). SNA was statistically different from normal in both groups (NS, P = .017; S, P = .007); however, SNB was not different from normal for either group (NS, P = .175; S, P = .537). SNPg (0.007) was significantly greater than normal in NS (P = .007) but not in S (P = .702) patients. SNA, SNB, and SNPg were not significantly different between groups. In both groups, mandibular length was short (P = .00), especially in S patients (P = .049), mandibular body was small (NS, P = .00; S, P = .00), and the gonial angle more obtuse (NS, P = .006; S, P = .000) than normal. Ramus length was significantly shorter than normal only in S patients (P = .019). Mandibular length (TmPg) was smaller than normal in all S subgroups but with wide variability. There were statistically significant differences among S subgroups with respect to mandibular sagittal position (SNB, P = .00; SNPg, P = .00) and mandibular length (TmPg, P = .008). There were no differences in S subgroups with respect to age, SNA, ArGo, GoPg, and ArGoPg. CONCLUSION: Mandibular morphology and position are variable in Robin sequence, based on the presence and type of associated syndromic diagnosis.

Author information

Author/s: Rogers, Gary (G); Lim, Asher A T (AA); Mulliken, John B (JB); Padwa, Bonnie L (BL);

Affiliation: Department of Plastic and Oral Surgery, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA.

Journal and publication information

Publication Type: Comparative Study; Journal Article

Journal: Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons (J Oral Maxillofac Surg), published in United States. (Language: eng)

Reference: 2009-Nov; vol 67 (issue 11) : pp 2323-31

Dates: Created 2009/10/19; Completed 2009/11/03;

PMID: 19837298, status: MEDLINE (last retrieved date: 11/3/2009)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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