Skeletal stability after Le Fort I maxillary advancement in patients with unilateral cleft lip and palate

Outcomes in 30 adults and adolescents judged skeletally mature who had unilateral cleft lip and palate and underwent Le Fort I advancement were investigated to determine amount and timing of relapse, correlation between advancement and relapse, effect of performing multiple jaw procedures, effect of different types of bone grafts, effect of pharyngoplasty in place at the time of osteotomy, and effectiveness of various methods of internal fixation. Tracings of preoperative and serial postoperative lateral cephalograms were digitized to calculate horizontal and vertical maxillary changes. No significant differences in outcome was seen between patients who had maxillary surgery alone and those who had operations on both jaws, nor did the outcome vary significantly with the type of autogenous bone graft used or the segmentalization of the Le Fort osteotomy. Mean "effective" advancement was greater immediately and 2 years after surgery in those patients who did not have a pharyngoplasty in place before the operation. Advancement also was greater immediately and after 2 years in the miniplate fixation group than in patients with direct-wire fixation. Mean downward (vertical) displacement was 2.6 mm with a relapse of 1.4 mm after 2 years. Amounts of relapse and of advancement or displacement did not correlate significantly.     

Genetics of cleft lip and cleft palate in China.

During the past 10 years, 60 cases of cleft lip with or without cleft palate [CL(P)] were recorded among 45,072 newborns at Shanghai International Peace Maternity and Infant Hospital, China. The incidence was 1.33 per 1,000 births. The family histories of 163 CL(P) patients were analyzed. The incidences of CL(P) in the first-, second-, and third-degree relatives of CL(P) patients were 11/246 (4.47%), 10/1,032 (0.97%), and 6/1,727 (0.35%), respectively. Of the 163 probands, three had a history of consanguinity of the parents (1.8%), in contrast to 0.77% in the general population. These data are suggestive of multifactorial inheritance. The heritability of CL(P) in our study calculated by Falconer's formula was 77.6%.     

Complex segregation analysis of nonsyndromic cleft lip and palate.

This study was undertaken to examine the inheritance pattern of nonsyndromic cleft lip with or without cleft palate (CL/P). Complex segregation analysis using the unified model as in POINTER and the regressive model as in REGD programs were applied to analyze a midwestern U.S. Caucasian population of 79 families ascertained through a proband with CL/F. In REGD, the dominant or codominant Mendelian major locus models of inheritance were the most parsimonious fit. In POINTER, besides the Mendelian major locus model, the multifactorial threshold (MF/T) model and the mixed model were also consistent with the observed data. However, the high heritability parameter of .93 (SD .063) in the MF/T model suggests that any random exogenous factors are unlikely to be the underlying mechanisms, and the mixed model indicates that this high heritability is accounted for by a major dominant locus component. These findings indicate that the best explanation for the etiology of CL/P in this study population is a putative major locus associated with markedly decreased penetrance. Molecular studies may provide further insight into the genetic mechanism underlying CL/P.     

Familial recurrence-pattern analysis of cleft lip with or without cleft palate.

Cleft lip with or without cleft palate (CL/P) is a common congenital malformation with an incidence in European white populations of about 1/1,000. The familial clustering of CL/P has been extensively characterized, and epidemiological studies have proposed monogenic models (with reduced penetrance), multifactorial/threshold models, and mixed major-gene/multifactorial models to explain its inheritance. The recognition of an association between two RFLPs at the transforming growth factor alpha (TGFA) locus and CL/P supports a major-gene component to the etiology of CL/P. Risch has shown that the recurrence risk ratio lambda R (risk to relatives, vs. population prevalence) is a useful pointer to the mode of inheritance. Here we further develop the use of lambda R to analyze recurrence-risk data for CL/P. Recurrence risks for first-, second-, and third-degree relatives equate well with oligogenic models with as few as four loci. A monogenic/additive model is strongly rejected. The limited available twin data are also consistent with this model. A "major gene" interacting epistatically with an oligogenic background is shown to be a plausible alternative. Power calculations for a linkage study to map the CL/P major-risk locus suggest that a sample of 50 affected sib pairs will be adequate, but linkage to minor-risk loci will require very much larger samples.     

Maternal effects in human cleft lip and palate.

To look for a persistent maternal effect of CL(P) and CP, 8,000 pedigrees were screened for half sibships, and data were pooled from 16 investigators. After excluding known genetic or cytogenetic diagnoses from the probands with facial clefts, a recurrence risk of .011 was obtained for CL(P) based upon 342 maternal half sibs. This was nearly identical to the risk of .014 based upon 210 paternal half sibs. CP proband frequencies of .004 for maternal half sibs and .009 for the paternal counterparts were also found. The lack of significant maternal effects in this data supports previously reported data from twin studies and from interracial crosses from Hawaii. The lack of maternal effect in human CL(P) and CP is in contrast to genetic data on clefting in mice.     

Modified technique of presurgical infant maxillary orthopedics for complete unilateral cleft lip and palate

This article introduces a modified device fabrication and facial taping method that increases the efficiency and efficacy of presurgical infant maxillary orthopedic therapy for babies born with complete cleft lip and palate. Interarch and intra-arch relationships of the maxillary and mandibular dental arches were evaluated on mounted stone models before and after treatment. The palatal plate device was custom-fabricated in a manner that bypassed the need for periodic acrylic addition and removal, thereby eliminating the risk of natural maxillary growth restriction during therapy. Elastic labial tapes were fabricated and applied in a configuration that mimicked normal function of the orbicularis oris muscle. A nasal stent wire was utilized from the initiation of therapy to enhance intraoral retention and stability of the device. Examples of infants undergoing a unilateral complete cleft lip and palate treatment protocol are presented. Treatment objectives were achieved within 7 to 8 weeks of therapy for patients who had an initial alveolar cleft size more than 10 to 12 mm. The modified protocol of presurgical infant maxillary orthopedic therapy is an effective and efficient treatment modality in reversing the pre-existing orofacial dysmorphism by redirecting the infant's natural growth.     

Modified technique of presurgical infant maxillary orthopedics for complete bilateral cleft lip and palate

This article introduces technical modifications to the conventional presurgical infant maxillary orthopedics device for newborns with complete bilateral cleft lip and palate, providing procedural simplicity and efficiency as well as therapeutic efficacy. The modifications incorporate a wax block-out on the stone model prior to device fabrication in a manner that the need for periodic acrylic addition and removal is not required, and thus eliminates the risk of natural maxillary growth restriction during infant maxillary orthopedics treatment. The premaxilla is completely excluded from the acrylic palatal plate and is repositioned primarily by the bilateral labial tape alone. In addition, nasal stent wires are installed on the same day of the palatal plate delivery to establish a tripod-like retention mechanism for the intraoral device to be able to replace the conventional mechanical lock-type retention methods. Applying these modifications, infant maxillary orthopedics treatment objectives for bilateral cleft lip and palate can be successfully achieved within 8 weeks of treatment, and the definitive primary cleft lip repair can be performed within 3-4 months of infant maxillary orthopedics treatment at our Center.